Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs)

1. Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title: [Resolution of TG6 comments: S6-513, S7-005, S7-125] Date Submitted: [22 September, 2010] Source: [Rick Powell] Company [Zarlink] Address [15822 Bernardo Center Dr, Ste B, San Diego, CA, 92127] Voice:[+1 858-675-3485], FAX: [+1 858-675-3450], E-Mail:[rick.powell@zarlink.com] Re: [Proposed Resolution of D0 Comments S6-513, S7-005, S7-125] Abstract: [Comment resolution for letter ballot 55 for S6-513, S7-005, S7-125] Purpose: [Propose Resolution of D0 Comment S6-513, S7-005, S7-125] Notice: This document has been prepared to assist the IEEE P802.15. It is offered as a basis for discussion and is not binding on the contributing individual(s) or organization(s). The material in this document is subject to change in form and content after further study. The contributor(s) reserve(s) the right to add, amend or withdraw material contained herein. Release: The contributor acknowledges and accepts that this contribution becomes the property of IEEE and may be made publicly available by P802.15. <Rick Powell>, <Zarlink>

2. Proposed Resolution of D0 Comment S6-513 S7-005, S7-125 Comments relative to Delayed Bilink and Type-II Access Phase <Rick Powell>, <Zarlink>

3. D0 Comment S6-513 • Page 55, Sub-clause 6.6.1.4, Line 14 • Comment: Having both Type-I and Type-II Access phases, in addition to Unscheduled Polling and Contention Access, is redundant and unnecessary. Type-I access phase handles variable data requirements with Improvised Polling. Unscheduled Polling and Contention Access also handles variable data requirements. Unscheduled Polling and Contention Access can provide both time based and frame based allocation. • Proposed Change:Either: • 1) Show that Type-II Type Access cannot be adequately covered with Scheduled Bilink, Improvised BiLink, Unscheduled Polling, and Contention Access • OR: • 2) Remove Type-II Access Phase. Retain the ability to specify either slot based allocation or frame based allocation in Polls and T-Polls for Unscheduled Polling Access and Contention Access. • Analysis: If Delayed Polling & Bilink are removed per S7-125, then there is no reason to have Type-II Access Phase. • Proposed Resolution: Remove Type-II Access Phase, and all references to it. <Rick Powell>, <Zarlink>

4. D0 Comment S7-005 • Page 77, Sub-clause 7.3.1 • Comment:(1) There is no technical justification for having separate Type I and Type II access phases, other than fragmenting the superframe and hence reducing bandwidth utilization efficiency as well as increasing implementation complexity. Everything the division can do a single access phase can do as well. (2) Delaye-polling access is broken: A node has to give up a partial or even the whole portion (D1) of its delayed bilink allocation interval, but it is not guaranteed to get the same portion (D2) back at the end of its interval even if it needs extra bandwidth badly, as that D2 portion is not under its control but rather at the mercy of another node (D2 may be easily << D1). If the delayed bilink allocation interval is the last one in the superframe, the node will simply not even get anything back. If extra space has to be set aside in the superframe after the last delayed bilink allocation interval, then the conventional scheduled access can function as well -- or even better since its interval is not subject to be used by another node. • Proposed Change:It is time to resolve technical comments on a technical basis. Remove delayed-polling access and delayed bilink allocation interval, and hence the division of the two access phases altogether, unless the issues are addressed at the July session. • Proposed Resolution: Same as S6-513 <Rick Powell>, <Zarlink>

5. D0 Comment S7-125 • Page 61, Sub-clause 6.7.5, Line 5 • Comment: Delayed BiLink Mode is not needed when Scheduled BiLink with Improvised Scheduling is available. Unscheduled Polling is also available, which provides both time based and frame based allocations. It may be argued that there is some slight efficiency advantage of Delayed BiLink over Scheduled BiLink with Improvised and/or unscheduled polling, but any improved efficiency is questionable and minimal at best. It does not justify yet another access mode type. • Proposed Change:Either: • 1) Show that Delayed-Bilink cannot be adequately satisfied with either Schedule BiLink with Improved Scheduling or with Unscheduled Polling. • Or: • 2) Remove Delayed-Bilink Access Mode, Delayed-Bilink Request IE, and Delayed-Bilink Assignment IE • Note: Removing Uplink, DownLink, and Delayed-BiLink still leaves Scheduled Bilink, Improvised BiLink, Unscheduled Polling, and Contention Access (CSMA/ALOHA) to provide a flexible and efficient set of access modes. These four remaining modes supply enough capability to satisfy all application needs, while still causing considerable complexity in definition and implementation. <Rick Powell>, <Zarlink>

6. D0 Comment S7-125 • Analysis: With an enhanced definition of unscheduled access, as defined in DCN 0746-01, and with the current capabilities provided by Improvised Access, there is insufficient advantage to Delayed Polling/Bilink Access to justify this additional access mode. • Proposed Resolution: Remove Delayed Polling/Bilink Access Mode. <Rick Powell>, <Zarlink>