Contention-based Random Access BR Procedure Document Number: IEEE C802.16m-09/1070 Date Submitted: 2009-04-30 Source: Heejeong Cho, E-mail: hj77cho@lge.com Jinyoung Chun, Youngsoo Yuk, Kiseon Ryu, Ronny Kim, Binchul Ihm LG Electronics Re: IEEE 802.16m-09/0020 -Call for Contributions on Project 802.16m Amendment Working Document (AWD) Content, on the topic of 802.16m AWD – Bandwidth Request Procedure Purpose: For discussion and adoption in section 15.2.y.1.5.1 Quick access message format of the IEEE C802.16m-09/0846 – Connection Management and QoS DG AWD text proposal 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 >.

Why we need partition of BR sequence? The detection performance of Quick Access Massage 2 Rx Antenna, Perfect channel estimation 2 codes detected, 1 quick access message included. 2.5 dB of detection performance degradation

Why we need partition of BR sequence? We propose that 24 BR sequences should be divided into 2 types. Sequence for 3 Step Sequence for 5 Step The number of sequences of each class is transmitted in S-SFH. ABS can select the number of sequences based on the cell radius and AMS’s distribution. When AMS requests UL bandwidth for a service flow, AMS can use the Sequence for 3 Step if it negotiated in DSx transaction for the service flow, and Sequence for 5 Step can be used according to AMS’s intention. Cell-edge users may use Sequence for 5 Step based on its required power level.

BR Information BR sequence Quick access message Priority, BR size An example of partition of BR sequence Quick access message Station ID 12 bits Class Sequence index BR size (bytes) Sequence_for_3_Step(e.g., 12) 0 ~ 2 20 3 ~ 5 30 6 ~ 8 50 9 ~ 11 80

3-step BR procedure Case 1 (All of the BR sequence and message are received successfully) AMS’s operation Step 1-1 : AMS sends a quick access message with a sequence selected from Sequence_for_3_Step. Step 2-1 : AMS starts differentiated timer of the value corresponding to the class. Step 2-4 : AMS waits for grant until the timer is expired. If grant is received within the timer, AMS stops the timer. Otherwise, AMS retries BR procedure (including back-off algorithm) ABS’s operation Step 1-2 : ABS detects a sequence. If the sequence is Sequence_for_3_Step, it tries to decode a quick access message. Step 2-1 : ABS starts the differentiated timer of the same value as AMS. Step 2-2 : ABS grants UL resource for data through UL Assignment A-MAP IE before the timer is expired. Step 2-3 : ABS stops the timer. AMS ABS BR indicator + Quick access message ACK (success) BR sequence & message success Grant for data though UL Assignment A-MAP IE Timer stop Timer stop Data

3-step BR procedure Case 2 (only the BR sequence is received successfully) AMS’s operation Step 1-1 : AMS sends a quick access message with a sequence selected from Sequence_for_3_Step. Step 2-1 : AMS starts differentiated timer of the value corresponding to the class. Step 2-4 : AMS waits for grant until the timer is expired. If grant is received within the timer, AMS stops the timer. Otherwise, AMS retries BR procedure (including back-off algorithm) ABS’s operation Step 1-2 : ABS detects a sequence. If the sequence is Sequence_for_3_Step, it tries to decode a quick access message, but fails. Step 2-1 : ABS starts the differentiated timer of the same value as AMS. Step 2-2 : ABS grants UL resource for data through CDMA Allocation A-MAP IE before the timer is expired. Step 2-3 : ABS stops the timer. ABS AMS BR indicator + Quick access message ACK (success) BR sequence success, Message failure Grant for data though CDMA Allocation A-MAP IE Timer stop Timer stop Data with STID

BR sequence & message failure 3-step BR procedure Case 3 (All of the BR sequence and message are not received successfully) AMS’s operation Step 1-1 : AMS sends a quick access message with a sequence selected from Sequence_for_3_Step. Step 2-1 : If AMS receives acknowledgement indicating fail BR, it retries BR procedure (including back-off algorithm). If AMS doesn’t receives any acknowledgement, it starts the BR timer and waits for grant until the timer is expired. After expired, AMS retries BR procedure. AMS ABS BR indicator + Quick access message BR sequence & message failure ACK (failure) BR indicator + Quick access message

Grant for BW-REQ message though CDMA Allocation A-MAP IE 5-step BR procedure Case 1 (only the BR sequence is received successfully) AMS’s operation Step 1-1 : AMS sends a sequence selected from Sequence_for_5_Step. Step 2-1 : AMS starts differentiated timer of the value corresponding to Sequence_for_5_Step. Step 2-4 : AMS waits for grant until the timer is expired. If grant is received within the timer, AMS stops the timer. Otherwise, AMS retries BR procedure (including back-off algorithm) ABS’s operation Step 1-2 : ABS detects a Sequence_for_5_Step. Step 2-1 : ABS starts the differentiated timer of the same value as AMS. Step 2-2 : ABS grants UL resource for BW-REQ message through CDMA Allocation A-MAP IE before the timer is expired. Step 2-3 : ABS stops the timer. ABS AMS BR indicator ACK (success) BR sequence success Grant for BW-REQ message though CDMA Allocation A-MAP IE Timer stop Timer stop BW-REQ message

5-step procedure Case 2 (the BR sequence is not received successfully) AMS’s operation Step 1-1 : AMS sends a sequence selected from Sequence_for_5_Step. Step 2-1 : If AMS receives acknowledgement indicating fail BR, it stops the timer and retries BR procedure (including back-off algorithm). If AMS doesn’t receives any acknowledgement, it starts the BR timer and waits for grant until the timer is expired. After expired, AMS retries BR procedure AMS ABS BR indicator BR sequence failure ACK (failure) BR indicator

Proposed text 15.2.y.1.5.1 quick access message format 24 BWREQ sequences are divided into 2 classes which are sequences for 3 step procedure and sequences for 5 step procedure. The number of BWREQ sequences of each class is transmitted in S-SFH. When AMS requests UL bandwidth for a service flow, sequences for 3 step procedure shall be used only for a service flow which is negotiated in DSx transaction for the service flow. Sequences for 5 step procedure may be used for bandwidth request for all service flow. The ABS shall try to decode a quick access message only if the detected sequence is sequences for 3 step procedure . 12-bit STID is carried in the quick access message and bandwidth request size is carried in BWREQ sequence.