U.S. patent application number 11/041779 was filed with the patent office on 2005-08-25 for video policy server.
This patent application is currently assigned to Camiant, Inc.. Invention is credited to Riley, Yusun Kim.
Application Number | 20050188415 11/041779 |
Document ID | / |
Family ID | 34830470 |
Filed Date | 2005-08-25 |
United States Patent
Application |
20050188415 |
Kind Code |
A1 |
Riley, Yusun Kim |
August 25, 2005 |
Video policy server
Abstract
A system for distributing digital content includes two or more
digital content sources. Each source has a separate session manager
that is distinct from other session managers associated with other
digital content sources. The system further includes at least one
set of network resources that receive digital content from the two
or more digital content sources, modulate the digital content onto
a carrier signal suitable for transmission over an access network,
and transmit the carrier signal over the access network. The system
also includes a receiving device for terminating the carrier
signal. The receiving device generates a digital content stream
corresponding to the digital content from the two or more digital
content sources. The system further includes a policy server for
allocating bandwidth of the network resources to the digital
content sources, and for monitoring a utilization state of the
network resources.
Inventors: |
Riley, Yusun Kim;
(Marlborough, MA) |
Correspondence
Address: |
WILMER CUTLER PICKERING HALE AND DORR LLP
60 STATE STREET
BOSTON
MA
02109
US
|
Assignee: |
Camiant, Inc.
Marlborough
MA
|
Family ID: |
34830470 |
Appl. No.: |
11/041779 |
Filed: |
January 24, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60538803 |
Jan 23, 2004 |
|
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60538802 |
Jan 23, 2004 |
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Current U.S.
Class: |
725/116 ;
348/E5.008; 348/E7.073; 725/114; 725/115; 725/144; 725/145;
725/146 |
Current CPC
Class: |
H04L 47/70 20130101;
H04L 47/724 20130101; H04L 47/821 20130101; H04N 21/2402 20130101;
H04N 21/2385 20130101; H04N 21/2381 20130101; H04N 7/17336
20130101; H04N 21/2225 20130101; H04L 47/781 20130101; H04L 47/10
20130101; H04N 21/47202 20130101 |
Class at
Publication: |
725/116 ;
725/145; 725/144; 725/146; 725/114; 725/115 |
International
Class: |
H04N 007/173; H04N
007/16 |
Claims
What is claimed is:
1. A system for distributing digital content, comprising: two or
more digital content sources, each having a separate session
manager that is distinct from other session managers associated
with other digital content sources; at least one set of network
resources for (i) receiving digital content from the two or more
digital content sources, (ii) modulating the digital content onto a
carrier signal suitable for transmission over an access network,
and (iii) transmitting the carrier signal over the access network;
a receiving device for terminating the carrier signal and
generating a digital content stream corresponding to the digital
content from the two or more digital content sources; a policy
server for monitoring a utilization state of the network resources,
and for allocating a set of bandwidth segments of the at least one
set of network resources to the two or more digital content
sources.
2. The system of claim 1, wherein the policy server allocates the
bandwidth segments according to the utilization state of the at
least one set of network resources.
3. The system of claim 1, wherein the policy server allocates the
bandwidth segments according to a set of policy rules.
4. The system of claim 3, wherein the policy rules define resource
allocation according to subscriber priority.
5. The system of claim 3, wherein the policy rules define resource
allocation according to a category of the digital content.
6. The system of claim 1, wherein each of the two or more digital
content sources includes a video-on-demand server for providing
video content.
7. The system of claim 1, wherein the receiving device includes a
set top box for generating an output signal suitable for one or
more subscriber video equipment components.
8. The system of claim 1, wherein the policy server issues
instructions to the session manager associated with a digital
content source to send video content to the at least one set of
network resources.
9. The system of claim 1, wherein the policy server is a video
policy server for allocating the set of bandwidth segments of the
at least one set of network resources to two or more video content
sources.
10. The system of claim 1, wherein the utilization state includes
information about how much bandwidth of the at least one set of
network resources is allocated and how much bandwidth of the at
least one set of network resources is available.
11. A method of distributing digital content, comprising: providing
digital content from two or more digital content sources, each
having a separate session manager that is distinct from other
session managers associated with other digital content sources;
receiving, at one or more sets of network resources, digital
content from the two or more digital content sources; modulating
the digital content onto a carrier signal suitable for transmission
over an access network; transmitting the carrier signal over the
access network; terminating the carrier signal and generating a
digital content stream corresponding to the digital content from
the two or more digital content sources; allocating, with a policy
server, a set of bandwidth segments of the at least one set of
network resources to the two or more digital content sources, and
for monitoring a utilization state of the network resources.
12. The method of claim 11, further including allocating, using
policy rules, the bandwidth segments according to the utilization
state of the at least one set of network resources.
13. The method of claim 11, further including allocating, using
policy rules, the bandwidth segments according to a set of policy
rules.
14. The method of claim 13, further including defining resource
allocation according to subscriber priority.
15. The method of claim 13, further including defining resource
allocation according to a category of the digital content.
16. The method of claim 11, further including issuing instructions
from the policy server to the session manager associated with a
digital content source to send video content to the at least one
set of network resources.
17. A method of distributing digital content from a content source
to a receiving device over a network, comprising: sending an
initiating request for digital content, from the receiving device
to a session manager associated with the content source; sending a
resource request for network resources, from the session manager to
a policy server, as a result of the initiating request; evaluating
and executing one or more policy rules to determine whether or not
the resource request should be granted; sending an instruction from
the policy server to the session manager instructing the session
manager to send digital content to a specific set of network
resources; sending receiving information for receiving the digital
content to the receiving device; and, sending digital content from
the session manager to the network resources.
18. The method of claim 17, further including sending a
notification from the policy server to the network resources
notifying the network resources of a transfer of digital content
from the session manager to the network resources.
19. The method of claim 17, wherein the network resources include
edge QAM interfacing devices.
20. The method of claim 17, wherein the digital content includes
video content, and the content source includes one or more
video-on-demand servers.
21. The method of claim 17, further including monitoring a
utilization state of the network resources.
22. The method of claim 17, wherein the policy rules define
resource allocation according to subscriber priority.
23. The method of claim 17, wherein the policy rules define
resource allocation according to a category of the digital
content.
24. The method of claim 17, furthering including evaluating and
executing the one or more policy rules to determine how much
bandwidth of the network resources should be allocated to the
session manager.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims benefit of the following U.S.
Provisional Patent Applications:
[0002] "VIDEO POLICY SERVER," U.S. Provisional Patent Application
Ser. No. 60/538,803; filed Jan. 23, 2004 and,
[0003] "POLICY BASED ADMISSION CONTROL," U.S. Provisional Patent
Application Ser. No. 60/538,802, filed Jan. 23, 2004.
BACKGROUND OF THE INVENTION
[0004] The present invention relates to content distribution over a
network, and more particularly, to managing distribution resources
for video-on-demand (VOD) and other content services on a cable
network.
[0005] Video-on-demand, one of several services offered by cable
multiple system operators (MSOs), enables a subscriber to customize
cable content according to their preferences and/or schedules. A
typical VOD distribution architecture 10, shown in FIG. 1, includes
a VOD server 12 and a session manager 14, a number of edge
quadrature amplitude modulation (QAM) interfacing devices 16, a
cable access network 18, and a set top box (STB) 20.
[0006] The VOD server 12 hosts a large volume of digital video
content. Portions of this content may be selected via a request
from the subscriber. (i.e., the end user). The session manager 14
is responsible for setting up a video session, i.e., processing
requests from the subscriber and providing an interface between the
VOD server 12 and the other components in the distribution
architecture 10. The VOD server 12 and the session manager 13 are
typically tightly coupled and sold as a set.
[0007] The edge QAM interfacing devices (edge QAM) 16 receive
digital video content from the session manager 14, QAM-modulate and
up-convert the content, then transmit resulting QAM signal onto the
coaxial infrastructures within the access network 18.
[0008] The STB 20 terminates the QAM signals at the site of the
subscriber and extracts the VOD content stream. The STB 20 then
generates an output signal suitable for the subscriber's video
equipment (e.g., televisions, recording devices, etc.).
[0009] In operation, the subscriber requests content (e.g., a
movie, a nature documentary or a classic sporting event) via the
STB 20. The STB 20 conveys the request to the session manager 14.
The session manager 14 allocates suitable bandwidth resources in
the edge QAM 16, and instructs the STB 20 to tune to the
appropriate frequency spectrum for those resources. The session
manager 14 then directs the VOD server 12 to begin streaming the
appropriate digital content to the edge QAM 16, and the edge QAM 16
translates the digital content to the appropriate frequency
spectrum.
[0010] One disadvantage of this architecture is that the edge QAM
16 is statically mapped to a particular session manager/VOD server
combination, and cannot be shared with another session manager. The
session manager 14 in FIG. 1 monitors and controls the resource
allocation of the edge QAM 16 for VOD content to multiple
subscribers. A second session manager/VOD server combination cannot
share the edge QAM 16 because different session managers cannot
communicate to coordinate the edge QAM resources.
[0011] For example, if a cable MSO desires to deploy a second VOD
server 22 (and associated session manager 24) for hosting content
different than what is on the first VOD server 12, the second VOD
server 22 must deliver its content via different edge QAM 26 than
that used by the first VOD server 12, as shown in FIG. 2. This
arrangement represents a highly inefficient use of network
resources.
SUMMARY OF THE INVENTION
[0012] In one aspect, a system for distributing digital content
includes two or more digital content sources, each having a
separate session manager that is distinct from other session
managers associated with other digital content sources. The system
further includes at least one set of network resources for
receiving digital content from the two or more digital content
sources, for modulating the digital content onto a carrier signal
suitable for transmission over an access network, and for
transmitting the carrier signal over the access network. The system
also includes a receiving device for terminating the carrier signal
and generating a digital content stream corresponding to the
digital content from the two or more digital content sources. The
system further includes a policy server for monitoring a
utilization state of the network resources, and for allocating a
set of bandwidth segments of the at least one set of network
resources to the two or more digital content sources.
[0013] The policy server allocates the bandwidth segments according
to the utilization state of the at least one set of network
resources. Alternatively, the policy server may allocate bandwidth
according to a set of policy rules. Policy rules may define
resource allocation according to subscriber priority, or they may
define resource allocation according to a category of the digital
content.
[0014] The receiving device includes a set top box for generating
an output signal suitable for one or more subscriber video
equipment components, and each of the two or more digital content
sources includes a video-on-demand server for providing video
content.
[0015] The policy server issues instructions to the session manager
associated with a digital content source to send video content to
the at least one set of network resources. In one embodiment, the
policy server is a video policy server for allocating the set of
bandwidth segments of the at least one set of network resources to
two or more video content sources.
[0016] The utilization state includes information about how much
bandwidth of the at least one set of network resources is allocated
and how much bandwidth of the at least one set of network resources
is available.
[0017] In another aspect, a method of distributing digital content
includes providing digital content from two or more digital content
sources, each having a separate session manager that is distinct
from other session managers associated with other digital content
sources. The method further includes receiving, at one or more sets
of network resources, digital content from the two or more digital
content sources. The method also includes modulating the digital
content onto a carrier signal suitable for transmission over an
access network, transmitting the carrier signal over the access
network, and terminating the carrier signal and generating a
digital content stream corresponding to the digital content from
the two or more digital content sources. The method further
includes allocating, with a policy server, a set of bandwidth
segments of the at least one set of network resources to the two or
more digital content sources, and for monitoring a utilization
state of the network resources.
[0018] In another aspect, a method of distributing digital content
from a content source to a receiving device over a network
includes
[0019] sending an initiating request for digital content, from the
receiving device to a session manager associated with the content
source;
[0020] sending a resource request for network resources, from the
session manager to a policy server, as a result of the initiating
request;
[0021] evaluating and executing one or more policy rules to
determine whether or not the resource request should be
granted;
[0022] sending an instruction from the policy server to the session
manager instructing the session manager to send digital content to
a specific set of network resources;
[0023] sending receiving information for receiving the digital
content to the receiving device; and,
[0024] sending digital content from the session manager to the
network resources.
[0025] The method further includes sending a notification from the
policy server to the network resources notifying the network
resources of a transfer of digital content from the session manager
to the network resources. The network resources may include edge
QAM interfacing devices. The digital content may include video
content, and the content source may include one or more
video-on-demand servers.
[0026] The method further includes evaluating and executing the one
or more policy rules to determine how much bandwidth of the network
resources should be allocated to the session manager.
BRIEF DESCRIPTION OF DRAWINGS
[0027] The foregoing and other objects of this invention, the
various features thereof, as well as the invention itself, may be
more fully understood from the following description, when read
together with the accompanying drawings in which:
[0028] FIG. 1 shows a prior art video-on-demand content
distribution architecture.
[0029] FIG. 2 shows another view of the distribution architecture
in FIG. 1.
[0030] FIG. 3 shows the content distribution architecture of the
described embodiment.
[0031] FIG. 4 shows a series of steps for setting up a video
session using the architecture in FIG. 3.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0032] The described embodiment is a cable network architecture in
which a video policy server (VPS) coordinates allocation of network
resources among two or more video-on-demand (VOD) servers each
coupled to session managers (also referred to herein more generally
as video content sources). As used herein, the term "network
resources" specifically refer to edge QAM resources, but in
general, the network resources may include any network components
in the cable network architecture from the data source to the
ultimate subscriber destination.
[0033] Although the described embodiment distributes video content
across a cable network, the concepts described herein also apply to
the distribution of more general digital content, such as video
gaming content and other application data from two or more digital
content sources. Central to this distribution of digital content is
a policy server that allocates network resources to two or more
digital content sources based on various considerations such as the
utilization state of the network resources and a set of policy
rules governing the digital content and the end consumers of the
digital content (i.e., the subscribers). This general architecture
allows digital content sources to share network resources, where
without this architecture, each of those digital content sources
would be bound to a single set of network resources.
[0034] In the described embodiment, the VPS takes on the resource
allocation functionality that, for prior art architectures,
typically resides in the session managers associated with VOD
servers. By abstracting the allocation functionality from the
session managers and centralizing it in the VPS, the described
embodiment allows multiple video data sources to utilize the same
set of edge QAM interface devices.
[0035] FIG. 3 shows the described embodiment of a policy-based
admission control scheme for use in a cable network architecture. A
first VOD server 102, a second VOD server 104 and a third VOD
server 106, each accompanied by an associated session manager (108,
110 and 112, respectively), host digital video content.
[0036] Each VOD server 102, 104 and 106 hosts a large amount of a
particular category of video content. For example, the first VOD
102 server may host full length movie content, the second VOD
server 106 may host classic sports content, and the third VOD
server 106 may host nature/wildlife content. Each VOD server merely
streams selected video content when instructed by its associated
session manager.
[0037] A session manager associated with each VOD server includes
all of the functionality necessary for setting up and tearing down
a video session. As used herein, a "video session" is transmission
of video content from one of the VOD servers, through the cable
network, with the video content terminating at the location of the
subscriber. The session manager may be integrated into the VOD
server, or it may be a separate component either attached to, in
close proximity to, or networked with, the VOD server.
[0038] Each VOD server/session manager can provide digital video
content to a set of edge QAM interfacing devices 114 (referred to
herein as "edge QAM"). The edge QAM 114 modulates and up-converts
the digital content from the VOD servers, then transmits the
resulting QAM signal onto the coaxial infrastructures within an
access network 116.
[0039] The edge QAM 114 is capable of providing a finite amount of
throughput bandwidth for the digital content. In the described
embodiment, the first VOD server 102, the second VOD server 104 and
the third VOD server 106 can share the throughput capacity of the
edge QAM 114, so that each VOD server can utilize one or more
bandwidth segments of the overall edge QAM 114 throughput capacity.
Each of the bandwidth segments can be any frequency width up to the
total bandwidth of the edge QAM 114.
[0040] The STB 120 is a receiving device that terminates the QAM
signals at the site of the subscriber and extracts the VOD content
stream from the QAM signals. The STB 120 generates an output signal
from the extracted VOD content stream suitable for subscriber video
equipment such as televisions, video recorders and the like.
[0041] A video policy server (VPS) 118 controls how much throughput
bandwidth of the edge QAM 114 each VOD/session manager uses. The
VPS 118 monitors the utilization state of the edge QAM 114, i.e.,
how much bandwidth of the edge QAM 114 is currently being utilized,
and how much of the edge QAM 114 is available.
[0042] In order for a VOD server/session manager to transmit
digital video content through the edge QAM 114, the session manager
must request edge QAM 114 resources from the VPS 118. The session
manager specifies a particular amount of edge QAM 114 resources
depending upon the nature of the digital video content to be
transmitted (e.g., high definition content requires more bandwidth
than ordinary video). The VPS 118 evaluates the state of the edge
QAM 114 to determine if the requested resources are available. If
those resources are available, and certain policy criteria are met,
the VPS 118 admits the VOD server/session manager to the requested
edge QAM bandwidth. Once admitted, the VOD server/session manager
begins streaming the digital video to the edge QAM 114.
[0043] Once the VPS 118 allocates edge QAM bandwidth to a VOD
server (for example, the first VOD server 102), the VPS 118 removes
that bandwidth from consideration for allocation to other sources.
The VPS 118 thus interprets the state of the edge QAM 118 as having
its availability reduced by the amount of bandwidth allocated to
the first VOD server 102.
[0044] The allocated bandwidth remains unavailable until
relinquished by the sourcing VOD server. The allocated bandwidth
may be relinquished by, for example, the expiration of a purchase
period during which the subscriber can access the video, or a
command from the session manager that the video data stream is
complete. Once the bandwidth is relinquished, the VPS 118 considers
that bandwidth available for allocation. As a result, the VPS
interprets the state of the edge QAM 116 as having its availability
increased by the amount of bandwidth relinquished.
[0045] As described above, the VPS 118 evaluates certain policy
rules in addition to resource availability before allocating
resources to a video source. Such policy rules allow for smooth
integration of VOD with other data types within the network (e.g.,
high speed internet access, voice-over-IP, video conferencing,
etc.). One type of policy may give priority to certain data types.
For example, policy rules may give resource requests from certain
data sources preferential treatment by giving them higher priority
access to the available resources. Further, policy rules can allow
certain high priority data sources to preempt a lower priority data
stream that is currently using allocated resources.
[0046] Another type of policy may give priority to particular
subscribers, creating a kind of "tier" system. For example,
consider a three-tier system where the highest-priority tier is the
`gold` tier, the next highest priority tier is the `silver` tier,
and the lowest tier is the `bronze` tier. Policy rules involving
subscriber tiers give preferential treatment to higher tiers, for
which subscribers in those tiers pay a premium price. One exemplary
tier-based rule may be:
[0047] if
((subscriber_tier==bronze)&&(current_network_utilization>80%)-
) then reject
[0048] With this rule, an allocation request for a bronze-tier
subscriber will be rejected if the current resource allocation is
greater than 80 percent. This and other tier-based policy rules
thus function to bias network availability towards the higher
paying subscribers.
[0049] FIG. 4 illustrates a series of steps for setting up a video
session and the corresponding allocation of resources at the edge
QAM 116. In this example, a subscriber requests, via the set top
box (STB) 120, digital video data from the second VOD server 104
and the associated session manager 110. Although this example shows
the steps for setting up a session from one particular VOD server
and session manager, these steps apply for a session with respect
to any of the other VOD sources.
[0050] In the first step 130, the STB 120 requests particular VOD
content from the session manager 110 associated with the relevant
VOD server 104. The STB 120 determines which of the three is the
relevant VOD server and session manager based upon (i)
configuration data within the STB 120 and (ii) the nature of the
requested VOD content. In this exemplary case, the STB 120 sends
the request to the second session manager 110 because its
associated VOD server 104 hosts the particular type of VOD content
the subscriber desires (e.g., a recently released movie).
[0051] In the second step 132, the session manager 110 sends a
request to the VPS 118 for resource allocation (in this case, edge
QAM 114 resources). This request includes information such as
subscriber ID, subscriber service tier, priority of the content,
and streaming characteristics (e.g., constant bit rate/variable bit
rate, bandwidth requirements, etc.).
[0052] In the third step 134, the VPS 118 evaluates and executes
the policy rules defined by the MSO, while considering various
factors, in order to decide whether to allocate network resources
to the session manager 110. Such factors include the current
utilization state of the network resources, the service tier of the
requesting subscriber, the nature of the content being requested,
among others.
[0053] In the fourth step 136, the VPS 118 instructs the service
manager 110 to send the requested video content to a particular IP
address and UDP port. This occurs only if the results of executing
the policy rules indicate such instruction is an appropriate
action, and if sufficient network resources are available. If the
result of executing the policy rules indicate such instruction is
an inappropriate action, the VPS 118 does not respond to the
service manager. Alternatively, the VPS 118 may respond to the
session manager 110 with a message indicating the request for
resource allocation has been denied.
[0054] In some cases, the network resources needed to fulfill the
request from the subscriber will not be available, or the policy
rules will not allow use of the resources. In these cases the VPS
118 will not allocate network resources to the session manager 110.
Alternatively, the VPS 118 may provide the service manager with
alternatives such as using a lower bit-rate stream or sending a
request to another VOD server hosting similar content.
[0055] In the fifth step 138, the VPS 118 notifies the relevant
edge QAM 114 to expect the video data stream from the session
manager 110 and to take any necessary actions. Such actions may
include converting the video data to a lower bit rate, changing
from constant bit rate to variable bit rate, or other processing
actions unique to the incoming VOD content.
[0056] In the sixth step 140, the session manager 110 communicates
tuning and other information to the STB 120 necessary for receiving
the requested VOD content. Such information includes which
frequency channel will carry the video content, which MPEG program
to monitor for a particular video stream, etc.
[0057] In the seventh step 142, the session manager 110 begins to
stream the requested VOD content to the edge QAM 114, which
converts the VOD content stream to the appropriate format for
viewing via the STB. The QAM 114 modulates and up-converts the VOD
content stream, then transmits the resulting QAM signal onto the
coaxial infrastructures within an access network 116.
[0058] In some cases, the subscriber may choose to "pause" the
video session described above once the session is established, and
the VPS 118 may take different actions as a result depending on
policy rules. For example, a subscriber may purchase a time slot
(e.g., 24 hours) during which the subscriber can watch the content
as many times as he or she desires. During this time slot, the
subscriber may stop watching the content before it ends, assuming
he or she will return later to watch the remainder of the content.
In this case, the service manager 110 informs the VPS 118 of the
interruption, and the VPS 118 may release the reserved resources
until the subscriber resumes watching the content. Policy rules
may, for example, dictate that those resources will not be released
for higher-level subscriber tiers, so that the resources are
guaranteed to be available for the entire time slot.
[0059] The above examples do not specify particular communication
protocols among the various components. In general, any protocol
appropriate for the particular media and content may be used for
the communication described above. Specific examples of
communication protocols for the above communications are listed
below.
[0060] I) Communication Between the STB 120 and the Session Manager
110:
[0061] 1. DSMCC--(Digital Storage Media--Command and Control): See
ISO/IEC JTC1/SC29/WG11.
[0062] 2. RTSP--(Real Time Streaming Protocol): See RFC-2326 (April
1998).
[0063] II) Communication Between the Session Manager 110 and the
VPS 118:
[0064] 1. RTSP.
[0065] 2. XML (eXtensible Markup Language).
[0066] 3. HTTP (HyperText Transfer Protocol).
[0067] 4. RSVP--(Resource reSerVation Protocol): See RFC-2205
(September 1997).
[0068] III) Communication Between the VPS 118 and the Edge QAM
116:
[0069] 1. SNMP (Simple Network Management Protocol) See RFCs 1155,
1157, and 1212 for SNMPv1 and RFCs 1441 through 1452 for
SNMPv2.
[0070] 2. XML.
[0071] 3. HTTP.
[0072] Other aspects, modifications and embodiments are within the
scope of the claims.
* * * * *