<January 2002> doc.: IEEE 802.15-<02/139r0> March, 2008 Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title: [Performance Issue in terms of ACK policies with/without Aggregation ] Date Submitted: [March 16, 2008] Source: [Wooyong Lee1, Jinkyeong Kim1, Yongsun Kim1, Kyeongpyo Kim1, Hyoungjin Kwon1, Seung-Eun Hong1, Kyungsup Kwak2, Seokho Kim2, Xizhi An2, Saurabh N. Mehta2, Sangkyoon Nam2, Bumjung Kim2 ] Company: [Electronics and Telecommunications Research Institute (ETRI)1,Inha University2] Address: [ETRI, 161 Gajeong-dong, Yuseong-gu, Daejeon, 305-700, Republic of Korea]1,[ 6-141B, Inha University, 253 Yonghyun-dong, Nam-gu, Incheon, 402-751, Republic of Korea]2 Voice: [], FAX: [], E-Mail: [kskwak@inha.ac.kr (other contributors are listed in “Contributors” slides)] Re: [] Abstract: [We analyze the performance of “3c” MAC when the frame error is introduced. The effects of ACK policies w/wo aggregation are considered. ] Purpose: [To be considered in IEEE 802.15.3c standard] Notice: This document has been prepared to assist the IEEE P802.15. It is offered as a basis for discussion and is not binding on the contributing individual(s) or organization(s). The material in this document is subject to change in form and content after further study. The contributor(s) reserve(s) the right to add, amend or withdraw material contained herein. Release: The contributor acknowledges and accepts that this contribution becomes the property of IEEE and may be made publicly available by P802.15. ETRI Chuck Brabenac, Intel Labs

Contributors Name E-mail Affiliation Wooyong Lee wylee@etri.re.kr ETRI March, 2008 Contributors Name E-mail Affiliation Wooyong Lee wylee@etri.re.kr ETRI Jinkyeong Kim jkkim@etri.re.kr Yongsun Kim doori@etri.re.kr Kyeongpyo Kim kpkim@etri.re.kr Hyoungjin Kwon kwonjin@etri.re.kr Seung-Eun Hong iptvguru@etri.re.kr Kyungsup Kwak kskwak@inha.ac.kr Inha University Seokho Kim sylvstar@inhaian.net Xizhi An anxizhi@inhaian.net Saurabh N. Mehta smehta@inhaian.net Sangkyoon Nam sknam@inhaian.net Bumjung Kim ufopoint@inhaian.net ETRI

Case Study 1080p video stream 16 ms superframe size March, 2008 Case Study 1080p video stream 16 ms superframe size Superframe Sizing Procedure for Uncompressed Video Traffic [doc.: IEEE 802.15-07-0897-02-003c] ETRI

Uncompressed Video Streaming March, 2008 Simulation Model (UM1) PNC Control/commands Beacon Uncompressed Video Streaming DEV-0 DEV 1 2000Mbps Common mode (48.5 Mbps) Uncompressed Traffic Model :1080p 30f 20b - 2200(1920+280)*1125(1080+45)*30*20 = 1.485 Gbps - CBR traffic -> 44000bit (2200*20) / 29.63us ETRI

802.15.3c Performance Metrics Throughput End-to-End Delay March, 2008 802.15.3c Performance Metrics Throughput measured in terms of bits per second, is the amount of data delivered successfully by the peer MAC-SAP. End-to-End Delay measured in terms of second, is the amount of time taken for a MAC SDU to be transferred from the MAC-SAP of the transmitter to the peer MAC-SAP of the receiver. Memory usage (MAC) Memory usage represent the minimum buffer size required for continuous video representation ETRI

Considering Superframe Structure March, 2008 Considering Superframe Structure ETRI

Preamble and PLCP Header March, 2008 Parameters Assumed Use common mode beacon to 47.8 Mbps Assume error free PHY channel Set video traffic to CBR traffic mode One MAC SDU is composed of data bits transmitted in one horizontal line. Assume no buffer delay due to higher data rate Assume no propagation delay due to short distance ( < 10 meter) Consider transmission delay in terms of Overhead & Payload Size Simulate in the NS-2 Parameters Value Superframe Size 1 msec ~ 64 msec Beacon Interval 15..344 usec CAP Duration 0 / 200 usec Guard Time 0.02 usec SIFS 2.5 usec Preamble and PLCP Header 8.157 usec PHY-SAP Rate 1632, 2000 Mbps Payload Size 2 KB ~ 64 KB Sub-header Size 4 Bytes ACK Policy N/A Aggregation Method Applied MAC-SDU Size 5.5 KB ETRI

MAC Throughput without Aggregation March, 2008 MAC Throughput without Aggregation Superframe size = 16 ms, Preferred payload size = 5.5k ETRI

MAC Throughput with Aggregation March, 2008 MAC Throughput with Aggregation ETRI

March, 2008 ETRI

March, 2008 Conclusions We present the performance comparison in terms of ACK polices with or without aggregation. Numerical and simulation results show that the aggregation scheme can improve the throughput results to a large extend. Different ACK policies result in different throughputs. No ACK has the highest efficiency, but it can not provide reliable data transfer. Imm-ACK has the lowest performance. Dly-ACK can improve throughput. Number of pending frames should not be small On the other hand, delay jitter may be larger. ETRI

Suggestions for setting ACK policies March, 2008 Suggestions for setting ACK policies RT traffic (video streaming) Constant bandwidth and stringent timing requirement No ACK policy is preferred Imm-ACK and Dly-ACK have poor throughput performance. Retransmission is useless and broken frames are directly discard. If a frame error occurs, retransmission doubles the delay. If n-Dly-ACK is applied, the delay due to retransmission is correspondingly increased n times. High power consumption to insure that frame can be successfully transmitted and received. NRT traffic (data transfer) ACK and retransmission is needed to correct frame errors n-Dly-ACK is preferred. Very high reliability (packet delivery ratio is almost 100%), if delay jitter requirement is not strict. Extend the coverage range or reduce the need for transmit power. Bi-directional communication Imp-ACK is preferred. ETRI

March, 2008 Appendix ETRI

Parameters on Video Resolution March, 2008 Parameters on Video Resolution Formant V Freq HRES VRES DE_CNT DE_LIN Rate 24bit Rate 20bit Hsync (sec) Vsync (sec) 1080i 30 2200 562/ 563 1920 1080 5760 4800 3.77104E-06 0.000652/ 0.000681 1080p 1125 0.001333 60 1.88552E-06 0.000667 ETRI