Clarification of Burst-based Forwarding in RS Group Document Number: IEEE S802.16j-08/049 Date Submitted: 2008-01-21 Source: Kanchei (Ken) Loa, Hua-Chiang Yin, Yung-Ting Lee, Voice: +886-2-6600-0100 Yi-Hsueh Tsai, Shiann-Tsong Sheu, Youn-Tai Lee E-mail: loa@iii.org.tw Institute for Information Industry (III) 7F, No. 133, Sec. 4, Minsheng E. Rd., Taipei City 105, Taiwan Re: IEEE 802.16j-07/059: “IEEE 802.16 Working Group Letter Ballot Recirc #28a: Announcement” Abstract: This contribution modifies the relaying support for combined ranging and initial topology discovery in order to consistent with the network entry procedure. Purpose: Text proposal for 802.16j Baseline Document. 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 >.

PDU Forwarding Whenever a new path is established between MR-BS and MS, CID to Path binding is required to update the routing table at the RSs along the relay path

In an RS Group The access RS of an MS may change very often Every time MS sends a CDMA code, the access station of the MS may be re-selected by the MR-BS The MR-BS has to update the routing table before PDU could be forwarded

Flow Chart of PDU Forwarding In an RS Group (1/2) The MR-BS re-selects RS2 as the access station of MS after BR MR-BS RS1 (access RS) RS2 MS RS1 is the access station BR Code MR_Code-REP MR_Code-REP MR-BS selects RS2 to forward the BR header UL_Burst_Receive IE CDMA Alloc IE BR Header MR-BS re-selects RS2 as the access station of MS BR Header

Flow Chart of PDU Forwarding In an RS Group (2/2) MR-BS RS1 RS2 (Access RS) MS DSD-REQ CID to path binding removal DSD-RSP CID to path binding (MS  RS2) DSA-REQ DSA-RSP BW allocation PDU PDU

Flow Chart of Burst-based Forwarding in an RS Group (1/2) The MR-BS re-selects RS2 as the access station of MS after BR MR-BS RS1 (access RS) RS2 MS RS1 is the access station BR Code MR_Code-REP MR_Code-REP MR-BS selects RS2 to forward the BR header UL_Burst_Receive IE CDMA Alloc IE BR Header MR-BS re-selects RS2 as the access station of MS BR Header

Flow Chart of Burst-based Forwarding In an RS Group (2/2) No CID to path binding updates are required whenever the access station is changed since the forwarding rules are encoded in Burst IE sent from MR-BS to RS MR-BS RS1 RS2 (Access RS) MS DSD-REQ CID to path binding removal DSD-RSP CID to path binding (MS  RS2) DSA-REQ DSA-RSP Burst IE (RS2 forwarding MS PDU) BW allocation PDU PDU

Enhance PDU Forwarding with Burst-based Forwarding In an RS Group In an RS group with non-transparent RSs, the burst-based forwarding + the MPDU-based forwarding + RS member list update messages provide the most efficient and complete solution When the RS group routing table is converged, MPDU-based forwarding is used to minimize the overhead Using the unicast/multicast RS member list update and the acknowledgement, the convergence of the routing table update could be time-consuming Burst-based forwarding are used to minimize the outage

Enhance PDU Forwarding with Burst-based Forwarding In an RS Group – MS Movement (1/2) The MS moves from RS1 to RS2, where RS1 and RS2 broadcast same preamble/FCH/MAP MR-BS RS1 (access RS) RS2 MS RS1 is the access station ……….. MSID  MS MAP IE (RS1) PDU (MSID) MAP IE (MS) PDU (MSID) MS move into the proximity of RS2. But MS is unaware RS_MOB_MEAS-REP Mode 1 or 2 Event trigger or periodic RS_MOB_MEAS-REP Mode 1 or 2 Event trigger or periodic MR-BS recognize MS attachment to RS2

Burst-based forwarding via RS2 Enhance PDU Forwarding with Burst-based Forwarding In an RS Group – MS Movement (2/2) MR_Member_List_Update message is used to update the forwarding rules of specific MSs in an unicast fashion as defined in D2. However, the period to complete the member list update could be long due to ACK failure Then burst-based forwarding can be used for data forwarding before the member list update is complete MR-BS RS1 RS2 (Access RS) MS RNG-RSP (Adjustments to sync with RS2) Burst-based forwarding via RS2 MR_Member_List_Update CID to path binding update ……….. MSID  MS ACK MR_Member_List_Update CID to path binding (MS  RS2) ……….. MSID  MS ACK MAP IE (RS2) PDU (MSID) MAP IE (MS) PDU (MSID)

Summary The burst-based forwarding scheme is the most efficient forwarding scheme for the RS group (transparent RS or non-transparent RS in a RS group) Burst-based forwarding scheme for the transparent RS has been accepted in D2. Burst-based forwarding scheme for an RS group with non-transparent RS is provided by comment #2216