ARQ for IEEE 802.16m Document Number: IEEE C802.16m-09/0512 Date Submitted: 2009-03-02 Source: Muthaiah Venkatachalam (muthaiah.venkatachalam@intel.com) Intel Corporation Xiangying Yang Intel Corporation Aran Bergman Intel Corporation Venue: Re: TGm Call for Contributions and Comments on AWD: C802.16m-09/0012 for Session 60 in Vancouver, BC for UMAC/ARQ Base Contribution: None Purpose: Discussion and approval of the proposal into the IEEE 802.16m AWD Notice: This document does not represent the agreed views of the IEEE 802.16 Working Group or any of its subgroups. It represents only the views of the participants listed in the “Source(s)” field above. It is offered as a basis for discussion. It is not binding on the contributor(s), who reserve(s) the right to add, amend or withdraw material contained herein. Release: The contributor grants a free, irrevocable license to the IEEE to incorporate material contained in this contribution, and any modifications thereof, in the creation of an IEEE Standards publication; to copyright in the IEEE’s name any IEEE Standards publication even though it may include portions of this contribution; and at the IEEE’s sole discretion to permit others to reproduce in whole or in part the resulting IEEE Standards publication. The contributor also acknowledges and accepts that this contribution may be made public by IEEE 802.16. Patent Policy: The contributor is familiar with the IEEE-SA Patent Policy and Procedures: <http://standards.ieee.org/guides/bylaws/sect6-7.html#6> and <http://standards.ieee.org/guides/opman/sect6.html#6.3>. Further information is located at <http://standards.ieee.org/board/pat/pat-material.html> and <http://standards.ieee.org/board/pat >.

Worst case of ARQ tpt Assume 16e ARQ 18x6 PRU => 96 data tones QPSK1/2 is the worst case data MCS => 12Bytes/PRU Minimum ARQ block size in 16m = 12B Worst case tpt = 12B*1024/RTT If RTT = 20msec, which is worst case tpt = 5 Mbps

IMT.TECH Avg cell spectral efficiency Test environment ** Downlink (b/s/Hz/cell) Uplink (b/s/Hz/cell) Indoor 3 2.25 Microcellular 2.6 1.80 Base coverage urban 2.2 1.4 High speed 1.1 0.7

ARQ Avg case throughputs for 16m 20 Mhz channel DL tpt = 3*20 = 60Mbps UL tpt = 2.25*20 = 45Mbps If the DL tpt can be met, then the UL tpt can also be met. Worst case assumption: total system tpt is gobbled up by 1 user!

ARQ proposal for 16m With 11bit BSN, worst case ARQ tpt is 5Mbps This meets the IMT.TECH avg tpt requirements for DL (and UL) Intel’s proposal for 802.16m ARQ: Keep 802.16e ARQ intact Use max of 15 bit BSN.

IMT.TECH Peak throughput Error free conditions. 40Mhz channel DL: 15 bits/s/Hz @PHY layer UL: 6.75 bits/s/Hz @PHY layer 25% MAC overhead DL tpt at ARQ layer = 450Mbps UL tpt at ARQ layer = 202 Mbps If the DL tpt can be met, then the UL tpt can also be met. Worst case assumption: total system tpt is gobbled up by 1 user!

IMT peak tpt with Intel’s ARQ proposal IMT peak tpt assumes error free conditions. Max block size that can be used in error free conditions = 1024B. With 1024B block, 15bit BSN and 20msec RTT, ARQ tpt = 6.8Gbps!!! Conclusion: Let us not change 16e ARQ unless we really need to!