1. doc.: IEEE 802.15- Submission August 18, 2004 Bill Shvodian, Freescale SemiconductorSlide 1 Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title: [Polling vs. Token Passing for bi-directional CTAs] Date Submitted: [16 August 2004] Source: [Bill Shvodian] Company [Freescale Semiconductor] Address [8133 Leesburg Pike, Suite 700, Vienna, VA 22182, USA] Voice:[703-269-3047], FAX: [], E-Mail:[bill.shvodian @ freescale.com] Re: [TG3b call for contributions] Abstract:[This proposal describes token passing vs. Polling for bi-directional CTAs. An accompanying Excel spreadsheet demonstrates performance differences.] Purpose:[The author would like the IEEE to consider adoption of polling for TG3b.] 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.

2. doc.: IEEE 802.15- Submission August 18, 2004 Bill Shvodian, Freescale SemiconductorSlide 2 Scenarios for comparison of polling and token passing for bi directional CTAs

3. doc.: IEEE 802.15- Submission August 18, 2004 Bill Shvodian, Freescale SemiconductorSlide 3 Background Token Passing has been proposed for bi-directional traffic for TG3b A comparison between polling and token passing throughout was made to compare the performance of the two The accompanying spreadsheet shows the relative performance of the two approaches

4. doc.: IEEE 802.15- Submission August 18, 2004 Bill Shvodian, Freescale SemiconductorSlide 4 Token Passing Owner of a CTA (srcID) always initiates transmission in a CTA. Because it is the only DEV that all DEVs using the CTA must hear, the token always comes back to the owner A new Token Frame is required. Token frames are not ACKed Token single: token holder can only send on frame per cycle. Token Multi – Token holder can send up to TBD frames or TBD duration

5. doc.: IEEE 802.15- Submission August 18, 2004 Bill Shvodian, Freescale SemiconductorSlide 5 Polling Polling single: Poller/pollee holder can only send on frame per cycle. Polling Multi – Poller/Pollee can send up to TBD frames or TBD duration

6. doc.: IEEE 802.15- Submission August 18, 2004 Bill Shvodian, Freescale SemiconductorSlide 6 Implied ACK Thrown in for old times sake

7. doc.: IEEE 802.15- Submission August 18, 2004 Bill Shvodian, Freescale SemiconductorSlide 7 Scenarios Scenario 1: only CTA Owner has traffic Scenario 2: only 1 CTA non-Owner has traffic Scenario 3: all DEVs have traffic Scenario 4: 2 DEVs have traffic (Osner has traffic to all) Scenario 5: only CTA Owner has traffic to one DEV Scenario 6: only CTA Owner & 1 DEV have traffic and only to each other

8. doc.: IEEE 802.15- Submission August 18, 2004 Bill Shvodian, Freescale SemiconductorSlide 8 Scenario 1: only CTA Owner has traffic Data/poll ACK Data/poll PACKACKPACK Data/poll ACKPACK Polling single Data ACK Token single Data ACKTKN Data Data/poll PACK Polling Data Token multi Data ACKTKN ACK Del ACK Imm ACK Data/poll PACK Data/poll PACK Polling single Data Token multi Data TKN No ACK Data1->n ACK Implied ACK Data1->n ACK Data1-n ACK Implied ACK TKN Data Token single Data TKN Data ACK Token multi Data ACK Data ACKTKN Polling multi? Data Data/poll PACK Data ACK Data ACK Data/poll ACKPACK TKN Data/poll PACK 1->22->11->33->11->44->1

9. doc.: IEEE 802.15- Submission August 18, 2004 Bill Shvodian, Freescale SemiconductorSlide 9 Scenario 2: only 1 CTA non-Owner has traffic Poll Data ACK Polling multi? Token single Data TKN Polling Data Token Data ACKTKN Del ACK Imm ACK No ACK Implied ACK PollPACK TKN ACK Data2->1 Poll Data PACKACKPoll PACK TKN Data Token single TKN Polling single Poll Data PollPACKPollPACK Data ACK TKN PACKPoll TKN ACKNull ACK Null Poll Data ACK Polling single PollPACKPollPACK Token multi Data ACKTKN ACKTKN Polling multi? Poll Data PACKPollPACKPoll Data Token multi Data TKN

10. doc.: IEEE 802.15- Submission August 18, 2004 Bill Shvodian, Freescale SemiconductorSlide 10 Scenario 3: all DEVs have traffic Data ACK Polling multi Token single Data Polling Data Token Data ACKTKN Del ACK Imm ACK Polling multi? Data Token multi Data TKN No ACK Implied ACK ACK Data Data2->x ACK Data Data/poll Data ACK TKN ACK Data/poll ACK Data ACK Data/poll Data Data/poll Data TKN Data1->2 Data3->x ACK Data1->3 Data ACK Polling single Data/poll ACK Token multi Data ACK TKN Polling single Data Data/poll Data Data/poll Data Token single TKN Data TKN Data TKN Data

11. doc.: IEEE 802.15- Submission August 18, 2004 Bill Shvodian, Freescale SemiconductorSlide 11 Scenario 4: 2 DEVs have traffic Polling multi Polling Data Token Data ACKTKN Del ACK Imm ACK Polling multi? Data Token multi Data TKN No ACK Implied ACK Data ACK Data Data/poll Token multi Data ACK TKN Data/poll Data Data/poll Data Data1->2 Data2->x ACK PACK Data ACK Polling single Data/poll ACK Data/poll ACK Data/poll Token single Data ACKTKN Data ACK Polling single Data Data/poll PACK Data Token single TKN Data TKN ACKNullACKNull Data ACK Data ACK Data/poll ACK Data

12. doc.: IEEE 802.15- Submission August 18, 2004 Bill Shvodian, Freescale SemiconductorSlide 12 Scenario 5: only CTA Owner has traffic to one DEV Data/poll ACKPACK Polling single Data ACK Token single Data ACKTKN Data Data/poll PACK Polling Data Token multi Data ACKTKN ACK Del ACK Imm ACK Data/poll PACK Polling single Data Token multi Data TKN No ACK Data1->n ACK Implied ACK Data1->n ACK Data1-n ACK Implied ACK TKN Data Token single Data TKN Data ACK Token multi Data ACK Data ACKTKN Polling multi? Data Data/poll PACK Data ACK Data ACK Data/poll ACKPACK TKN PollPACK Data/poll ACKPACK Data/poll ACKPACK Data/poll PACK Data/poll PACK Data

13. doc.: IEEE 802.15- Submission August 18, 2004 Bill Shvodian, Freescale SemiconductorSlide 13 Scenario 6: only CTA Owner & 1 DEV have traffic to each other Data/poll ACK Polling single Data ACK Token single Data ACKTKN Data Data/poll PACK Polling Data Token multi Data ACKTKN ACK Del ACK Imm ACK Data/poll PACK Polling single Data Token multi Data TKN No ACK Data1->n ACK Implied ACK Data1->n ACK Data1-n ACK Implied ACK TKN Data Token single Data TKN Data ACK Token multi Data ACK Data ACKTKN Polling multi? Data Data/poll PACK Data ACK Data ACK Data/poll TKN PollPACK Data/poll ACKPACK Data/poll PACK Data/poll PACK Data 1->22->11->33->11->44->1 1->2 2->1