U.S. patent application number 12/281760 was filed with the patent office on 2009-04-16 for information processing apparatus, information processing method, and computer program.
Invention is credited to Tatsuya Igarashi.
Application Number | 20090100147 12/281760 |
Document ID | / |
Family ID | 38474971 |
Filed Date | 2009-04-16 |
United States Patent
Application |
20090100147 |
Kind Code |
A1 |
Igarashi; Tatsuya |
April 16, 2009 |
Information Processing Apparatus, Information Processing Method,
and Computer Program
Abstract
A configuration is provided in which a device in a home network
receives content from a server outside the home network and plays
the content. A home IMS gateway maps an external server outside the
home network as a virtual home network device, and executes a
process of receiving a content providing service provided by the
external server by using mapping information. Furthermore, switched
reception of multicast distribution content provided by the
external server and unicast distribution content is executed.
Inventors: |
Igarashi; Tatsuya; (Tokyo,
JP) |
Correspondence
Address: |
FINNEGAN, HENDERSON, FARABOW, GARRETT & DUNNER;LLP
901 NEW YORK AVENUE, NW
WASHINGTON
DC
20001-4413
US
|
Family ID: |
38474971 |
Appl. No.: |
12/281760 |
Filed: |
March 7, 2007 |
PCT Filed: |
March 7, 2007 |
PCT NO: |
PCT/JP2007/054460 |
371 Date: |
December 15, 2008 |
Current U.S.
Class: |
709/218 |
Current CPC
Class: |
H04N 21/6408 20130101;
H04N 7/17309 20130101; H04N 21/2747 20130101; H04N 21/64322
20130101; H04N 21/4826 20130101; H04N 21/6405 20130101; H04N
21/43615 20130101 |
Class at
Publication: |
709/218 |
International
Class: |
G06F 15/16 20060101
G06F015/16 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 7, 2006 |
JP |
2006-061230 |
Claims
1. An information processing apparatus characterized by comprising:
a communication unit that executes a communication process via a
home network; and a data processing unit that executes a process of
receiving a content providing service provided by an external
server existing outside a home network, by using mapping
information in which the external server is set as a virtual home
network device, and characterized in that the data processing unit
is configured to: execute switched reception of multicast
distribution content provided by the external server and unicast
distribution content.
2. The information processing apparatus according to claim 1,
characterized in that the data processing unit is configured to
execute a process of: on occasion of reception of multicast
distribution content provided by the external server, sending an
IGMP (Internet Group Management Protocol)-join message to the
external server or a management server as a message according to
IGMP, and in a case where the reception of multicast distribution
content is to be stopped and reception of unicast distribution
content is to be started, sending an IGMP leave message to the
external server or the management server as a message according to
IGMP.
3. The information processing apparatus according to claim 1,
characterized in that the data processing unit is configured to:
execute a process of receiving multicast distribution content in
reception of TV broadcasting, and execute a process of switching to
unicast distribution on occasion of execution of VoD (Video on
Demand).
4. The information processing apparatus according to claim 1,
characterized in that the data processing unit is configured to:
execute a process of switching to unicast distribution on occasion
of an nPVR (network Personal Video Recording) executed as a
user-specific content recording process.
5. The information processing apparatus according to claim 1,
characterized in that the data processing unit is configured to:
execute a process of switching to unicast distribution on occasion
of execution of a trick play as a special content playing
process.
6. The information processing apparatus according to claim 1,
characterized in that the data processing unit is configured to:
execute a process of switching to unicast distribution as a process
for receiving a content list corresponding to a user profile or a
client profile.
7. An information processing method executed at an information
processing apparatus, characterized by executing: a communication
step in which a communication unit executes a communication process
via a home network; a content receiving step in which a data
processing unit executes a process of receiving content provided by
an external server existing outside a home network, by using
mapping information in which the external server is set as a
virtual home network device; and a content switching process step
in which the data processing unit executes switched reception of
multicast distribution content provided by the external server and
unicast distribution content.
8. The information processing method according to claim 7,
characterized in that the content switching process step is a step
of executing either: on occasion of reception of multicast
distribution content provided by the external server, sending an
IGMP (Internet Group Management Protocol)-join message to the
external server or a management server as a message according to
IGMP, or in a case where the reception of multicast distribution
content is to be stopped and reception of unicast distribution
content is to be started, sending an IGMP leave message to the
external server or the management server as a message according to
IGMP.
9. The information processing method according to claim 7,
characterized in that the data processing unit executes a process
of receiving multicast distribution content in reception of TV
broadcasting, and executes a process of switching to unicast
distribution on occasion of execution of VoD (Video on Demand).
10. The information processing method according to claim 7,
characterized in that the data processing unit executes a process
of switching to unicast distribution on occasion of an nPVR
(network Personal Video Recording) executed as a user-specific
content recording process.
11. The information processing method according to claim 7,
characterized in that the data processing unit executes a process
of switching to unicast distribution on occasion of execution of a
trick play as a special content playing process.
12. The information processing method according to claim 7,
characterized in that the data processing unit is configured to
execute a process of switching to unicast distribution as a process
for receiving a content list corresponding to a user profile or a
client profile.
13. A computer program for causing execution of information
processing at an information processing apparatus, characterized by
causing execution of: a communication step of causing a
communication unit to execute a communication process via a home
network; a content receiving step of causing a data processing unit
to execute a process of receiving content provided by an external
server existing outside a home network, by using mapping
information in which the external server is set as a virtual home
network device; and a content switching process step of causing the
data processing unit to execute switched reception of multicast
distribution content provided by the external server and unicast
distribution content.
Description
TECHNICAL FIELD
[0001] The present invention relates to information processing
apparatuses, information processing methods, and computer programs.
Particularly, the present invention relates to an information
processing apparatus, an information processing method, and a
computer program for implementing use of data supplied from outside
a home network at a device in the home network.
BACKGROUND ART
[0002] With the spread of PCs and digital home appliances, it is
becoming a reality to interconnect these devices via a home IP
(Internet Protocol) network and to share and enjoy digital content,
such as video, audio, and pictures. For example, DLNA (Digital
Living Network Alliance) defines technical specification and
implementing guideline needed for sharing digital content among
these digital devices so that it is possible to interconnect
devices of different vendors with each other, and DLNA has become
as an industry standard of home IP networks.
[0003] FIG. 1 shows an example of a home network 100 proposed by
DLNA. A DVR (Digital Video Recorder) 101 and a PC 102 with a
built-in TV tuner, as digital video content recording apparatuses,
are capable of receiving satellite and terrestrial analog
broadcasting and digital broadcasting, and record and save
broadcast programs on built-in hard disk recorders. In DLNA, a
device that stores content and that provides the content to devices
in a home network is called a digital media server (DMS). In FIG.
1, the DVR 101 and the PC 102 are DMSs.
[0004] A DMS is capable of performing streaming transmission of,
for example, video content of a TV program recorded on a hard disk
to a digital media player (DMP) connected via a home IP network.
The digital media player (DMP) is a device that receives content
from a DMS and plays the content.
[0005] In the example shown in FIG. 1, a DMP is implemented on a TV
103, and, for example, by using an infrared remote controller or
the like of the TV 103, a user can operate the TV 103 to play video
content stored on the PC 102 or the DVR 101 placed in a remote
room. Note that a residential gateway (RG) 104, which is used as a
network connecting device in a case where a device in a home is
connected to an IP broadband network 120 as the Internet, is used
as a bridge for IP connection of a device in a home in the example
of use of DLNA.
[0006] Meanwhile, a revolution is seen in broadcasting systems, and
IPTV services, VOD (Video On Demand) services, and so forth that
transmit video content via IP broadband networks, which has
hitherto been broadcast using terrestrial waves or satellites, are
coming to be commercialized. FIG. 2 shows a schematic diagram of
IPTV and VOD services.
[0007] In a home, an STB (Set Top Box) 105 is installed so that it
is possible to receive via the RG (Residential Gateway) 104 and via
the IP broadband network 120 content based on services from various
IPTV service providing servers 121 a1 to an and VOD service
providing servers 122 b1 to bn. The STB (Set Top Box) 105 has a
function of receiving video information, application executing
functions needed for command transmission and reception, for MPEG
decoding, and also for playing of received data, and so forth.
[0008] The residential gateway (RG) 104, in some cases, receives
services (content) provided by a plurality of IPTV service
providing servers 121 or VOD service providing servers 122 via the
same agent, for example, an access line providing company such as a
telephone company or a CableTV company, and in other cases,
receives individual services separately. However, it is necessary
that the STB (Set Top Box) 105 itself, used by the user, is
configured as a system supporting an IPTV service of a connection
destination.
[0009] As such IPTV services and VOD services become common in the
future, similarly to the conventional sharing and viewing by DLNA
devices of TV broadcast content as ordinary broadcast broadcasting,
user's need arises for using video content provided from IPTV
services on DLNA devices.
[0010] As proposed solutions for meeting such demand, a method in
which a device having a large-capacity hard disk, such as a home
server, downloads video content from an IPTV service and shares the
video content in a home network, or a method in which a protocol,
media format, and so forth of an IPTV service are converted at a
residential gateway (RG) into a protocol and media format of a DLNA
device and the IPTV service is provided to a home network
connecting device, is conceivable. Note that a home-network
embedded module that executes a format converting process is
described in Patent Document 1.
[0011] However, in the former case, a time for downloading is
needed for temporary storage at a home server, so that it is
difficult to enjoy video when desired, which is possible with a
video on demand service, and it is not suitable for live viewing.
In the latter configuration in which processing is executed by a
residential gateway (RG), it is necessary that the residential
gateway (RG) executes protocol conversion and media conversion, so
that high-performance hardware is needed and software becomes
complex, and the RG becomes expensive.
[0012] Generally, in many cases, an RG is supplied from an access
line providing company (telephone company or the like) of a
broadband network, and this becomes an obstacle in a case where
IPTV services are provided on the open Internet, for example, IPTV
services available for the user are limited to the vendor provided
by the access line. Although it is possible to provide a new
gateway device in a home IP network separately from the residential
gateway (RG), in this case, depending on the network topology,
content streaming data is transmitted in duplicates in the home
network, so that such a situation occurs that a band in the home
network is used in vain.
[0013] Note that an example of connection between a DLNA device in
a home network and a content distribution service on the Internet
is the Viiv (registered trademark) technology of the U.S. Intel
Corporation. Viiv is considered as a platform of PC hardware and
software, and is intended for stream viewing of content on a PC
from the Internet by a Dual Core high-performance CPU. At the same
time, Viiv has a DLNA function, and serves as a DLNA media server
that performs streaming of content temporarily downloaded from the
Internet to the PC to another DLNA device.
[0014] Patent Document 1: Japanese Unexamined Patent Application
Publication (Translation of PCT Application) No. 2005-531231
DISCLOSURE OF INVENTION
Technical Problem
[0015] As described above, in a case where content provided by IPTV
services or VOD services is also to be used by a DLNA device
similarly to TV broadcasting content as ordinary broadcast
broadcasting, in existing network configurations, it is necessary
to download content in advance at a digital media server (DMS),
such as a PC, a DVR, or the like in a home network, or to provide a
residential gateway (RG) with protocol and media conversion
functions. The former case lacks real-time characteristics, so that
it is unsuitable for a streaming playing process or the like, and
the latter case leads to the problem of increased cost.
[0016] The present invention has been made in view of the problems
described above, and it is an object thereof to provide an
information processing apparatus, an information processing method,
and a computer program with which it is possible to view content
provided by an external server outside a home network, such as an
IPTV service, by using an existing DLNA device in, for example, an
open Internet connection environment that does not depend on
infrastructure such as an access line and gateway to the
Internet.
Technical Solution
[0017] A first aspect of the present invention is an information
processing apparatus characterized by comprising:
[0018] a communication unit that executes a communication process
via a home network; and
[0019] a data processing unit that executes a process of receiving
a content providing service provided by an external server existing
outside a home network, by using mapping information in which the
external server is set as a virtual home network device,
[0020] and characterized in that the data processing unit is
configured to:
[0021] execute switched reception of multicast distribution content
provided by the external server and unicast distribution
content.
[0022] Furthermore, an embodiment of the information processing
apparatus according to the present invention is characterized in
that the data processing unit is configured to execute a process
of, on occasion of reception of multicast distribution content
provided by the external server, sending an IGMP (Internet Group
Management Protocol)-join message to the external server or a
management server as a message according to IGMP, and in a case
where the reception of multicast distribution content is to be
stopped and reception of unicast distribution content is to be
started, sending an IGMP leave message to the external server or
the management server as a message according to IGMP.
[0023] Furthermore, an embodiment of the information processing
apparatus according to the present invention is characterized in
that the data processing unit is configured to execute a process of
receiving multicast distribution content in reception of TV
broadcasting, and execute a process of switching to unicast
distribution on occasion of execution of VoD (Video on Demand).
[0024] Furthermore, an embodiment of the information processing
apparatus according to the present invention is characterized in
that the data processing unit is configured to execute a process of
switching to unicast distribution on occasion of an nPVR (network
Personal Video Recording) executed as a user-specific content
recording process.
[0025] Furthermore, an embodiment of the information processing
apparatus according to the present invention is characterized in
that the data processing unit is configured to execute a process of
switching to unicast distribution on occasion of execution of a
trick play as a special content playing process.
[0026] Furthermore, an embodiment of the information processing
apparatus according to the present invention is characterized in
that the data processing unit is configured to execute a process of
switching to unicast distribution as a process for receiving a
content list corresponding to a user profile or a client
profile.
[0027] Furthermore, a second aspect of the present invention is an
information processing method executed at an information processing
apparatus, characterized by executing:
[0028] a communication step in which a communication unit executes
a communication process via a home network;
[0029] a content receiving step in which a data processing unit
executes a process of receiving content provided by an external
server existing outside a home network, by using mapping
information in which the external server is set as a virtual home
network device; and
[0030] a content switching process step in which the data
processing unit executes switched reception of multicast
distribution content provided by the external server and unicast
distribution content.
[0031] Furthermore, an embodiment of the information processing
method according to the present invention is characterized in that
the content switching process step is a step of executing either,
on occasion of reception of multicast distribution content provided
by the external server, sending an IGMP (Internet Group Management
Protocol)-join message to the external server or a management
server as a message according to IGMP, or in a case where the
reception of multicast distribution content is to be stopped and
reception of unicast distribution content is to be started, sending
an IGMP leave message to the external server or the management
server as a message according to IGMP.
[0032] Furthermore, an embodiment of the information processing
method according to the present invention is characterized in that
the data processing unit executes a process of receiving multicast
distribution content in reception of TV broadcasting, and executes
a process of switching to unicast distribution on occasion of
execution of VoD (Video on Demand).
[0033] Furthermore, an embodiment of the information processing
method according to the present invention is characterized in that
the data processing unit executes a process of switching to unicast
distribution on occasion of an nPVR (network Personal Video
Recording) executed as a user-specific content recording
process.
[0034] Furthermore, an embodiment of the information processing
method according to the present invention is characterized in that
the data processing unit executes a process of switching to unicast
distribution on occasion of execution of a trick play as a special
content playing process.
[0035] Furthermore, an embodiment of the information processing
method according to the present invention is characterized in that
the data processing unit is configured to execute a process of
switching to unicast distribution as a process for receiving a
content list corresponding to a user profile or a client
profile.
[0036] Furthermore, a third aspect of the present invention is a
computer program for causing execution of information processing at
an information processing apparatus, characterized by causing
execution of:
[0037] a communication step of causing a communication unit to
execute a communication process via a home network;
[0038] a content receiving step of causing a data processing unit
to execute a process of receiving content provided by an external
server existing outside a home network, by using mapping
information in which the external server is set as a virtual home
network device; and
[0039] a content switching process step of causing the data
processing unit to execute switched reception of multicast
distribution content provided by the external server and unicast
distribution content.
[0040] Note that the computer program according to the present
invention is a computer program that can be provided, for example,
to a general-purpose computer system capable of executing various
program codes via a storage medium or communication medium that
provides the program in a computer-readable format. By providing
such a program in a computer-readable format, a process according
to the program is implemented on the computer system.
[0041] Other objects, features, and advantages of the present
invention will become apparent from more detailed description based
on embodiments of the present invention described later and the
accompanying drawings. Note that in this specification, a system is
a logically combined configuration of a plurality of apparatuses,
and is not limited to one in which the constituent apparatuses
exist within the same case.
ADVANTAGEOUS EFFECTS
[0042] According to the configuration of the present invention, it
becomes possible for a DMP as a content playing apparatus, which is
a client device in a home network, to receive content from a
content providing server outside the home network and to play the
content. That is, a home IMS gateway, which is an information
processing apparatus according to the present invention, executes
communication with a content providing server to map the content
providing server as a virtual home network device, and in response
to reception of a device discovery request from a content playing
apparatus in a home network, the home IMS gateway provides the
content playing device with server information of the content
providing server as information of a device that is allowed to
receive a service. Furthermore, by executing switched reception of
multicast distribution content provided by the external server and
unicast content, it becomes possible to receive content with
increased flexibility on the client side.
BRIEF DESCRIPTION OF DRAWINGS
[0043] FIG. 1 is a diagram showing an example of a home network
proposed by DLNA.
[0044] FIG. 2 is a diagram showing a schematic diagram of IPTV and
VOD services.
[0045] FIG. 3 is a diagram for explaining an example configuration
of an information communication system according to the present
invention.
[0046] FIG. 4 is a diagram for explaining functional components
according to the DLNA guideline, to which DLNA devices conform.
[0047] FIG. 5 is a diagram showing an example hardware
configuration of a home IMS gateway.
[0048] FIG. 6 is a diagram for explaining an example configuration
of software modules of a home IMS gateway.
[0049] FIG. 7 is a diagram for explaining a sequence of a procedure
for subscribing to an AS (IPTV).
[0050] FIG. 8 is a diagram for explaining a sequence of a procedure
for subscribing to an AS (IPTV).
[0051] FIG. 9 is a diagram for explaining an example of a sequence
of using content provided by an AS (IPTV).
[0052] FIG. 10 is a diagram for explaining an example of a sequence
of using content provided by an AS (IPTV).
[0053] FIG. 11 is a diagram for explaining an overview of data
communication in a content using process.
[0054] FIG. 12 is a diagram for explaining an example configuration
of software modules of a home IMS gateway.
[0055] FIG. 13 is a diagram for explaining an example of a sequence
of using content provided by an AS (IPTV).
[0056] FIG. 14 is a diagram showing an example of a service screen
provided by an AS (IPTV) and a screen display on occasion of a
streaming playing process.
[0057] FIG. 15 is a diagram for explaining components of an IPTV
terminal function, which is a function needed for receiving an IPTV
service.
[0058] FIG. 16 is a diagram for explaining CSCF, HSS, and AS, which
are main functions of an IMS (IP Multimedia Subsystem).
[0059] FIG. 17 is a diagram for explaining functions used in a
network configuration in order to receive an IPTV service at a
device in a home network.
[0060] FIG. 18 is a diagram for explaining a process of managing
quality of communication data.
[0061] FIG. 19 is a diagram for explaining a communication sequence
executed by a client in order to receive an IPTV service.
[0062] FIG. 20 is a diagram for explaining a communication sequence
executed by a client in order to receive an IPTV service.
[0063] FIG. 21 is a diagram for explaining a communication sequence
executed by a client in order to receive an IPTV service.
[0064] FIG. 22 is a diagram for explaining a communication sequence
executed by a client in order to receive an IPTV service.
[0065] FIG. 23 is a diagram for explaining a communication sequence
executed by a client in order to receive an IPTV service.
[0066] FIG. 24 is a diagram for explaining a network connecting
process sequence of a client for receiving an IPTV service.
[0067] FIG. 25 is a diagram for explaining a network connecting
process sequence of a client for receiving an IPTV service.
[0068] FIG. 26 is a diagram for explaining a network connecting
process sequence of a client for receiving an IPTV service.
BEST MODE FOR CARRYING OUT THE INVENTION
[0069] Hereinafter, with reference to the drawings, an information
processing apparatus, an information processing method, and a
computer program according to the present invention will be
described in detail. The description will be given in order
regarding the following items.
[0070] 1. Configuration for receiving an IPTV service by a device
in a home network
[0071] 2. Description of functions applied to an IPTV service
[0072] 3. Regarding specific process example of an IPTV service
[0073] 3-1. Regarding specific process example of a communication
process
[0074] 3-2. Regarding specific process examples of various types of
services
[0075] [1. Configuration for Receiving an IPTV Service by a Device
in a Home Network]
[0076] First, with reference to FIG. 3, an example configuration of
an information communication system according to the present
invention will be described. IPTV service systems have been
developed and commercialized by various vendors, such as U.S.
Microsoft Corporation. In this embodiment, description will be
given regarding an example where an IPTV service architecture that
uses an IP multimedia subsystem (IMS) is used.
[0077] IMS has originally been developed by 3GPP (3rd Generation
Partnership Project), which is a project for standardizing 3rd
generation mobile communication systems, as base technologies for
providing, for example, push to talk conference systems, which
enable conversation by three or more cellular phones, communication
such as instant messages, and multimedia additional services in
voice telephony services on wireless communication infrastructure
for cellular phones.
[0078] IMS is based on IP technologies, and is highly compatible
with Internet infrastructure for fixed communication systems. In
the midst of movement for integrating wired and wireless
communication network infrastructure, called FMC (Fixed Mobile
Convergence), attention is being given to IPTV systems that use
IMS.
[0079] IMS is composed of functional elements such as a home
subscriber subsystem (HSS) and an application server (AS), with a
functional component called CSCF (Call Session Control Function) as
a core, which is based on SIP (Session Initiation Protocol) defined
by RFC-3261 of IETF (The Internet Engineering Task Force).
[0080] An IMS network 230 shown in FIG. 3 includes a CSCF 231, an
HSS 232, and an AS (IPTV) 233 as these individual functional
elements, and it provides services to a cellular phone 260 via a
mobile phone network 240.
[0081] The CSCF 231 performs user registration and session setting
control on the basis of SIP (Session Initiation Protocol).
Furthermore, it executes activation of service processes needed
according to setting of a user profile registered in the HSS 232.
The HSS 232 includes databases for management of user IDs used in
IMS, management of profiles of services that each user subscribes
to, management of authentication information, management as to
whether use of each IMS service is allowed, and management of user
movement. The AS 233 is a server that executes processes of
individual services, and it is activated by the CSCF 231 in
accordance with the service subscription status of each user to
provide services to the user.
[0082] As described above, in IMS, a terminal for which a user ID
has been set accesses the CSCF 231 to perform terminal registration
and session setting control, services needed are activated
according to setting of a user profile registered in the HSS 232,
and the AS 233 actually executes processes of individual
services.
[0083] For example, a representative example of a service that uses
IMS is "Push To Talk". In "Push To Talk", a user terminal is
configured to connect to an application server (AS) AS that
executes a "Push To Talk" service in the IMS network 230, establish
sessions with a plurality of members from the AS with registered
group members, and perform conversation among the members via a
relaying server using VoIP (Voice over IP).
[0084] In an IPTV viewing service, an AS for an IPTV service, set
in the IMS network 230, is used. The AS (IPTV) 233 shown in FIG. 3
corresponds to an AS that executes the IPTV service. The AS 233
actually executes a service for the user terminal in cooperation
with an IPTV service 250 as an entity that executes the IPTV
service, i.e., an entity that provides content.
[0085] The IPTV service 250 includes an EPG server 251, which is a
server that provides an EPG (Electronic Program Guide), i.e.,
program information guide such as a content list, and a video
server 252, which is a server that provides video content, and it
implements a service of providing a content list and a service of
providing content to the user terminal by cooperation between the
respective servers and the AS (IPTV) 233 of the IMS network
230.
[0086] In the system of the present invention, a home network 210,
as its basic configuration, is configured by a conventional-type
home network described earlier with reference to FIGS. 1 and 2,
i.e., by existing DLNA (Digital Living Network Alliance) devices.
FIG. 3 shows a residential gateway (RG) 211 used as a bridge, which
is a network connecting device for connecting a device in the home
network to an IP broadband network 221, a home IMS gateway 212 that
executes a process for allowing a device in the home network 210
(e.g., a content playing device such as a TV (DMP) 213) to use a
service provided by a server outside the home network, and a TV 213
as a digital media player (DMP), which is a client device that
receives and plays content.
[0087] The broadband IP network 220 is a network, such as the
Internet, that allows mutual communication among the IPTV service
250, the IMS network 230, and the home network 210.
[0088] Note that in the system of the present invention, the home
IMS gateway 212 is set as a terminal that receives an IMS network
service. In the home IMS gateway 212, an IMS user ID is set. That
is, a user ID and a user profile of the home IMS gateway 212 are
registered in the home subscriber subsystem (HSS) 232 of the IMS
network 230.
[0089] The home IMS gateway 212 receives an IPTV service by
executing a process similarly to a case where the cellular phone
260 executes an IPTV service. That is, it accesses the CSCF 231 and
performs terminal registration and session setting control,
activates services needed according to setting of the user profile
registered in the HSS 232, and receives a service using the AS
(IPTV) 233. In addition to the function of connecting to an IMS
service as described above, the home IMS gateway 212 executes a
gateway function for access by a DLNA device, such as the TV (DMP)
213 shown in the figure, to video content provided by the IPTV
service 250. That is, the home IMS gateway 212 has the following
functions:
[0090] (a) Function for connecting to an IMS service
[0091] (b) Gateway function
[0092] These functions are implemented using a network
communication function, a basic configuration of an information
processing apparatus, and software. The home IMS gateway 212 can be
implemented on various devices connected to an existing home IP
network having a network communication function.
[0093] Note that in a case where the home IMS gateway 212 executes
a process of relaying video content or the like provided by the
IPTV service 250 to a DLNA device, such as the TV (DMP) 213 shown
in the figure, the following function is further provided:
[0094] (c) DMS function as a function for executing a content
providing process
[0095] However, this function is not necessary, and such a
configuration is possible that transmission and reception of
content are executed by communication between a DMP as a DLNA
device and an external server without the home IMS gateway 212
intervening therebetween. In this case, the home IMS gateway 212
need not have the DMS function. Specific process configurations of
these will be described later.
[0096] By setting the home IMS gateway 212 having a function for
receiving an IMS network service in the home network, it becomes
possible for an existing DLNA device (e.g., the TV (DMP) 213 shown
in the figure) to receive IPTV video content by a process
substantially similar to receiving content provided from the home
IMS gateway 212.
[0097] It becomes possible for the TV (DMP) 213, which is a client
device in the home network, to execute an IPTV service executed as
a process of providing content from a device outside the home
network, by a content using process similar to receiving content
provided from a DMS in the home network, i.e., the home IMS gateway
212.
[0098] The home IMS gateway 212 implements a DMS (Digital Media
Server) function as a content providing server of a DLNA device. An
access is made from the TV 213 on which a DMP (Digital Media
Player) is implemented to the home IMS gateway 212, so that the
home IMS gateway 212 can provide an IPTV service received via the
IMS network 230 to the TV 213.
[0099] As described earlier, the home IMS gateway 212 can be
implemented on various devices having a network communication
function and connected to an existing home IP network. For example,
it is possible to implement an IMS network service receiving
function on a residential gateway (RG: Residential) supplied from
an access line vendor that provides a network circuit, such as a
telephone company or a cable TV company. In this case, the RG 211
and the home IMS gateway 212 shown in FIG. 3 are integrated.
[0100] Alternatively, in the conventional-type home network
configuration described with reference to FIG. 1, it is possible to
implement an IMS network service receiving function on a DVR
(Digital Video Recorder) or a PC that functions as a digital media
server (DMS) as a device that provides content.
[0101] As described above, in the configuration of the present
invention, since devices on which an IMS network service receiving
function can be implemented are not limited, it becomes possible to
support an IPTV service using the open Internet, and it also
becomes possible to support an arbitrary home network configuration
without limitation regarding network topology.
[0102] Hereinafter, an example configuration of the home IMS
gateway and a process of receiving an IPTV service using the home
IMS gateway will be described in detail. First, before describing
the home IMS gateway, functional components of the DLNA guideline,
to which DLNA devices conform, will be described with reference to
FIG. 4.
[0103] FIG. 4 shows functional components of the DLNA guideline.
From the top row, configurations of a media format layer (Media
Format), a media transport layer (Media Transport), a device
discovery control and media control layer (Device Discovery,
Control, and Media Management), a network layer (Network Stack),
and a network connectivity layer (Network Connectivity) are
defined. A home network device (DLNA device) executes data
communication according to network protocols compliant with the
DLNA (Digital Living Network Alliance) guideline according to the
basic components shown in FIG. 4.
[0104] First, the network connectivity on the lowermost layer is a
definition of a physical layer and a link layer of a home network.
On a DLNA device, communication functions conforming to the IEEE
802.3u and 802.211a/b/g are implemented. However, the communication
standard regarding home network infrastructure is not limited as
long as IP connection is allowed, such as PLC (Power line
communication).
[0105] In the network layer, the IPv4 protocol is used, and each
DLNA device performs communication using TCP or UDP. In UPnP
(registered trademark) Device Architecture 1.0 defined in the
device discovery control and media control layer, SSDP (Simple
Service Discovery Protocol) for device discovery, SOAP (Simple
Object Access Protocol) for performing control, and so forth are
defined, and UPnP AV is implemented over UPnP DA (UPnP Device
Architecture). UPnP AV version 1 defines UPnP Media Server and UPnP
Media Renderer. A DMS, which is a content providing server defined
in DLNA, implements UPnP Media Server, and a DMP, which is a
content playing device defined in DLNA, implements a controller of
UPnP Media Server.
[0106] On UPnP Media Server, a main content directory service is
implemented, so that a method of obtaining a content list and
metadata is provided. By using the content directory service, the
DMP, which is a content playing device defined in DLNA, obtains a
content list streamed by the DMS, which is a content providing
server defined in DLNA.
[0107] As a definition of the media transport layer, which is a
next upper layer, it is defined that HTTP1.0/1.1 is used for
streaming playing. As a media format, in the case of video content,
it is defined that content of Media Formats conforming to the
MPEG2-PS profile defined by DLNA is transferred by streaming from
the DMS to the DMP. For example, the DMP, which is a content
playing device defined by DLNA, sequentially decodes and plays
MPEG2-PS data received by streaming transmission, whereby the user
can view the content.
[0108] FIG. 5 shows an example hardware configuration of the home
IMS gateway 212 described with reference to FIG. 3. As described
earlier, the home IMS gateway 212 has the following functions:
[0109] (a) Function for connecting to an IMS service
[0110] (b) Gateway function
[0111] These functions are implemented by a network communication
function, a basic configuration of an information processing
apparatus, and software. The hardware shown in FIG. 5 shows an
example hardware configuration for implementing these functions (a)
to (b).
[0112] As shown in FIG. 5, the home IMS gateway 212 is configured
by a CPU 301 as a data processing unit that executes various types
of software (computer programs), a memory 302 formed of a ROM as a
program storage area, a RAM used as a work area or the like during
execution of data processing, and so forth, a network I/F 303 as a
network connecting unit, and furthermore, a bus 304 for
transferring commands and data between these components.
[0113] The network I/F 303 is, for example, a network I/F for a
wired LAN, such as IEEE 802.3u. An OS and other software programs
are stored in a flash-ROM constituting the memory 302, and these
programs are copied to a RAM constituting the memory 302 and
executed. Furthermore, a user ID and various types of setting
information needed in a process of establishing an IMS session are
also saved in the flash-ROM constituting the memory 302.
[0114] Next, an example configuration of software modules of the
home IMS gateway 212 will be described with reference to FIG. 6. As
shown in the figure, the software modules can be classified into
three types:
[0115] (1) Network modules
[0116] (2) Protocol modules
[0117] (3) Application modules
[0118] (1) The network modules are modules in charge of controlling
communication in an IP network.
[0119] (2) The protocol modules are modules in charge of protocol
control that controls the individual functions of IMS and DLNA,
i.e., performing control so that the IMS side executes
communication according to a protocol defined on the IMS side and
so that that the DLNA side executes communication according to a
protocol defined on the DLNA side. Since communication according to
different protocols are executed on the IMS side and on the DLNA
side, configurations supporting different protocols are
provided.
[0120] (3) The application modules are modules that implement an
actual gateway function using the protocol modules, i.e., that
implements relaying between the DLNA side on the home network side
and the IMS network, which is a network outside the home
network.
[0121] In the figure, in order to clarify the distinction between
functions used on the DLNA side on the home network side and
functions used in the IMS network, which is a network outside the
home network, areas are separated by a broken line, with software
modules applied to the IMS/IPTV side shown on the left side of the
broken line, and software module applied to the DLNA side shown on
the right side. Note, however, that the network modules are
commonly used in both networks. Hereinafter, each of the modules
will be described in detail.
[0122] First, in the network modules, a TCP IP stack, and an Auto
IP/DHCP (Dynamic Host Configuration Protocol) Client module for
executing a process of setting an IP address, defined in UPnP DA,
are implemented. The same network modules can be used by both IMS
and DLNA.
[0123] Basically, it suffices for the home IMS gateway 212 to be
connected to a home IP network, so that it is not necessary to
separately set network I/Fs. Note, however, that in a case where it
is configured as integrated with a residential gateway, a home
network connection I/F and an external network connection I/F may
be configured separately.
[0124] Since protocols that are used on the DLNA side on the home
network side and protocols used in the IMS network, which is a
network outside the home network, are currently different, the
protocol modules are set individually in accordance with the
individual protocols.
[0125] The DLNA side is composed of SOAP defined in DA, GENA
(Generic Event Notification Architecture), Presentation Page and
Device Description modules by an HTTP (Hyper Text Transfer
Protocol) server, SSDP in charge of Device Discovery as a device
discovery process, and an AKE module that executes authentication
and key exchange (AKE) of DTCP-IP (Digital Transmission Content
Protection--Internet Protocol) needed for implementing content in a
home network.
[0126] The IMS side is composed of SIP/Module that establishes a
session with an AS (Application Server), which is a server that
provides an IMS service, and SOAP and GENA modules that perform
message communication with the AS. Furthermore, on the IMS side,
since communication over the open Internet is assumed,
communication executing protocols, such as SIP and SOAP, are
implemented over the TLS (Transport Layer Security) protocol
defined in IETF RFC 2246 for security, so that the protocol setting
is such that communication is executed under a secure
environment.
[0127] One of the features of the home IMS gateway 212, which is an
information processing apparatus of the present invention, is that
it has such a configuration that a process of mapping an AS (IPTV
service) of IMS as a UPnP device is executed using a function
called Device Discovery Control as a device discovery process
function used on a DLNA-side device. That is, the home IMS gateway
212 maps a server outside the home network as a virtual home
network device. Specifically, by using UPnP Device Proxy Manager
(refer to FIG. 6) or the like that is set as an application module
on the home IMS gateway 212, the home IMS gateway 212 generates a
UPnP Media Server instance corresponding to an AS (IPTV), which is
an external server, and records it on a memory.
[0128] As described above, the home IMS gateway 212 maps and sets
an AS (IPTV service) of IMS, which is an external device not
existing in the home network, as a DMS of DLNA. This process is a
process of making setting as if an AS (IPTV service) of IMS were a
content providing server (DMS) existing in the home network.
[0129] In a case where a device discovery process according to UPnP
is executed through the mapping process by a DLNA device in the
home network, e.g., a DMP as a content playing executing device
such as a TV, it becomes possible for the home IMS gateway 212 to
notify the DMP that it has a service providing function based on
the UPnP Media Server instance corresponding to the AS (IPTV). This
makes it possible for the DMP to recognize, on the basis of this
notification, the AS (IPTV service) of IMS as a device similar to a
content providing server (DMS) in the home network. This makes it
possible to receive a service of the AS (IPTV service) of IMS,
which is an external network, by a process similar to reception of
a service based on providing of content from within the home
network.
[0130] Note that regarding the home IMS gateway 212, which is an
information processing apparatus of the present invention, it is
possible to make arbitrary setting as to whether a process of
relaying content provided by the AS (IPTV service) of IMS is to be
relayed to a DMP as a content playing executing device in the home
network. It is possible to make setting such that, without
performing relaying of content, a DMP directly obtains content data
from an external network by communication between a DLNA device
(DMP as a content playing executing device) and a backend Video
Server of the AS (IMS) of IMS. Specific process examples these will
be described later.
[0131] In a case where the home IMS gateway 212 performs relaying
of content provided by the AS (IPTV service) of IMS, functions
called Media Management, for example, a Content Directory service
that obtains metadata of a content list, and a protocol for
transferring video content, called Media Transport of DLNA, are
implemented. In a configuration where the home IMS gateway 212 does
not perform relaying of content provided by the AS (IPTV service)
of IMS, it is not necessary to implement these functions, i.e., the
Media Management functions, on the home IMS gateway 212.
[0132] Furthermore, it is also possible to make setting such that
the home IMS gateway 212 does not perform a relaying process either
for a content list request from a client device in the home
network, i.e., a DMP as a content playing executing device, and
such that a client device (DMP) is caused to issue a content list
request directly to an external server such as an AS (IPTV
service). In this configuration, it suffices for the home IMS
gateway 212 to be configured to be capable of responding to a
device discovery request from a client. Note that in order to send
a request from a client directly to an external server without
passing it through the home IMS gateway 212, it is implemented by
setting the URL of the external server, not the home IMS gateway,
as a URL specified in [ControlURL] and [eventSubURL] of device
information [Device Description] defined in Device Architecture of
UPnP. The home IMS gateway 212, by providing device information
[Device Description] having such setting to a client device, sets
in an external server, such as the AS (IPTV service), a
counterparty to which a client subsequently issues a content list
request or various types of requests with reference to the device
information. In this case, the model is such that the home IMS
gateway is in charge of only device discovery, so that the load is
further reduced. Note that it is also possible to set a URL of an
external server instead of the home IMS gateway 212 also in URL
[SCPDURL] for obtaining device information, defined in Device
Architecture of UPnP.
[0133] The application modules, by using the protocol modules,
execute a gateway function, i.e., a function of setting a
communication environment between a DLNA device in the home network
and a server outside the home network. The application modules are
broadly classified into a set of modules that perform a mapping
process for setting an AS (IPTV) service of IMS as a DMS of DLNA,
and a set of modules that passes requests sent from, for example, a
DMP, which is a content playing device in the home network, to an
AS (IPTV) service of IMS.
[0134] The former set of modules that perform the mapping process
are AS Discovery, ServiceManager, and UPnP Device Proxy Manager,
and the latter modules that execute the request transferring
process are UPnP Message Proxy and AKE Proxy.
[0135] As described above, the home IMS gateway 212, which is an
information processing apparatus of the present invention, performs
a process of mapping an AS (IPTV service) of IMS, which is an
external device not existing in the home network, as a DMS of DLNA.
Furthermore, the home IMS gateway 212 has a function of selectively
mapping only a service entity [AS(IPTV)] selected by a user at the
time of the mapping process.
[0136] That is, in a configuration where a plurality of ASs (IPTVs)
of IMS/IPTV exist in the external network and each provides
content, only an AS (IPTV) that a user has purchased and selected
using an IMS charging system is selected and mapped to a DMS of
DLNA.
[0137] Among the application modules that perform the mapping
process, AS Discovery shown in FIG. 6, which is a module on the
IMS/IPTV side, executes a process of discovering an IPTV service
provided by an IMS system, and UPNP Device Proxy Manager, which is
a DLNA-side module, manages a list of ASs discovered and obtained
by AS Discovery, and presents the user with this list to allow the
user to execute a process of purchasing or selecting an AS
(IPTV).
[0138] Specifically, the home IMS gateway 212, which is an
information processing apparatus of the present invention, becomes
an HTTP server, and connects to a UPnP Control Point having an HTML
browser thereon, the user selects a desired IPTV service from a
displayed HTML screen using a browser function, and performs a
procedure of subscribing to the service. Specifically, for example,
by using a PC or TV set as a DLNA device in the home network having
a browser function, it is possible to present a list owned by the
home IMS gateway 212 on a display and to select an IPTV
service.
[0139] Furthermore, in the procedure of receiving the IPTV service,
by using UPnP Message Proxy as an executing module, it is possible
to cause the request transferring process described earlier to
cooperate with the charging system provided by the IMS system, and
charging on the user is performed on the basis of customer
information of the IMS user ID that has been set as an ID
corresponding to the home IMS gateway 212.
[0140] As described above, on condition of the procedure of
subscribing to the AS (IPTV) by the user, it becomes possible for
the home IMS gateway 212 to perform selective mapping such as
selecting an IPTV service for which the subscription procedure has
been executed by the process of UPnP Device Proxy Manager, which is
an application module, and to map the IPTV service to a DLNA DMS.
Note, however, that in a case where an AS (IPTV) or the like exists
for which it is not necessary to perform a subscription procedure,
such as an AS (IPTV) that provides content free of charge, the
process of subscription procedure by the user is not necessary, and
user's selection is not a necessary condition for mapping.
[0141] The DMP as a content playing device, which is a DLNA device
in the home network, interprets the AS (IPTV) for which the mapping
process has been completed at the home IMS gateway 212 as a content
providing server (DMS) in the home network, so that it becomes
possible to receive the AS (IPTV) service.
[0142] UPnP Message Proxy, which is an application module, relays a
message supplied from the DLNA DMP to the AS (IPTV). As protocols
for this purpose, SOAP and GENA, equivalent to UPnP, are used, and
the AS tries to achieve mutual compatibility by directly processing
a message of a UPnP Media Server and Content Directory service
defined in UPnP AV, by performing protocol conversion for AS (IPTV)
at UPnP Message Proxy, or the like.
[0143] Note that the example configuration of software modules of
the home IMS gateway 212 shown in FIG. 6 is a configuration of
software modules in a case where the home IMS gateway is allowed to
execute both communication according to communication protocols on
the IMS/IPTV side and communication according to communication
protocols on the side of DLNA in the home network, and the home IMS
gateway 212 executes protocol conversion as needed in communication
between the IMS/IPTV side and the DLNA side.
[0144] The configuration for the process of conversion of
communication protocols may be such that it is executed by the home
IMS gateway 212, or, for example, the configuration may be such
that it is executed by an external server that executes
communication directly with the side of the home IMS gateway 212,
for example, an AS on the IMS side or a server that executes an
IPTV service. As described above, in the configuration where
necessary protocol conversion is executed at the external server,
it suffices for the home IMS gateway 212 to have DLNA-side protocol
modules and application modules. Note that in the case of such a
configuration, the process of mapping the external server is
executed by executing a device discovery process according to the
SSDP protocol defined by DLNA.
[0145] Furthermore, in the process of obtaining a content list and
metadata, executed by a client device in the home network, i.e., a
DMP as a content playing executing device, in the embodiment
described below, a method is employed in which an AS directly
processes a UPnP Content Directory service. In the embodiment, a
procedure for subscription to a service is executed by UPnP Control
Point on which an HTML browser is implemented. Although this may be
a DMP of a DLNA, it need not necessarily be a DMP of a DLNA, and a
similar process can also be executed, for example, by a HTML
browser of a personal computer of a third party. Also, in a case
where an HTML browser is implemented on a cellular phone or the
like, a purchase procedure can be executed similarly.
[0146] Furthermore, by making setting such that the home IMS
gateway 212 itself has a user interface such as a display apparatus
and an input unit, it is possible to input information input by the
user by directly presenting a list obtained from an AS (IPTV) on
the user interface, so that it is possible to execute a procedure
for service subscription without depending on control by an HTML
browser.
[0147] Note that various modes are possible as modes of the
procedure for subscribing to an AS (IPTV). That is, various setting
is possible, such as selection on the basis of each service as
selection of an AS (IPTV) itself, or selection on the basis of each
content provided by an AS (IPTV). In these cases, a scheme for
selecting purchase by each content on the basis of setting of AS
(IPTV) is provided by Presentation Page, selection information is
registered on the IMS side as configuration data of user profile
information, and the AS (IPTV) side provides content according to
the registered information.
[0148] As described above, for the home IMS gateway 212, setting is
possible both for a case where it is configured to execute a
process of relaying content provided by an AS (IPTV service) of IMS
to a DMP as a content playing executing device in the home network,
and for a case where the process is not executed. In the latter
case, processing of service logic at an application level, for
example, data processing corresponding to each service, such as
interpretation of a service provided by an AS (IPTV) service, or a
process of conversion into a format understandable by a DMP, is not
necessary. Furthermore, a process of temporary saving of content
data or conversion is not necessary, either, so that it is possible
to implement a home IMS gateway by a device with very inexpensive
software and hardware configurations.
[0149] By making service logic processing by the gateway apparatus
unnecessary, compared with a configuration in which these processes
are executed, flexibility of extension of services can be improved.
For example, there are cases where an AS (IPTV), which is an entity
that provides content, performs addition of metadata of content or
the like. In a configuration where a gateway apparatus executes
processing of service logic, in order to make it possible for the
gateway to interpret and process the added metadata, for example,
updating of a program becomes necessary. However, in a home IMS
gateway of the present invention, such a setting is possible that
such processing is not executed, and it becomes possible to make
various changes in service logic only by changes on the
distribution service side without making changes at the gateway
itself.
[0150] As described earlier, the following two configurations exist
as modes of processing by the home IMS gateway 212:
[0151] (1) Configuration in which a process of relaying content
provided by an AS (IPTV service) of IMS to a content playing device
(DMP) in the home network is executed.
[0152] (2) Configuration in which a process of relaying content
provided by an AS (IPTV service) of IMS to a content playing device
(DMP) in the home network is not executed, and content is played by
communication between DMP and AS (IPTV service).
[0153] In the above configuration (2) where content is played by
communication between DMP and AS (IPTV service), content is
transmitted directly from a content distribution service on the
Internet to a DMP, which is a playing device. Thus, as opposed to a
method in which content is temporarily downloaded to a home server
and is then redistributed into a home, since it is possible to play
content on demand, convenience for the user is also high.
Furthermore, in the method in which transmission of content is not
relayed, since duplicate transmission of content data does not
occur in the home network, it is possible to prevent using a band
in vain. Furthermore, limitation regarding the topology of the home
network becomes absent, so that there exists an advantage that the
variety of products on which a gateway function is implemented
becomes increases.
[0154] Hereinafter, a process sequence in a case where content is
played by the process of the above (2), i.e., communication between
DMP and AS (IPTV service), will be described with reference to
sequence diagrams in FIGS. 7 to 10. The sequence diagrams in FIGS.
7 to 10 are diagrams for explaining sequences of the following
processes.
[0155] (A) Sequence of procedure for subscribing to AS (IPTV)
(FIGS. 7 and 8)
[0156] (A1) IMS registration process
[0157] (A2) Device discovery process
[0158] (A3) AS (IPTV) selection process
[0159] (B) Sequence of usage of content provided by AS (IPTV)
(FIGS. 9 and 10)
[0160] (B1) Device Discovery Process
[0161] (B2) Content list obtaining process
[0162] (B3) Authentication and key exchange process
[0163] (B4) Content streaming process
[0164] First, with reference to FIGS. 7 and 8, the sequence of the
procedure for subscribing to an AS (IPTV) will be described. FIGS.
7 and 8 show the following components from the left side:
[0165] (1) Three IPTV services AS1, AS2, and AS3 as application
servers that execute content providing services supporting IPTV in
an IMS network
[0166] (2) HSS having databases for management of user IDs used in
IMS, management of profiles of services that each user subscribes
to, management of authentication information, management of whether
use of each IMS service is allowed, and management of user
movement
[0167] (3) CSCF that performs user registration and session setting
control on the basis of SIP (Session Initiation Protocol) in an IMS
network
[0168] (4) Home IMS gateway
[0169] (5) HTML browser (user interface) as a UPnP control
point
[0170] Furthermore, [Cx], [SIP], [SSDP], and [HTTP] shown in
individual steps indicate protocols applied to individual
communications.
[0171] The sequence of subscribing to an AS (IPTV), shown in FIGS.
7 and 8, can be divided into the following three phases:
[0172] (A1) IMS registration process
[0173] (A2) Device discovery process
[0174] (A3) AS (IPTV) selection process
[0175] Hereinafter, each of the processes will be described.
[0176] (A1) IMS Registration Process
[0177] In the IMS registration process, which is the first phase,
first, in step S11, the home IMS gateway sends an IMS user ID
preset to the home IMS gateway to a CSCF of the IMS network, and in
step S12, the home IMS gateway receives an acknowledgement of
registration and performs registration to the IMS network. Then, in
step S13, configuration information (config) is presented to the
CSCF, and in step S14, an acknowledge response is received.
[0178] In step S15, the CSCF issues a request for available service
information registered in association with the IMS user ID to the
HSS having a database for managing user profile information and
obtains the available service information (step S16), and in step
S17, the CSCF sends the obtained list of available serves to the
home IMS gateway. In step S18, the home IMS gateway sends an
acknowledgement of receipt to the CSCF.
[0179] The home IMS gateway obtains a list of available services as
described above and stores it in a memory. The home IMS gateway
generates an HTML document from the list of IPTV services obtained
as described above, and prepares for the subsequent setting of AS
by the HTML browser.
[0180] (A2) Device Discovery Process
[0181] The second phase is the device discovery process. At the
initial stage, the AS to use is not specified by the user. Thus, at
this stage, the home IMS gateway has not mapped the AS (IPTV) as a
DLNA DMS, so that the DMP as a content playing device in the home
network cannot interpret the AS (IPTV) as a DMS and receive
content.
[0182] As described earlier, when selection of an AS (IPTV) is
executed, the home IMS gateway becomes an HTTP server, and by using
the scheme of Presentation defined in UPnP DA, it connects to UPnP
Control Point implemented on an HTML browser and selects a desired
IPTV service from an HTML screen displayed by the user using a
browser function. (A2) Device discovery process shown in FIG. 7 is
a sequence of this process.
[0183] The user who executes selection of an AS (IPTV) discovers
that the home IMS gateway is connected on the home network by the
process according to the device discovery protocol defined in UPnP
from UPnP Control Point, for example, a PC or the like having a
browser function, i.e., by sending SSDP M-Search in step S19 and
receiving SSDP M-Response as a response thereto in step S20. Steps
S21 and S22 are steps of requesting and receiving specific device
information.
[0184] (A3) AS (IPTV) Selecting Process
[0185] FIG. 8 shows the sequence of the AS (IPTV) selecting process
that is executed subsequently. In this phase, the user views the AS
(IPTV) service list obtained in the first phase by the home IMS
gateway from the UPnP Control Point of a PC or the like, and
executes service (AS) selection.
[0186] First, in steps S23 and S24, to the home IMS gateway as an
HTTP server, on the basis of HTTP GET, an HTML document is obtained
and an HTML page is displayed. In the screen, the AS (IPTV) service
list is displayed.
[0187] The user selects an AS (IPTV) from which a service is to be
received or selects content from the list, and then, in step S25,
the request information is input to the home IMS gateway, and in
step S26, the home IMS gateway requests subscription to the
service. In step S27, on the basis of the service subscription
request at the home IMS gateway, the CSCF executes registration of
information corresponding to the service subscription request to
the HSS as registration information associated with the user. Upon
completion of the service subscription registration process, in
step S28, a notification of a process completion response is sent
from the HSS to the CSCF, is sent from the CSCF to the home IMS
gateway in step S29, and is further sent to an apparatus having a
user interface, such as a PC that is UPnP Control Point, and is
acknowledged by the user in step S30.
[0188] Note that in (A3) AS (IPTV) selecting process, there are
cases where, for example, a charging process or the like is
performed. In this case, input and communication of information
needed for the charging process are executed.
[0189] As described above, (A) the sequence of subscribing to AS
(IPTV) is composed of the following three processes:
[0190] (A1) IMS registration process
[0191] (A2) Device discovery process
[0192] (A3) AS (IPTV) selecting process
[0193] By completing these processes, the process of subscribing to
an AS (IPTV) is completed.
[0194] Upon completion of the AS (IPTV) subscription procedure, the
home IMS gateway executes mapping so that the selected AS (IPTV)
becomes a DMS, thereby making setting such that the DMP as a
content playing device in the home network can interpret the
selected AS (IPTV) as a DMS and receive content. That is, by using
UPnP Device Proxy Manager and so forth shown in FIG. 6, the home
IMS gateway generates an instance of UPnP Media Server
corresponding to the selected AS (AS3 in the example), and records
the instance in a memory.
[0195] Through the mapping process, the AS (IPTV) as an IMS
application server existing outside the home network is dealt with
similarly to a DMS (DLNA Media Server) similar to a content
providing server in the home network, and it becomes possible to
use the AS (IPTV) from a DMP (DLNA Media Player), which is a
content playing device in the home network.
[0196] Hereinafter, with reference to FIGS. 9 and 10, a sequence of
usage of AS (IPTV) provided content by a DMP, which is a content
playing device in the home network, will be described.
[0197] FIGS. 9 and 10 shows the following components from the left
side:
[0198] (1) IPTV service (AS) (content providing entity)
[0199] (2) HSS having databases for management of user IDs used in
IMS, management of profiles of services that individual users
subscribe to, management of authentication information, management
of whether use of each IMS service is permitted or not, and
management of user transfer
[0200] (3) CSCF that controls user registration and session setting
on the basis of SIP (Session Initiation Protocol) in an IMS
network
[0201] (4) Home IMS gateway
[0202] (5) DMP (DLNA Media Player), which is a content playing
device in a home network.
[0203] Note that (1) IPTV service (AS) is either an IPTV service
alone or a combination of an IPTV service and an AS, and either
mode is possible. Furthermore, [SSDP], [HTTP], [SOAP], and [AKE]
shown in individual steps indicate protocols applied to individual
communications.
[0204] The sequence of usage of AS (IPTV) provided content, shown
in FIGS. 9 and 10, can be divided into the following four
phases:
[0205] (B1) Device discovery process
[0206] (B2) Content list obtaining process
[0207] (B3) Authentication and key exchange process
[0208] (B4) Content streaming process
[0209] Hereinafter, each of these processes will be described.
[0210] (B1) Device Discovery Process
[0211] The first process is the device discovery phase. By the AS
subscription sequence described earlier with reference to FIGS. 7
and 8, the home IMS gateway has already mapped an AS (IPTV) as a
DLNA DMS, and it has been made public to each device DLNA device in
the home network that the AS (IPTV) can be used as a DLNA DMS. That
is, all the DMPs connected to the home network, which are content
playing devices, can obtain AS (IPTV) information as DMS from the
home IMS gateway by the device discovery sequence defined in UPnP
DA. The device discovery sequence is a process of steps S31 to
S34.
[0212] The DMP, which is a content playing device, discovers the AS
(IPTV) set as a DMS, by the process according to the device
discovery protocol defined in UPnP, i.e., by sending SSDP M-Search
to the home IMS gateway in step S31 and receiving SSDP M-Response
from the home IMS gateway as a response thereto in step S32. Steps
S33 and S34 are steps of requesting and receiving specific device
information.
[0213] Note that in the device discovery process, the home IMS
gateway provides information based on the UPnP Media Server
instance corresponding to the AS (IPTV), generated by the home IMS
gateway in the mapping process, i.e., server information
corresponding to the AS (IPTV), to the DMP, which is a content
playing device. By receiving this information, the DMP interprets
the AS (IPTV) as being a content providing server (DMS) in the home
network.
[0214] (B2) Content List Obtaining Process
[0215] The second process is a process of obtaining a content list
from the AS (IPTV) set as a DMS. As in the example already shown in
the AS subscription sequence, it is assumed that the home IMS
gateway has already established a session with the IMS network. In
a case where a session is not established or is disconnected, a
reconnection is performed using a request for obtaining content or
the like as a trigger. By establishing a session with the IMS
network, information of the AS for which subscription has been
completed has already been obtained.
[0216] In step S35, the DMP issues a Browse action of UPnP Content
Directory Service to the AS (IPTV) set as a DMS that has been
discovered in the first phase. Upon receiving the Browse action
from the DMP, in step S36, the home IMS gateway relays this request
and transfers it to the IPTV (AS).
[0217] The IPTV (AS) interprets the content of the Browse action,
generates a list of video content from a backend electronic program
information storage server (EPG server) or the like, and sends a
response to the DMP via the home IMS gateway (steps S37 and S38).
For example, in a case where the content list has a hierarchy, a
plurality of Browse actions are issued. Note that as defined in
UPnP Content Directory Service, a content list is represented by an
XML document called DIDL-Lite, conforming to XML Schema, and
resource information (URI) of video data of each content indicates
video content provided by a backend Video Server of AS.
[0218] Note that as described earlier, such setting is possible
that the home IMS gateway does not execute the process of relaying
a content list request from a DMP, and a content list request is
issued directly from a client device (DMP) to an external server
such as an AS (IPTV service). For this purpose, URLs specified by
[controlURL] and [eventSubURL] of device information [Device
Description] defined in UPnP Device Architecture are set to be a
URL of an external server, not the home IMS gateway. By the home
IMS gateway providing device information [Device Description]
having such URL setting to a client device, a counterparty to which
the client subsequently issues a content list request or various
types of request with reference to the device information is set to
an external server such as an AS (IPTV service).
[0219] (B3) Authentication and Key Exchange Process
[0220] The third phase is authentication and key exchange. In a
case where copy-protected content is transmitted, a DLNA encrypts
the content according to DTCP-IP and transmits the content. Also in
streaming from an AS (IPTV) video server, encryption conforming to
DTCP-IP is performed to send encrypted content.
[0221] A key applied to content encryption is generated by an
authentication and key exchange (AKE) process according to
definition of DTCP-IP. As shown in FIG. 6, the home IMS gateway has
a function of DTCP-IP AKE Proxy, and at the time of content
reception, a DMP, which is a content playing device, performs
authentication and key exchange with the home IMS gateway having a
DMS that the DMP recognizes as a content providing service
entity.
[0222] The setting of a content resource URI set in a list obtained
in (B2) content list obtaining process is such that it includes an
IP address of an AS video server. An address as a subject of the
authentication and key exchange process needed to execute obtaining
of content, i.e., the AKE processes, is set to the home IMS
gateway. That is, the DMP performs authentication and key exchange
with the home IMS gateway in which a DMS instance recognized as a
content providing service entity is registered.
[0223] Note that although the subject of execution of
authentication and key exchange at the DMP is often an entity that
sends encrypted content, i.e., an IP address of an AS video server
included in a content resource URI, in the configuration of the
present invention, the subject of the AKE processes executed by the
DMP at the time of a request for obtaining content included in the
content list provided to the DMP in (B2) content list obtaining
process is set to be the home IMS gateway.
[0224] This becomes possible, for example, by including, in
metadata associated with content, metadata with which setting is
such that the subject of AKE is the home IMS gateway. The
configuration may be such that the setting of content list that the
home IMS gateway receives from the IPTV service (AS) is a list set
in advance as described above or such that metadata is added or
changed at the home IMS gateway. Alternatively, the configuration
may be such that at the time when the home IMS gateway provides a
content list to the DMP, a notification that the subject of AKE is
the home IMS gateway is executed.
[0225] The authentication and key exchange process is executed
according to an authentication and key exchange (AKE) process
sequence defined in DTCP-IP.
[0226] In the configuration of the present invention, through the
processes of steps S39 to S46 shown in FIG. 10, i.e.; [0227] S39:
AKE Challenge&Response [0228] S40: AKE [0229] S41: RTT (Round
Trip Time) Check request [0230] S42: RTT Check response [0231] S43:
AKE Key Exchange [0232] S44: Key Exchange [0233] S45: Key Exchange
[0234] S46: AKE Key Exchange
[0235] Through these processes, the authentication and key exchange
between the DMP and the home IMS gateway are completed.
[0236] In the course of the authentication and key exchange
process, in order to confirm that the home IMS gateway, which is
the subject of AKE, is in the proximity of the DMP, confirmation of
TTL (Time To Live) of an IP packet and confirmation of a response
time are executed as RTT measurement in steps S41 and S42.
[0237] Furthermore, steps S44 and S45 are processes that are
characteristic of the configuration of the present invention, and
these are processes of passing a key shared between the home IMS
gateway and the DMP in the AKE sequence to the IPTV service (AS) so
that the key applied as an encryption key is shared between the
IPTV service (AS) as a content providing entity and the DMP as a
content using entity. By adding the processes of steps S44 and S45,
the IPTV service (AS) as a content providing entity and the DMP as
a content using entity can share the encryption key. Here, the IPTV
service (AS) is a legitimate service that is allowed to share the
key, and steps S44 and S45 are performed by secure
communication.
[0238] (B4) Content Streaming Process
[0239] The last, fourth phase is a content streaming process. In
step S47, the DMP, which is a content playing device, applies a
resource URL obtained in the preceding (B2) content list obtaining
process, and issues a content request based on HTTP GET to request
HTTP streaming.
[0240] The video server of the IPTV service (AS) encrypts content
data using the key shared with the DMP in the preceding AKE phase,
and in step S48, starts streaming transmission of content to the
DMP, which is a DLNA device in the home network.
[0241] The DMP, which is a content playing device in the home
network, decrypts the data received from the IPTV service (AS) by
applying the encryption key shared with the IPTV service (AS) in
the preceding AKE phase, and executes content playing by
decoding.
[0242] Regarding the process configuration of the present
invention,
[0243] (B3) Authentication and key exchange process
[0244] (B4) Content streaming process
[0245] It differs in that in these third and fourth phases, an IP
address to which the AKE module is applied is set to be the home
IMS gateway, which is an entity different from the server as a
content providing entity, and it is a process otherwise conforming
to streaming playing by DTCP-IP defined in DLNA.
[0246] An overview of data communication in the content using
process described with reference to FIGS. 9 and 10 will be
described with reference to FIG. 11. In FIG. 11, as devices in a
home network 500, a DMP 501 as a content playing device, a home IMS
gateway 502, and a residential gateway (RG) 503 are shown.
Furthermore, as a configuration outside the home network 500, an IP
multimedia subsystem (IMS) 510 and an IPTV service 520 are
shown.
[0247] As described earlier with reference to FIG. 3, the IP
multimedia subsystem (IMS) 510 is the base of wireless
communication infrastructure for cellular phones, which is being
developed by 3GPP (3rd Generation Partnership Project), which is a
project for standardizing 3rd generation mobile communication
systems. With a functional element called CSCF (Call Session
Control Function) as a core, it is configured by functional
components such as Home Subscriber Subsystem (HSS) and Application
Server (AS). FIG. 11 shows an application server (AS) 511. The
application server (AS) 511 includes CDS (Content Directory
Service) 512 as a directory service executing section that performs
processes such as registration of a function of a service providing
server.
[0248] The IPTV service 520 has an EPG server 521, which is a
server that provides EPG (Electronic Program Guide), which is a
program information guide such as a content list, and a video
server, which is a server that provides video content, and it
implements a content list providing service and a content providing
service to the DMP 501, which is a user terminal, by cooperation
between the respective servers and the CDS 512 of the AS (IPTV)
511.
[0249] A basic process flow in a case where the DMP 501, which is a
content playing device in the home network 500, obtains content
from the IPTV service 520 outside the home network will be
described. Through the AS subscription sequence described earlier
with reference to FIGS. 7 and 8, the home IMS gateway has already
mapped the IPTV service (AS) as a DLNA DMS.
[0250] First, in step S101, the DMP 501 executes device discovery
as a UPnP action to obtain information of an AS (IPTV) set as a DMS
from the home IMS gateway 502. In the device discovery process, the
home IMS gateway 502 provides the DMP 501, which is a content
playing device, with information based on a UPnP Media Server
instance corresponding to the AS (IPTV) generated by the home IMS
gateway 502 in the mapping process. By receiving this information,
the DMP 501 interprets the AS (IPTV) as being a content providing
server (DMS) in the home network.
[0251] Furthermore, the DMP 501 issues a Browse action of Content
Directory Service of UPnP to the AS (IPTV) set as a DMS. Upon
receiving the Browse action from the DMP 501, the home IMS gateway
502 relays the request to the AS 511 (CDS 512). The AS 511 (CDS
512) obtains a list of video content provided by the EPG server 521
of the IPTV service 520, and the home IMS gateway 502 sends a
content list to the DMP 501 as a response.
[0252] Note that as described earlier, in the content list, a
content URL applied to obtaining of content as metadata, and
subject device information of the authentication and key exchange
(AKE) processes executed as a presupposition of content obtaining
are recorded, and the subject device information of the key
exchange process (AKE) is set to the home IMS gateway 502.
Alternatively, without using content metadata, the home IMS gateway
502 may notify the DMP 501 that the subject device of the key
exchange (AKE) process is the home IMS gateway 502.
[0253] Prior to receiving content, in step S102, the DMP 501
executes the authentication and key exchange (AKE) process
according to the definition of DTCP-IP. The DMP executes the
process considering the home IMS gateway 502 as a subject of
execution of authentication and key exchange. Note, however, that
in the authentication and key exchange (AKE) process, in step S103,
the home IMS gateway 502 provides the key applied as a content
encryption key to the video server 522 of a video server 522 as an
IPTV service 520 as a content providing entity. By this process, at
the time of completion of the authentication and key exchange (AKE)
process, the video server 522 of the IPTV service 520 as a content
providing entity and the DMP as a content using entity share the
key.
[0254] Then, in step S104, the DMP 501, which is a content playing
device, issues a content request based on HTTP GET by applying a
resource URL obtained in the content list obtaining process,
thereby requesting HTTP streaming to the video server 522. The
video server 522 of the IPTV service 520 encrypts content data by
applying the key shared with the DMP 501 in the preceding AKE
phase, and sends it to the DMP 501. The DMP 501 executes a
decrypting process on the data received from the IPTV service 520
by applying the shared encryption key, and executes content
playing.
[0255] As described above, with the configuration of the present
invention, it becomes possible for the DMP as a content playing
apparatus in the home network to receive content from a content
providing server outside the home network and to play the
content.
[0256] In order to enable this process, the home IMS gateway
provided in the home network executes a process of executing
communication with the content providing server, mapping the
content providing server as a home network device, generating an
instance in which server information of the external server is
recorded and storing the instance in a storage unit, in response to
reception of a device discovery request according to the UPnP
definition from the content playing device in the home network,
providing server information corresponding to the content providing
server based on the instance to the content playing device as
information of a device that can receive the service.
[0257] Furthermore, in a case where a content obtaining request
from the content playing apparatus, i.e., a request for obtaining
content provided by the content providing server, is received, the
home IMS gateway transfers this request to the content providing
server so that the content providing server sends the content to
the content playing apparatus, thereby enabling reception and
playing of content at the content playing apparatus.
[0258] Furthermore, since the configuration is such that, regarding
the authentication and key exchange demanded to be executed as a
content sending condition defined in DLNA, the process (AKE) as
defined is executed between the content playing apparatus and the
home IMS gateway, and the home IMS gateway sends the generated key
to the content providing server, it becomes possible for the
content providing server and the content playing apparatus to share
the key generated in the authentication and key exchange process.
Similarly to the content sending process executed by the DMS in the
home network, content on which encryption has been performed is
sent from the content providing server to the content playing
apparatus, so that secure content transmission and reception is
achieved.
[0259] Note that this content transmission method can also be
applied to Home to Home content transmission. Instead of the video
server 522 of the IPTV service 520 in FIG. 11, by causing a home
server of another home to provide a similar service, it is possible
to transmit content of that home. In such non-commercial content
transmission, there are cases where transmission is performed
without performing encryption.
[0260] Hereinabove, an embodiment regarding a home IMS gateway for
causing a DMP, which is a content playing device conforming to the
DLNA guideline shown in FIG. 4 to receive an IPTV service has been
described. As described earlier with reference to FIG. 4, in the
DMS, which is a content providing server defined in DLNA, a UPnP
media server (UPnP Media Server) is implemented, and on the UPnP
Media Server, a main Content Directory Service is implemented, so
that it is made possible to obtain a content list and metadata by
applying it. That is, by using the Content Directory Service, the
DMP, which is a content playing device defined in DLNA, obtains a
content list streamed by the DMS, which is a content providing
server defined in DLNA. The embodiment described with reference to
FIG. 9 is an embodiment in which the content list obtaining process
by the UPnP Content Directory Service is executed by applying SOAP
and GENA message communication defined in UPnP DA. Next, an example
of a process in which a scheme of Presentation defined in UPnP DA
is used will be described.
[0261] [Example of Process in which a Scheme of Presentation
Defined in UPnP DA is Used]
[0262] The embodiment described below is an embodiment in which the
home IMS gateway 212 shown in FIG. 3, which is an information
processing apparatus of the present invention, becomes an HTTP
server, and connects to UPnP Control Point implemented on an HTML
browser by using a scheme of Presentation defined in UPnP DA, and
the user selects a desired IPTV service from an HTML screen
displayed using a browser function and receives the service.
[0263] That is, it is an example of a process in which by applying
the scheme of Presentation defined in UPnPDA described earlier, a
process of providing HTML data describing a service screen
including, for example, a content list, content information, and so
forth, from the home IMS gateway 212 to a DMP, which is a content
playing device, for example, the TV (DMP) 213 shown in FIG. 3, is
executed, the service screen formed of the HTML data is displayed
on a display on the side of the DMP, which is a content playing
device, the user selects content on the basis of the display data,
and receives the IPTV service. That is, for example, by using a PC
or TV having a browser function, set as a DLNA device in the home
network, a list owned by the home IMS gateway 212 is presented on
the display, and an IPTV service is selected to receive the
service.
[0264] In this embodiment, on the content playing device, i.e., for
example, the TV (DMP) 213 shown in FIG. 3, an HTML browser for
implementing the Presentation function defined in UPnP DA is
implemented. In this embodiment, although the UPnP Content
Directory service is not used, for the streaming playing function,
the content playing device is implemented on the basis of the DLNA
media transfer definition and the DTCP-IP content protection
definition.
[0265] The sequence of using content provided by an AS (IPTV) is
divided into the following four phases.
[0266] (B1) Device discovery process
[0267] (B2a) Service screen obtainment
[0268] (B3) Authentication and key exchange process
[0269] (B4) Content streaming process
[0270] Among the above phases, the processes in the individual
phases (B1), (B3), and (B4) are the same as the processes described
earlier with reference to FIGS. 9 and 10 earlier in the embodiment.
In the processes described with reference to FIGS. 9 and 10, (B2)
content list obtaining process in steps S35 to S38 described with
reference to FIG. 9 is executed. In this embodiment, in which the
scheme of Presentation defined in UPnP DA is used, (B2a) service
screen obtaining process is executed instead of (B2) content list
obtaining process.
[0271] FIG. 12 shows an example configuration of software modules
of the home IMS gateway 212 for executing the (B2a) service screen
obtaining process. In this embodiment of service screen operating
method, in order to obtain a service screen by using the function
of an HTML browser, the SOAP and GENA software modules described
with reference to FIG. 6 are not implemented, and furthermore,
instead of the UPnP Message Proxy described with reference to FIG.
6, an HTTP Proxy that relays HTML data between an HTTP server and
an HTTP client is implemented.
[0272] With reference to the sequence diagram shown in FIG. 13,
[0273] (B1) Device discovery process
[0274] (B2a) Service screen obtaining process
[0275] These sequences in this embodiment will be described.
[0276] The (B1) device discovery process is similar to the process
described earlier with reference to FIG. 9. The DMP (e.g., the TV
(DMP) 213 shown in FIG. 3), which is a content playing device,
executes the device discovery process by processing steps S31 to
S34 according to the device discovery protocol defined in UPnP. By
this process, the DMP as a content playing device discovers a
content providing server (DMS) implemented on the home IMS gateway,
and obtains a Presentation URL for obtaining HTML data provided by
an HTTP server implemented on the DMS, by Device Description of the
DMS according to the definition of UPnP DA.
[0277] In the (B2a) service screen obtaining process executed next,
first, in step S201, the DMP as a content playing device sends an
HTTP:GET request to the HTTP server of the DMS by using a
Presentation URL obtained in the (B1) device discovery process.
[0278] In step S202, the HTTP Proxy implemented on the home IMS
gateway transmits the HTTP:GET request received by the HTTP server
from the DMP as a content playing device to the application server
(AS) of the IPTV service.
[0279] The application server (AS) of the IPTV service generates,
as HTML (HyperText Markup Language) data, a service screen
including a content list by using content information obtained from
the EPG server, and in step S203, it returns the HTML data
representing the service screen to the home IMS gateway as an OK
response.
[0280] In step S204, the home IMS gateway transfers the response
including the HTML data, received from the application server (AS)
of the IPTV service, to the DMP as a content playing device by the
HTTP Proxy.
[0281] The DMS as a content playing device generates and presents
to the user a service screen formed of a content list and so forth
by executing a drawing process in which an HTML browser is applied
to the HTML data transferred via the home IMS gateway and sent by
the application server (AS) of the IPTV service. The service screen
includes a content list of the IPTV service, and the user selects
content to be played from the content list.
[0282] The content selecting process is executed as, for example, a
process of selecting a content list displayed on the screen by a
remote controller, switch, keyboard, or a pointer such as a mouse.
By the content selecting process, a resource URL of content
included in the HTML data is identified. By using the URL
corresponding to the selected content, the subsequent processes,
i.e., the processes described earlier with reference to FIG.
10:
[0283] (B3) Authentication and key exchange process
[0284] (B4) Content streaming process
[0285] These processes are executed. By these processes, the DMP as
a content playing device performs content playing. That is, the
client device inputs content selection of the user regarding the
content list included in the service screen, and on the basis of
the content selection information, the client device identifies a
URL corresponding to the selected content, i.e., a resource URL of
content included in HTML data, and executes an authentication and
key exchange process based on the URL and a content streaming
process.
[0286] Note that although the service screen obtaining process
executed in steps S201 to S204 is a one-time process in the
sequence diagram shown in FIG. 13, the service screen can take on a
structural menu configuration represented by a plurality of items
of HTML data, and it becomes possible to execute reobtaining of the
service screen on the basis of user's operation of an HTML browser.
That is, the configuration can be such that a process equivalent to
the process of steps S201 to S204 is repeatedly executed. It is
possible to provide various service screens from an AS of an IPTV
service of a DMP, and the user on the DMP side can select arbitrary
content from content lists presented on various service
screens.
[0287] Furthermore, in a case where a content providing process
provided by an IPTV service is a video on demand service, or in a
case where confirmation of charging on user's purchase of a content
viewing right is executed, HTML data representing a confirmation
screen is transmitted from an AS of an IPTV service to a DMP via a
home IMS gateway.
[0288] The user can operate the service screen displayed on a
display of the DMP and receive services provided by various IPTV
services while executing interactive processes.
[0289] FIG. 14 shows an example of a service screen and a streaming
playing screen provided from an AS of an IPTV service to a DMP and
displayed on a display of the DMP.
[0290] FIG. 14 (1) is an example of a service screen displayed on
the display of the DMP in (B2) the service screen obtaining process
in steps S201 to S204 described in the sequence diagram of FIG.
13.
[0291] FIG. 14 (2) is an example of a screen displayed on the
display of the DMP at the time of the subsequent content streaming
process. That is, it is an example of a screen displayed on a
content playing apparatus in a case where (B4) the content
streaming process described with reference to FIG. 10 is being
executed.
[0292] Note that the two screens shown in FIG. 14, i.e.;
[0293] (1) Service screen
[0294] (2) Content streaming screen
[0295] These two process screens can be switched by user's
operations at appropriate timing, and the service screen presenting
and content streaming processes can be executed repeatedly.
[0296] Note that although the embodiment described here has been
described as an example of a process in which the scheme of
Presentation defined in UPnP DA is used, for example, a similar
process can be also executed in a configuration in which the scheme
of an HTML Browser defined in the CEA-2014 standard.
[0297] The CEA-2014 standard will be described briefly. The
CEA-2014 standard is a standard of Web-based protocols and
frameworks, and it is a standard for remote user interfaces that
use UPnP networks and the Internet. The CEA-2014 standard is a
standard that defines a mechanism needed for providing a user
interface under the control of a remote device connected via, for
example, a network or the like. The basic process of the device
that provides the user interface is a process conforming to the
UPnP Device Architecture (v1.0), which is a definition regarding
UPnP networks and Home UPnP. The CEA-2014 standard allows a remote
display process of a user interface provided to a home UPnP device
by an Internet service of a third party, and defines various UI
functions used in TV, mobile phones, and portable devices. Note
that the CEA-2014 standard is configured as a standard including
definitions corresponding to specific specifications of CEA-2027-A,
which is a UI standard of home networks.
[0298] In a device on which an HTML Browser defined in the CEA-2014
standard is implemented, by obtaining a service screen using the
HTML Browser, a process similar to the process described with
reference to FIG. 13 is achieved. Note that in this case, the UPnP
Device class of the home IMS gateway becomes a Remote UI Server,
and HTML data according to an HTML browser profile defined in
CEA-2014 is used.
[0299] [2. Description of Functions Applied to IPTV Service]
[0300] Hereinabove, description has been given regarding a
configuration that allows viewing of content provided by an
external server outside a home network, such as an IPTV service, by
using an existing DLNA device in an open Internet connection
environment that does not depend on infrastructure such as an
access line to the Internet or a gateway. Hereinafter, functions
used for receiving an IPTV service from an external server by a
device in a home network will be described regarding the items
listed below:
[0301] 2-A. Functions of IPTV service receiving client
[0302] 2-B. Functions of IMS (IP Multimedia Subsystem)
[0303] 2-C. Functions used in network configuration
[0304] [2-A. Functions of IPTV service receiving client]
[0305] First, functions of an IPTV service receiving client will be
described. As described earlier with reference to FIG. 3, in the
home network 210,
[0306] Residential Gateway (RG) 211, which is a network connecting
device for connecting a device in a home network to the IP
broadband network 211, and which is used as a bridge;
[0307] Home IMS gateway 212 that executes a process for allowing a
content playing device, such as a device (e.g., TV (DMP) 213 in the
home network 210, to use a service provided by a server outside the
home network; and
[0308] Digital Media Player DMP) TV 213, which is a client device
that receives and plays content.
[0309] These devices exist.
[0310] These devices may be configured either as physically
separate individual apparatuses or as a single apparatus.
[0311] That is, various settings are possible regarding the device
configuration of the home network 210. However, in such various
device configurations, it is necessary that functions needed to
receive an IPTV service are provided in one of the apparatuses.
[0312] A single information processing apparatus or a combination
of a plurality of information processing apparatuses as a client
connected in a home network basically includes a communication unit
that executes a communication process via a home network, and a
data processing unit that executes a process of receiving a content
providing service provided by an external server by using mapping
information that sets an external server outside the home network
as a virtual home network device. Hereinafter, functions that are
needed or effective for the information processing apparatus
connected in the home network to receive an IPTV service, i.e.,
functions of an IPTV service receiving client, will be
described.
[0313] The function needed for the IPTV service receiving client is
an IPTV terminal function. The IPTV terminal function is a function
needed at a logical end point of the IPTV service. For example, in
the example configuration shown in FIG. 3, each of the home IMS
gateway 212 and the TV (DMP) 213 executes a part of the IPTV
terminal function. By each of these devices executing a part of the
IPTV terminal function according to their individual roles, it
becomes possible to receive a service provided from an external
server and to present it at a device in the home network, for
example, the TV (DMP) 213 shown in FIG. 3. Note that although not
shown in FIG. 3, furthermore, a process of providing a service from
the external server to another home network device, and
maintaining, printing, displaying, or the like is implemented.
[0314] FIG. 15 shows constituent elements of the IPTV terminal
function, which is a function needed for receiving an IPTV service.
As shown in FIG. 15,
[0315] (A1) IPTV client
[0316] (A2) IMS gateway
[0317] (A3) Others
[0318] The IPTV terminal function can be divided into these
individual components. Hereinafter, functional elements included in
each of these components will be described.
[0319] (A1) IPTV Client
[0320] An IPTV client is a component that serves to receive an IPTV
service reliably at an IPTV device, for example, the TV (DMP) 213
shown in FIG. 3. As shown in FIG. 15,
[0321] IPTV application client
[0322] IMS communication client
[0323] IPTV navigation client
[0324] Content protection client
[0325] IPTV-DLNA application gateway
[0326] The IPTV client includes subcomponents as these functional
elements. These functional elements (subcomponents) will be
described below.
[0327] The IPTV application client receives a media signal and
sends it to a display system. For example, the IPTV application
client receives a command from a user via a remote controller or
the like, and executes a process pat the command. Specifically, for
example, the IPTV application client performs display of an EPG
(Electronic Program Guide), or a channel specification or changing
process using the EPG, and so forth.
[0328] The IMS communication client is a set of IMS applications
used for distributing message information such as messages or video
data, and service information based on other IMS, not related to
IPTV.
[0329] The IPTV navigation client is used to download an EPG
(Electronic Program Guide), a content list corresponding to VoD
(Video on Demand), and other metadata, and to display these using a
special GUI for content selection.
[0330] The IPTV navigation client executes a process of integrating
other metadata from sources such as a broadcast TV or a DLNA home
network.
[0331] The content protection client executes protection of content
provided by an IPTV service, for example, an encryption process for
protecting the copyright of a content owner, a process of managing
an encryption key, and so forth.
[0332] The IPTV-DLNA application gateway executes a process of
receiving a medium and an EPG (Electronic Program Guide) from an
IPTV client, converting it into a format usable at a DLNA device,
and sending an EPG (Electronic Program Guide) or the like via a
network, and so forth.
[0333] The IPTV-DLNA application gateway acts as an SIP (Session
Initiation Protocol) client, and executes a registration process
for other home devices connected to the home network. For example,
it executes registration of family members or devices.
[0334] (A2) IMS Gateway
[0335] Next, functional components of (A2) the IMS gateway shown in
FIG. 15 will be described. In the configuration shown in FIG. 3,
this corresponds to functions of the home IMS gateway 212. The home
IMS gateway 212 is a component that connects a device in a home
network to an IMS network. It executes conversion among various
signal protocols as needed to execute relaying of messages between
devices in the home network and apparatuses outside the home
network.
[0336] As shown in the figure,
[0337] IMS B2BUA
[0338] IMS proxy
[0339] IMS client
[0340] GBA client
[0341] Home router interface
[0342] The home IMS gateway includes these functional elements
(subcomponents). These functional elements (subcomponents) will be
described below.
[0343] The IMS B2BUA functions as a inter-working unit between a
pure SIP client and an IMS system, and it executes processes such
as conversion between SIP messages and IMS messages and message
transfer.
[0344] The IMS proxy simply sends a message without performing
message conversion like B2BUA, and executes a process of
determining a route, a process of mapping between an IP address
(local and global) and a port number, and so forth.
[0345] The IMS client executes a client registration process (IMS
registration process) by applying identification information or the
like of a client. Furthermore, it performs support for processes
such as an authentication process and IPSec security connection
setting with CSCF.
[0346] The home router interface function provides routing
functions, such as providing a NAT function. For example, it
obtains a P-CSCF address by an SIP server DHCP option [DHCP-SIP] or
by DNS lookup based on an SRV record, and executes a process of
opening and closing a port for control signals defined in UPnP and
a port for unicast media stream.
[0347] (A3) Others
[0348] The IPTV terminal function includes,
[0349] (A1) IPTV client
[0350] (A2) IMS gateway
[0351] in addition to these components described above,
[0352] (A3) Others
[0353] as functional elements (subcomponents) shown in FIG. 15,
[0354] HTTP proxy
[0355] Caching function
[0356] Multicast data channel control function
[0357] These functional elements (subcomponents) will be described
below.
[0358] The HTTP proxy is an intermediary program that executes a
process according to protocol definition of [HTTP] to act both as a
server and a client for the purpose of issuing a request on behalf
of another client (HTTP client). For example, the HTTP proxy can
interrupt into HTTP GET sent to the outside, and cache and use data
that can be referred to by a URI requested. Furthermore, the HTTP
proxy acts as an HTTP client, and executes data searching based on
a requested URI, and so forth.
[0359] The caching function is used to cache data received by the
client by unicast download or multicast. The caching function
executes a caching process of temporarily recording data such as
Web pages (EPG and other IPTV menu) image, and metadata.
[0360] For example, the caching function is used to minimize
interaction wait time of the user, to minimize the amount of
unicast download from an IPTV application and control function, and
so forth. In a case where direct access by the client is allowed
and the IPTV client and the caching function are physically remote
within the same network, for example, the caching function can
issue a notification from the caching function to the IPTV client
using the GENA protocol according to definition of DLNA regarding
an event such as occurrence of new cache data.
[0361] The multicast data channel (MDC) control function is a
function that performs intermediation between the caching function
and applications installed on the client, and it includes a
Multicast Data Channel inserting function. The MDC inserting
function receives a content request to MDC from various
applications, and distributes content by multicasting on a
multicast channel.
[0362] The multicast data channel (MDC) control function identifies
requests from various applications by tags. For example, it becomes
possible for a browser executed on the client side to obtain EPG by
issuing a request with specification of an EPG page tag. The MDC
control function filters reception MDC, and sends MDC objects
together with tags to individual applications.
[0363] Note that the multicast data channel (MDC) control function
includes an MDC proxy, and in a case where the MDC proxy has
registered as specific number of requests regarding certain objects
such as EPG pages, it can request the MDC control function to
include the EPG page in the MDC. That is, it is possible to
distribute the same data to a plurality of clients by multicast,
and it becomes possible to exclude the necessity of a data request
by a unicast channel from each client, so that processing becomes
efficient.
[0364] [2-B. Functions of IMS (IP Multimedia Subsystem)]
[0365] Next, functions of an IMS (IP Multimedia Subsystem) used for
receiving an IPTV service from an external server by a device in a
home network will be described. That is, the functions are
functions of the IMS network 230 shown in FIG. 3.
[0366] As described earlier, IMS is based on IP technologies, and
is highly compatible with Internet infrastructure of fixed
communication systems. IMS is constituted by functional elements
such as a Home Subscriber Subsystem (HSS) and an Application Server
(AS), with a functional element called CSCF (Call Session Control
Function) as a core, the CSCF being based on SIP (Session
Initiation Protocol) defined in RFC-3261 of the IETF (The Internet
Engineering Task Force).
[0367] The IMS network 230 shown in FIG. 3 includes the CSCF 231,
the HSS 232, and the AS (IPTV) 233 as these functional elements,
and it provides a service to the cellular phone 260 via the mobile
phone network 240.
[0368] The CSCF 231 performs control of user registration and
session setting based on the SIP (Session Initiation Protocol).
Furthermore, according to setting of a user profile registered in
the HSS 232, it executes activation of service processes needed.
The HSS 232 has a database for management of user IDs used in the
IMS, management of profiles of services that each user subscribes
to, management of authentication information, management of whether
use of each IMS service is allowed, and management of user
transfer. The AS 233 is a server that executes processes of
individual servers. The AS 233 is activated by the CSCF 231 in
accordance with the status of service subscription of each user and
provides services to the user.
[0369] As described above, in the IMS, for example, a user with a
registered user ID accesses the CSCF 231 by using a client
apparatus to perform registration of the terminal (client) and
control of setting of a session, services needed are activated
according to setting of a user profile registered in the HSS 232,
and the AS 233 actually executes processes of individual
services.
[0370] In an IPTV viewing service, an AS of the IPTV service set in
the IMS network 230 is used. The AS (IPTV) 233 shown in FIG. 3
corresponds to the AS that executes the IPTV service. The AS (IPTV)
233 shown in FIG. 3 actually executes services for the user
terminal in cooperation with the IPTV service 250 as an entity that
executes the IPTV Service, i.e., as an entity that provides
content.
[0371] The IPTV service 250 includes an EPG server 251, which is a
server that provides an EPG [Electronic Program Guide], which is a
program information guide such as a content list, and a video
server 252, which is a server that provides AV content. A content
list providing service and a content providing service for the user
terminal are implemented by cooperation between the respective
servers and the AS (IPTV) 233 of the IMS network 230.
[0372] As described with reference to FIG. 3, main parts of the
functions of the IMS (IP Multimedia Subsystem) include the CSCF
(Call Session Control Function) 231, the Home Subscriber Subsystem
(HSS) 232, and the Application Server (AS) 233. The CSCF 231
performs control of user registration and session setting, and
executes activation of services processes that are needed according
to setting of a user profile registered in the HSS 232. The HSS 232
has a database for management of user IDs used in the IMS,
management of profiles of services that each user subscribes to,
management of authentication information, management of whether use
of each IMS service is allowed, and management of user transfer.
The AS (IPTV) 233 executes services for the user terminal in
cooperation with the IPTV service 250 as an entity that executes
the IPTV Service, i.e., as an entity that provides content.
[0373] FIG. 16 is a diagram showing the main functions of the IMS
(IP Multimedia Subsystem):
[0374] (B1) CSCF
[0375] (B2) HSS
[0376] (B3) AS
[0377] The functions of these (B1) CSCF, (B2) HSS, and (B3) AS will
be described below individually.
[0378] (B1. CSCF)
[0379] As shown in FIG. 16, CSCF (Call Session Control Function)
are divided into three logical entities, i.e., Proxy CSCF,
Interrogating CSCF, and Serving CSCF.
[0380] The Proxy CSCF serves as, for example, a client as an IMS
terminal in a home network, for example, the first point of entry
to an external network from the home IMS gateway 212 shown in FIG.
3. The Proxy CSCF uses a key obtained from the Serving CSCF in
order to establish an IPSec security relationship with a client as
an IMS terminal in the home network, for example, the home IMS
gateway 212 shown in FIG. 3.
[0381] Regarding each SIP message protected by IPSec communication
coming from a terminal, for example, the home IMS gateway 212 shown
in FIG. 3, the Proxy CSCF verifies integrity and decodes the SIP
message. For example, in a case where the message is encrypted,
decoding is executed by decrypting. Upon successful decoding, the
Proxy CSCF executes a process of confirming a client identifier,
and so forth.
[0382] The Interrogating CSCF executes, for example, a query to the
HSS, and so forth, and obtains subscriber information (user
profile, etc.) and supports the registration process. Furthermore,
it executes processes regarding SIP messages and determination of
route for fee charging.
[0383] The Serving CSCF is a contact point with the home network,
and it functions as an SIP registrar and functions as an SIP server
that maintains association between a user's position and a recorded
user SIP address. It performs a process of obtaining from the HSS
an AKA verification vector (AV), which is data applied to client
authentication, and a user profile/service profile. The Serving
CSCF executes a client authentication process using the AKA
protocol, and upon successful authentication, it provides a key
included in the AKA authentication vector (AV) to the Proxy
CSCF.
[0384] Furthermore, the Serving CSCF checks all SIP messages with
the IMS terminal, for example, the client, and determines the route
for the messages. This process can be executed as a process in
which a trigger rule/event based on the user service profile
obtained from the HSS is considered.
[0385] (B2. HSS)
[0386] The Home Subscriber Subsystem (HSS: Home Subscriber
Subsystem) maintains a list of client (user information) relating
to IMS subscriber information, user profiles, and so forth. At a
client, as a plurality of items of identification information, a
private user identity (IMPI) and a public user identity (IMPU) are
set, and user information is recorded and managed in association
with at least either of these items of identification
information.
[0387] For example, a subscriber profile of an IPTV service is
associated with IMPI, which is client (user) information, and
includes a service profile associated with each client. The service
profile includes one or more public user identities (IMPU), core
network authentication information (option), one or more items of
filter criterion information, and so forth.
[0388] The Serving CSCF described earlier, by using these filter
criteria owned by the HSS, determines whether it is appropriate to
define a route to an AS (Application Server), whether this is
requested for certain SIP requests, and so forth, and performs
filtering. Note that information applied to the filter is saved and
reported for each AS regarding each user. For example, regarding
IPTV, the HSS maintains information regarding an entity that
provides the IPTV service and a service identifier, and executes
filtering on the basis of these. Furthermore, the HSS also performs
generation of an AKA authentication vector (AV) used during a
legitimate IMS registration procedure.
[0389] (B3. AS)
[0390] Another main element of the main functions of the IMS (IP
Multimedia Subsystem) is an IMS application server (AS). The IMS
application server (AS) has the following IPTV functions:
[0391] Service Discovery Function
[0392] This is a function for determining the position of an access
point for an IMS AS that provides an IPTV service.
[0393] nPVR (Network Personal Video Recording) Function
[0394] This is a function for recording received data on behalf of
a user, and a function for charging a fee relating to the nPVR
function, permission, and providing other services.
[0395] Join Function
[0396] This is a function that resides on a communication path to
execute various services, fee charging, and so forth.
[0397] Control Function
[0398] This is a function for termination of SIP traffic, setup
adjustment of a media stream, recording of an end user and
information set in logging and so forth, charging of fee from an
IPTV service, processes for permission and other services, a
process of delegating these services and functions to an external
device connected to an IMS network, and so forth.
[0399] [2-C. Functions Used in Network Configuration]
[0400] Next, functions used in a network configuration for
receiving an IPTV service from an external server at a device in a
home network will be described. As shown in FIG. 17, the functions
used in a network configuration includes these functional
elements:
[0401] (C1) Media server
[0402] (C2) Transcoding function
[0403] (C3) Home router
[0404] These elements can be disposed on a network in a distributed
manner. For example, the (C1) media server and (C2) transcoding
function may be configured in the IPTV service 250 in FIG. 3 or may
be set as an independent configuration in another device connected
to the network. In the configuration of FIG. 3, the (C3) home
router is provided in a device in the home network 210, for
example, it is provided in the home IMS gateway 212. Hereinafter,
processes of these functions will be described:
[0405] (C1) Media server
[0406] (C2) Transcoding function
[0407] (C3) Home router
[0408] Furthermore,
[0409] (C4) Details of communication process via a network will be
described.
[0410] (C1. Media Server)
[0411] The media server is a most important component of the media
layer. For example, the media server executes saving and output of
VoD (video on demand) content, storage of content for network
personal video recording (nPVR) executed as a client-specific
content recording process at each client, and so forth.
Furthermore, for example, when a trick play, such as slow play,
fast forward, rewind, or skip chapter, is performed in VoD (video
on demand) or the like, the media server executes media stream
processing as needed. The Vod (video on demand) content is input
from a content management system to the media server.
[0412] (C2. Transcoding)
[0413] The transcoding function is, for example, a function for
executing conversion and encoding of data corresponding to SD
(Standard Definition), which is a standard image quality, and HD
(High Definition), which is a high image quality. For example, a
client performs negotiation with an IPTV service providing server
regarding a manner of coding a stream, and so forth, by using
normal SIP SDP negotiation in an SIP session setup, so that it is
possible to receive data coded in a form suitable for the client.
The transcoding function needs to execute coding in consideration
of a manner of coding usable on the network and also of a bandwidth
available on a stream path, and to execute a process in
consideration of suitability of a screen size, resolution, and so
forth of a client.
[0414] (C3. Home Router)
[0415] In many cases, a home network is connected to a distribution
network via a home router that provides a NAT/NAPT (network address
translation/network address port translation) function. The home
router can be classified into two profiles of full support and
restricted home routers. For example, in order to receive an IPTV
service, [0416] UPnP, IGD [0417] IP multicast pass through, IGMP,
proxy, and IGMP SNOOPING [0418] QoS (Quality of Services) support
with priority including mapping from DSCP to layer 2 priority tag
(802.1p WMM) [0419] Relay according to parameters by DHCP server
function
[0420] It is preferable that these abilities are supported.
[0421] (C4. Details of Communication Process Via a Network)
[0422] Next, details of network communication using the functions
described above, i.e.;
[0423] (C1) Media server
[0424] (C2) Transcoding function
[0425] (C3) Home router
[0426] will be described.
[0427] (Communication and Session Setup)
[0428] In a communication process via a home router, for example,
NAT (network address translation) or NAPT (network address port
translation) is used. NAT is used to convert a private address into
a global address, and NAPT is used to convert many network
addresses into TCP/UDP ports. These processes may be executed by a
home router, or by a NAT/NAPT router on a network.
[0429] For example, an SIP message between an IMS client, such as
the home IMS gateway 212 in the home network 210 shown in FIG. 3,
and the proxy CSCF in the CSCF 231 in the IMS network 230 is
transferred using IPsec. In a case where a NAT/NAPT router exists
between these, a UDP capsule of an IPsec ESP packet [ESP] is
used.
[0430] In order to support multicast streaming distribution via the
home router, the NAT/NAPT router also has IGMP (Internet Group
Management protocol) and IGMP snooping functionality. In a case
where the home router has a NAT/NAPT route determining
functionality, it is managed by the IMS gateway. For the IGMP
snooping function to operate properly, an IGMP membership report
must be generated by a device that wishes to receive IP multicast
packets. For example, an IGMP membership report of multicast
streaming is generated by an IPTV client, not by the IMS
gateway.
[0431] (Use of SNTP (Simple Network Time Protocol))
[0432] In order to set a timestamp and start recording, or the
like, a client in an IPTV system, for example, the home IMS gateway
212 or the TV 213 shown in FIG. 3, requires an accurate time, for
example, in units of 0.1 seconds. In the IPTV system, a client
implements a Simple Network Time Protocol client [SNTP]. The SNTP
client can receive time signals via a defined multicast
channel.
[0433] (Protocol)
[0434] The media protocol used for media (program) communication in
an IPTV service must provide transport and control functions of
real-time audio/video streaming of the media plane, and, for
example, the following protocols are used.
[0435] MPEG-2TS
[0436] All media streaming of IPTV broadcast TV and VoD service
conforms to MPEG transport stream (MPEG-2TS). For media
synchronization, MPEG timestamps are used.
[0437] RTP (Real-time Transport Protocol)
[0438] MPEG2-TS packets are transported according to the RTP
protocol conforming to RFC 3550 and RFC 2250.
[0439] RTCP (Real-time Control Protocol)
[0440] RTCP can be applied to both a media server and a client as
an option. It is assumed that the RTCP protocol conforms to RFC
3550 regarding either unicast or multicast. In order to achieve
compatibility, it is presupposed that all the media servers and
clients implement both support for RTCP and no support for RTCP.
For example, although a media server can send a sender report, a
client cannot respond by a receiver report. Furthermore, RTCP
information can be disregarded by SDP before streaming.
[0441] FEC (Forward Error Correction)
[0442] Although loss of a packet in an IPTV network does not occur
so frequency compared with the current Internet, in a case where
data transmission at a high bitrate (e.g., HD streaming) is
executed, robust transport is needed, and as a criterion of packet
loss rate, for example, "the packet loss rate per two-hour content
is less than or equal to 1" is used. The two-hour content includes
approximately 10M-IP packets, and thus it is required that the
packet loss rate be less than or equal to 10 to 7.
[0443] In order to maintain audio/video quality, in a case where
the packet loss rate is greater than the above definition, it is
possible to recover packet loss. IPTV employs forward error
correction (FEC) to perform error correction. Note that in order to
achieve compatibility, FEC is sent from the original RTP stream
using another IP port. The FEC transport format is based on RFC
2377 and its extension. The FEC information is described by SDP so
as to support another version in the future.
[0444] RTSP (Real-Time Streaming Protocol)
[0445] In order to implement playing control including trick play,
for example, slow playing, fast forward, rewinding, skip chapter,
or the like, all media servers and clients supports RTSP (RFC
2326). For the purpose of transport of RTSP, TCP is used. In a case
of multicast, RTSP is not used.
[0446] In an IPTV system, a client establishes a media session by
the SIP protocol, and after the session setup, RTSP is used for
playback control.
[0447] (Format and Distribution of Media Content)
[0448] For a media codec of video content, MPEG-2 Part 2 and MPEG-4
Part 10 (also known as AVC or H.264) are used. Distribution of
media such as a TV program can be managed by a dedicated media
server after setting of a session between a client and a server,
and transcoding or encoding of distribution data is also executed
via a network for media distribution.
[0449] (Data Sending and Receiving Process by Unicast
Streaming)
[0450] For example, at a time of VoD (video on demand) or EPG
obtaining, according to a request from a client, a unicast stream
is set up by browsing. For example, in a case where a user on the
client side selects a VoD title, by the IPTV control function on
the client side, SIP-invite identifying a stream is sent from the
client to a media server having desired content (e.g., the IPTV
service 250 shown in FIG. 3) using a protocol such as RTSP.
[0451] When the preparation for starting a session is ready, the
IPTV control function of the client responds to SIP invite of the
client, and the stream is started by RTSP PLAY from the client
directly to the media server or via the IPTV control function
acting as RTSP proxy.
[0452] The unicast stream is used, for example, in nPVR (network
personal video recording) or VoD (video on demand). An IPTV unicast
stream encapsulates MPEG-2 or MPEG-4 Part 10 frames as an MPEG-2
transport stream, and is then set as an RTP packet. The RTP packet
is transferred by UDP/IP.
[0453] (Data Sending and Receiving Process by Multicast
Streaming)
[0454] Multicast streaming is usually used to implement viewing of
TV broadcast. The following two options are available for saving
multicast resources.
[0455] (a) Resource request issued from SIP SDP by Proxy CSCF
[0456] (b) Resource request issued from IGMP, issued by IP edge (IP
edge device is the first IP node between a home network and an IP
backbone network and located at an upstream edge of an access and
total network.
[0457] In the above scenario (a), when the user first starts
viewing of TV from a specific IPTV provider (browses an EPG in
order to check which channels are available), for example, the home
IMS gateway 212 or the TV 213 as a client shown in FIG. 3 executes
SIP invite to, for example, the AS 233 of the IMS network 230 shown
in FIG. 3 or the IPTV control function of the IPTV service 250 to
obtain available resources from the network. In a process of
receiving from an external server a content list corresponding to
content that can be provided by the external server, the client
executes a process of obtaining a content list corresponding to a
channel selected according to a provided profile, on the basis of a
user profile or client profile provided to the external server.
[0458] A resource ID, which is an identifier of an available
resource, is written in EPG metadata. Upon assignment of a
resource, in order to join the relevant multicast group, the client
sends an IGMP-join message defined in IGMP (Internet Group
Management Protocol). The multicast group to join is found by
searching the EPG by a linking mechanism. In the process of
receiving from an external server a content list corresponding to
content that can be provided by the external server, the client
executes a process of obtaining a content list corresponding to a
channel selected according to a provided profile on the basis of a
user profile or client profile provided to the external server.
[0459] For example, when switching between different channels
belonging to the same IPTV service provider having the same
resource ID is performed by the user on the client side, sending of
an additional SIP message is not executed. This is because
unnecessary concealing by channel switching/zapping is to be
avoided. Channel switching is executed by sending IGMP-leave for
the previous channel and IGMP-join for the new channel. However,
when the user has switched to a channel with different resource
requirements, the client sends SIP UPDATE to the IPTV control
function in order to report change in session parameters and to
enable the proxy CSCF to modify resource allocation. Upon
modification of the resources, the client sends an IGMP-join
message for the new multicast group. As described above, the client
executes sending of an SIP message according to SIP (Session
Initiation Protocol) in a case where channel switching involves
switching of service provider, and does not execute sending of an
SIP message in channel switching between content provided by the
same service provider.
[0460] In the above scenario (b), with the exception that an SIP
update message is not needed during channel switching between
channels with different resource requirements, the channel
switching operation is the same. Furthermore, all resource requests
are executed by an IP edge device as results of IGMP reports. In a
case where resources are not sufficient due to channel switching,
multicast join is not performed. In the scenario (b), the purpose
of an SIP session is service monitoring rather than resource
management.
[0461] The client includes a function of restricting IGMP channels
that the user is allowed to join, for example, according to a
subscriber profile owned by the HSS 233 shown in FIG. 3.
Furthermore, as an option, an access node of the network can
execute verification for permission of a subscriber to join certain
channels. The basics of the communication mechanism of a multicast
stream are the same as those of unicast, but the source and
destination addresses in the IP layer are set according to the
media server and the multicast group.
[0462] The process of switching between multicast distribution
content and unicast distribution content, executed on the client
side, will be summarized. At a time of receiving multicast
distribution content provided by an external server, for example,
the IPTV service 250 shown in FIG. 3, a data processing unit of a
client apparatus sends an IGMP-join message as a message conforming
to IGMP (Internet Group Management Protocol) to the external server
or management server, and stops reception of the multicast
distribution content, and in a case where reception of unicast
distribution content is to be started, the data processing unit
executes a process of sending an IGMP-leave message as a message
conforming to IGMP to the external server or management server.
[0463] Furthermore, the data processing unit of the client executes
a process of receiving multicast distribution content in TV
broadcast reception, and executes a process of switching to unicast
distribution at a time of execution of VoD (video on demand).
Furthermore, at a time of an nPVR (network personal video
recording) process executed as a user-specific content recording
process, the data processing unit executes a process of switching
to unicast distribution. Furthermore, also at a time of execution
of a trick play as a special content playing process, the data
processing unit executes a process of switching to unicast
distribution as a process of receiving a content list corresponding
to a user profile or client profile.
[0464] (Management of Quality of Service)
[0465] In an IPTV system, except inside the home network, it is
possible to manage quality of services in all network segments.
Traffic management is executed in communication via the network in
the network configuration shown in FIG. 3. A process of managing
quality of communication data will be described with reference to
FIG. 18. As shown in FIG. 18, IPTV QoS (Quority of Services)
control/management is executed on the basis of RACS (Resource and
Admission Control Subsystem). RACS is in charge of policy control,
resource saving, and admission control. This enables the service to
request transport resources via RACS. The current range of RACS
includes mutual connection of a plurality of networks used in the
IPTV system. The RACS architecture includes SPDF (Service Policy
Determining Function) and A-RACF (Access Resource and Admission
Control Function).
[0466] A communication executing application (e.g., the proxy CSCF
of the CSCF 231 of the IMS network 230 shown in FIG. 3) maps
application layer QoS information (e.g., parameters defined in SDP)
to QoS information sent to SPDF. The SPDF can serve as a logical
entity of the proxy CSCF or another physical node, and information
needed for this process is obtained from an SIP invite message sent
from the client when the user requests a multicast channel or a
unicast session.
[0467] A-RACF located in the access network receives requests from
SPDF, and on the basis of the requests and policy information saved
in A-RACF, A-RACF can either accept or reject the requests to
transport resources under the control thereof. This includes an IP
edge and an access node, and finally a response is generated and
provided to the application.
[0468] (Failure of Resource Saving and Failure Report)
[0469] RACS is in charge of resource saving. Hereinafter, failure
of resource saving and a failure reporting process will be
described. In a case where RACS fails in resource saving, i.e.,
upon the SPDF receiving a saving failure report from the A-RACF, as
a process of reporting a communication error code, the RACS returns
Experimental-Result-Code AVP together with the following value to
the proxy CSCF, which is the communication executing application.
[0470] In a case of failed resource saving, INSUFFICIENT_RESOURCES
[0471] In a case of failed change of resource saving,
MODIFICATION_FAILURE
[0472] The proxy CSCF, which is the communication executing
application, must map the received error code to an SIP error code,
and return it to the terminal (client), i.e., must reject SIP
INVITE or SIP UPDATE. Note that for the purpose of [SETUP] of this
process, a "Precondition Failure" SIP status code can be used.
[0473] (Ordering of Communication Data)
[0474] For example, the priority ordering of communication data in
the home network can be performed on the basis of priority marking.
This approach conforms to the DLNA guideline. For example, a rule
of mapping between types of communication data (traffic types) and
priorities (priority [DLNA]) is set, and the priority of
communication data is determined on the basis of this rule.
[0475] [3. Specific Process Examples of IPTV Services]
[0476] Next, specific process examples of IPTV services will be
described in order, individually regarding the following two
items:
[0477] 3-1. Specific process example of communication process
[0478] 3-2. Specific process examples of various services
[0479] [3-1. Specific Example Process of Communication Process]
[0480] In an IPTV service, a medium as content, such as a program,
is distributed via an IP network, and IMS is used for identity
(identifier) management, authentication, permission, and so forth.
The IPTV system uses IMS in order to ensure that data communication
is handled by a reliable, authenticated, and permitted method. In
the IPTV service, SIP is used at a time of distribution of a media
stream, and SIP is also used to execute other functions. An
advantage of using IMS is that all SIP messages automatically pass
through the IMS proxy. This means that the content and headers of
messages can be used for automated interaction, such as setting of
a correct quality of service.
[0481] The IPTV architecture is designed so that mutual connection
is allowed with DLNA communication converted into SIP. In other
parts of the system, for example, when it interacts with components
of the content management function, the IPTV application function
receives SIP signal communication from the IPTV control function,
and converts it into another protocol (HTTP or the like). The
processes are executed mainly by the IMS application server
(AS).
[0482] Hereinafter, as three specific deployment examples of IPTV
service,
[0483] 3-1-1. Deployment scenario 1
[0484] 3-1-2. Deployment scenario 2
[0485] 3-1-3. Deployment scenario 3
[0486] These three types of deployment scenarios will be described.
Furthermore,
[0487] 3-1-4. Network connecting process of client
[0488] 3-1-5. Network disconnecting process of client
[0489] 3-1-6. Service discovery process of client
[0490] These will be described.
[0491] Although the deployment scenarios 1 and 2 seem to be very
similar, they are actually very different. A main difference is
that although it is assumed in the scenario 1 that each terminal
has its own IMS identifier (identity), in the scenario 2, terminals
share the same private IMS identifier. Although this is not seen
from the user's viewpoint, this makes a big difference for an
operator regarding the method of network management and a
processing method for subscription. Note that the scenarios
described below are not mutually exclusive but are complementary,
and can occur simultaneously in the same network.
[0492] (3-1-1. Deployment Scenario 1: Case where Each Client is
Configured as an IMS Terminal)
[0493] First, with reference to FIG. 19 and subsequent figures, a
process example in a case where each client is configured as an IMS
terminal will be described.
[0494] FIG. 19 shows a client (home network client) 710, an IMS
network 720, a home network 730, and an IP network 740. The client
(home network client) 710 includes a TV (DMP) 711 and a home IMS
gateway 712 as configurations for receiving an IPTV service, and as
described with reference to FIG. 3, the IMS network 720 includes a
CSCF 721, an HSS 722, and an AS 723. Furthermore, these are shown
as divided into a control management function that executes content
control, a service providing function that provides services, and
an IMS core section that controls other processes such as a
registration process and communication relaying. Various processes
are executed separately in (a) application layer, (b) control
layer, and (c) media layer as processes involving communication
between the individual layers.
[0495] First, the deployment scenario 1 is a process example in a
case where there is no physical boundary between the TV (DMP) 711
and the home IMS gateway 712 in the client (home network client)
710 and these apparatuses are integrated. FIG. 19 is an example of
a process of registering a client. A registration request is sent
from the TV (DMP) 711 to the IMS core of the IMS network 720 via
the home IMS gateway 712, and the service providing function
executes the registration process.
[0496] After the registration is performed, the TV (DMP) 711, which
is a client, sends [SIP SUBSCRIBE] to the IPTV control function
included in the content management function of the IMS network 720.
Then, as shown in FIG. 20, the IPTV control function of the content
management function provides the client with [SIP NOTIFY] including
an address of a multicast data channel and a URL of EPG.
[0497] Upon receiving SIP NOTIFY, the TV (DMP) 711, which is a
client, starts listening by the multicast channel. Furthermore, it
downloads the first page of EPG and displays it (in a case where
the configuration is such that the user starts with EPG), or
downloads many pages depending on cases. After receiving EPG, the
user selects a channel for viewing. At this time, [T SIP INVITE] is
sent to the IPTV control function, and this function captures it
and sets up a correct QoS. Then, the user starts viewing the
channel, and performs switching among multicast channels. FIG. 21
is shows a communication sequence in an occasion when the user has
executed a channel selecting process.
[0498] When the user request for a stream, QoS is managed by A-RACF
(refer to FIG. 18) according to a request from a proxy CSCF that
uses information picked up from [SIP Invite] or according to a
request from an IP edge device that uses IGMP and knowledge of
requirements of multicast streams. For an option at a time when the
proxy CSCF requests for access resources, when the user performs
switching between channels in a group of channels having the same
resource requirements, an SIP message is not sent to the IPTV
control function. However, for example, when the user switches to a
pay-per-view channel or switches to a channel in a group having
different resource requirements, the IPTV control function must
receive a notification since P-CSCF can change necessary conditions
of resources. In an option in which an IP edge device requests for
access to resources, an SIP message is needed only when the user
switches to pay-per-view.
[0499] (3-1-2. Deployment Scenario 2: Case where a Client is an SIP
Client but not an IMS Client)
[0500] Next, in the deployment scenario 2, a case will be described
where there exists physical separation between a TV (DMP) 711,
which is an IPTV client, and a home IMS gateway 712, and these
apparatuses are separate apparatuses that are not integrated, as
shown in FIG. 22. IPTV clients do not have separate ISIMs (IP
Multimedia Services Identity Modules). ISIM of IMS GW is shared by
all clients.
[0501] In this case, the home IMS gateway 712 is used as a proxy,
and although the TV (DMP) 711, which is an IPTV client, is directly
registered in the IMS core, the home IMS gateway 712 passes
messages to the IMS core. Control information is passed through the
home IMS gateway 712 by using SIP, and media are distributed
directly from a media server (in a content provider domain) to the
IPTV client. In order to access a service, IMS identification
information (IMS PUID) is needed. The flow in this case is
basically the same as the flow of the deployment scenario 1, and a
main difference is that registration is performed through the home
IMS gateway 712. The user obtains an EPG and a media stream
similarly to the scenario 1.
[0502] (3-1-3. Deployment Scenario 3: Case of DLNA-IPTV
Interconnection)
[0503] In a case where a home network uses DLNA, it is necessary to
bridge SIP communication of an IPTV system and HTTP communication
of a DLNA system, and to bridge IP (which uses DVB encapsusation)
media distribution by the IPTV system and HTTP-based media
distribution by the DLNA system. For this purpose, an IPTV-DLNA
application gateway, which is a gateway that bridges two different
systems, is provided.
[0504] As shown in FIG. 23, when a DLNA device 713 requests a media
stream from an IPTV service provider, the IPTV-DLNA application
gateway connects to the home IMS gateway 712, and it is registered
similarly as an SIP client not having an IMS client, similarly to
the scenario 2. For example, in the example shown in FIG. 23, the
TV (DMP) 711 functions as the IPTV-DLNA application gateway. The
IPTV-DLNA application gateway can perform registration also when
connecting to a network as an SIP client similarly to a case where
there is no IMS client.
[0505] The deployment scenario can be implemented by two methods.
One is a method based on the deployment scenario 1, and the other
is implemented as a process based on the deployment scenario 2. A
dotted line 715 shown in FIG. 23 means that the TV 711, which is an
IPTV client, and the home IMS gateway 712 may be either physically
integrated or separable. Hereinafter, five use cases of the IPTV
and DLNA application gateway will be described. From the viewpoint
of the IPTV system, the IPTV-DLNA application gateway acts as an
IPTV client.
[0506] The following specific process examples executed in the
deployment scenario 3 will be described.
[0507] 3-1-3a. 2BOX PULL
[0508] 3-1-3b. 3BOX PULL
[0509] 3-1-3c. Download
[0510] 3-1-3d. 2BOX PUSH
[0511] 3-1-3e. Upload
[0512] (3-1-3a. 2BOX PULL)
[0513] In the 2BOX PULL scenario defined by DLNA, i.e., in a
configuration where processes are executed by connecting a DMS
(digital media server) and a DMP (digital media player) one to one,
the IPTV-DLNA application gateway acts as a DLNA digital media
server (DMS) that implements a UPnP AV media server (UPnP device).
In response to a request by a DLNA digital media player (operated
by the user), the IPTV-DLNA application gateway converts a media
format and protocol of an EPG/VoD content list, program content,
and so forth into a DLNA protocol.
[0514] (3-1-3b. 3BOX PULL)
[0515] In the 3BOX PULL scenario defined by DLNA, i.e., in a
configuration where processes are executed by connecting a DMS, a
DMP, and a DMC (Digital Media Controller), in the 3BOX PULL
scenario, the IPTV-DLNA application gateway functions as a DLNA
digital media server, similarly to the use case of 2BOX PULL.
However, there is a difference from the 2BOX PULL scenario. The
user browses an EPG/VoD content list by operating the DLNA digital
media controller (DMC), and causes a digital media renderer to play
video content.
[0516] (3-1-3c. Download)
[0517] In a download process, similarly to the 2BOX PULL use case,
the IPTV-DLNA application gateway functions as a DLNA digital media
server. A difference from 2BOX pull is that a download controller
(+DN+) downloads video content provided by the DMS. Although it is
not possible to output content to the IPTV-DLNA application
gateway, instead, content is downloaded in response to a request
(e.g., for a VoD service).
[0518] (3-1-3d. 2BOX PUSH)
[0519] In the 2BOX PUSH use case defined by DLNA, i.e., in the 2BOX
PUSH use case where processes are executed by connecting a
controller having a content distribution function and a digital
media renderer (DML) having a playing function one to one, the
IPTV-DLNA application gateway functions as a DLNA Push controller
(+PU+) that implements a UPnP control point for a UPnP AV
renderer.
[0520] Generally, the user operates a client device to browse a
content list corresponding to EPG/VoD of an IPTV service, and can
cause the DLNA digital media renderer to play selected video
content by a method in which the DLNA Push controller controls the
DLNA media renderer in order to transmit video streaming provided
by the DLNA Push controller of the IPTV-DLNA application
gateway.
[0521] (3-1-3c. Upload)
[0522] In an upload process, the IPTV-DLNA application gateway
functions as a DLNA upload controller (+UP+) that implements a UPnP
control point for a UPnP AV server (UPnP device). Generally, the
user can operate a client device to browse an EPG/VoD content list
of an IPTV service. The DLNA digital media server saves selected
video content provided by the DLNA upload controller of the
IPTV-DLNA application gateway.
[0523] (3.1.3. Network Connecting Process of a Client)
[0524] Next, an example of a network connecting process of a client
for receiving an IPTV service will be described with reference to
FIG. 24 and subsequent figures.
[0525] FIG. 24 is a sequence diagram showing an example of a
network connecting process of a client. From the left, a client
corresponding to, for example, the TV (DMP) shown in FIG. 3, a home
IMS gateway, and furthermore, CSCF, HSS, and AP (IPTV), which are
components of an IMS network, are shown. Note that regarding CSCF
of the IMS network, the proxy CSCF (P-CSCF), the interrogating CSCF
(I-CSCF), and the serving CSCF (S-CSCF), described earlier, are
shown individually.
[0526] First, the client obtains an IP address in step S501, and
outputs a registration request in step S502. The registration
request is sent from the home IMS gateway to the proxy CSCF
(P-CSCF), the interrogating CSCF (I-CSCF), and the serving CSCF
(S-CSCF) of CSCF, which are components of the IMS network. In step
S503, S-CSCF executes obtainment of a user profile from the HSS,
and in step S504, notification of a request response to the client
is performed.
[0527] Then, in step S505, setting is made such that IPSec
communication is allowed between the client and the proxy CSCF
(P-CSCF) of CSCF, which is a component of the ISM network, and the
subsequent communication is executed according to IPSec. In step
S506, the client outputs an IPTV service registration request,
which is received by the serving CSCF (S-CSCF) of CSCF, which is a
component of the IMS network. In step S507, an AS selection process
is performed, and in step S508, a registration request is issued to
the selected AS.
[0528] The AS (IPTV) obtains an IPTV profile in step S509, and
issues a registration completion notification to the client in step
S510. On the basis of reception of the registration completion
notification, the client outputs a content obtaining request to the
AS in step S511, and obtains content from the AS in step S512.
[0529] FIG. 25 is a sequence diagram of a case where a registration
process by the home IMS gateway, not the registration process by
the client, is executed. First, the home IMS gateway obtains an IP
address in step S521, and outputs a registration request in step
S522. The registration request is sent from the home IMS gateway to
the proxy CSCF (P-CSCF), the interrogating CSCF (I-CSCF), and the
serving CSCF (S-CSCF) of CSCF, which are components of the IMS
network. In step S523, S-CSCF executes obtainment of a user profile
from the HSS, and in step S524, notification of a request response
to the home IMS gateway is performed.
[0530] Then, in step S525, setting is made such that IPSec
communication is allowed between the home IMS gateway and the proxy
CSCF (P-CSCF) of CSCF, which is a component of the ISM network, and
the subsequent communication is executed according to IPSec. In
step S526, the home IMS gateway outputs an IPTV service
registration request, which is received by the serving CSCF
(S-CSCF) of CSCF, which is a component of the IMS network. In step
S527, an AS selection process is performed, and in step S528, a
registration request is issued to the selected AS.
[0531] The AS (IPTV) obtains an IPTV profile in step S529, and
issues a registration completion notification to the home IMS
gateway in step S530.
[0532] FIG. 26 is an example of a sequence in a case where
communication between the client and the home IMS gateway and
communication between the home IMS gateway and the IMS network are
executed individually. First, in step S541, the client sends a
registration request to the home IMS gateway.
[0533] The client address in this case is an address (@home) in the
home network. Upon receiving the registration request from the
client, the home IMS gateway converts it into a global address
(@op.com) and outputs the registration request to the IMS network.
The registration request is sent to the proxy CSCF (P-CSCF), the
interrogating CSCF (I-CSCF), and the serving CSCF (S-CSCF) of CSCF,
which are components of the IMS network. In step S542, S-CSCF
executes obtainment of a user profile from the HSS, and in step
S543, notification of a request response to the home IMS gateway is
performed.
[0534] Then, in step S544, setting is made such that IPSec
communication is allowed between the home IMS gateway and the proxy
CSCF (P-CSCF) of CSCF, which is a component of the ISM network, and
the subsequent communication is executed according to IPSec. In
step S545, the home IMS gateway outputs an IPTV service
registration request, which is received by the serving CSCF
(S-CSCF) of CSCF, which is a component of the IMS network. In step
S546, an AS selection process is performed, and in step S547, a
registration request is issued to the selected AS.
[0535] The AS (IPTV) obtains an IPTV profile in step S548, and
issues a registration completion notification to the home IMS
gateway in step S549. This notification is sent from the home IMS
gateway to the client via the home network. On the basis of
reception of the registration notification request, the client
outputs a content obtaining request to the home IMS gateway in step
s550. The home IMS gateway outputs this request to the AS, and
obtains content from the AS and transfers the content to the client
in step S551.
[0536] Note that in a case where setting is made such that it is
possible to provide an IPTV service to the DLNA device 713 as
described earlier with reference to FIG. 23, the home IMS gateway
discovers an IPTV control function, receives EPG data, and then
enables [IPTV DLNA app GW] for executing interconnection between
the DLNA device and the IPTV service. In a case where [IPTV DLNA
app GW] functions as a UPnP device, i.e., as a DLNA media server,
IPTV DLNA app GW starts the SSDP (Simple Service Discovery
Protocol) discovered by a UPnP control point [SSDP]. In a case
where IPTV DLNA app GW functions as a UPnP control point, i.e., as
a DLNA Push controller, IPTV DLNA app GW need not start SSDP of a
UPnP device, and instead starts SSDP of the UPnP control point in
order to discover a UPnP device.
[0537] Note that since the DLNA protocol, i.e., device discovery
and device control in the UPnP device architecture, is based on
sessionless communication, there is no concept of establishment of
a session in which the UPnP control point performs communication
with the UPnP device. While the digital media server, i.e., the
UPnP device, is usable on the network, the digital media player and
the digital media renderer, i.e., the UPnP control point, can
anytime request a SOAP message for control regarding media
streaming and for an HTTP request, and the DMS of IPTV DLNA app GW
must respond to the request within, for example, 30 seconds even in
the worst case.
[0538] IPTV DLNA app GW can maintain a session with the IMS core
(CSCF) and the IPTV control function while the DMS of IPTV DLNA app
GW is usable on the network. In a case where the session is
terminated, IPTV DLNA app GW can reset a session when an SOAP
request and an HTTP request from the DMP exist. In a case where
IPTV DLNA app GW acts as a Push controller, i.e., as a UPnP control
point, it is possible to know the length of period during which the
session is maintained.
[0539] In a case where the channel of IPTV service is changed, an
HTTP request for channel changing from the DLNA device is converted
into IGMP (Internet Group Management Protocol). For example, it is
converted into IGMP (Internet Group Management Protocol) by the
IPTV-DLNA application gateway.
[0540] (3-1-5. Network Disconnection of a Client)
[0541] Next, a process of disconnecting from an IPTV service will
be described. At an IPTV service receiving client, it is possible
to turn off a display and to disconnect the client from a network.
This process of disconnecting from the IPTV service is executed,
for example, according to the following sequence.
[0542] (Step 1)
[0543] The client stops media reception.
[0544] Note that in the case of multicast, IGMP leave is used to
leave from a multicast stream relating to the channel that the user
has been viewing.
[0545] (Step 2)
[0546] The client sends SIP BYE to the IPTV service providing
entity to establish an SIP session relating to media reception.
[0547] Note that in the case of unicast, the IPTV service providing
entity executes an RTSP TEARDOWN command to stop the RTP unicast
flow, and closes the port in a case where the media server does not
notice the SIP protocol.
[0548] (Step 3)
[0549] The client sends SUBSCRIBE to the IPTV service providing
entity by Expire 0 to notify IPTV AS that a switch off will occur
on the client side.
[0550] (Step 4)
[0551] Upon expiration of the service period, the client sends SIP
REGISTER to cancel registration of the client identifier. Note that
for obtaining the registration information, data (GRUU: Globally
Routable User Agent URI) received from the serving CSCF is
needed.
[0552] (Step 5)
[0553] The client sends IGMP leave for the control channel.
[0554] (Step 6)
[0555] Disconnected from the IPTV service and IMS.
[0556] (Uncontrolled Disconnection from an IPTV Service)
[0557] In some cases, for example, in a case where a power failure
occurs, disconnection is performed without executing the sequence
described above. That is, in some cases, uncontrolled disconnection
from an IPTV service is performed. In this case, it is necessary to
stop a media flow of a program or the like being transmitted.
However, in this case, a process must be executed in consideration
of the following matters:
[0558] (a) Process of stopping the media flow
[0559] (b) SIP dialog of the network
[0560] These will be described below.
[0561] (a) Process of Stopping the Media Flow
[0562] In a case where the client is receiving multimedia streams,
the only method that can be used to stop the media streams is a
default timeout of IGMPv3 (a group membership interval of 225
seconds according to [IGMP]).
[0563] In the case of unicast transmission, in most media unicast
transport mechanisms, a process of receiving feedback information
is performed, and a timeout time is set in the feedback
information, so that a stopping process using the timeout time
becomes possible.
[0564] (b) SIP Dialog of the Network
[0565] For all SIP states of the network, usually, the default
expiration value is 3600 seconds. This state relates to SIP
REGISTER, SUBSCRIBE, and INVITE. The timeout mechanism clears the
state of the IMS core (in a case where a reconnection occurs before
a timeout, the timer increases after a new registration).
[0566] The fact that the state of SIP is maintained to be active
for one hour does not mean that traffic is sent for one hour.
Actually, after the first NOTIFY that does not reach a destination,
the IMS core is notified of the unavailability of a client, and
clears the state accordingly.
[0567] (3-1-6. Service Discovery Process of a Client)
[0568] A process in which discovery of IPTV services is performed
in an IMS network will be described. IPTV service providers are
discovered and presented to the user so that selection by the user
is allowed, for example, as described below. Note that for this
process, completion of UMS registration by the user is a
presupposed condition.
[0569] The first issues a request to the IMS provider to attempt
discovery of IPTV service providers. In a case where this fails, it
is possible to issue a request to an entity other than the IMS
provider, for example, a root. The service provider discovery
process starts with discovery of IPTV service providers that
provide IPTV services.
[0570] There exist many models that can be used for discovering
IPTV service providers in an IMS network. These are all based on
the presupposition that application servers (ASs (IPTVs)) capable
of providing services exist in the network, and that the IPTV
service providers can be identified by PSIs, feature tags, or other
SIP headers.
[0571] The step of discovering service providers is executed
according to, for example, high-level description of "transport of
an MPEG-2 TS-based DVB service in an IP-based network". SIP is used
as communication for user authentication, and an IMS trust model
for boot-strapping information, such as P-Asserted-Identity, is
used. An SIP request that uses DVB IP del that starts with a
service IPTV can serve as an IPTV provider. For example, it is
identified by that SP CANAL+ is a domain name, and it is possible
to assign to a service a name corresponding to the service.
[0572] In a case where this fails, the process described below is
executed.
[0573] In a case where an IPTV server has not been assigned when an
IPTV application is started, an IPTV service bootstrap service or a
default address is used.
[0574] The IPTV client sets control signal communication for IPTV
SIP dialog, and defines a route in the IMS network CSCF. This also
means that it is not necessary to know an accurate address of a
service since it can be added later. In the IMS network, CSCF must
understand that the SIP dialog is an IPTV dialog, and define the
route in IPTV CF (Control Function). This allows IPTV CF to provide
discovery information regarding the service provider and the
service provided.
[0575] Information (e.g., SIP URI or the like) regarding the IPTV
service provider is provided to the user by using the SIP dialog,
and when the user has discovered IPTV service providers, these
providers are presented to the user. The user can then receive EPGs
(or VOD and nPVR content lists or the like) provided by the IPTV
service providers.
[0576] (Service Discovery by UPnP)
[0577] Next, a service discovery process by UPnP will be
described.
[0578] The IPTV client obtains an IP address of the proxy CSCF from
the DHCP option of SIP, or uses a default IP address of the proxy
CSCF, written on an ISIM (IP Multimedia Services Identity Module)
card of an IMS operator.
[0579] Alternatively, the IPTV client discovers a home IMS gateway
by using a UPnP discovery mechanism. The home IMS gateway
implements a UPnP IMS GW service, which is a UPnP service. In order
to discover the UPnP IMS GW service, the IPTV client performs a
process in which SSDP is used, such as sending or receiving
SSDP:M-Search. Upon discovering the UPnP IMS GW service, the IPTV
client issues a request for obtaining an IP address and port of IMS
B2BUA of IMS GW. Then, the IPTV client starts an SIP session with
the IMS core via the home IMS GW, and discovers IPTV services.
[0580] For example, a process sequence in the case of service
discovery by a DLNA device, described with reference to FIG. 23, is
as follows. The UPnP control point of the DLNA device can discover
DMS by IPTV DLNA app GW in the case of 2BOX PULL, DOWNLOAD, and
3BOX PULL described earlier. The service discovery of IPTV services
is executed by the home IMS GW by the method that is the same as
the method described earlier. Methods of deploying a plurality of
IPTV services vary among vendors. For example, IPTV DLNA app GW can
use a plurality of DMSs individually corresponding to IPTV
services. To each DMS, a name as a UPnP device, which allows the
corresponding IPTV service, is set so that the user can select an
appropriate DMS for the IPTV service.
[0581] In the case of 2BOX PUSH and UPLOAD, the IPTV-DLNA
application gateway controls the UPnP device of the DLNA device so
that it is not necessary to implement a UPnP device with which the
IPTV-DLNA application gateway is discovered.
[0582] [3-2. Specific Process Examples of Various Services]
[0583] Next, various services executed in IPTV services will be
described. The following items will be described in order.
[0584] 3-2-1. TV broadcasting
[0585] 3-2-2. nPVR (network Personal Video Recording)
[0586] 3-2-3. VoD (Video on Demand)
[0587] 3-2-4. Content filtering and personalization
[0588] 3-2-5. Interaction with TV
[0589] 3-2-6. Profile management
[0590] 3-2-7. Process for matching with device capabilities
[0591] (3-2-1. TV Broadcasting)
[0592] In IPTV services, in addition to channel switching, EPG
browsing must be provided to the user as quickly as TV
broadcasting. In order to minimize the user metadata waiting time
of EPG metadata transmission, EPG metadata regarding programs
during a certain period (e.g., 8 days) is preloaded on the client,
and in order to minimize transactions per second and the necessary
bandwidth in the EPG distribution system, service information,
i.e., TV channel information and EPG, i.e., TV program information,
is distributed via a multicast data channel. The IPTV content
browser and IPTV navigation application of the client, described
with reference to FIG. 15, searches for EPG metadata by using the
MDC control function.
[0593] The EPG metadata is also distributed by unicast. Although
EPG metadata corresponding to basic programs corresponding to
programs provided by IPTV services, or EPG metadata of
statistically popular programs, or the like is distributed by
multicast, high-level EPG metadata with rich information, such as
other program information or thumbnail images, can be obtained
through searching by using unicast.
[0594] EPG metadata provided by IPTV service providers is
distributed regularly through a single multicast data channel. The
multicast channel control function of the client, described with
reference to FIG. 15, filters tagged EPG metadata, such as channel
subscription, according to the client configuration, and saves the
filtered EPG metadata in a memory. The IPTV service browser and
IPTV navigation application uses the MDC control function to search
for EPG data. The cycle time of transmission of EPG metadata varies
depending on the information types.
[0595] Service information including multicast channel addresses of
TV channels and EPG metadata regarding content (programs) currently
being broadcast and next content is sent frequency, for example, at
intervals of 2 seconds. EPG metadata corresponding to programs on
the current day is sent, for example, at intervals of 30
seconds.
[0596] Since the schedule of TV programs of broadcasting TV
services is determined in advance, it suffices for the client to
search for new EPG metadata for future programs once a day.
However, in order to notify the client of changes in program
schedule that occur occasionally, such as urgent news or extra
innings of a baseball game, updating of EPG metadata is also
distributed regularly, for example, at intervals of 2 seconds,
through the multicast data channel. In order to receive the
updating of EPG metadata, the client monitors the multicast data
channel for the EPG metadata when receiving a media stream via the
multicast channel.
[0597] The EPG metadata distributed through the multicast data
channel is data including basic information regarding programs,
which is program information. In order to obtain detailed
information regarding programs and related information regarding
programs, linked to the basic information of programs, the client
can use a unicast request to an EPG server. The program information
is composed of text, video, audio, and so forth, and interaction
with the user in presentation of these programs can be implemented
by bilateral unicast communication. In an EPG or program
information menu, it is possible to set a subscreen on a display of
the client displaying the menu and to display a preview video
stream.
[0598] Note that EPG can be personalized for each user or client,
i.e., EPG can be presented with a specific EPG setting
corresponding to the user or client. For example, personalization
of EPG for each channel can be implemented similarly to configuring
EPG according to channel subscription regarding a user profile.
Depending on the user profile, program information regarding
particular channels is not displayed. Also regarding the display
order of channels regarding the EPG menu, personalization according
to the user profile, i.e., a process corresponding to each user, is
allowed.
[0599] Switching of TV Broadcasting Channels
[0600] When an IPTV service is provided, packet buffering is
performed at the client in order to perform a playing process
smoothly, such as removal of jitter caused by the network. The
client stores data received from an IPTV service providing server
until the data reaches a certain threshold, and then executes a
process for playing, such as decoding. Furthermore, in some cases,
transmission and reception of intra-frames are executed by
multicast forwarding for reconstruction of images.
[0601] Furthermore, in order to avoid consumption of bandwidth, on
occasion of channel switching, a process of concluding an old
channel for which the previous viewing has been finished is
executed. This process can be executed by IGMP leave, which is a
process similar to IGMP join. On occasion of this process, checking
is performed at all IGMP aware nodes, comparison with a list of
nodes that receive old multicast data is executed, and in a case
where a certain node is to stop reception of multicast data, a
process of cutting out the node from a multicast tree is
performed.
[0602] In order to execute decoding and playing of a received video
stream at the client, it is necessary to collect much information
from the received stream. These information is sent using a
particular frequency. Particularly, to start display of new video
forwarding movie, a decoder must wait until intra-frames arrive in
the video stream. The intra-frames are configured as frames
including sufficient information in itself so that complete video
can be reconstructed. Depending on the encoding type, usually,
these are sent at intervals of 0.5 to 5 seconds.
[0603] There exist various types of delay that can occur in data
communication in IPTV services. For example, a process of SIP
interaction on occasion of setting a new stream can become a factor
that causes a delay. For example, a process regarding SIP INVITE,
which is executed in the SIP interaction process, is a conceivable
factor that can cause a delay. Thus, a measure for avoiding delay
is to reduce the SIP interaction process. Specifically, it is
effective to make setting such that an SIP dialog occurs only when
the characteristics of multicast streams change between multicast
channels. According to this idea, a configuration is employed in
which when the client tunes in to an ordinary broadcasting channel,
an SIP session is established by requesting multicast transmission
having stream characteristics, and setting is made such that other
changes in multicast channels require only IGMP interaction, which
does not involve SIP intervention, and it is switched to an SIP
dialog only when the characteristics of received streams differ.
Furthermore, SIP INVITE and IGMP join for the new channel are sent.
Regarding delay that occurs in IGMP setup, it is possible to make
improvements by allowing use of multicast channels at a point as
close as possible to the end user. However, this results in
consumption of a larger bandwidth in the access network.
[0604] An improvement should also be made regarding delay of
intra-frames needed to start decoding of an MPEG stream. It is
possible to overcome delay of intra-frames by a configuration in
which intra-frames are obtained by a pull mechanism from a point
relatively close to the client in the network or by providing
intra-frames to the client by an out-of-band mechanism.
[0605] (3-2-2. nPVR (network Personal Video Recording))
[0606] Next, nPVR (network Personal Video Recording), which is a
service available in IPTV services, will be described.
[0607] nPVR (network Personal Video Recording) can be started by
various methods. This varies depending mainly on IPTV service
providers. [0608] A simplest method of recording a program, such as
a program, is to select a program on EPG and to press a recording
button by a remote controller owned by the user. Furthermore, a
configuration in which a time, day, length, and so forth of
recording by the user are input.
[0609] Alternatively, setting may be such that all the programs
provided to the client are recorded. This means that the IPTV
service provider record all and save it on a server for a
predetermined period. In this way, the user is not bothered with
recording, and is allowed to view a past nPVR EPG that seems
similar to an ordinary EPG.
[0610] What must be supported by the IPTV architecture are an
interface for identifying a program to be recorded and an
identification mechanism for achieving this with EPG. The same link
mechanism as that for TV broadcasting is used if possible, and in
command communication for a recording process, an RTSP RECORD
command, an SIP INVITE to nPVR including recording details, or the
like can be used.
[0611] For example, trick play is a process used in a case where
the user requests personal recording regarding content that is
being received and played in an IPTV service. For example, the
client presses a pause button by a remote controller to execute an
nPVR recording function, and then freezes the picture to execute
IGMP leave from the multicast channel. Furthermore, the client
saves content. Note that the configuration may be such that data
saving is executed at a server. When the user wishes to view it
again later, it is possible to execute nPVR searching and to
perform playing by an RTSP PLAY command.
[0612] Regarding a content list (index) that can be used in nPVR,
the content format and metadata that are the same as those for EPG
and VoD can be used. The linking mechanism that is the same as that
for TV broadcasting must be used, except that linking is performed
by the IPTV control function in order to identify a unicast
resource, as in the case of VoD. Usually, searching for an nPVR
content list is executed as HTTP GET. For a process of searching
for nPVR content available to the client, the IPTV service provider
provides a server-based searching function. The interface of the
searching page completely depends on the service provider.
[0613] In a process of playing content recorded by nPVR, it is
necessary to first select intended nPVR content. Searching is
performed by clicking on a link to nPVR content list. Content
searching is executed as a unicast stream. That is, a stream starts
when the user has pressed "play" or has clicked on the link to the
content list.
[0614] The configuration of the client apparatus in a case where
the nPVR (network Personal Video Recording) process executed as a
user-specific content recording process is executed is, for
example, as follows. An information processing apparatus as a
client includes a data processing unit that executes a process of
receiving a content providing service provided by an external
server existing outside a home network, by using mapping
information in which the external server is set as a virtual home
network device, and the data processing unit controls the nPVR
(network Personal Video Recording) process executed as the
user-specific content recording process regarding content provided
by the external server.
[0615] The data processing unit executes a process of receiving
multicast distribution content when receiving TV broadcasting
provided by the external server, and executes a process of
switching to unicast distribution on occasion of the nPVR (network
Personal Video Recording) process executed as the user-specific
content recording process. Furthermore, in a case where reception
of unicast distribution content is to be started, it sends an IGMP
(Internet Group Management Protocol) leave message to the external
server or a management server as a message according to IGMP.
[0616] Furthermore, regarding nPVR (network Personal Video
Recording), the data processing unit of the client can request the
external server or another network-connected server to execute
content recording by using storage means of these servers. In this
case, information needed for recording, such as recording content
information and time information, is provided to these servers.
Furthermore, in a process of receiving from the external server a
content list corresponding to content for which nPVR (network
Personal Video Recording) can be executed, the data processing unit
of the client performs a process of obtaining a content list
selected in accordance with a provided profile based on a user
profile or a client profile provided to the external server.
Furthermore, on occasion of execution of nPVR (network Personal
Video Recording), the data processing unit of the client executes a
process of outputting content selection information or recording
time specifying information in EPG (Electronic Program Guide) to
the external server or a management server. nPVR is executed by
these processes.
[0617] Furthermore, the client is an information processing
apparatus that receives content regarding IPTV provided via a
public network, which is not a home network, and includes means for
setting an external server connected to the public network as a
virtual home network device; and control means for controlling a
process of recording or playing content at the external server via
the public network so that the external server functions as a
personal video recorder that records or plays user-specific
content. Furthermore, the control means of the client executes a
process of controlling a process of playing content at the external
server via the public network in order to implement unicast in
which particular content is provided only to a particular user, and
furthermore, it executes a process of controlling a process of
recording or playing content at the external server via the public
network so that the external server functions as a personal video
recorder that records user content.
[0618] (3-2-3. VoD (Video on Demand))
[0619] VoD (Video on Demand) is a specification for distributing
content in response to a request by a user on the client side.
Basically, it is executed by unicast. It is possible to insert an
advertisement to content (media) distributed by VOD and to perform
searching based on the advertisement similarly to a broadcasting
service or EPG.
[0620] Furthermore, it is possible to view on the client side a
content list (index) that can be used for VOD. It is possible to
make setting that the content list (index) is limited to content
that the user is permitted to view, i.e., it is possible to browse
a result of filtering. Although the filtering can be executed
within the network, in that case, the VoD content list must be
unicast, or the client can use multicast in order to preload a
cache of the VoD content list. The VoD content list is obtained in
a manner partially similar to obtaining EPG information.
[0621] Searching for available VoD content requires that the client
can execute an operation for query to the network. The content
searching is executed with content metadata.
[0622] In a case where content is played by VoD, from the VoD
content list, the client must select a piece of available content
that the user is permitted to view and output a content request.
For example, if content in the content list is specified, a link to
URI of the VoD service is activated, the IPTV control function
processes the request. It is checked whether the user has already
purchased the content, and in a case where the content has not been
purchased, a charge for the content is checked. In other cases, the
content request is rejected.
[0623] (3-2-4. Content Filtering and Personalization)
[0624] Next, content filtering and personalization executed in an
IPTV service will be described. The content filtering is a content
selecting process of providing an end user with only content
suitable for the user on the basis of the IMS of the end user, the
IPTV profile, and a set of channels that are subscribed to. The
personalization is a process of selecting content to be provided to
the user on the basis of the profile of the user. For example, it
includes a process of distributing messages and advertisements with
an individual as a target based on the user profile.
[0625] By the content filtering, for example, only channels for
which the user has paid are displayed in an EPG or VoD list
obtained by the user. The content filtering makes it possible to
generate and display an EPG suitable for the logged-in user. The
user profile is downloaded from a server storing the profile, for
example, the HSS 232 of the IMS network 230 shown in FIG. 3, by
using XCAP at the time of log-in, and is saved on the user
apparatus. As for VoD, the content filtering is applied when a view
of VoD provided by the server is generated or VoD metadata is
received at the client. Note that the user profile may be stored at
the client, which is an apparatus on the user side, and this user
profile may be used.
[0626] The user profile information existing at the external server
or the client apparatus is presented to the server that provides
content, and the content providing server executes content
personalization to select and edit content on the basis of the user
profile and to generate and provide content corresponding to the
user. Alternatively, the configuration may be such that these
personalization processes are executed on the client side.
[0627] The content personalization includes a process of
distributing messages and advertisements with an individual as a
target based on the user profile. These data directed to a
particular user are overlaid on the screen at the user apparatus,
and is displayed in, for example, a PinP (picture in picture) mode.
Personalization is executed by inserting an intended advertisement
when a show enters into an advertisement pause while the user is
viewing a broadcast show or VoD content. Interactivity can also be
considered as a form of personalization based on the user profile.
Information included in interactivity data is displayed by means
that is the same as the means for personal messages or
advertisements, i.e., by overlaying or by using a dedicated window.
Personalization is distributed via a dedicated unicast channel, or
by a much smaller multicast group target to a profile set
(information of location, age, sex, income range, etc.)
[0628] (3-2-5. Interaction with TV)
[0629] A description will be given regarding interaction with a TV
program, for example, a process in which a user on the client side
send an opinion or cast a vote while viewing an IPTV service. For
interactivity with a television program, the user can send data
from the user (for example, via SMS), such as a vote. FOR EXAMPLE,
the vote is collected and used for creating feedback information
regarding the program.
[0630] Note that there is also an existing digital broadcasting
system in which interaction with TV programs is already supported
by a mechanism that inserts a trigger in an MPEG-TS stream and that
gives an interactive object, such as HTML or BML, at the timing of
the trigger. Usually, an interactive object is embedded in an
MPEG-TS stream together with a TV program. However, the digital
broadcasting system may distribute an interactive object via a
bilateral communication channel separated from distribution of the
MPEG-TS stream.
[0631] A mechanism that uses a browser applied to an IPTV service
is used for interaction with TV programs. For example, reference
information to an XHTML document representing interaction with a
program is embedded in content metadata. While the user is viewing
the program, the interactivity system invokes the IPTV service
browser for interaction with the program. The XHTML document is
distributed via a multicast data channel and unicast communication.
Feedback of interaction is implemented by an IPTV service browser
based on unicast communication.
[0632] (3-2-6. Profile Management)
[0633] In an IPTV service, various profiles, such as a user profile
of the client, are managed. For example,
[0634] Service Profile Regarding a Service of an Operator, and a
User Profile
[0635] Profiles such as fee charging, a user identifier, an
authentication vector used for an authentication process, and a
service trigger, are stored and maintained on the HSS 232 of the
IMS network 230 shown in FIG. 3.
[0636] Profile of the User Himself/Herself
[0637] A profile of the user himself/herself is saved on a client
apparatus on the user side.
[0638] In a case where the IPTV provider differs from the IMS
provider, the IPTV provider can save a user profile specific to the
IPTV provider in a database of its own.
[0639] IPTV Provider Profile
[0640] An IPTV provider profile as information regarding an IPTV
provider can be saved on the client side, and is also saved in a
database of the IPTV provider itself.
[0641] The user profile includes, for example, an SIP identifier,
language, nationality, age (information provided by an operator and
information provided by the user), an E-mail address, a phone
number, interests and hobbies (hobby and preference information),
IPTV-specific parameters, and so forth. The user profile is used
for service personalization. Specifically, it becomes possible to
set and provide data corresponding to the user (My . . . ) on the
basis of preferences of the user. For example, it becomes possible
to execute, by using the user profile, setting of a my channel,
setting of a startup channel, and furthermore, a process of
personally mapping a button to My VoD, My Pay TV, or channel, local
control, and so forth.
[0642] The IPTV provider profile includes, for example, [0643]
Information regarding which user is allowed to access which channel
[0644] Subscriber profile used to determine what the user is
permitted to view and what the user is not permitted to view and so
forth.
[0645] On the client side, which is an end user, user management
and user profile management are executed. The user management means
that it is possible for the user to add the user to a domain,
change the user, or delete the user. The user profile management
means that the user can change information of the user profile.
[0646] The processing steps in a case where the end user of the
client performs user management are as follows:
[0647] 1. The end user provides new user information to an HTTP
portal.
[0648] 2. The information is sent by the HTTP portal to the IMS
network 230 (refer to FIG. 3) that executes user management,
whereby the HSS and IPTV database are updated.
[0649] The user profile management executed by the end user of the
client is executed, for example, by the following processes:
[0650] 1. New user profile information is input to the client
apparatus.
[0651] 2. The client sends data to a preset profile output
destination, such as a server that manages the user profile
information, for example, the HSS 232 or the IPTV service 250 of
the IMS network 230 shown in FIG. 3.
[0652] 3. Each server that has executed updating of the information
notifies the client and other related servers of completion of the
data updating.
[0653] 4. The client downloads the updated user profile.
[0654] Note that the registration and updating of the user profile
can also be executed through an IPTV service portable. In this
case, the user profile is provided from the client to the IPTV
service portal, and then the IPTV service portal sends these data
to a user profile management server (e.g., the HSS 232 or the IPTV
service 250 of the IMS network 230 shown in FIG. 3).
[0655] As described above, the data processing unit of the
information processing apparatus executes a process of receiving
data from the external server as personalized data selected or
edited on the basis of a user profile, which is user information
registered in advance. The data processing unit of the client
obtains a user profile stored in advance in a management server,
for example, an HSS, and provides the user profile obtained to an
external server such as a content providing server. Furthermore,
the user profile updated at the client apparatus is sent to the
management server, such as an HSS, and a process of updating the
user profile stored in the management server is executed.
[0656] The data processing unit of the client executes a process of
receiving, from an external server such as a content providing
server, a content list, advertisement information, VoD (Video on
Demand) content, or the like set as personalized data on the basis
of the user profile, and displaying it on a display unit. Note that
the user profile includes at least a language used by the user,
nationality, address, phone number, and hobby and preference
information.
[0657] (3-2-7. Process of Matching with Device Capability)
[0658] It is possible to set various apparatuses as clients, and
processes that can be executed by individual clients differ
depending on the clients. That is, the device capabilities of
clients are various. In order to ensure interoperability between
such various clients and IPTV services, a set of device capability
profiles is specified to define capabilities requested for
clients.
[0659] In order to play content distributed to a client favorably
at the client, it is necessary to clarify the capabilities of the
client. The client device capabilities include, for example, a
screen size, a screen resolution, a size of an available memory,
types of codecs supported, and so forth.
[0660] When a client device first registers a service, description
of the CSCF 231 device of the IMS network 230 is downloaded, and
the downloaded description and its URI are recorded in a database
or a repository and shared with other entities, such as servers.
Note that in a case where a global repository, such as a W3C DCI
repository, can be used, such as a DCI repository, the repository
may be used.
[0661] In the process of matching AV content with a client device,
in some cases, it is necessary to select a suitable content
version. For example, matching of text content is implemented by
using modification, combination, formatting (e.g., XSLT), or the
like in accordance with a version. An entity that executes the
matching process (e.g., a target server or a proxy that executes
transcoding) executes a process of receiving device capabilities
and match the document according to a set of rules expressed in
document metadata. This means that the content metadata must
include rules regarding modification that must be applied, and also
means that the service profile must include restrictions regarding
applied transport, terminal, and so forth.
[0662] As described above, in a content providing system including
a content providing server and a content receiving client, the data
processing unit of the content receiving client executes a process
of obtaining device information of the client, and sending and
registering the device information to a home subscriber subsystem
(HSS) defined in an IP multimedia system (IMS). The content
providing server executes a process of obtaining the device
information of the client, registered in the HSS, and providing the
client with content suitable for the device. Specifically, the
device information includes at least one of a screen size, a screen
resolution, a size of available memory, and types of codecs
supported of the client. The content providing server executes a
process of obtaining these device information and providing the
client with content that can be played by the device.
[0663] The present invention has been described above in detail
with reference to specific embodiments. However, obviously, it is
possible for those skilled in the art to make modifications or
alternatives without departing from the spirit of the present
invention. That is, the present invention has been disclosed by way
of examples, and the present invention should not be construed
restrictively. The spirit of the present invention should be
determined on the basis of the claims.
[0664] Furthermore, the series of processes described in this
specification can be executed by hardware, by software, or by
combination of hardware and software. When the series of processes
is executed by software, a program in which the processing
sequences are recorded can be executed by installing it on a memory
of a computer embedded in special hardware or on a general-purpose
computer that is capable of executing various processes. For
example, the program may be recorded in advance on a recording
medium. Instead of installing the program from a recording medium
to a computer, the program can be received via a network such as a
LAN (Local Area Network) or the Internet and installed on an
internal recording medium such as a hard disk.
[0665] The various processes described in this specification need
not necessarily be executed sequentially in the orders described,
and may be executed in parallel or individually as needed or in
accordance with the processing ability of an apparatus that
executes the processes. A system in this specification refers to a
logical combination of a plurality of apparatuses, and is not
limited to one in which the constituent apparatuses are disposed
within the same case.
INDUSTRIAL APPLICABILITY
[0666] As described hereinabove, according to the configuration of
the present invention, it becomes possible for a DMP as a content
playing apparatus, which is a client device in a home network, to
receive content from a content providing server outside the home
network and to play the content. That is, a home IMS gateway, which
is an information processing apparatus according to the present
invention, executes communication with a content providing server
to map the content providing server as a virtual home network
device, and in response to reception of a device discovery request
from a content playing apparatus in a home network, the home IMS
gateway provides the content playing device with server information
of the content providing server as information of a device that is
allowed to receive a service. Furthermore, by executing switched
reception of multicast distribution content provided by the
external server and unicast content, it becomes possible to receive
content with increased flexibility on the client side.
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