Reverse link lower layer assisted video error control

• US 20070091816A1
• Filed: 06/15/2006
• Published: 04/26/2007
• Est. Priority Date: 10/21/2005
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Lee, Yen-Chi, Tinnakornsrisuphap, Peerapol, Gupta, Vikram, Lott, Christopher
• Granted Patent: US 8,514,711 B2
• Time in Patent Office: Days
• US Class Current: 370/252
• CPC Class Codes: H04N 19/895 in combination with error concealment
• 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 21/6131 involving transmission via a mobile phone network wireless downlink channel access H04W74/006
• CPC Class Codes: H04N 21/6181 involving transmission via a mobile phone network arrangements for providing broadcast or conference services to substation in data switching networks in combination with wireless systems H04L12/189; wireless uplink channel access H04W74/004
• CPC Class Codes: H04N 21/6473 Monitoring network processes errors for recovering from a failure of a protocol instance or entity H04L69/40
• CPC Class Codes: H04N 21/64776 for requesting retransmission, e.g. of data packets lost or corrupted during transmission from server ARQ protocols H04L1/18; implementation or adaptation of Internet protocol [IP], of transmission control protocol [TCP] or of user datagram protocol [UDP] H04L69/16
• CPC Class Codes: H04N 21/6583 Acknowledgement

Abstract

The disclosure relates to reverse link lower layer assisted video error control. A method may encode video data, form a packet with the encoded video data, and transmit the packet across a wireless channel to an access network. A medium access control (MAC) layer may receive a negative acknowledgement (NAK) from the access network. The method may determine whether the received NAK is associated with a packet that contains video data. If the received NAK is associated with a packet that contains video data, the method may perform error control.

Claims

1. A method comprising:

encoding video data;

forming an Internet protocol (IP) packet with the encoded video data;

transmitting the packet across a wireless channel to an access network;

at a medium access control (MAC) layer, receiving a negative acknowledgement (NAK) from the access network;

determining whether the received NAK is associated with a packet that contains video data;

determining which IP packet contains data that was lost in transmission; and

if the received NAK is associated with a packet that contains video data, performing error control.

2. The method of claim 1, wherein the packet comprises macroblocks (MBs) of video data, the method further comprising passing information of the macroblocks from a video encoder to a real-time transport protocol (RTP) layer.

3. The method of claim 1, further comprising:

after encoding a frame of video data and before encoding a new frame of video data, querying the MAC layer to determine whether the MAC layer received a NAK; and

if the MAC layer received a NAK, performing error control.

4. The method of claim 1, further comprising informing a packet consolidation protocol (PCP) module of the received NAK.

5. The method of claim 1, further comprising, if the received NAK is associated with a packet that contains video data, informing a radio link protocol (RLP) module of the received NAK.

6. The method of claim 5, further comprising determining which RLP queue contains a packet that experienced an error in transmission.

7. The method of claim 1, further comprising informing an application layer of the packet associated with the received NAK.

8. The method of claim 1, further comprising:

maintaining a map between Internet protocol (IP) packets and macroblocks of video data;

after determining which IP packet contains data that was lost in transmission using the map to convert the IP packet into macroblocks of a video frame to determine which macroblocks were lost in transmission; and

performing error control for the macroblocks that were lost in transmission.

9. The method of claim 8, wherein error control comprises at least one of (a) restricting a motion estimation search range so that a damaged part will not be used as a prediction, (b) intra-code co-located macroblocks and neighboring macroblocks, and (c) using different reference frames for co-located macroblocks.

10. The method of claim 1, wherein the wireless channel comprises a code division multiple access 2000 1×

Evolution Data Optimized Revision A (CDMA2000 1×

EV-DO Rev A) channel.

11. The method of claim 1, wherein the wireless channel comprises a wideband code division multiple access (WCDMA) High Speed Uplink Packet Access (HSUPA) channel.

12. A method comprising:

encoding a first frame of video data;

forming a packet with the encoded first frame of video data;

transmitting the packet across a wireless channel to an access network;

before encoding a second frame of video data, determining whether a medium access control (MAC) layer received a negative acknowledgement (NAK) from the access network;

determining whether the received NAK is associated with a packet that contains video data; and

if the received NAK is associated with a packet that contains video data, then performing error control.

13. The method of claim 12, wherein determining whether a medium access control (MAC) layer received a negative acknowledgement (NAK) from the access network comprises checking whether a flag is set in a radio link protocol (RLP) module.

14. The method of claim 12, further comprising informing an application layer of the received NAK.

15. The method of claim 12, further comprising informing a video encoder of the received NAK.

16. The method of claim 12, further comprising setting a one-bit flag in a radio link protocol (RLP) module to indicate the MAC layer received a NAK.

17. The method of claim 12, wherein error control comprises at least one of (a) encoding the second frame as an I-frame, (b) increasing percentage of intra-coded macroblocks, and (c) using a frame before the first frame as a reference for motion estimation.

18. An apparatus comprising a machine-readable memory storing a set of instructions configured to:

encode video data;

form an Internet protocol (IP) packet with the encoded video data;

transmit the packet across a wireless channel to an access network;

at a medium access control (MAC) layer, receive a negative acknowledgement (NAK) from the access network;

determine whether the received NAK is associated with a packet that contains video data;

determine which IP packet contains data that was lost in transmission; and

if the received NAK is associated with a packet that contains video data, perform error control.

19. The apparatus of claim 18, wherein the packet comprises macroblocks (MBs) of video data, the instructions further comprising passing information of the macroblocks from a video encoder to a real-time transport protocol (RTP) layer.

20. The apparatus of claim 18, wherein the instructions are further configured to:

after encoding a frame of video data and before encoding a new frame of video data, query the MAC layer to determine whether the MAC layer received a NAK; and

if the MAC layer received a NAK, perform error control.

21. The apparatus of claim 18, wherein the instructions are farther configured to inform a packet consolidation protocol (PCP) module of the received NAK.

22. The apparatus of claim 18, wherein the instructions are further configured to, if the received NAK is associated with a packet that contains video data, inform a radio link protocol (RLP) module of the received NAK.

23. The apparatus of claim 22, wherein the instructions are further configured to determine which RLP queue contains a packet that experienced an error in transmission.

24. The apparatus of claim 18, wherein the instructions are further configured to inform an application layer of the packet associated with the received NAK.

25. The apparatus of claim 18, wherein the instructions are further configured to:

maintain a map between Internet protocol (IP) packets and macroblocks of video data;

after determining which IP packet contains data that was lost in transmission use the map to convert the IP packet into macroblocks of a video frame to determine which macroblocks were lost in transmission; and

perform error control for the macroblocks that were lost in transmission.

26. The apparatus of claim 25, wherein error control comprises at least one of (a) restricting a motion estimation search range so that a damaged part will not be used as a prediction, (b) intra-code co-located macroblocks and neighboring macroblocks, and (c) using different reference frames for co-located macroblocks.

27. The apparatus of claim 18, wherein the wireless channel comprises a code division multiple access 2000 1×

Evolution Data Optimized Revision A (CDMA2000 1×

EV-DO Rev A) channel.

28. The apparatus of claim 18, wherein the wireless channel comprises a wideband code division multiple access (WCDMA) High Speed Uplink Packet Access (HSUPA) channel.

29. An apparatus comprising a machine-readable memory storing a set of instructions configured to:

encode a first frame of video data;

form a packet with the encoded first frame of video data;

transmit the packet across a wireless channel to an access network;

before encoding a second frame of video data, determine whether a medium access control (MAC) layer received a negative acknowledgement (NAK) from the access network;

determine whether the received NAK is associated with a packet that contains video data; and

if the received NAK is associated with a packet that contains video data, then perform error control.

30. The apparatus of claim 29, wherein determining whether a medium access control (MAC) layer received a negative acknowledgement (NAK) from the access network comprises checking whether a flag is set in a radio link protocol (RLP) module.

31. The apparatus of claim 29, the instructions being further configured to inform an application layer of the received NAK.

32. The apparatus of claim 29, the instructions being further configured to inform a video encoder of the received NAK.

33. The apparatus of claim 29, the instructions being further configured to set a one-bit flag in a radio link protocol (RLP) module to indicate the MAC layer received a NAK.

34. The apparatus of claim 29, wherein error control comprises at least one of (a) encoding the second frame as an I-frame, (b) increasing percentage of intra-coded macroblocks, and (c) using a frame before the first frame as a reference for motion estimation.

35. An apparatus comprising:

a video encoder configured to encode video data;

a module configured to form an Internet protocol (IP) packet with the encoded video data;

a transceiver configured to (a) transmit the packet across a wireless channel to an access network, and (b) receive a medium access control (MAC) layer negative acknowledgement (NAK) from the access network;

wherein the module is configured to determine whether the received NAK is associated with a packet that contains video data and determine which IP packet contains data that was lost in transmission; and

if the received NAK is associated with a packet that contains video data, the video encoder is configured to perform error control.

36. An apparatus comprising:

a video encoder configured to encode a first frame of video data;

a first module configured to form a packet with the encoded first frame of video data;

a transceiver configured to (a) transmit the packet across a wireless channel to an access network and (b) receive a medium access control (MAC) layer negative acknowledgement (NAK) from the access network;

before encoding a second frame of video data, a second module configured to determine whether the MAC layer received a NAK from the access network and determine whether the received NAK is associated with a packet that contains video data; and

an error control module configured to perform error control if the received NAK is associated with a packet that contains video data.