1. TSG-C SWG1.2 Ad hoc, Montréal, Québec C12-20040517-012 1 of 40 Video Delivery in cdma2000® Networks Hari Garudadri hgarudadri@qualcomm.com Phoom Sagetong phooms@qualcomm.com Nik Leung nleung@qualcomm.comhgarudadri@qualcomm.comphooms@qualcomm.comnleung@qualcomm.com

2. TSG-C SWG1.2 Ad hoc, Montréal, Québec C12-20040517-012 2 of 40 Notice QUALCOMM Incorporated grants a free, irrevocable license to 3GPP2 and its Organization Partners to incorporate text or other copyrightable material contained in the contribution and any modifications thereof in the creation of 3GPP2 publications; to copyright and sell in Organizational Partner’s name any Organizational Partner’s standards publication even though it may include portions of the contribution; and at the Organization Partner’s sole discretion to permit others to reproduce in whole or in part such contributions or the resulting Organizational Partner’s standards publication. QUALCOMM Incorporated is also willing to grant licenses under such contributor copyrights to third parties on reasonable, non-discriminatory terms and conditions for purpose of practicing an Organizational Partner’s standard which incorporates this contribution. This document has been prepared by QUALCOMM Incorporated to assist the development of specifications by 3GPP2. It is proposed to the Committee as a basis for discussion and is not to be construed as a binding proposal on QUALCOMM Incorporated. QUALCOMM Incorporated specifically reserves the right to amend or modify the material contained herein and nothing herein shall be construed as conferring or offering licenses or rights with respect to any intellectual property of QUALCOMM Incorporated other than provided in the copyright statement above.

3. TSG-C SWG1.2 Ad hoc, Montréal, Québec C12-20040517-012 3 of 40 Abstract & Recommendation This contribution presents an approach to deliver video content efficiently over cdma2000 wireless channels Explicit Bit Rate Control (EBR), matches encoder packet sizes to physical layer packet sizes EBR benefits include –Improved Error Resiliency –Lower latency –Ability to strip IP headers Video codec modifications are completely “Standards Compliant”; Other changes include –Rate control at the encoder –QoS support for synchronous video packet delivery in a particular window –Header Compression support at the PDSN (header removal or compression) Recommendation –Review and adopt

4. TSG-C SWG1.2 Ad hoc, Montréal, Québec C12-20040517-012 4 of 40 Overview VBR encoding for CBR Delivery EBR restrictions on rate control –cdma2000 provides VBR channels with “Explicit Rates” –Simulation results demonstrate compression efficiency comparable to true VBR Error Resiliency –Improved resilience to channels errors –Simulations demonstrate quality improvements Lower Latency –QoS constraint on delay –Enables lower latency with EBR rate control Header Compression –EBR supports header removal –Other header compressions schemes also supported

5. TSG-C SWG1.2 Ad hoc, Montréal, Québec C12-20040517-012 5 of 40 VBR Encoding for CBR Delivery

6. TSG-C SWG1.2 Ad hoc, Montréal, Québec C12-20040517-012 6 of 40 Anatomy of a Video frame SCFHVideo_packet(1)RM Video_packet(2) RMVideo_packet(3) RMVideo_packet(n) SC = start_code FH = frame_header RM = resync_marker

7. TSG-C SWG1.2 Ad hoc, Montréal, Québec C12-20040517-012 7 of 40 VBR Sources on CBR Channels Video is inherently a VBR source Delivery of a VBR source over a CBR channel requires traffic shaping

8. TSG-C SWG1.2 Ad hoc, Montréal, Québec C12-20040517-012 8 of 40 VBR encoding on CBR Encoder Buffer Video Frame index Size Phy. layer Frame index Channel

9. TSG-C SWG1.2 Ad hoc, Montréal, Québec C12-20040517-012 9 of 40 Buffer Delay MPEG-4 SPL0 with Qp = 15, 64kbps on 64kbps channel Buffer delay of 1 second (10 frames in buffer, to prevent underflow)

10. TSG-C SWG1.2 Ad hoc, Montréal, Québec C12-20040517-012 10 of 40 VBR Channels? What if the Channel is capable of variable rates? –Similar to FCH, but with higher rates –Higher rates can be used for I frames and dtx’ed for P frames What if the Encoder is capable of generating Video Slices accordingly?

11. TSG-C SWG1.2 Ad hoc, Montréal, Québec C12-20040517-012 11 of 40 MS BSC/PCFPDSN Internet FCH DCCH SCH PDCH RANTCP/IP RTP/RTCP RTSP Wireless Network Architecture Generic wireline to wireless communication diagram FCH: Variable rate channel in RS-1 and RS-2; used mainly for voice DCCH: Constant rate channel in RS-1 and RS-2 SCH: High rate channel; Shared in TDM PDCH: High rate channel; Fast allocation among many users; uses hybrid ARQ

12. TSG-C SWG1.2 Ad hoc, Montréal, Québec C12-20040517-012 12 of 40 EBR Restrictions on Rate Control

13. TSG-C SWG1.2 Ad hoc, Montréal, Québec C12-20040517-012 13 of 40 EBR: SCH Constraints Constant frame rate (10 fps, 15 fps, …) DTX, DCCH, SCH, DCCH+SCH for each 20 ms slot 4 rates result in a spectrum of 20 unique options for slice sizes in one frame –One Video frame every 100 ms: Up to 5 slices per frame –Two Video frames every 200 ms: Up to 9 slices per frame DCCH = {9.6, 14.4} based on the radio configuration (RC) SCH = {n * 9.6, n * 14.4} based on RC; n={1, 2, 4, 8, 16} 41235 20 ms dtx DCCH SCH DCCH+SCH 4 possible rates each 20 ms

14. TSG-C SWG1.2 Ad hoc, Montréal, Québec C12-20040517-012 14 of 40 SCH + DCCH Packet Sizes Video Slice SizesDCCH ConfigurationSCH Configuration 120, 40, 60RS12x in RC3 220, 80, 100RS14x in RC3 320, 160, 180RS18x in RC3 431, 40, 71RS22x in RC3 531, 80, 111RS24x in RC3 631, 160, 191RS28x in RC3 720, 64, 84RS12x in RC5 820, 128, 148RS14x in RC5 920, 256, 276RS18x in RC5 1031, 64, 95RS22x in RC5 1131, 128, 159RS24x in RC5 1231, 256, 287RS28x in RC5

15. TSG-C SWG1.2 Ad hoc, Montréal, Québec C12-20040517-012 15 of 40 PDCH Packet Sizes F-PDCH (BYTES)R-PDCH (BYTES)R-PDCH STUFFING BITS 360 (45) 0 720 (90) 24 1440 (180) 72 2880 (360) 168

16. TSG-C SWG1.2 Ad hoc, Montréal, Québec C12-20040517-012 16 of 40 EBR: PDCH Constraints Constant frame rate (10 fps, 15 fps, …) n Video frames every nT ms, T = 1000/frames_per_second Video slices are fixed in size (e.g. 90 bytes) Variable number of slices per frame –I frames need ~5 to 8 more slices than P frames –Number of frames depends on the source characteristics

17. TSG-C SWG1.2 Ad hoc, Montréal, Québec C12-20040517-012 17 of 40 VBR: source distribution

18. TSG-C SWG1.2 Ad hoc, Montréal, Québec C12-20040517-012 18 of 40 EBR – SCH+DCCH: source distribution

19. TSG-C SWG1.2 Ad hoc, Montréal, Québec C12-20040517-012 19 of 40 EBR – PDCH: – source distribution

20. TSG-C SWG1.2 Ad hoc, Montréal, Québec C12-20040517-012 20 of 40 EBR Performance Comparison No loss in compression efficiency due to EBR constraints Significant improvements under channel errors VBR: If Packet I is lost, both Packets 1 and 2 are lost –Packet Error Rate = (1 + m) FER –where m=avg. # frames per packet, FER = frame error rate of PHY EBR: Packet loss is restricted to one slice –Packet Error Rate = FER

21. TSG-C SWG1.2 Ad hoc, Montréal, Québec C12-20040517-012 21 of 40 EBR Vs VBR : Foreman 1% Packet Loss, most of the errors in the beginning

22. TSG-C SWG1.2 Ad hoc, Montréal, Québec C12-20040517-012 22 of 40 EBR Vs VBR : Carphone 1% Packet Loss, most of the errors in the beginning

23. TSG-C SWG1.2 Ad hoc, Montréal, Québec C12-20040517-012 23 of 40 EBR Vs VBR : Stefan 1% Packet Loss, most of the errors in the beginning

24. TSG-C SWG1.2 Ad hoc, Montréal, Québec C12-20040517-012 24 of 40 EBR Vs VBR : News 1% Packet Loss, most of the errors in the beginning

25. TSG-C SWG1.2 Ad hoc, Montréal, Québec C12-20040517-012 25 of 40 Latency Revisited

26. TSG-C SWG1.2 Ad hoc, Montréal, Québec C12-20040517-012 26 of 40 Video Delays EncoderChannelDecoder DeDe DdDd DbDb DbDb DtDt Buffers at Encoder and Decoder are of same size Total delay due to buffering is D b

27. TSG-C SWG1.2 Ad hoc, Montréal, Québec C12-20040517-012 27 of 40 Buffer Delay MPEG-4 SPL0 with Qp = 15, 64kbps on 64kbps channel Buffer delay of 1 second (10 frames in buffer, to prevent underflow)

28. TSG-C SWG1.2 Ad hoc, Montréal, Québec C12-20040517-012 28 of 40 Delay Considerations (Revisited) When Channel rate is exactly matched to encoder output, buffer delay is zero

29. TSG-C SWG1.2 Ad hoc, Montréal, Québec C12-20040517-012 29 of 40 Delivery in PDCH 14 users, with 300 ms (n=3) max delay per user

30. TSG-C SWG1.2 Ad hoc, Montréal, Québec C12-20040517-012 30 of 40 Header Compression

31. TSG-C SWG1.2 Ad hoc, Montréal, Québec C12-20040517-012 31 of 40 Protocol Stack : Data Services Traditional Wireless IP Protocol Stacks Basis for streaming and conversational services in 3G Header compression/removal is required for efficiency RTP MAC GRE IP GRE IP UDP RTP Application MAC MSBS/PCFPDSNHost UDP IP Application

32. TSG-C SWG1.2 Ad hoc, Montréal, Québec C12-20040517-012 32 of 40 Protocol Stack : VoIP Protocol Stack for Header Removal (SO60) in cdma2000 Application (codec) talks directly to the MAC PDSN performs IP Gateway function between VoIP and circuit-switched voice over the air to provide improvement in radio efficiency Air interface efficiency is same as that for CS domain (send minimum bits required OTA)

33. TSG-C SWG1.2 Ad hoc, Montréal, Québec C12-20040517-012 33 of 40 Wireless IP Layers

34. TSG-C SWG1.2 Ad hoc, Montréal, Québec C12-20040517-012 34 of 40 Header Removal Reducing IP Overhead... RLP Payload One Physical Layer Frame Codec RLP MUX Physical Layer SHPayload RLP... MUX... CRCtail Internet Wireless Network SHPayloadSHPayload

35. TSG-C SWG1.2 Ad hoc, Montréal, Québec C12-20040517-012 35 of 40 IP Overhead Computation Assume one video slice per one physical layer frame Average Data Rate = C kbps Video Frame Rate = 10 fps Phy. Frame Duration = 20 ms Number of slots / sec = 1/ 20 ms = 50 IP Overhead per slice = 44 bytes (RTP+UDP+IP+PPP) –Bandwidth expansion due to PPP is ignored IP Overhead data rate = 44 * 50 bytes/sec = 17.6 kbps IP Overhead = 17.6 / C

36. TSG-C SWG1.2 Ad hoc, Montréal, Québec C12-20040517-012 36 of 40 Header Removal Savings

37. TSG-C SWG1.2 Ad hoc, Montréal, Québec C12-20040517-012 37 of 40 Header Removal Synchronous delivery of video at constant frame rate and no frame dropping –Play out information can be recreated –RTP/UDP/IP headers can be removed over the air interface, similar to SO60 For PDCH, scheduler constraints can be relaxed to deliver n frames in n/f s (e.g. 300 ms for n = 3 for 10 fps) This is similar to multiple video frames in one RTP packet in VBR case Requires RTP termination at the PDSN

38. TSG-C SWG1.2 Ad hoc, Montréal, Québec C12-20040517-012 38 of 40 Header Compression Let S = [ r 1 r 2 … r i ]’ be the EBR rates for video codec payload only (with no IP overhead) Let x = {0, 1, 2, 3, 4} be maximum compressed header size –The value of x depends on Compression Scheme, whether UDP checksum is enabled, etc. x=0 for header removal EBR rates with header compression = S-x EBR rates S and compression scheme need to be negotiated between mobiles, PDSN and content servers This can be done via SDP parameter exchange or new Service Option definition

39. TSG-C SWG1.2 Ad hoc, Montréal, Québec C12-20040517-012 39 of 40 Standards Changes Match slice sizes to physical layer packet sizes –Can be specified as a new SO or exchanged in SDP –Compliant with MPEG-4 and ITU codecs Changes to PDSN –RTP termination at PDSN –For header removal on FL and header generation on RL –Straight forward extension of Service Option 60 procedures for video slice sizes Changes to Base Station –Straight forward extension of Service Option 60 procedures for video slice sizes QoS on Delay Constraints –Need an upper limit for delivery of video packets –Enables synchronous delivery of video and speech –Lip-sync is easier to accomplish

40. TSG-C SWG1.2 Ad hoc, Montréal, Québec C12-20040517-012 40 of 40 Summary of EBR Benefits It is better –1 to 2 dB of gain in PSNR It is faster –Rate Control Buffer delay can be eliminated or combined with Scheduler delay –1240 ms reduced to 440 ms for DCCH+SCH with 200ms delivery window –1240 ms to 540 ms for PDCH with 300ms delivery window Enables Header Removal –IP overhead is not required; 50% to 25% savings for 32 to 64 kbps video Support for Generic Header Compression Recommendations –Adopt for MCS and MSS