HTTP ADAPTIVE STREAMING SERVER WITH AUTOMATIC RATE SHAPING

• US 20130091249A1
• Filed: 10/07/2011
• Published: 04/11/2013
• Est. Priority Date: 10/07/2011
• Status: Active Grant

• Current Assignee: Ericsson Television Incorporated (Telefonaktiebolaget LM Ericsson)
• Original Assignee: Ericsson Television Incorporated (Telefonaktiebolaget LM Ericsson)
• Inventors: Dasher, Charles, Phillips, Chris, McHugh, Kevin
• Granted Patent: US 8,751,679 B2
• Time in Patent Office: Days
• US Class Current: 709/219
• CPC Class Codes: H04L 43/08 Monitoring or testing based on specific metrics, e.g. QoS, energy consumption or environmental parameters
• CPC Class Codes: H04L 65/60 Network streaming of media packets
• CPC Class Codes: H04L 65/80 Responding to QoS
• CPC Class Codes: H04N 21/23439 for generating different versions
• CPC Class Codes: H04N 21/2402 Monitoring of the downstream path of the transmission network, e.g. bandwidth available traffic monitoring in data switching networks H04L43/00; monitoring data switching networks utilization H04L43/0876
• CPC Class Codes: H04N 21/2662 Controlling the complexity of the video stream, e.g. by scaling the resolution or bitrate of the video stream based on the client capabilities
• CPC Class Codes: H04N 21/47202 for requesting content on demand, e.g. video on demand
• CPC Class Codes: H04N 21/6332 directed to client
• CPC Class Codes: H04N 21/64322 IP
• CPC Class Codes: H04N 21/8456 by decomposing the content in the time domain, e.g. in time segments

Abstract

An adaptive streaming server and a method are described herein for determining if a congestion level within a network exceeds a predetermined threshold and when this occurs then one or more lower bit rate segments of a content stream will be transmitted to a client.

Claims

1. An adaptive streaming server for transmitting a content stream through a network to a client, the adaptive streaming server comprising:

a server comprising an input interface configured to receive a request from the client to play the content stream;

a segmenting unit configured to receive multiple files of the content stream where the multiple files are encoded at different bit rates and further configured to segment each of the multiple files into a plurality of segments;

a segment storage unit configured to store the plurality of segments;

the server further comprising;

a processing unit configured to generate a master manifest that includes a plurality of child manifests, wherein the first child manifest has references to the segments having a first bit rate, the second child manifest has references to the segments having a second bit rate, and the third child manifest has references to the segments having a third bit rate, and wherein the first bit rate is higher than the second bit rate which is higher than the third bit rate;

an output interface configured to send the master manifest to the client;

the input interface configured to receive a request from the client to fetch a specific one of the segments corresponding to the content stream;

the processing unit configured to obtain the requested segment from the segment storage unit;

the output interface configured to send the requested segment to the client;

a bandwidth monitor configured to monitor a congestion level within the network; and

the processing unit is configured to determine if the congestion level within the network exceeds a predetermined threshold and when this occurs is further configured to send an additional requested segment to the client where the sent additional requested segment has a bit rate that is less than at least the first bit rate associated with the first child manifest.

2. The adaptive streaming server of claim 1, wherein the server when the network exceeds the predetermined threshold is configured to prevent the client from requesting the segments associated with the first child manifest by:

the processing unit configured to generate another master manifest that does not include the first child manifest but includes the second child manifest which has references to the segments having the second bit rate, and the third child manifest which has references to the segments having the third bit rate;

the output interface configured to send the another master manifest along with an indicator to the client, where the indicator indicates that the another master manifest is to replace the master manifest;

the input interface configured to receive another request from the client to fetch a specific one of the segments associated with the second child manifest or the third child manifest corresponding to the content stream;

the processing unit configured to obtain the requested segment from the segment storage unit; and

the output interface configured to send the requested segment to the client'"'"'which playbacks the requested segment.

3. The adaptive streaming server of claim 1, wherein the content stream is a linear content stream of a video-on-demand content stream.

4. The adaptive streaming server of claim 1, wherein the server when the network exceeds the predetermined threshold is configured such that if the client requests the segments associated with the first child manifest then send the client segments which have a bit rate that is less than the first bit rate by:

the input interface configured to receive a request from the client to fetch one of the segments associated with the first child manifest corresponding to the content stream;

the processing unit configured to obtain a corresponding segment associated with one of the multiple files which has a bit rate that is less than the first bit rate rather than obtain the requested segment; and

the output interface configured to send the obtained segment to the client which playbacks the obtained segment.

5. The adaptive streaming server of claim 4, wherein the processing unit is configured to consider the segments referenced by the first child manifest to be the segments referenced by the second child manifest.

6. The adaptive streaming server of claim 5, wherein the content stream is a linear content stream.

7. The adaptive streaming server of claim 4, wherein the processing unit is configured to consider the requested segment referenced by the first child manifest to be the corresponding segment referenced by the second child manifest.

8. The adaptive streaming server of claim 7, wherein the content stream is a linear content stream of a video-on-demand content stream.

9. The adaptive streaming server of claim 1, wherein the server when the network exceeds the predetermined threshold is configured such that if the client requests an additional segment associated with the first child manifest then send the client the additional segment which has a bit rate that is less than the first bit rate by:

the input interface configured to receive a request from the client to fetch one of the segments associated with the first child manifest corresponding to the content stream;

the processing unit configured to obtain requested segment and then rate shape the obtained requested segment so has a bit rate that is less than the first bit rate; and

the output interface configured to send the obtained segment which has the bit rate that is less than the first bit rate to the client which then playbacks the obtained segment.

10. The adaptive streaming server of claim 9, wherein the processing unit is configured to rate shape the obtained requested segment so has a bit rate that is less than the first bit rate but also different than the second bit rate and the third bit rate.

11. The adaptive streaming server of claim 1, wherein the server is configured to send the master manifest to a plurality of clients and when the congestion level within the network exceeds the predetermined threshold then the server is further configured to allow a portion of the clients to continue to receive segments associated with the first child manifest while preventing another portion of the clients from requesting the segments associated with the first child manifest or if those clients requests the segments associated with the first child manifest then sending the corresponding segments which have a bit rate that is less than the first bit rate to those clients.

12. The adaptive streaming server of claim 1, wherein the client is one of a personal computer, a mobile phone, a tablet, or a Hypertext Transfer Protocol (HTTP) capable television.

13. A method implemented by an adaptive streaming server for transmitting a content stream through a network to a client, the method comprising the steps of:

receiving a request from the client to play the content stream;

receiving multiple files of the content stream where the multiple files are encoded at different bit rates;

segmenting each of the multiple files into a plurality of segments;

storing the plurality of segments;

generating a master manifest that includes a plurality of child manifests, wherein the first child manifest has references to the segments having a first bit rate, the second child manifest has references to the segments having a second bit rate, and the third child manifest has references to the segments having a third bit rate, and wherein the first bit rate is higher than the second bit rate which is higher than the third bit rate;

sending the master manifest to the client;

receiving a request from the client to fetch a specific one of the segments corresponding to the content stream;

obtaining the requested segment;

sending the requested segment to the client;

monitoring a congestion level within the network; and

determining if the congestion level within the network exceeds a predetermined threshold and when this occurs then sending an additional requested segment to the client where the sent additional requested segment has a bit rate that is less than at least the first bit rate associated with the first child manifest.

14. The method of claim 13, wherein when the network exceeds the predetermined threshold the client is prevented from requesting the segments associated with the first child manifest by:

generating another master manifest that does not include the first child manifest but includes the second child manifest which has references to the segments having the second bit rate, and the third child manifest which has references to the segments having the third bit rate;

sending the another master manifest along with an indicator to the client, where the indicator indicates that the another master manifest is to replace the master manifest;

receive another request from the client to fetch a specific one of the segments associated with the second child manifest or the third child manifest corresponding to the content stream;

obtaining the requested segment; and

sending the requested segment to the client which playbacks the requested segment.

15. The method of claim 14, wherein the content stream is a linear content stream of a video-on-demand content stream.

16. The method of claim 13, wherein when the network exceeds the predetermined threshold and if the client requests the segments associated with the first child manifest then the client is sent segments which have a bit rate that is less than the first bit rate by:

receiving a request from the client to fetch one of the segments associated with the first child manifest corresponding to the content stream;

obtaining a corresponding segment associated with one of the multiple files which has a bit rate that is less than the first bit rate rather than obtaining the requested segment; and

sending the obtained segment to the client which playbacks the obtained segment.

17. The method of claim 16, wherein during the obtaining step further considering the segments referenced by the first child manifest to be the segments referenced by the second child manifest.

18. The method of claim 17, wherein the content stream is a linear content stream.

19. The method of claim 16, wherein during the obtaining step further considering the requested segment referenced by the first child manifest to be the corresponding segment referenced by the second child manifest.

20. The method of claim 19, wherein the content stream is a linear content stream of a video-on-demand content stream.

21. The method of claim 13, wherein when the network exceeds the predetermined threshold and if the client requests an additional segment associated with the first child manifest then the client is sent the additional segment which has a bit rate that is less than the first bit rate by:

receiving a request from the client to fetch one of the segments associated with the first child manifest corresponding to the content stream;

obtaining requested segment and then rate shape the obtained requested segment so has a bit rate that is less than the first bit rate; and

sending the obtained segment which has the bit rate that is less than the first bit rate to the client which then playbacks the obtained segment.

22. The method of claim 21, wherein the obtained requested segment is rate shaped so has a bit rate that is less than the first bit rate but also different than the second bit rate and the third bit rate.

23. The method of claim 13, further comprising sending the master manifest to a plurality of clients and when the congestion level within the network exceeds the predetermined threshold then allowing a portion of the clients to continue to receive segments associated with the first child manifest while preventing another portion of the clients from requesting the segments associated with the first child manifest or if those clients requests the segments associated with the first child manifest then sending the corresponding segments which have a bit rate that is less than the first bit rate to those clients.

24. The method of claim 13, wherein the client is one of a personal computer, a mobile phone, a tablet, or a Hypertext Transfer Protocol (HTTP) capable television.

25. A system for providing a content stream through a network to a client, the system comprising:

a content provider;

an adaptive streaming server configured to;

receive a request from the client to play the content stream;

receive multiple files of the content stream where the multiple files are encoded at different bit rates and further configured to segment each of the multiple files into a plurality of segments;

store the plurality of segments;

generate a master manifest that includes a plurality of child manifests, wherein the first child manifest has references to the segments having a first bit rate, the second child manifest has references to the segments having a second bit rate, and the third child manifest has references to the segments having a third bit rate, and wherein the first bit rate is higher than the second bit rate which is higher than the third bit rate;

send the master manifest to the client;

receive a request from the client to fetch a specific one of the segments corresponding to the content stream;

obtain the requested segment from the segment storage unit;

send the requested segment to the client;

monitor a congestion level within the network; and

determine if the congestion level within the network exceeds a predetermined threshold and when this occurs is further configured to send an additional requested segment to the client where the sent additional requested segment has a bit rate that is less than at least the first bit rate associated with the first child manifest.