U.S. patent application number 12/797134 was filed with the patent office on 2010-09-30 for system and method for processing packet domain signal.
This patent application is currently assigned to HUAWEI TECHNOLOGIES CO., LTD.. Invention is credited to Youzhu Shi, Dongming Zhu.
Application Number | 20100246574 12/797134 |
Document ID | / |
Family ID | 36036062 |
Filed Date | 2010-09-30 |
United States Patent
Application |
20100246574 |
Kind Code |
A1 |
Shi; Youzhu ; et
al. |
September 30, 2010 |
System and Method for Processing Packet Domain Signal
Abstract
Embodiments of the present invention disclose a system and a
method for processing a packet domain service signal, which enable
a terminal that does not support an access control protocol of an
Internet Protocol Multimedia Subsystem (IMS) to access the IMS and
acquire the services in the IMS. An AGCF is added for shielding the
differences of the users on the basis of the IMS defined in the
3GPP R5/R6 standard, specifically, a PSTN/ISDN user accesses an AGF
first, accesses the IMS through an agent function of the AGCF, and
the AGCF also manages and controls the AGF. Control of the
PSTN/ISDN services may be implemented in the AGCF, or in an AS
added to the IMS, or the control of basic services and
supplementary services may be implemented in the AGCF while the
control of value-added services may be implemented in the AS.
Inventors: |
Shi; Youzhu; (Shenzhen,
CN) ; Zhu; Dongming; (Shenzhen, CN) |
Correspondence
Address: |
Slater & Matsil, L.L.P.
17950 Preston Road, Suite 1000
Dallas
TX
75252
US
|
Assignee: |
HUAWEI TECHNOLOGIES CO.,
LTD.
Shenzhen
CN
|
Family ID: |
36036062 |
Appl. No.: |
12/797134 |
Filed: |
June 9, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11682392 |
Mar 6, 2007 |
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12797134 |
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PCT/CN05/00734 |
May 26, 2005 |
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11682392 |
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Current U.S.
Class: |
370/352 |
Current CPC
Class: |
H04L 65/1043 20130101;
H04L 65/1016 20130101; H04L 12/66 20130101; H04M 7/123
20130101 |
Class at
Publication: |
370/352 |
International
Class: |
H04L 12/66 20060101
H04L012/66 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 7, 2004 |
CN |
200410079901.0 |
Claims
1. A system for processing a packet domain service signal, the
system comprising: an access gateway function; an access gateway
control function for implementing access management and call
control for an access gateway function, and for enabling a user
equipment of a Public Switched Telephone Network (PSTN) or a user
equipment of Integrated Services Digital Network (ISDN) which
accesses the access gateway control function through the access
gateway function to access a Call Session Control Function (CSCF)
in an Internet Protocol Multimedia Subsystem (IMS), wherein the
CSCF is connected with a Media Gateway Control Function (MGCF)
separate from the access gateway control function.
2. The system of claim 1, further comprising a first application
server for providing a function of a service control of a Public
Switched Telephone Network (PSTN)/Integrated Services Digital
Network (ISDN) according to service triggering of the CSCF.
3. The system of claim 2, wherein the first application server
comprises means for implementing the service control of the
PSTN/ISDN including control of a basic service, a supplementary
service and an extended value-added service.
4. The system of claim 1, wherein the access gateway control
function implements a service control for the PSTN user equipment
or the ISDN user equipment.
5. The system of claim 1, wherein the access gateway control
function implements access management and control of the access
gateway function.
6. The system of claim 1, wherein the access gateway function
implements a function of conversion between a narrowband voice in a
circuit domain and an Internet Protocol (IP) media flow in a packet
domain, and a function of conversion between user interface
signaling in the circuit domain and call control signaling in the
packet domain.
7. An access gateway control function entity, comprising: a module
configured to acquire a private user identity and a public user
identity according to an identity of an Access Gateway Function
(AGF) and an identity of a user port when an outgoing call from a
user reaches the module, the user being a Public Switched Telephone
Network (PSTN) user or an Integrated Services Digital Network
(ISDN) user, the module further configured to locate the identity
of the AGF and the identity of the user port corresponding to the
private user identity and the public user identity when an incoming
call to the user reaches the module.
8. The apparatus of claim 7, wherein the identity of the AGF and
the identity of the user port correspond to the user; and wherein
the private user identity and the public user identity is for
accessing an Internet Protocol Multimedia Subsystem (IMS) domain
for the user.
9. The apparatus of claim 7, wherein the AGF has a unique
identifier.
10. The apparatus of claim 7, further comprising a second module
for processing a basic service and a supplementary service of the
PSTN/ISDN.
11. The apparatus of claim 7, further comprising a third module for
generating a charging request, and sending the charging request to
a charging collection unit in the IMS.
12. The apparatus of claim 7, further comprising a fourth module
for implementing a registration and an authentication of the
AGF.
13. The apparatus of claim 7, further comprising a fifth module for
converting between a Session Initiation Protocol (SIP) and an
interface protocol of an interface through which the access gateway
control function is connected to the access gateway function.
14. The apparatus of claim 7, further comprising: a second module
for processing a basic service and a supplementary service of the
PSTN/ISDN; a third module for generating a charging request, and
sending the charging request to a charging collection unit in the
IMS; a fourth module for implementing a registration and an
authentication of the AGF; and a fifth module for converting
between a Session Initiation Protocol (SIP) and an interface
protocol of an interface through which the access gateway control
function is connected to the access gateway function.
15. A method, comprising: receiving an outgoing call from a user by
an access gateway control function, the user being a Public
Switched Telephone Network (PSTN) user or an Integrated Services
Digital Network (ISDN) user; and acquiring a private user identity
and a public user identity according to an identity of an Access
Gateway Function (AGF) and an identity of a user port, wherein the
identity of the AGF and the identity of the user port correspond to
the user, and the private user identity and the public user
identity are for accessing an Internet Protocol Multimedia
Subsystem (IMS) domain for the user.
16. A method, comprising: receiving an incoming call to a user by
an access gateway control function, the user being a Public
Switched Telephone Network (PSTN) user or an Integrated Services
Digital Network (ISDN) user, wherein the incoming call comprises a
private user identity and a public user identity; and locating an
identity of an Access Gateway Function (AGF) and an identity of a
user port corresponding to the private user identity and the public
user identity, wherein the identity of the AGF and the identity of
the user port correspond to the user.
Description
[0001] This application is a continuation of U.S. patent
application Ser. No. 11/682,392, filed on Mar. 6, 2007, which is a
continuation of International Application No. PCT/CN2005/000734,
filed on May 26, 2005, which claims the benefit of Chinese Patent
Application No. 200410079901.0, filed on Sep. 7, 2004. The entire
contents of the above identified applications are incorporated
herein by reference.
TECHNICAL FIELD
[0002] The present invention relates to the telecommunication
service network technology based on wideband packet transmission,
and especially, to a system and a method for processing a packet
domain signal.
BACKGROUND
[0003] The Integrated Services Digital Network (ISDN) originated in
1967 is a communication network developed on the basis of the
Integrated Digital Network (IDN). The ISDN supports end-to-end
digital connections and various communication services, such as a
telephone service, and provides standard user-network interfaces to
be accessed by various terminals.
[0004] The Public Switched Telephone Network (PSTN), as a public
communication network, provides voice and data communication
services which are based on switched lines.
[0005] The PSTN/ISDN services generally refer to various services
provided to users in the conventional PSTN/ISDN networks.
[0006] Conventionally, the PSTN/ISDN services are implemented in a
circuit switched domain. With the fast development of the
packet-based communication technologies, at present, the PSTN/ISDN
services may also be implemented in a packet domain through the
softswitch of a Next Generation Network (NGN).
[0007] There is a broad sense NGN and a narrow sense NGN.
[0008] The broad sense NGN generally refers to all the softswitch
architectures in which bearer is separated from control, and the
telecommunication service networks using broadband packets as
bearer whether the network provides fixed services or mobile
services to the users. The telecommunication service networks using
broadband packets as bearer may be Internet Protocol (IP) networks
or Asynchronous Transfer Mode (ATM) networks. Referring to the
following definition of NGN given in the Telecommunication
Standardization Sector of International Telecommunication Union
(ITU-T) in February 2004, an NGN is a packet-based network,
provides multiple services including the telecommunication service,
and is capable of using multiple bandwidths and transmission
techniques of abilities of Quality of Service (QoS) to implement
separation of service functions from bottom-layer transmission
techniques; the NGN allows an access of users to networks of
different service providers and supports general mobility, which
realizes consistent and continuous provision of services to
users.
[0009] The narrow sense NGN refers to networks based on broadband
packet bearer, providing C4/C5 services and IP multimedia services
to the users accessing fixed networks. In embodiments of the
present invention, the NGN refers to a "narrow sense NGN" unless
otherwise mentioned.
[0010] In a fixed NGN, the softswitch serves as a call processing
node in the network, implementing the PSTN/ISDN services. A PSTN
user or an ISDN user accesses the softswitch through access
devices, such as an Audio Gateway (AG) and an Integrated Access
Device (IAD), the softswitch implements the session control, the
service control, and the functions of storing and managing user
data, and thus the PSTN/ISDN services are provided to the PSTN user
or the ISDN user.
[0011] In a technical solution implemented through the softswitch,
the functions of call control and service control are coupled to
one network node and implemented in the network node, which results
in poor flexibility and is unfavorable to fast deployment and
extension of services.
[0012] Furthermore, modification of a function may bring about
changes of other functions, increasing the potential risk. And
deployment and extension of some services will even lead to the
upgrading of the whole network node, resulting in a high cost. The
softswitch can be accessed by fixed terminals through various
access devices, such as access devices based on different protocols
including the AG and the IAD, and the implementation of the
PSTN/ISDN services is related to the access of the users.
[0013] Besides the implementation of the PSTN/ISDN services, the
softswitch also needs to provide the Service Switch Point (SSP)
function to trigger an intelligent service. And the PSTN/ISDN
services and the intelligent service conflict with each other
because there is no unified trigger mechanism.
[0014] The PSTN/ISDN services are distributed and implemented in
call processing nodes in the NGN, thus the call processing nodes
may not cooperate with each other to implement the PSTN/ISDN
services. And there is no definite service arbitrating point when a
service conflict occurs.
[0015] Since the PSTN/ISDN services are distributed and implemented
in the call processing nodes in the NGN, each service needs to be
implemented repeatedly in all the softswitches in the network when
a unified service brand is popularized, leading to the high cost of
service popularization.
[0016] The PSTN/ISDN services are distributed and implemented in
the call processing nodes in the NGN, it is difficult for the
PSTN/ISDN services to function as a basic network service ability,
i.e., as a shared network component, to cooperate with other
services in the NGN to provide combined value-added services.
[0017] The user data are distributed in the call processing nodes
in the NGN and the users could only acquire services at access
points of the users, thus it is difficult to acquire the same
services as previous services if the terminals of the users are
allowed to move, and the popularization of the unified service
brand is also limited.
[0018] The call processing nodes in the NGN may not share the user
data of the users accessing the NGN owing to the distribution of
the user data, and it is thus difficult to provide a cross call
processing node service (a wide area service).
[0019] There is also a system with the function similar to that of
the fixed NGN above in a Third Generation (3G) mobile
telecommunication network, which is an Internet Protocol Multimedia
Subsystem (IMS).
[0020] The IMS is an IP multimedia subsystem in a Wideband Code
Division Multiple Access (WCDMA) network defined in the 3rd
Generation Partnership Project (3GPP) R5/R6 standard and is a
target network in the 3G mobile telecommunication network for
implementing packet voice and packet data and providing unified
multimedia services and applications. The IMS uses an IP packet
domain as its bearer channel of signaling control and media
transmission, uses the Session Initiation Protocol (SIP) as
signaling of the call control, and achieves separation of service
management, session control and bearer accessing. FIG. 1 shows
network architecture of the IMS in the 3GPP R5/R6 standard. Refer
to "3GPP TS 23.002" for detailed descriptions of each network
entity and related interfaces in the IMS.
[0021] Although the IMS provides a mechanism for separation of the
service management, the session control and the bearer accessing, a
PSTN user and an ISDN user may not access the IMS through a visited
domain node defined by the IMS standard because the IMS standard is
put forward initially for a 3G mobile system, requires the terminal
to support an access control protocol of the IMS (typically the
SIP) and does not support the access management of the PSTN user
and the ISDN user.
SUMMARY OF THE INVENTION
[0022] Embodiments of the present invention provide a system for
processing a packet domain service signal and a method for
processing a packet domain service signal, enabling a terminal that
does not support an accessing control protocol of an Internet
Protocol Multimedia Subsystem (IMS) to access the IMS and acquire
services in the IMS.
[0023] An embodiment of the present invention provides a system for
processing a packet domain service signal, including:
[0024] an Internet Protocol Multimedia Subsystem (IMS);
[0025] at least one access gateway function for implementing a
function of conversion between a narrowband voice in a circuit
domain and an Internet Protocol (IP) media flow in a packet domain,
and a function of conversion between user interface signaling in
the circuit domain and call control signaling in the packet domain;
and
[0026] at least one access gateway control function for
implementing access management and call control for the access
gateway function, and enabling the user equipment which accesses
the access gateway control function through the access gateway
function to access a Call Session Control Function (CSCF) in the
IMS.
[0027] The system further includes a first application server for
providing a function of service control of the PSTN/ISDN according
to service triggering of the CSCF.
[0028] Preferably, the first application server includes means for
implementing the service control of the PSTN/ISDN including control
of a basic service, a supplementary service and an extended
value-added service.
[0029] Preferably, the access gateway control function includes a
sixth module for processing a basic service and a supplementary
service of the PSTN/ISDN; and the first application server
comprises means for processing an extended value-added service.
[0030] Preferably, the access gateway control function includes a
seventh module for generating a charging request according to a
requirement defined by a standard of the IMS, and sending the
charging request to a charging collection unit in the IMS.
[0031] Preferably, the access gateway control function includes a
second module for implementing registration and authentication of
the access gateway function.
[0032] Preferably, the access gateway control function includes a
fourth module for converting between Session Initiation Protocol
(SIP) and an interface protocol of an interface through which the
access gateway control function is connected to the access gateway
function; and a fifth module for obtaining a user identify of a
calling user according to an access gateway function identity and a
user port identity, or locating an access gateway function and a
user port which a called user accesses according to a user
identity.
[0033] The interface adopts one of H.248 protocol, Media Gateway
Control Protocol, the SIP and the IUA/V5UA over SIGTRAN
protocol.
[0034] Another embodiment of the present invention provides a
method for processing a packet domain service signal. When a user
makes an outgoing call, the method includes:
[0035] transferring a first message to an access gateway control
function upon receiving a dialing signal from a user equipment
processing a service signal of a Public Switched Telephone Network
(PSTN)/Integrated Services Digital Network (ISDN);
[0036] upon receiving the first message, obtaining, by the access
gateway control function, a user identity according to an identity
of the access gateway function and a user port identity, converting
the first message to an Session Initiation Protocol (SIP) request
message, and sending the SIP message to a Call Session Control
Function (CSCF) in an Internet Protocol Multimedia Subsystem
(IMS);
[0037] implementing, by the CSCF, service triggering according to
user subscription information, and sending a second message to a
first application server;
[0038] upon receiving the second message, implementing, by the
first application server, service control of the PSTN/ISDN, and
notifying the CSCF to continue to implement session control by a
third message.
[0039] Preferably, the process of continuing to implement the
session control includes:
[0040] determining whether the third message received triggers a
new service;
[0041] if the third message received triggers a new service,
triggering the new service and sending a new SIP request message to
an application server corresponding to the new service; otherwise,
implementing connection control and routing.
[0042] Preferably, the process of implementing the connection
control and the routing includes determining whether a called user
is in a domain of the IMS;
[0043] if the called user is in the domain of the IMS, sending an
SIP request message to a Serving Call Session Control Function in a
home domain of the called user;
[0044] otherwise, sending an SIP request message to a Breakout
gateway control function.
[0045] Preferably, the service control of the PSTN/ISDN includes
control of a basic service, a supplementary service and an extended
value-added service.
[0046] Preferably, the method further includes:
[0047] before converting the first message to the SIP request
message, and sending the SIP request message to the CSCF in the
IMS, controlling a basic service and a supplementary service of the
PSTN/ISDN; wherein the service control of the PSTN/ISDN implemented
by the first application server includes control of an extended
value-added service.
[0048] Preferably, the first message adopts one of H.248 protocol,
Media Gateway Control Protocol, the SIP and the IUA/V5UA over
SIGTRAN protocol.
[0049] Another embodiment of the present invention provides a
method for processing a packet domain service signal. When a user
makes an incoming call, the method includes:
[0050] upon receiving a Session Initiation Protocol (SIP) request
message, triggering, by a Call Session Control Function (CSCF) in a
home domain of a called user, a service according to user
subscription information, and sending a fourth message to a first
application server;
[0051] upon receiving the fourth message, implementing, by the
first application server, service control of a Public Switched
Telephone Network (PSTN)/Integrated Services Digital Network
(ISDN), and sending a fifth message to the CSCF;
[0052] upon receiving the fifth message, implementing, by the CSCF,
connection control and routing, and sending a Session Initiation
Protocol (SIP) request message to an access gateway control
function;
[0053] upon receiving the SIP request message, locating, by the
access gateway control function, an access gateway function that a
called user accesses and a user port according to a called user
identity, converting the SIP request message to a sixth message,
and notifying the access gateway function to send an incoming call
signal to a user equipment processing a service signal of the
PSTN/ISDN.
[0054] The processes of implementing the connection control and the
routing, and sending the SIP request message to the access gateway
control function include:
[0055] upon receiving the fifth message, determining whether a new
service is triggered;
[0056] if the new service is triggered, triggering the new service
and sending an SIP request message to an application server
corresponding to the new service;
[0057] otherwise, implementing the connection control and the
routing, and sending an SIP request message to the access gateway
control function.
[0058] Preferably, the service control of the PSTN/ISDN implemented
by the first application server includes control of a basic
service, a supplementary service and an extended value-added
service.
[0059] Preferably, the service control of the PSTN/ISDN implemented
by the first application server includes control of an extended
value-added service;
[0060] upon receiving the SIP request message, the access gateway
control function determines whether a basic service and a
supplementary service of the PSTN/ISDN are triggered;
[0061] if the basic service and the supplementary service are
triggered, the access gateway control function controls the basic
service and the supplementary service that are triggered, and
determines whether to carry out the session control again for the
incoming call;
[0062] if determining to carry out the session control again for
the incoming call, the access gateway control function sends an SIP
request message to the CSCF, and the CSCF continues to implement
the session control again;
[0063] if determining not to carry out the session control again
for the incoming call, the incoming call is terminated;
[0064] if the basic service and the supplementary service are not
triggered, the access gateway control function locates an access
gateway function that a called user accesses and a user port
according to the called user identity, converts the SIP request
message to the sixth message, and notifies the access gateway
function to send an incoming call signal to a user equipment
processing the service signal of the PSTN/ISDN.
[0065] Preferably, the sixth message adopts one of H.248 protocol,
Media Gateway Control Protocol, the SIP and the IUA/V5UA over
SIGTRAN protocol.
[0066] As can be seen from the above, in the embodiments of the
present invention, the Access Gateway Control Function (AGCF) for
shielding differences between access users is added on the basis of
the IMS defined in the 3GPP R5/R6 standard; a PSTN user and an ISDN
user first access an Access Gateway Function (AGF), then access the
IMS through the agent function of the AGCF which is also configured
for performing access management and control of the AGF. Control of
the PSTN/ISDN services may be implemented in the AGCF or
implemented in a dedicated Application Server (AS) added to the
IMS; or the control of the basic service and the supplementary
service may be implemented in the AGCF while the control of the
value-added service may be implemented in the AS.
[0067] Through adopting the technical solutions, the terminal which
is not supported by the IMS previously, such as a PSTN/ISDN
terminal, can access the IMS, and the resources of the IMS may be
used fully to provide the terminals with the services. Thus, the
extended IMS becomes a general telecommunication service network
allowing the access of various terminals.
BRIEF DESCRIPTION OF THE DRAWINGS
[0068] FIG. 1 shows a schematic diagram illustrating the network
architecture of the IMS in the 3GPP R5/R6 standard.
[0069] FIG. 2 shows a schematic diagram illustrating the network
architecture of a system for processing a packet domain service
signal in accordance with an embodiment of the present
invention.
[0070] FIG. 3 shows a schematic flowchart of an outgoing call from
a user accessing through an AGF in the method for processing a
packet domain service signal in accordance with an embodiment of
the present invention.
[0071] FIG. 4 shows a schematic flowchart of an incoming call to a
user accessing through an AGF in the method for processing a packet
domain service signal in accordance with an embodiment of the
present invention.
[0072] FIG. 5 shows a schematic flowchart of an outgoing call from
a user accessing through an AGF in the method for processing a
packet domain service signal in accordance with another embodiment
of the present invention.
[0073] FIG. 6 shows a schematic flowchart of an incoming call to a
user accessing through an AGF in the method for processing a packet
domain service signal in accordance with another embodiment of the
present invention.
DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS
[0074] In an embodiment of the present invention, a new network
node, that is, an AGCF, is introduced to the IMS defined in the
3GPP R5/R6 standard. Through managing an access device, a PSTN user
and an ISDN user are able to access an IMS domain, and PSTN/ISDN
services are provided to the PSTN user and the ISDN user.
Furthermore, functions of each network node in the IMS defined in
the 3GPP standard remain unchanged, and an accessing user may be
regarded as a user in the IMS domain, such as a 3G mobile user
because the AGCF shields differences between accessing users. The
PSTN/ISDN services may be implemented by the AGCF, or be managed by
a PSTN/ISDN Simulation Application Server (AS), i.e. a first
application server, in the IMS in a centralized manner; or a basic
service and a supplementary service are managed by the AGCF while
an extended value-added service is managed by the PSTN/ISDN
Simulation AS.
[0075] The network architecture and the principle of the system for
processing the packet domain service signal is hereinafter
described in detail with reference to FIG. 2.
[0076] In an embodiment of the present invention, the system for
processing the packet domain service signal includes IMS 10,
PSTN/ISDN Simulation AS 20, AGCF 30, AGF 40, Access Network (AN)
51, PSTN User Equipment (UE) 52, ISDN UE 53, and Private Branch
eXchange (PBX) 54. In the embodiments of the present invention,
PSTN UE 52, ISDN UE 53 and PBX 54 are uniformly referred to as UE
50.
[0077] The connection relations of sub-systems in the system for
processing the packet domain service signal are described below.
PSTN/ISDN Simulation AS 20 is connected with the Home Subscriber
Server (HSS) in IMS 10 through the Sh interface, connected with the
Subscription Locator Function (SLF) in IMS 10 through the Dh
interface, and connected with the Call Session Control Function
(CSCF) in IMS 10 through the IP multimedia Service Control (ISC)
interface. AGCF 30 is connected with the CSCF in IMS 10 through the
I1 interface, and connected with AGF 40 through the I2 interface.
Furthermore, AGF 40 is connected with AN 51 through the V5
interface, connected with PSTN UE 52 through the Z interface,
connected with ISDN UE 53 through the Basic Rate Interface (BRI),
and connected with PBX 54 through the Foreign Exchange Office (FXO)
interface/Primary Rate Interface (PRI)/E1 interface.
[0078] Functions of the sub-systems are hereinafter described in
detail.
[0079] IMS 10 is an IMS defined in the 3GPP R5/R6 standard, in
which network entities and related interfaces are completely the
same as those defined in the 3GPP IMS standard. Refer to the
published "3GPP TS 23.002" for detailed information.
[0080] Several network entities in the IMS which are relatively
related to the embodiment of the present invention are hereinafter
described in brief.
[0081] The CSCF is configured for implementing the session control
function of the Session Initiation Protocol (SIP) of users
accessing through the AGF (the PSTN user and the ISDN user
accessing through AGF 40).
[0082] The HSS is configured for providing the storing and managing
function of the user subscription data of the users accessing
through the AGF, and the storing and managing function of the
PSTN/ISDN service related data of the users accessing through the
AGF.
[0083] The SLF is configured for providing the subscription
locating function of the users accessing through the AGF.
[0084] Although the network entities above serve the users
accessing through the AGF, those skilled in the art may appreciate
that no modification to the network entities is needed in fact, and
the users accessing through the AGF may be regarded and processed
as common users in the IMS domain (e.g. the 3G mobile users)
because AGCF 30 shields differences between the users accessing the
IMS.
[0085] PSTN/ISDN Simulation AS 20 is configured for providing the
PSTN/ISDN service control for the users accessing through the AGF.
An AS is a standard network entity in the IMS, and the difference
between PSTN/ISDN Simulation AS 20 and the other AS is that
PSTN/ISDN Simulation AS 20 is dedicated to providing the PSTN/ISDN
service control while the other AS in the IMS may not provide the
PSTN/ISDN service control. The interfaces between PSTN/ISDN
Simulation AS 20 and each network entity in IMS 10 are standard
interfaces.
[0086] PSTN/ISDN Simulation AS 20 may be applied in two
methods.
[0087] In an embodiment of the present invention, PSTN/ISDN
Simulation AS 20 provides all the PSTN/ISDN service control. The
advantage of this method is that call control is completely
separated from service control, and the PSTN/ISDN services function
as a network service ability provided by the AS in the IMS. In this
method, all the user subscription data and service related data of
the users are stored in the HSS in IMS 10.
[0088] In another embodiment of the present invention, AGCF 30
implements the control of the basic service and the supplementary
service while PSTN/ISDN Simulation AS 20 implements the control of
the extended value-added service. The advantage of this method is
that, compared with the former method, the PSTN/ISDN services may
be implemented faster. The SIP was not designed to implement the
PSTN/ISDN services initially, in order to implement the basic
service and supplementary service by PSTN/ISDN Simulation AS 20,
AGCF 30 needs to implement mapping between part of the user
interface signaling and the SIP or to encapsulate part of the user
interface signaling into the SIP, and the usage of the SIP may
further be extended, such as mapping a hooking event (the key of R
is pressed) in the user interface signaling, mapping the dialing
scheme including *# type using the KPML, mapping the dialing scheme
of a second dialing tone by the KPML, mapping the pulse charging
event and antipolar charging event using the message of SIP from
the PSTN/ISDN Simulation AS. In the latter method, the subscription
data and service data related to the basic services and
supplementary services of the PSTN/ISDN are stored in AGCF 30,
other subscription data and service data are stored in the HSS in
IMS 10. In this method, unless an outgoing call of the user is
terminated by AGCF 30 owing to the service control, all the calls
of the user still have to pass IMS 10 in which the S-CSCF
implements connection control and routing.
[0089] In actual applications, the latter method may be applied as
a transition method before existing networks can implement the
service control according to the former method.
[0090] AGCF 30, as a key device of the embodiments of the present
invention, is a network entity newly added for providing the access
control function of AGF 40 and shielding the differences between
the users accessing through the AGF and common users in the IMS
domain, which may meet the demand that the session control function
and the service control function in the IMS core network be
independent of the accessing users. AGCF 30 may be regarded as
another kind of node of a visited domain in the IMS 10, providing
an access agent function to the users accessing through AGF 30.
[0091] AGCF 30 includes a first module for implementing access
management and control function of AGF 40.
[0092] Signaling protocols in the I2 interface between AGCF 30 and
AGF 40 may include but are not limited to the H.248 protocol, the
Media Gateway Control Protocol (MGCP), the SIP, the ISDN Q.921 User
Adaptation Layer/V5.2-User Adaptation Layer over Signaling
Transport (IUA/V5UA over SIGTRAN) protocol.
[0093] AGCF 30 may manage and control one or more AGFs 40 and only
one AGF 40 is shown in FIG. 2 for the convenience of description.
Each of AGFs 40 has a unique ID in AGCF 30. Those skilled in the
art may appreciate that the access management and control function
of AGF 40 by AGCF 30 may be implemented with reference to the
management and control function of the Media Gateway (MG) by the
Media Gateway Controller (MGC) in the related art.
[0094] AGCF 30 may include a second module for implementing the
registration/authentication of AGF 40, as well as the function of
mapping bi-directionally between the registration/authentication of
AGF 40 and the registration/authentication process defined in the
IMS domain. Those skilled in the art may appreciate that such
registration/authentication mechanism may be implemented with
reference to the registration/authentication mechanism of a user
signaling layer of the terminal by the Proxy-CSCF (P-CSCF).
[0095] AGCF 30 may include a third module for implementing access
agent function for the PSTN user and the ISDN user.
[0096] AGCF 30 in the visited location provides the access agent
function for the PSTN user and the ISDN user that access through
AGF 40, and shields the access differences between the PSTN user
and the ISDN user, which meets the demand that the session control
function and the service control function of the IMS core network
are independent of the accessing users. Therefore, no modification
to the functions of the network nodes in the IMS defined by the
3GPP standard is needed.
[0097] The interface between AGCF 30 and the S-CSCF or the I-CSCF
in IMS 10 is the I1 interface, the reference point of which is
based on the SIP. The reference point of I1 interface may be based
on the SIP-I in some cases, e.g. when information of the ISDN
supplementary service needs to be carried.
[0098] AGCF 30 may include a fourth module for implementing mapping
between the signaling processes of an I2 interface protocol and an
I1 interface protocol. In the case that the signaling protocol of
the I2 interface is the SIP, AGCF 30 need not perform the mapping
between the I2 interface protocol and the I1 interface protocol,
but certain modification to contents of the I2 interface protocol
or the I1 interface protocol may be needed.
[0099] AGCF 30 may make the identities of the PSTN user and ISDN
user correspond to the S-CSCF according to a mode of data
configuration, thus obtaining the address of the home S-CSCF of the
PSTN user and ISDN user.
[0100] AGCF 30 may obtain the address of the I-CSCF according to
the mode of data configuration, and the I-CSCF chooses an S-CSCF as
the home S-CSCF of the PSTN user and ISDN user.
[0101] AGCF 30 should configure a Private User Identity and a
Public User Identity which are needed for accessing the IMS domain
for the PSTN user and the ISDN user accessing through AGF 40.
[0102] AGCF 30 may include a fifth module. When an outgoing call
from a user accessing through AGF 40 reaches AGCF 30, the fifth
module may acquire the Private User Identity and the Public User
Identity corresponding to the user according to, but not limited
to, an identity of AGF 40 and an identity of a user port. When an
incoming call to a user accessing through AGF 40 reaches AGCF 30,
the fifth module may locate, according to, but not limited to, the
Private User Identity and the Public User Identity of the called
user, the user port of the user and AGF 40 through which the user
accesses the IMS.
[0103] The second module of AGCF 30 implements the
registration/authentication of the PSTN user and the ISDN user
accessing through AGF 40, and maps the registration/authentication
with the process of registration/authentication defined in the IMS
domain.
[0104] AGCF 30 also provides the QoS control based on each session
and the Network Address Translation (NAT) control mechanism, which
are similar to those of the P-CSCF.
[0105] AGCF 30 may include a sixth module for implementing control
of the basic service and the supplementary service of the
PSTN/ISDN. The sixth module of AGCF 30 can also provide the control
of the basic service and the supplementary service of the PSTN/ISDN
for the PSTN user and the ISDN user accessing through AGF 40, and
the service related data needed by the control are stored in AGCF
30.
[0106] AGCF 30 may include a seventh module for charging.
[0107] During the calling processes of the PSTN user and the ISDN
user accessing through AGF 40, the seventh module of AGCF 30 may
generate a charging request according to the requirement defined in
the IMS standard and send charging information to the Charging
Collection Function (CCF) in IMS 10.
[0108] AGF 40 is an access device located between a circuit domain
and a packet domain, providing an access function enabling the PSTN
user and the ISDN user to access the AGCF 30, and implementing the
conversion function between a narrowband voice in the circuit
domain and an IP media flow in the packet domain.
[0109] At the same time, AGF 40 implements the conversion function
between the user interface signaling in the circuit domain and the
call control signaling in the packet domain, and the call control
signaling in the packet domain is transferred by the I2 interface
between AGF 40 and AGCF 30. The signaling protocols over the I2
interface may include but are not limited to the H.248 protocol,
the MGCP protocol, the SIP, and the IUA/V5UA over SIGTRAN
protocol.
[0110] AGF 40 may be, but not limited to, an access device of AG,
or an access device of IAD.
[0111] AN 51 is an access network, connected with AGF 40 through a
V5 interface. A user in the access network may be a PSTN user and
an ISDN user. The V5 interface provides V5 digital access
signaling.
[0112] PSTN UE 52 is a PSTN terminal, connected with AGF 40 through
a Z interface which provides analog user signaling.
[0113] ISDN UE 53 is an ISDN terminal, connected with AGF 40
through a BRI interface which provides ISDN digital user
signaling.
[0114] PBX 54 is a Private Branch eXchange, connected with AGF 40
through an FXO interface, a PRI interface, an E1 interface or the
like. A PBX 54 user may be a PSTN user or an ISDN user. The FXO
interface provides the loop trunk signaling, the PRI interface
provides the ISDN digital user signaling, and the E1 interface
provides the digital trunk signaling. Those skilled in the art may
appreciate that AN 51, PSTN UE 52, ISDN UE 53 and PBX 54 are
devices in the related art, and are applied in the embodiments of
the present invention without improvement of the devices.
[0115] To sum up, compare FIG. 1 with FIG. 2, it can be seen that
AGCF 30 is added in the embodiments of the present invention, and
the PSTN user or the ISDN user using AN 51, PSTN UE 52, ISDN UE 53
or PBX 54 is able to access the IMS through AGCF 30 and AGF 40
managed by AGCF 30. In addition, PSTN/ISDN Simulation AS 20
managing the PSTN/ISDN services is also added. The PSTN/ISDN
services are implemented using the architecture shown in FIG. 2 in
the embodiments of the present invention.
[0116] It should be noted that the core of the method for the
processing packet domain service signal in accordance with the
embodiments of the present invention is the port/identity
conversion and protocol conversion which are implemented by AGCF
30, and there may be multiple implementing manners for the method
according to specific conditions (for example, it is needed to make
full use of existing devices in some cases). The detailed process
of the method for processing the packet domain service signal in
accordance with two embodiments of the present invention is
hereinafter described.
[0117] In an embodiment, PSTN/ISDN Simulation AS 20 provides
control of all the services, including the basic service, the
supplementary service and the extended value-added service of the
PSTN/ISDN, for the PSTN user and the ISDN user accessing through
AGF 40.
[0118] The calling process of an outgoing call from a user
accessing through the AGF is shown in FIG. 3.
[0119] In Step 310, the user hooks off and dials through PSTN/ISDN
UE 50. For the convenience of description, PSTN/ISDN UE 50
represents various user equipments of the PSTN/ISDN services,
including all the related user equipments of AN 51, PSTN UE 52,
ISDN UE 53 and PBX 54.
[0120] In Step 320, AGF 40 sends the called number to AGCF 30
through the I2 interface protocol upon receiving the dialing signal
from PSTN/ISDN UE 50.
[0121] In Step 330, AGCF 30 acquires the Private User Identity and
the Public User Identity corresponding to the user according to the
identity of AGF 40 and the identity of the user port, maps the I2
interface protocol to the SIP, and sends an INVITE message to
S-CSCF 11. Those skilled in the art may appreciate that the INVITE
message is an SIP request message defined in the SIP. S-CSCF 11 is
a network entity in IMS 10.
[0122] In Step 340, S-CSCF 11 triggers the service according to the
user subscription information and sends the INVITE message to
PSTN/ISDN Simulation AS 20. The user subscription information may
be acquired from the HSS in IMS 10.
[0123] In Step 350, PSTN/ISDN Simulation AS 20 sends the INVITE
message to S-CSCF 11 upon performing corresponding control of the
PSTN/ISDN services.
[0124] In Step 360, S-CSCF 11 keeps the session control and
determines whether to trigger a new service subsequently or to
implement the connection control and the routing. If S-CSCF 11
determines according to the user subscription data that a new
service needs to be triggered in another AS, perform Step 370;
otherwise, S-CSCF 11 implements the connection control and the
routing, specifically, sends the INVITE message to the I-CSCF of
the home domain of the called user if the called user is in the IMS
domain, for example, the called user is also a user accessing
through AGF 40, and sends the INVITE message to the Breakout
Gateway Control Function (BGCF) if the called user is outside the
IMS domain.
[0125] In Step 370, when S-CSCF 11 determines according to the user
subscription data that a new service needs to be triggered in
another AS, S-CSCF 11 triggers the new service and sends an INVITE
message to AS 21 corresponding to the new service.
[0126] The calling process of an incoming call to a user accessing
through the AGF is shown in FIG. 4.
[0127] In Step 410, S-CSCF 11 in the home domain of the called user
triggers the service according to the user subscription information
upon receiving the INVITE message. The user subscription
information may be acquired from the HSS in IMS 10.
[0128] In Step 420, S-CSCF 11 sends the INVITE message to PSTN/ISDN
Simulation AS 20.
[0129] In Step 430, PSTN/ISDN Simulation AS 20 sends the INVITE
message to S-CSCF 11 upon performing appropriate service
control.
[0130] In Step 440, S-CSCF keeps the session control and determines
whether to trigger a new service subsequently or to implement the
connection control and the routing. If S-CSCF 11 determines
according to the user subscription data that a new service needs to
be triggered in another AS, perform Step 470; otherwise, S-CSCF 11
implements the connection control and the routing, specifically,
sends the INVITE message to AGCF 30 and performs Step 450 if the
called user is a user accessing through AGF 40.
[0131] In Step 450, AGCF 30 locate AGF 40 accessed by the user and
the user port according to the Public User Identity of the called
user and the information stored when the user registers, maps the
SIP to the I2 interface protocol, and transfers the called number
to AGF 40 through the I2 interface protocol.
[0132] In Step 460, AGF 40 sends an incoming call signal to
PSTN/ISDN UE 50.
[0133] In Step 470, S-CSCF 11 triggers a new service and sends the
INVITE message to AS 22 corresponding to the new service.
[0134] In an embodiment, AGCF 30 provides the control of the basic
service and the supplementary service for a user accessing through
AGF 40 while PSTN/ISDN Simulation AS 20 provides the control of the
extended value-added service.
[0135] The calling process of an outgoing call from a user
accessing through AGF 40 is shown in FIG. 5.
[0136] In Step 510, the user hooks off and dials through PSTN/ISDN
UE 50. In Step 520, AGF 40 sends the called number to AGCF 30
through the I2 interface protocol upon receiving the dialing signal
from PSTN/ISDN UE 50. In Step 530, AGCF 30 controls the basic
service and supplementary service of the PSTN/ISDN first. The basic
service and the supplementary service of the PSTN/ISDN mentioned
herein include such services as abbreviated dialing and
registration of a new service. When the processing of the services
is completed, AGCF 30 terminates the call if the call ends
accordingly, for example, in the case that AGCF 30 processes the
registration of a new service; if the call continues, for example,
in the case that AGCF 30 processes an abbreviated dialing service,
AGCF 30 acquires the Private User Identity and the Public User
Identity corresponding to the user according to the identity of AGF
40 and the identity of the user port, maps the I2 interface
protocol to the SIP, and sends an INVITE message to S-CSCF 11. It
should be noted that the user subscription information and service
data related to the basic service and the supplementary service of
the PSTN/ISDN are stored in AGCF 30, or stored in the HSS and
downloaded to AGCF 30 when AGCF 30 starts up or when the user
registers; other user subscription information and service data are
stored in the HSS in IMS 10.
[0137] In Step 540, S-CSCF 11 triggers the service according to the
user subscription information and sends the INVITE message to
PSTN/ISDN Simulation AS 20.
[0138] In Step 550, PSTN/ISDN Simulation AS 20 sends the INVITE
message to S-CSCF 11 upon performing the corresponding control of
the value-added service of the PSTN/ISDN.
[0139] In Step 560, S-CSCF 11 keeps controlling the session and
determines to trigger a new service or to implement the connection
control and the routing subsequently. If S-CSCF 11 determines
according to the user subscription data that a new service needs to
be triggered in another AS, perform Step 570; otherwise, S-CSCF 11
implements the connection control and the routing, specifically,
sends the INVITE message to the I-CSCF of the home domain of the
called user if the called user is in the IMS domain, e.g., the
caller user is also a user accessing through AGF 40; sends the
INVITE message to the BGCF if the called user is outside the IMS
domain.
[0140] In Step 570, when S-CSCF 11 determines according to the user
subscription data that a new service needs to be triggered in
another AS, S-CSCF 11 triggers the new service and sends the INVITE
message to AS 21 corresponding to the new service.
[0141] The calling process of an incoming call to a user accessing
through the AGF is shown in FIG. 6.
[0142] In Step 610, the S-CSCF 11 of the home domain of the called
user triggers a service according to the user subscription
information upon receiving an INVITE message.
[0143] In Step 620, S-CSCF 11 sends the INVITE message to PSTN/ISDN
Simulation AS 20.
[0144] In Step 630, PSTN/ISDN Simulation AS 20 sends the INVITE
message to S-CSCF 11 upon implementing the corresponding control of
the value-added services.
[0145] In Step 640, S-CSCF 11 keeps controlling the session and
determines to trigger a subsequent new service or to implement the
connection control and the routing. If S-CSCF 11 determines
according to the user subscription data that a service needs to be
triggered in another AS, perform Step 680; otherwise, S-CSCF 11
implements the connection control and the routing, specifically,
sends the INVITE message to AGCF 30 when the called user is a user
accessing through the AGF, then perform Step 650.
[0146] In Step 650, AGCF 30 determines whether one of the basic
services and the supplementary services of the PSTN/ISDN has been
triggered. If yes, perform Step 670. If no, that is, if the called
user is idle, AGCF 30 locates both the AGF accessed by the user and
the user port according to such information as the Public User
Identity and the Private User Identity of the called user, maps the
SIP to the I2 interface protocol, and transfers the called number
to AGF 40 through the I2 interface protocol; then perform Step
660.
[0147] In Step 660, AGF 40 sends the incoming call signal to
PSTN/ISDN UE 50.
[0148] In Step 670, because AGCF 30 has triggered the service, AGCF
30 performs the corresponding control of the PSTN/ISDN service, and
when the control is finished, determines whether the call requires
S-CSCF 11 to perform session control again. For example, when AGCF
30 completes the call forwarding service of the called user and
sends the INVITE message to S-CSCF 11, S-CSCF 11 continues with the
session control. When the call ends accordingly, AGCF 30 terminates
this call, for example, terminates this call if AGCF 30 finishes
processing a Don't Disturb Service. If the called user is called
sequentially, for example, when AGCF 30 completes processing the
queuing service and the called user is idle, AGCF 30 locates both
AGF 40 accessed by the user and the user port according to the
Public User Identity of the called user and the information
recorded when the user registers, maps the SIP to the I2 interface
protocol, and transfers the called number to AGF 40 through the I2
interface protocol. Then perform Step 660.
[0149] In Step 680, S-CSCF 11 triggers a new service and sends an
INVITE message to AS 22 corresponding to the new service.
[0150] As can be seen from the embodiments above, new application
services may be customized quickly for PSTN/ISDN users. The
PSTN/ISDN services, as a network service ability of the IMS, can
participate in fast combination of services or customization of new
application services. All the services in the IMS are combination
of multiple ASs, and each AS provides a basic network service
ability or a specific value-added service, and all the ASs can
perform combination of new application services by a service
subscription rule as network sharing components; all the ASs can
also be open through a third party application interface, by which
new application services may be customized by a third party.
[0151] Seamless integration of the fixed network architecture and
service with the mobile network architecture and service is
achieved. Specifically, in the embodiments of the present
invention, each of the network nodes defined in the 3GPP IMS
standard need not be changed, and the existing IMS is used as the
IMS defined by the mobile network, only adding a new network node,
i.e. the AGCF, which enables a PSTN user and an ISDN user to access
the IMS domain through the AGF, achieving the seamless integration
of the fixed network with the mobile network. With the shielding
function of the AGCF, the IMS need not distinguish the manner in
which the user accesses the terminal, that is, the services
provided by the IMS are the services independent of the networks,
and a PSTN/ISDN Simulation AS can also provide service control to
mobile users; the ASs customized for the mobile users can also
serve the fixed users in the same way if the fixed terminals have
the abilities, achieving the seamless integration of the fixed
network with the mobile network in service provision.
[0152] Bran-new services may be provided to the PSTN user and the
ISDN user. The IMS serves as a system providing IP multimedia
services, and PSTN/ISDN Simulation AS can provide multiple
value-added services and combine such services with other service
abilities of the IMS network so as to provide bran-new services to
an accessing PSTN user and ISDN user. With the cooperation of
terminals, such as a Web Client, the services, such as network
directory, instant message, Presence service, unified message
service, click dialing, click transfer, click queue, click
convention, intelligent routing, customized ring back tone, calling
user colored imacolored customization and prompt, and self-help
management. Especially, with the ubiquitous click control, service
customization and self-help management, it is more convenient to
use the PSTN/ISDN services, the Average Revenue Per Unit (ARPU) of
a fixed network user may increase and new service grow points may
be found.
[0153] The access via a Private Branch eXchange (PBX) is supported,
which facilitates construction of a cross-domain enterprise
network. A PBX user may enjoy the same services as other users
accessing through the AGF. The cross-domain enterprise network can
be constructed between multiple PBXs and the PBX users may enjoy a
wide area IP Centrex service. Because such functions are the
existing functions in the IMS, the access of the terminal to the
IMS allows convenient provision of the functions for the terminal
accessing newly.
[0154] Besides the advantages above, such as achieving seamless
integration of the fixed network with the mobile network in terms
of the IMS, because the improvement on the basis of the IMS, the
technical solutions also have the following characteristics.
[0155] The implementation of services is independent of the
network, thus deploying and extending the services quickly and
achieving a low cost of customizing the services. In the
embodiments of the present invention, the PSTN/ISDN services are
all implemented by the PSTN/ISDN Simulation AS, or part of the
services are implemented by the PSTN/ISDN Simulation AS and others
are implemented by the AGCF. Specifically, the S-CSCF provides the
session control function independent of all the services, and the
session control function and the service control function are
implemented by different network nodes. The newly added network
node, i.e. the AGCF, shields difference between a PSTN user and an
ISDN user accessing through the AGF, and a unified session control
interface of the SIP is provided to the IMS.
[0156] Conflicts between multiple services are effectively avoided,
and problems, such as multiple triggering of a service, providing a
service by multiple points, nesting dialing of a service, are
resolved. All the services in the IMS are triggered by the S-CSCF
through the user service subscription data, and conflicts between
triggering of the PSTN/ISDN services and triggering of other
services, such as the intelligent service, may be effectively
avoided by setting an appropriate trigger rule. The PSTN/ISDN
services are uniformly implemented by one network node, that is,
the AS, and the AS can coordinate various PSTN/ISDN services
properly and arbitrate when the conflicts between services
occur.
[0157] The user subscription data are uniformly managed by the HSS
and all the services of the users are uniformly provided by the AS
in a centralized manner, which makes it convenient for the operator
to promote services of a unified brand.
[0158] The nomadism characteristic and service mobility of the
fixed network user are supported. Because the user subscription
data are collected and managed in the HSS of the IMS and the
terminal port of a user at the access point is separated from the
public ID of the user, the nomadism characteristic of the fixed
network user is supported. The user always acquires the services in
the home domain to which the user has subscribed, and the user may
always be routed through different access points to the home domain
to which the user has subscribed when the terminal moves. Thereby,
the services acquired are completely the same as the previous
services.
[0159] The wide area service is implemented easily, and plenty of
cross-domain IP Centrex services may attract more enterprise
clients. Because all the user data of the PSTN/ISDN services are
collected and managed in HSSs in the IMS and the location between
the multiple HSSs may be determined using the SLF in the IMS, thus
the wide area service may be implemented easily.
[0160] The enterprise services and group services may be customized
quickly and conveniently. In the IMS, the PSTN/ISDN Simulation AS
may exist as multiple physical entities, and a separate AS of the
enterprise services and group services may be customized for the
users with a special demand. Thereby, customized services with
individualized characteristics may be provided quickly and
conveniently without impact on other services and users.
[0161] Though the present invention has been illustrated and
described by referring to some preferred embodiments of the present
invention, those skilled in the art should understand that various
changes can be made in its form and detail without departing from
the spirit or scope of the present invention described in the
appended claims.
* * * * *