Access Procedure Enhancement for HRPD Rev C VIA Telecom 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. VIA Telecom are 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 VIA Telecom 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 VIA Telecom. VIA Telecom specifically reserves the right to amend or modify the material contained herein and to any intellectual property of VIA Telecom other than provided in the copyright statement above. Tony Lee Jian Gu David Wang Shu Wang Sep 15, 2009

Page 2 Background This contribution provide more details on the Access Procedure enhancement as presented in C R1 The M2M machine’s position is usually static and traffic is usually delay insensitive. And the modem can always work in non-slotted mode.

Page 3 Existing Access Procedure

Proposed changes to Access Procedure Two options: 1.Increase probe delay 2.Keep current transmit power for additional probes Page 4

Increase the probe delay Page 5

Page 6 Proposed Access Procedure Increase the random delay between probes  The delay is configurable through attributes  The procedure can be something similar to PN randomization delay The Tx power of each probe steps up until response from AN is received or the maximum of probes is reached

Page 7 Rational for longer delay In non-slotted mode, AT can measure pilot strength in very long time ( in hundreds of millisecond or longer) and do averaging for it. So the pilot strength and received power is very accurate. Then AT can easily determine a good tx power based on open loop Also, with larger random delay between probes, the fast fading can be irrelevant. That means when the first probe experiences severe fading, the condition for the next one might be better

Inter-Probe Delay in Existing Access Scheme The delay between probes is determined by τ P = T ACMPATProbeTimeout + (y Total × AccessCycleDuration) – ProbeTimeOutAdjust  y Total is a uniformly distributed integer random number between 0 and ProbeBackoff (the Max value of ProbeBackoff is 16)  T ACMPATProbeTimeout is a constant of 128 slots which is the time for receiving ACK. The max value of ProbeTimeOutAdjust is 112 slots  The PNRandomizationDelay is not included as it is chip level

Inter-Probe Delay in Existing Access Scheme The lower limit of the delay between probes is T ACMPATProbeTimeout – ProbeTimeOutAdjust = = 16 slots= ms

Coherence Time for Static Users Based on the channel model E specified by C.R1002, which is used for static users, the Doppler Frequency Shift f D is 1.5 Hz  The coherence time can be estimated as T c ≈1/f D =0.667 s In existing scheme, the lower limit of the delay between probes of ms is smaller than the coherence time for static users. So additional time delay is required

M2MOffset A configurable attribute M2MOffset is added which introduces additional delay for M2M ATs  The delay between probes is given by τ P = T ACMPATProbeTimeout + (y Total × AccessCycleDuration) – ProbeTimeOutAdjust + M2MOffset  M2MOffset has 8 bits in unit of 16 slots which means the range of M2MOffset is from 0 to seconds  For non-M2M ATs, it shall be omitted  For M2M ATs, M2MOffset shall be negotiated and the delay between probes should be larger than T c (0.667 s)

Maintaining Tx power for more than one probe Page 12

Page 13 Maintaining the Tx Power The access probe shall be transmitted for N times with the same Tx power if the first transmission fails  N is configurable  The probe shall be re-transmitted until ACK is received or the maximum number of probes is reached If failure still occurs, then the Tx power for following probe shall be stepped up The picture shows an example with N=2

Page 14 Maintaining the Tx power Setting of N  Can be added as a negotiable attribute  N has 3 bits  The value should be set in the range [1…7] and smaller than the value of ProbeNumStep as specified in AccessParameters message

Page 15 Maintaining the Tx power To introduce smaller power step up for adjacent access probes A negotiable attribute is added as M2MProbePowerSetp to allow less amount Tx power level up for probes  M2MProbePowerSetp has 5 bits and is in unit of 0.25 dB  M2M ATs should process according to M2MProbePowerStep instead of PowerStep in AccessParameters message

Page 16 THANK YOU!