1. 1 A Simple Comparison of Latency Between 802.16m Relay Frame Structures IEEE 802.16 Presentation Submission Template (Rev. 9) Document Number: IEEE C802.16m-08/926 Date Submitted: 2008-09-05 Source: Aeran Youn, Jin Sam Kwak, Ji Wook Chung Voice: +82-31-450-7188 e-mail : {aryoun; samji; jwChung}@lge.com{aryoun; samji; jwChung}@lge.com LG Electronics LG R&D Complex, 533 Hogye-1dong, Dongan-gu, Anyang, 431-749, Korea Ki-Dong, Li-Hsiang e-mail : {kidonglee; lsun}@lge.com{kidonglee; lsun}@lge.com LG Electronics Mobile Research, San Diego Venue: SDD Session 56 Cleanup; in response to the TGm Call for Contributions and Comments 802.16m-08/033 for Session 57 Purpose: This contribution proposes clarification of latency based on Relay Frame Structure in IEEE 802.16m-08/003r4. 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: and.http://standards.ieee.org/guides/bylaws/sect6-7.html#6http://standards.ieee.org/guides/opman/sect6.html#6.3 Further information is located at and.http://standards.ieee.org/board/pat/pat-material.htmlhttp://standards.ieee.org/board/pat

2. 2 A Simple Comparison of Latency Between 802.16m Relay Frame Structures

3. 3 Contents  Introduction  Latency Comparison of Each Relay Frame structure  Option 1  Access-Relay/Transmit-Receive Zone  Relay-Access/Receive-Transmit Zone  Option 2  MSs use only Access Zone for reception/transmission  MSs can use Bi-Directional transmit/Receive Zone for reception/transmission  Summary  References

4. 4  Latency Comparison with each relay frame structure  Option 1: The order of DL subframe of the BS/RS  Access Zone/Relay Zone (Transmit Zone/Receive Zone)  Relay Zone/Access Zone (Receive Zone/Transmit Zone)  Option 2: Whether the MS can use Bi-directional Zone or not  MSs use only Access Zone for reception/transmission  MSs can use Bi-Directional transmit/Receive Zone for reception/transmission  Assumption  TDD system in the legacy support mode  The duration of the DL/UL legacy zone of the BS: 3-subframe/1-subframe  The base station, relay station, or mobile station processing time is approximately 2*TTI = 1.23 ms  DL/UL traffic ratio = 5:3  Scenario  2-hop: 16m BS ↔ 16m RS3 ↔ 16m MS3  3-hop: 16m BS ↔ 16m RS3 ↔ 16m RS2 ↔ 16m MS2  4-hop: 16m BS ↔ 16m RS3 ↔ 16m RS2 ↔ 16m RS1 ↔ 16m MS1 Introduction 16m MS316m MS2 16m BS 16m RS316m RS2 16m RS116m MS

5. 5  Access-Relay/Transmit-Receive Zone  2-hop: 2-frame(8-subframe) BS(N th [RL]: transmit)  RS3(N th [R]: receive, N+1 th [T]: transmit)  MS(N+1 th : receive)  3-hop: 3-frame(17-subframe) BS(N th [RL]: transmit)  RS3(N th [R]: receive, N+1 th [T]: transmit)  RS2(N+1 th [R]: receive, N+2 th [T]: transmit)  MS(N+2 th : receive)  4-hop: 4-frame(24-subframe) BS(N th [RL]: transmit)  RS3(N th [R]: receive, N+1 th [T]: transmit)  RS2(N+1 th [R]: receive, N+2 th [T]: transmit)  RS1(N+2 th [R]: receive, N+3 th [T]: transmit)  MS(N+3 th : receive) * [A]: Access Zone, [RL]: Relay Zone, [R]: Receive Zone, [T]: Transmit Zone Option 1 case (Downlink) BS RS3 RS2 RS1 e.g., BS  MS (using RS3, RS2, RS1)Latency: 4-frame (24-subframe) N frameN+1 frame N+2 frameN+3 frame ARLA TR RT RTTR TRRT ULDL LLL L L L LL LL LL L L L L ARLA TR RT RTTR TRRT ULDL LLL L L L LL LL LL L L L L ARLA TR RT RTTR TRRT ULDL LLL L L L LL LL LL L L L L ARLA TR RT RTTR TRRT ULDL LLL L L L LL LL LL L L L L Legacy BS RS3 RS2 RS1 16m MS316m MS2 16m BS 16m RS316m RS2 16m RS116m MS

6. 6  Relay-Access/Receive-Transmit Zone  2-hop: 2-frame(10-subframe)  BS(N th [RL]: transmit)  RS3(N th [R]: receive, N+1 th [T]: transmit)  MS(N+1 th : receive)  3-hop: 3-frame(17-subframe)  BS(N th [RL]: transmit)  RS3(N th [R]: receive, N+1 th [T]: transmit)  RS2(N+1 th [R]: receive, N+2 th [T]: transmit)  MS(N+2 th : receive)  4-hop: 4-frame(26-subframe)  BS(N th [RL]: transmit)  RS3(N th [R]: receive, N+1 th [T]: transmit)  RS2(N+1 th [R]: receive, N+2 th [T]: transmit)  RS1(N+2 th [R]: receive, N+3 th [T]: transmit)  MS(N+3 th : receive) * [A]: Access Zone, [RL]: Relay Zone, [R]: Receive Zone, [T]: Transmit Zone Option 1 case (Downlink) BS RS3 RS2 RS1 N frameN+1 frame N+2 frameN+3 frame RLAA RT RT TRTR RTRT ULDL LLL L L L LL LL LL L L L L RLAA RT RT TRTR RTRT ULDL LLL L L L LL LL LL L L L L RLAA RT RT TRTR RTRT ULDL LLL L L L LL LL LL L L L L RLAA RT RT TRTR RTRT ULDL LLL L L L LL LL LL L L L L Legacy BS RS3 RS2 RS1 16m MS316m MS2 16m BS 16m RS316m RS2 16m RS116m MS

7. 7  Access-Relay/Transmit-Receive Zone  Relay-Access/Receive-Transmit Zone  2-hop: 2-frame(10-subframe)  MS(N th [R]: transmit)  RS3(N th [R]: receive, N+1 th [T]: transmit)  BS(N+1 th [RL]: receive)  3-hop: 3-frame(17-subframe)  MS(N th [R]: transmit)  RS2(N th [R]: receive, N+1 th [T]: transmit)  RS3(N+1 th [R]: receive, N+2 th [T]: transmit)  BS(N+2 th [RL]: receive)  4-hop: 4-frame(26-subframe)  MS(N th [R]: transmit)  RS1(N th [R]: receive, N+1 th [T]: transmit)  RS2(N+1 th [R]: receive, N+2 th [T]: transmit)  RS3(N+2 th [R]: receive, N+3 th [T]: transmit)  BS(N+3 th [RL]: receive) * [A]: Access Zone, [RL]: Relay Zone, [R]: Receive Zone, [T]: Transmit Zone Option 1 case (Uplink) BS RS3 RS2 RS1 N frameN+1 frame N+2 frameN+3 frame RLAA RT RT TRTR RTRT ULDL LLL L L L LL LL LL L L L L RLAA RT RT TRTR RTRT ULDL LLL L L L LL LL LL L L L L RLAA RT RT TRTR RTRT ULDL LLL L L L LL LL LL L L L L RLAA RT RT TRTR RTRT ULDL LLL L L L LL LL LL L L L L Legacy BS RS3 RS2 RS1 16m BS16m RS316m RS216m RS116m MS 16m MS3 16m MS2

8. 8  MSs use Access Zone for reception  2-hop: 2-frame(8-subframe)  BS(N th [RL]: transmit)  RS3(N th [Bi-R]: receive, N+1 th [A]: transmit)  MS(N+1 th : receive)  3-hop: 2-frame(8-subframe)  BS(N th [RL]: transmit)  RS3(N th [Bi-R]: receive, N th [Bi-T]: transmit)  RS2(N th [Bi-R]: receive, N+1 th [A]: transmit)  MS(N+1 th : receive)  4-hop: 3-frame(16-subframe)  BS(N th [RL]: transmit)  RS3(N th [Bi-R]: receive, N th [Bi-T]: transmit)  RS2(N th [Bi-R]: receive, N+1 th [Bi-T]: transmit)  RS1(N+1 th [Bi-R]: receive, N+2 th [A]: transmit)  MS(N+2 th : receive) * [A]: Access Zone, [RL]: Relay Zone, [Bi-R]: Bi-directional Receive Zone, [Bi-T]: Bi-Directional Transmit Zone Option 2 case (Downlink) BS RS3 RS2 RS1 N frameN+1 frame N+2 frameN+3 frame ARLA ABi-R ABi-T A ABi-R A ABi-T ULDL LLL L L L LL LL LL L L L L ARLA ABi-R ABi-T A ABi-R A ABi-T ULDL LLL L L L LL LL LL L L L L ARLA ABi-R ABi-T A ABi-R A ABi-T ULDL LLL L L L LL LL LL L L L L ARLA ABi-R ABi-T A ABi-R A ABi-T ULDL LLL L L L LL LL LL L L L L Legacy BS RS3 RS2 RS1 16m BS16m RS316m RS216m RS116m MS 16m MS3 16m MS2

9. 9  MSs use Bi-directional transmit Zone for reception  2-hop: 1-frame(4-subframe)  BS(N th [RL]: transmit)  RS3(N th [Bi-R]: receive, N th [Bi-T]: transmit)  MS(N th : receive)  3-hop: 2-frame(8-subframe)  BS(N th [RL]: transmit)  RS3(N th [Bi-R]: receive, N th [Bi-T]: transmit)  RS2(N th [Bi-R]: receive, N+1 th [A]: transmit)  MS(N+1 th : receive)  4-hop: 2-frame(12-subframe)  BS(N th [RL]: transmit)  RS3(N th [Bi-R]: receive, N th [Bi-T]: transmit)  RS2(N th [Bi-R]: receive, N+1 th [Bi-T]: transmit)  RS1(N+1 th [Bi-R]: receive, N+1 th [Bi-T]: transmit)  MS(N+1 th : receive) * [A]: Access Zone, [RL]: Relay Zone, [Bi-R]: Bi-directional Receive Zone, [Bi-T]: Bi-Directional Transmit Zone Option 2 case (Downlink) 16m MS316m MS2 16m BS 16m RS316m RS2 16m RS116m MS

10. 10  MSs use Access Zone for transmission  2-hop: 2-frame(10-subframe)  MS(N th [A]: transmit)  RS3(N th [A]: receive, N+1 th [Bi-T]: transmit)  BS(N+1 th [RL]: receive)  3-hop: 2-frame(10-subframe)  MS(N th [A]: transmit)  RS2(N th [A]: receive, N+1 th [Bi-T]: transmit)  RS3(N+1 th [Bi-R]: receive, N+1 th [Bi-T]: transmit)  BS(N+1 th [RL]: receive)  4-hop: 3-frame(18-subframe)  MS(N th [A]: transmit)  RS1(N th [A]: receive, N+1 th [Bi-T]: transmit)  RS2(N+1 th [Bi-R]: receive, N+2 th [Bi-T]: transmit)  RS3(N+1 th [Bi-R]: receive, N+2 th [Bi-T]: transmit)  BS(N+2 th [RL]: receive) * [A]: Access Zone, [RL]: Relay Zone, [Bi-R]: Bi-directional Receive Zone, [Bi-T]: Bi-Directional Transmit Zone Option 2 case (Uplink) BS RS3 RS2 RS1 N frameN+1 frame N+2 frameN+3 frame ARLA ABi-R ABi-T A ABi-R A ABi-T ULDL LLL L L L LL LL LL L L L L ARLA ABi-R ABi-T A ABi-R A ABi-T ULDL LLL L L L LL LL LL L L L L ARLA ABi-R ABi-T A ABi-R A ABi-T ULDL LLL L L L LL LL LL L L L L ARLA ABi-R ABi-T A ABi-R A ABi-T ULDL LLL L L L LL LL LL L L L L Legacy BS RS3 RS2 RS1 16m MS316m MS2 16m BS 16m RS316m RS2 16m RS116m MS

11. 11  MSs use Access/Bi-directional receive Zone for transmission  2-hop: 2/1-frame(10/4-subframe)  MS(N th [A]: transmit)  RS3(N th [A]: receive, N+1 th [Bi-T]: transmit)  BS(N+1th[RL]: receive)  MS(N th [Bi-R]: transmit)  RS3(N th [Bi-R]: receive, N th [Bi-T]: transmit)  BS(Nth[RL]: receive)  UL-Map decoding problem  3-hop: 2-frame(10-subframe)  MS(Nth[A]: transmit)  RS2(Nth[A]: receive, N+1th[Bi-T]: transmit)  RS3(N+1th[Bi-R]: receive, N+1th[Bi-T]: transmit)  BS(N+1th[RL]: receive)  4-hop: 3/2-frame(18/12-subframe)  MS(Nth[A]: transmit)  RS1(Nth[A]: receive, N+1th[Bi-T]: transmit)  RS2(N+1th[Bi-R]: receive, N+2th[Bi-T]: transmit)  RS3(N+1th[Bi-R]: receive, N+2th[Bi-T]: transmit)  BS(N+2th[RL]: receive)  MS(Nth[Bi-R]: transmit)  RS1(Nth[Bi-R]: receive, Nth[Bi-T]: transmit)  RS2(Nth[Bi-R]: receive, N+1th[Bi-T]: transmit)  RS3(N+1th[Bi-R]: receive, N+1th[Bi-T]: transmit)  BS(N+1th[RL]: receive)  UL-Map decoding problem Option 2 case (Uplink) 16m MS316m MS2 16m BS 16m RS316m RS2 16m RS116m MS

12. 12  DL/UL Latency based on Multi-hop Relay Frame Structures  Latency comparison between Option 1 and Option 2  Option 2 has smaller latency than Option 1.  Further latency analysis and comparison are necessary Summary # of hops Option 1Option 2 Access/RelayRelay/AccessMS use access zoneMS use Bi-D zone DL 2 2-frame(8-subframe)2-frame(10-subframe)2-frame(8-subframe)1-frame(4-subframe) 33-frame(17-subframe) 2-frame(8-subframe) 44-frame(24-subframe)4-frame(26-subframe)3-frame(16-subframe)2-frame(12-subframe) UL 2 2-frame(10-subframe) 33-frame(17-subframe) 2-frame(10-subframe) 44-frame(26-subframe) 3-frame(18-subframe)

13. 13 References [1] IEEE C802.16m-08_848r2, “IEEE 802.16m Relay Ad HoC Group – Final Report”. [2] IEEE C802.16m-08_003r4, “The Draft IEEE 802.16m System Description Document” [3] IEEE C80216m-08_1107, “Clarifications on Open Items of Option 2 in Relay Frame Structure”