1. HRPD Reverse Link Improvement -- Adaptive DRC/DSC/SSI/SRI Transmission ZTE grants a free, irrevocable license to 3GPP2 and its Organizational Partners to incorporate text or other copyrightable material contained in the contribution and any modifications thereof in the creation of 3GPP2 publications; to copyright and sell in Organizational Partner's name any Organizational Partner's standards publication even though it may include all or portions of this contribution; and at the Organizational Partner's sole discretion to permit others to reproduce in whole or in part such contribution or the resulting Organizational Partner's standards publication. ZTE is also willing to grant licenses under such contributor copyrights to third parties on reasonable, non-discriminatory terms and conditions for purpose of practicing an Organizational Partner’s standard which incorporates this contribution. This document has been prepared by ZTE to assist the development of specifications by 3GPP2. It is proposed to the Committee as a basis for discussion and is not to be construed as a binding proposal on contributors. ZTE specifically reserves the right to amend or modify the material contained herein and to any intellectual property of contributors other than provided in the copyright statement above. Yonggang Fang, Ting Lu, YuanFang Yu, Xiaowu Zhao yfang@zteusa.comyfang@zteusa.com, lu.ting, yu.yuanfang, zhao.xiaowu@zte.com.cn

2. © 2006, ZTE Corporation. All rights reserved. 2 HRPD RL Overhead In C30-20090817-023, ZTE expressed the concerns about the reverse link overhead channels. Those reverse link overhead channels include DSC/DRC and/or ACK, which are used to control the forward link transmission. Even DRC/DSC is same as previous transmitted values and/or there is no forward link transmitting over the air, AT is still required to constantly transmit those reverse link overhead channels. This will cause to waste the reverse link capacity and reduce the battery life of the access terminal. In HRPD Rev C, it introduced forward link MIMO, which requires to adds two new reverse link overhead channels for the feedback. Spatial Signature Indication (SSI): Indicates pre-coding matrix Index Spatial Rank Indication (SRI): Indicates channel dimensionality In addition, Rev C also introduced a single carrier multi-link feature. To support this feature, it requires to use additional reverse link connection (a separate RL long code mask) to transmit another set of DRC/DSC for control the second link. Those new control channels will require additional transmission over the reverse link(s), which takes more capacity of reverse link and make the reverse link efficiency worse. Background

3. © 2006, ZTE Corporation. All rights reserved. 3 Adaptive DRC/DSC/SSI/SRI Transmission In C30-20090817-023, ZTE proposed an adaptive transmission of RL control channel which is controlled by AT AT could determine the transmission of DRC/DSC based on its previous transmission of DRC/DSC. The value of DRC/DSC is same as the previous one, AT may not need to transmit. An approach could be used for AN to control the adaptive RL control channel transmission when not necessary. When AN does not have a buffered data for AT, AN will send indication to AT for not sending FL control information (DRC/DSC/SSI/SRI) over the RL air link. Adaptive DRC/DSC/SSI/SRI Proposal

4. © 2006, ZTE Corporation. All rights reserved. 4 Adaptive DRC/DSC/SSI/SRI Transmission AT AT Controlled Adaptive Transmission DRC/SSI/SRI ACKDSCACK AN Controlled Adaptive Transmission Data DRCLock=1 AN DRCLock=0 … ACKDSC DRC/SSI/SRI DSC DRCLock=1 ACK Data

5. © 2006, ZTE Corporation. All rights reserved. 5 Access Network After a connection is established, AN should monitor DRC/DSC/SSI/SRI channels. Access network should transmit the packet to the access terminal over the forward traffic channel(s) specified by DSC/DRC/SSI/SRI. AN may send DRCLock = 0 to inform AT to stop transmission of DSC/DRC/SSI/SRI, start a timer and stop monitoring DRC/DSC/SSI/SRI channels when it has no forward link buffered data for the AT. AN may send DRCLock = 1, stop the timer and start monitoring DRC/DSC/SSI/SRI channels if AN has buffered data for the AT, or the timer expires. Adaptive DRC/DSC/SSI/SRI Transmission

6. © 2006, ZTE Corporation. All rights reserved. 6 Access Terminal After a connection is established, AT should transmit DRC/DSC/SSI/SRI to AN to provide the forward link control information. AT shall monitor DRCLock channel and process the received DRCLock bits. If AT receives a DRCLock bit that is set to ‘0’ from a cell associated with a sector in its active set and the access terminal is pointing its DRC to a sector associated with that cell, the access terminal should stop pointing its DRC at that sector If AT receives a DRCLock bit that is set to ‘0’ from a cell associated with a sector in its active set and the AT is pointing its DRC to a sector associated with that cell, then the AT should not point the DSC to the Data Source associated with that sector. If AT receives DRCLock = 0 from all the sector(s) in the active set, it shall stop transmitting DRC/DSC/SSI/SRI over the reverse link If AT receives DRCLock = 1 from any sector in the active set, the AT shall transmit DRC/DSC/SSI/SRI. Adaptive DRC/DSC/SSI/SRI Transmission

7. © 2006, ZTE Corporation. All rights reserved. 7 Adaptive DRC/DSC/SSI/SRI Transmission for SC-SL ATAN ConnectionRequest TrafficChannelAssignment DRC/DSC/SSI/SRI FL packets DRCLock = 0 If AN has no data to send Disable transmission of DRC/DSC/SSI/SRI DRCLock = 1 if AN has buffered data Transmit DRC/DSC/SSI/SRI AN transmits FL packets according to DRC/DSC/SSI/SRI Start a timer DRCLock = 0 If AN has no data to send Disable transmission of DRC/DSC/SSI/SRI DRCLock = 1 when the timer expires Start a timer

8. © 2006, ZTE Corporation. All rights reserved. 8 Adaptive DRC/DSC/SSI/SRI Transmission for SC-ML ATAN1 Connection is established and first DRC is pointing to Connection is established and second DRC is pointing to First DRC/DSC/SSI/SRI DRCLock = 0 If AN1 has no data to send Disable transmission of DRC/DSC/SSI/SRI DRCLock = 1 if AN2 has buffered data Send the second DRC/DSC/SSI/SRI AN2 sends FL packets according to DRC/DSC/SSI/SRI AN2 Second DRC/DSC/SSI/SRI AN2 sends FL packets according to DRC/DSC/SSI/SRI DRCLock = 0 If AN2 has no data to send AN1 sends FL packets according to DRC/DSC/SSI/SRI Start a timer