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:Proposal for merging mode H and mode L of AFH Date Submitted: August 6, 2001 Source: (1) HK Chen, YC Maa, and KC Chen(2) Anuj Batra, Kofi Anim-Appiah, and Jin-Meng Ho Company: (1) Integrated Programmable Communications, Inc. (2) Texas Instruments, Inc. Address: (1)Taiwan Laboratories Address: P.O. Box 24-226, Hsinchu, Taiwan 300 (2) 12500 TI Boulevard, Dallas, TX 75243 TEL(1) +886 3 516 5106, FAX: +886 3 516 5108, E-Mail: {hkchen, ycmaa, kc}@inprocomm.com (2) +1 214 480 4220, FAX: 972 761 6966, E-Mail: {batra, kofi, jinmengho}@ti.com Re: [] Abstract: This presentation shows why mode H is a superset of mode L and suggests how to merge them. Purpose: Submission to Task Group 2 for consideration as the baseline for merging mode H and mode L of AFH in response to the action item of the July-01 meeting. 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. Integrated Programmable Communications, Inc. and Texas Instruments, Inc.

2. Proposal for Merging Mode H and Mode L of AFH HK Chen, YC Maa, and KC Chen Integrated Programmable Communications Anuj Batra, Kofi Anim-Appiah, and Jin-Meng Ho Texas Instruments Integrated Programmable Communications, Inc. and Texas Instruments, Inc.

3. Channel classification terminology • Old terminologies: • Mode H: good/bad/unused channels • Mode L: good/bad channels • New terminologies: • SG: the set of good channels, NG=size(SG) • SB: the set of bad channels, NB=size(SB) • SBK: the set of bad channels kept in the new hopping sequence, NBK=size(SBK) • SBN: the set of bad channels not used in the new hopping sequence, NBN=size(SBN) • N: total number of channels Integrated Programmable Communications, Inc. and Texas Instruments, Inc.

4. N=NG+NB NB=NBK+NBN Channel classification terminology (2) SBN SG SBK SB=SBK U SBN Integrated Programmable Communications, Inc. and Texas Instruments, Inc.

5. On the numbers • Nmin: minimal number of channels in the new hopping sequence < if N N G min = - N N N BK min G = - N N N BN min otherwise When NG is large enough, no bad channels are usedin the new hopping sequence. This is where mode H reduces to mode L. = N 0 BK = N N BN B Integrated Programmable Communications, Inc. and Texas Instruments, Inc.

6. Block diagram of mode L mapping Top path: the bad channels are replaced by good channels . . . . Mod SG XL NG 0 fadp fgen bank of good channels 1 YL fgen: hopping sequence before doing AFH fadp: hopping sequence after mapping XL: shifting signal of mode L to equalize channel utilization YL: bypass control signal of mode L Bottom path: bypass if original channel is already good Integrated Programmable Communications, Inc. and Texas Instruments, Inc.

7. Block diagram of mode H mapping Top path: the bad channels are replaced by good channels The black parts have exactly the same structure as mode L . SG. . Mod XH 1 0 bank of good channels 1 fgen 0 fadp 0 NG NBK 1 . . . YH Middle path: the good channels are replaced by bad channels SBK pseq bank of bad channels kept XH: shifting signal of mode H to equalize channel utilization YH: bypass control signal of mode H pseq: partition sequence specifying using SG or SBK Bottom path: bypass if original channel is already in the desired set specified by pseq Integrated Programmable Communications, Inc. and Texas Instruments, Inc.

8. When will mode H reduce to mode L? (1) • Mathematically, mode H reduces to mode L when three conditions holds: • pseq = 1 • Do not select the middle path in mode H • XH=XL • The two modes have the same shifting signal • YH=YL • The two modes switch to the bypass path (bottom path) in the same way Integrated Programmable Communications, Inc. and Texas Instruments, Inc.

9. When will mode H reduce to mode L? (2) • Partition sequence • pseq=1 => select SG, • pseq=0 => select SBK • When good channels are enough ( ) • Mode H sets NBK=0. • The second channel bank SBK becomes empty and is not used. • pseq becomes a constant 1, and the middle path of mode H is never selected. • Thus the first condition is satisfied. Integrated Programmable Communications, Inc. and Texas Instruments, Inc.

10. When will mode H reduce to mode L? (3) • Shifting signal (XH and XL) • The shifting signal is added to make the selection probability of each channel in the banks uniform. • Mode H and L can (and are desired to) share the same shifting signal. • Thus the second condition is satisfied. Integrated Programmable Communications, Inc. and Texas Instruments, Inc.

11. When will mode H reduce to mode L? (4) • Bypass control signal (YH and YL) • Eqs: • Mode H bypass occurs when: • pseq = 1 and original hopping channel is in SG. • pseq = 0 and original hopping channel is in SBK. • When there are enough good channels: • The bank of SBK is never selected. • Mode H bypass reduces to mode L bypass. • Thus the third condition is satisfied. • It is easily seen that YL = YH if pseq=1. Integrated Programmable Communications, Inc. and Texas Instruments, Inc.

12. Mode H : a superset of Mode L • When there are enough good channels: • mode H performs the same operation as mode L. • In this case, both modes support all types of traffic. • In this case, both modes support broadcast packets to the same degree. • When there are not enough good channels: • Mode H keeps some of the bad channels in the new hopping sequence to meet minimal channel number requirement. • Mode H properly arranges the position of bad channel slots to support all types of traffic and QoS. Integrated Programmable Communications, Inc. and Texas Instruments, Inc.

13. Direction to merge • Since the function of mode L mapping is already included in mode H mapping, we suggest to use the block diagram of mode H mapping as the basis of merging. • One common shifting signal should be determined for both modes. • The LMP procedures and commands require further considerations. Integrated Programmable Communications, Inc. and Texas Instruments, Inc.