1 / 16 Differentiated Random Access Schemes Document Number: IEEE C802.16m-09/0620 Date Submitted: Source: Heejeong Cho Kiseon Ryu Doohyun Sung Ronny(Yong-Ho) Kim Jin Sam Kwak LG Electronics Re: IEEE m-09/0012 -Call for Contributions on Project m Amendment Working Document (AWD) Content, on the topic of m AWD – Bandwidth Request Procedure (based on the section QoS and 11.9 UL Control Structure in SDD) Purpose: To provide the details of the C802.16m-09/ Proposed Text Related to Bandwidth Request Procedure for the IEEE m Amendment Notice: This document does not represent the agreed views of the IEEE 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 IEEEs name any IEEE Standards publication even though it may include portions of this contribution; and at the IEEEs 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 Patent Policy: The contributor is familiar with the IEEE-SA Patent Policy and Procedures: and. Further information is located at and.

2 / 16 Outline Differentiated Random Access Schemes for Bandwidth Request –Differentiated Timer based Random Access Scheme was proposed in Session #59 (IEEE C80216m- 09/0293, IEEE C80216m-09/0180r4) and adopted in the SDD text (IEEE C80216m-09/003r7). –Acknowledgement based Random Access Scheme was adopted in the SDD text (IEEE C80216m- 09/003r7). In this contribution, we provide more details for two schemes.

3 / 16 Differentiated Random Access Scheme AMSs operation phases –Phase 1 - To transmit a bandwidth request indicator Transmit an access sequence (and quick access message only for 3-step procedure) and go to phase 2 –Phase 2 - To wait for UL grant Transmit a BW-REQ message and go to phase 2 Transmit data and finish Go to phase 1 ABSs operation phases –Phase 1 - To wait for a bandwidth request indicator Transmit UL grant –5-step procedure : go to phase 3 –3-step procedure : finish Go to phase 2 –Phase 2 - To wait for available resource Transmit UL grant –5-step procedure : go to phase 3 –3-step procedure : finish Transmit acknowledgement and go to phase 2 (if ABS supports acknowledgement) –Phase 3 - To wait for BW-REQ message Transmit UL grant and finish Go to phase 2 Finish

4 / 16 AMSs phase 1 - transmit bandwidth request indicator (1/2) Step 1 –Transmit an access sequence. –Transmit a quick access message along with the access sequence for the optional 3-step quick access procedure. Step 2 –Start differentiated timer according to service type/priority. Step 3 –Go to phase 2 - wait for UL grant Wait for BR opportunity BR opportunity Information Start differentiated timer Wait for UL grant Send access sequence (and quick access message)

5 / 16 AMSs phase 1 - transmit bandwidth request indicator (2/2) t 50 ms No grant Transmission of BR indicatorRetransmission of BR indicator Grant t 100 ms No grant Grant Time durationTime An example of timeout values at step 2 ValueService typePriorityTimeout value 00Delay-sensitiveHigh50ms 01Delay-sensitiveLow100ms 10Delay-tolerantHigh 150ms 11Delay-tolerantLow200ms

6 / 16 AMSs phase 2 - wait for UL grant (1/3) Event 1 - receive UL grant before timeout –Step 1 Stop differentiated timer –Step 2 Perform step 2-1 or 2-2 –Step 2-1 : Transmit BW-REQ message and go to phase 2 –Step 2-2 : Transmit data and finish this procedure Event 2 – timeout of differentiated timer –Step 1 Increment retry counter –Step 2 Go to phase 1 unless the maximum number of retries has been reached.

7 / 16 AMSs phase 2 - wait for UL grant (2/3) Event 3 - receive acknowledgement –Step 1 Restart differentiated timer –Step 2 Go to phase 2 Event 4 – not receive acknowledgement –Step 1 Stop differentiated timer –Step 2 Increment retry counter –Step 3 Go to phase 1 unless the maximum number of retries has been reached.

8 / 16 AMSs phase 2 - wait for UL grant (3/3) Wait for UL grant UL grant For BW- REQ Send BW-REQ Wait for UL grant Yes No Timeout differentiated timer ACK at the specific sub-frame Wait for UL grant Restart differentiated timer ACK not received at the specific sub-frame Restart differentiated timer Unsuitable size Send data No Send data with additional BR information Yes End Stop differentiated timer Increment retry counter Retry counter == MAX Wait for BR opportunity No Increment retry counter Retry counter == MAX Wait for BR opportunity No End Yes

9 / 16 ABSs phase 1 – wait for bandwidth request indicator (1/2) Step 1 –Detect an access sequence Step 2 –Perform step 2-1 or 2-2 when the ABS has available resource Step 2-1 : allocate UL resource for transmitting BW-REQ message and go to phase 3 Step 2-2 : decode a quick access message and –If decoding success, allocate UL resource for transmitting data and finish this procedure. –If decoding failure, allocate UL resource for transmitting BW-REQ message and go to phase 3. –Perform step 2-3 when the ABS doesnt have available resource Step 2-3 : go to phase 2

10 / 16 ABSs phase 1 – wait for bandwidth request indicator (2/2) Wait for BR indicator Access sequence (and quick access message) Good enough for access sequence YesNo End Good enough for quick access message YesNo Have available resource Yes Send UL grant for BW-REQ Have available resource Yes Send UL grant for data End Wait for BW-REQ Wait for available resource No 3-step procedure No Yes

11 / 16 ABSs phase 2 – wait for available resource (1/3) Event 1 – have available resource –Step 1 Perform step 1-1 or 1-2 Step 1-1 : allocate UL resource for transmitting BW-REQ message and go to phase 3 Step 1-2 : allocate UL resource for transmitting data and finish this procedure. Event 2 – have no available resource until frame offset –Step 1 Transmit acknowledgement at the specific sub-frame decided by frame offset –Step 2 Go to phase 2

12 / 16 ABSs phase 2 – wait for available resource (2/3) If the frame offset where the acknowledgement will be transmitted is not defined, –AMS should check whether it was received or not every frame until the predefined period. –ABS should send acknowledgement message including some information such as frame number in which the access sequence to which this message responds was transmitted. It is necessary to define frame offset between the bandwidth request indicator or BW-REQ message and the acknowledgement.

13 / 16 ABSs phase 2 – wait for available resource (3/3) Send ACK at the specific sub-frame Wait for available resource Available resource Send UL grant for data End For data YesNo Resource not exist until the specific sub-frame Wait for available resource Send UL grant for BW-REQ Wait for BW-REQ

14 / 16 ABSs phase 3 – waiting for BW-REQ message (1/2) Event 1 – receive BW-REQ –Step 1 Decode BW-REQ message –Step 2 Perform step 2-1 or 2-2 when the ABS has available resource –Step 2-1 : If decoding success, allocate UL resource for transmitting data and finish this procedure. –Step 2-2 : If decoding failure, finish this procedure Perform step 2-3 or 2-4 when the ABS doesnt have available resource –Step 2-3 : If decoding success, go to phase 2 –Step 2-4 : If decoding failure, finish this procedure Event 2 – not receive BW-REQ –Step 1 Finish this procedure

15 / 16 ABSs phase 3 – waiting for BW-REQ message (2/2) BW-REQ Good enough YesNo Have available resource Yes Send UL grant for data End Wait for available resource No Wait for BW-REQ BW-REQ not receive at the allocated resource End

16 / 16 Amendment Text Proposal Adopt text proposal for the m amendment in the contribution IEEE C802.16m-09/0619 or its latest version.