1. doc.: IEEE 802.15-01/435r2 Submission September, 2001 H. Gan, V. Sapozhnykov, et. al.Slide 1 Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title: [Adaptive Frequency Hopping - An instant channel replacement approach for both ACL and SCO] Date Submitted: [September, 2001] Source: [H. Gan, V. Sapozhnykov, B. Treister, E. Skafidas, et. al.] Company [Bandspeed Inc.] Address [Level 9, 500 Collins Street, Melbourne, Victoria, Australia] Voice:[61 3 9614 6299, FAX: [61 3 9614 6699] E-Mail:[h.gan, b.treister, v.sapozhnykov@bandspeed.com.au] Re: [A new simple approach for adaptive frequency hopping] Abstract:[This document describes a new simple approach for adaptive frequency hopping, an instant channel replacement to intelligently use bad channels in the hopping sequence] Purpose:[Introducing a new approach for adaptive frequency hoping to include in 802.15.2] 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 802.15-01/435r2 Submission September, 2001 H. Gan, V. Sapozhnykov, et. al.Slide 2 Adaptive Frequency Hopping (AFH) - A Simple Instant Channel Replacement Approach for both ACL and SCO Hongbing Gan, Vitaliy Sapozhnykov, Bijan Treister, Stan Skafidas, et. al. Bandspeed Inc.

3. doc.: IEEE 802.15-01/435r2 Submission September, 2001 H. Gan, V. Sapozhnykov, et. al.Slide 3 Definition of Channel Pair A channel pair is comprised of two channels: First channel, Master Tx/Slave Rx channel, at even-numbered timeslot Second channel, Slave Tx/Master Rx, ie, Slave return channel, at odd-numbered timeslot f1f1 f2f2 Master Tx Rx Tx Rx Slave Rx Tx Rx Tx f3f3 f4f4 Channel Pair Even-numbered Timeslot Even-numbered Timeslot Odd-numbered Timeslot Odd-numbered Timeslot

4. doc.: IEEE 802.15-01/435r2 Submission September, 2001 H. Gan, V. Sapozhnykov, et. al.Slide 4 Definitions N: Total number of hopping channels N min : Minimum number of channels to be used, set by regulations such as FCC G: Good channel B: Bad channel B N : Bad channel to be removed legally from the hopping sequence B K : Bad channel to keep in the hopping sequence N G, N B, N BN, N BK : Number of good channel, Number of bad channel, Number of bad channel to remove, Number of bad channel to keep, respectively N = N G + N B N B = B K + B N

5. doc.: IEEE 802.15-01/435r2 Submission September, 2001 H. Gan, V. Sapozhnykov, et. al.Slide 5 AFH Covers All Possible Channel Classification Scenarios Scenario 1: B N = 0, B k > 0, all Bad channels are kept, the AFH intelligently use B K in the new hopping sequence Scenario 2: B N > 0, B K > 0, the AFH replaces B N with good channels G or B K, and intelligently use B K in the new hoping sequence Scenario 3: (Ideal scenario) B N > 0, B K = 0, all Bad channels are replaced with Good channels in the new hopping sequence

6. doc.: IEEE 802.15-01/435r2 Submission September, 2001 H. Gan, V. Sapozhnykov, et. al.Slide 6 AFH Covers All the Traffic Types

7. doc.: IEEE 802.15-01/435r2 Submission September, 2001 H. Gan, V. Sapozhnykov, et. al.Slide 7 AFH Approach 1 - Standard Instant Channel Replacement (Standard ICR) (Details in IEEE 802.15 Document 01/435r0, 01/438r0)

8. doc.: IEEE 802.15-01/435r2 Submission September, 2001 H. Gan, V. Sapozhnykov, et. al.Slide 8 Principle of Standard ICR GGGBBGBB Original PassBlocked Re-transmission GGGGBBBB New PassBlocked Pass Original ‘Good Good’ and ‘Bad Bad’ channel pairs are kept in their original positions in the hopping sequence ‘Good Bad’ channel pairs are instantly replaced to ‘Good Good’ channel pairs ‘Bad Good’ channel pairs are instantly replaced to ‘Bad Bad’ channel pair Throughput improved due to newly created ‘Good Good’ channel pairs

9. doc.: IEEE 802.15-01/435r2 Submission September, 2001 H. Gan, V. Sapozhnykov, et. al.Slide 9 Principle of Standard ICR For each channel pair, starting from Master Tx channel:  Removing B N by replacing it with a randomly selected G or B K, to maintain equal usage of G and B K  Whenever Master Tx channel is OR replaced to G, replace the Slave return channel to G if it is B N or B K originally, to form a ‘G G’ channel pair and secure a transaction  Whenever Master Tx channel is OR replaced to B K, replace the Slave return channel to B K if it is B N or G originally, to form a ‘B K B K ’ channel pair, to remove B N and save a usage of G  Channel replacement on a per channel pair basis

10. doc.: IEEE 802.15-01/435r2 Submission September, 2001 H. Gan, V. Sapozhnykov, et. al.Slide 10 Standard ICR Processing Table When NO B K, Case 1, 3,4, 6 are processed When NO B N, Case 1, 2, 10, 11 are processed In case Master TX B N replaced with a B K In case Master TX B N replaced with a G

11. doc.: IEEE 802.15-01/435r2 Submission September, 2001 H. Gan, V. Sapozhnykov, et. al.Slide 11 Example Portion of Original and AFH Hopping Sequence GGGBKBK GBNBN GGBNBN BNBN BNBN BKBK BNBN GBKBK GBKBK BNBN BKBK BKBK BNBN GGGBNBN GGBKBK GGGG G GGGGGG G G G BKBK BKBK BKBK BKBK BKBK BKBK G G GGBKBK BKBK GG In this example, 7 more ‘Good Good’ channel pairs are created AFH

12. doc.: IEEE 802.15-01/435r2 Submission September, 2001 H. Gan, V. Sapozhnykov, et. al.Slide 12 Flowchart A: Used for Master Tx/Slave Rx timeslots, i.e., Even-numbered timeslot

13. doc.: IEEE 802.15-01/435r2 Submission September, 2001 H. Gan, V. Sapozhnykov, et. al.Slide 13 Flowchart B: Used for Slave Tx/Master Rx timeslots, i.e., Odd-numbered timeslot

14. doc.: IEEE 802.15-01/435r2 Submission September, 2001 H. Gan, V. Sapozhnykov, et. al.Slide 14 AFH Approach 2 - ‘Fit Best’ Instant Channel Replacement (Fit Best ICR)

15. doc.: IEEE 802.15-01/435r2 Submission September, 2001 H. Gan, V. Sapozhnykov, et. al.Slide 15 General Principle of Fit Best ICR For HV2 and HV3: –Fit the best channels to channel pairs of the reserved SCO Timeslots For mixed SCO + ACL: –Fit the best channels to channel pairs of the reserved SCO Timeslots, if SCO has higher priority –Fit the best channels to channel pairs of the ACL Timeslots, if ACL has higher priority –Use Standard ICR if neither ACL nor SCO has higher priority

16. doc.: IEEE 802.15-01/435r2 Submission September, 2001 H. Gan, V. Sapozhnykov, et. al.Slide 16 Mixed SCO (HV2, HV3) and ACL Links TRTRTRTRTRTRTRTRTRTRTRTR HV2 HV3 HV2 ACL HV3 HV2 reserves half Timeslots, transmits every four Timeslots HV3 reserves one third Timeslots, transmits every six Timeslots

17. doc.: IEEE 802.15-01/435r2 Submission September, 2001 H. Gan, V. Sapozhnykov, et. al.Slide 17 How Fit Best ICR works For channel pairs at higher priority timeslots: Case 1: ‘Good Good’‘Good Good’ Case 2: ‘Good Bad’‘Good Good’ Case 3: ‘Bad Good’‘Good Good’ Case 4: ‘Bad Bad’’Good Good’ For every Case 3 replacement, a Good Channel Usage Debt (GUD) Counter is incremented by 1; For every Case 4 replacement, the GUD Counter is incremented by 2. In lower priority timeslots, if there is GUD debt, a ‘Good Bad’ channel pair will be replaced to ‘Bad Bad’ channel pair to repay the GUD by 1; A ‘Good Good’ channel pair will be replaced to ‘Bad Bad’ channel pair to repay the GUD by 2. GUD balance is always towards ZERO, to maintain equal channel usage.

18. doc.: IEEE 802.15-01/435r2 Submission September, 2001 H. Gan, V. Sapozhnykov, et. al.Slide 18 How Fit Best ICR works Example: HV2 + ACL, HV2 Voice Link has higher priority (shown in next slide) In HV2 slots, do the following replacement: –‘Good Good’ channel pairs are kept as usual –‘Good Bad’ replaced to ‘Good Good’ as usual –‘Bad Good’ replaced to ‘Good Good’, increment GUD debt counter by 1 –‘Bad Bad’ replaced to ‘Good Good’, increment GUD debt counter by 2 In ACL slots, do the following replacements –If any GUD Debt, ‘Good Good’ channel pairs are replace to ‘Bad Bad’, decrease GUD debt counter by 2 –If any GUD Debt, ‘Good Bad’ replaced to ‘Bad Bad’, decrease GUD debt counter by 1 –‘Bad Good’ replaced to ‘Bad Bad’ as usual –‘Bad Bad’ are kept as usual If ACL has higher priority, just do the reverse.

19. doc.: IEEE 802.15-01/435r2 Submission September, 2001 H. Gan, V. Sapozhnykov, et. al.Slide 19 How Fit Best ICR works (Assuming HV2 has higher priority) GGGBKBK GBKBK BKBK BKBK GBKBK BKBK GBKBK GGGBKBK BKBK BKBK GGGG G GBKBK AFH HV2 ACL HV2 GBKBK GGGGGGGGBKBK BKBK GGBKBK BKBK BKBK BKBK BKBK BKBK BKBK BKBK GGG G GG ACL HV2 GG 1 2 3 4 5 6 7 8 9 10 11 12 13 14

20. doc.: IEEE 802.15-01/435r2 Submission September, 2001 H. Gan, V. Sapozhnykov, et. al.Slide 20 Fit Best ICR Processing Table At timeslots for higher priority traffic, such as voice HV2 At timeslots for lower priority traffic

21. doc.: IEEE 802.15-01/435r2 Submission September, 2001 H. Gan, V. Sapozhnykov, et. al.Slide 21 Traffic Type VS. AFH Method