project: ieee p802.15 working group for wireless personal area networks (wpans)

Integrated Programmable Communications, Inc.August, 2001 doc.: IEEE 802.15-01/382r0

Submission

Integrated Programmable Communications, Inc. and Texas Instruments, Inc.Slide 1

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

Submission Title: Proposal for merging mode H and mode L of AFHDate 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 75243TEL(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.comRe: []

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.


Submission


Proposal for Merging Mode H and Mode L of AFH

HK Chen, YC Maa, and KC ChenIntegrated Programmable Communications

Anuj Batra, Kofi Anim-Appiah, and Jin-Meng HoTexas Instruments


Submission


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


Submission


Channel classification terminology (2)

SG

SBN

SBK

SB=SBK U SBN

N=NG+NB

NB=NBK+NBN


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On the numbers

Nmin:minimal number of channels in the new hopping

sequence

BBN

BK

BN

GBK

G

NN

N

otherwise

N NN

N NN

NNif

0

min

min

min

When NG is large enough, no bad channels are used in the new hopping

sequence. This is where mode H reduces to mode L.


Submission


Block diagram of mode L mapping

fgen

Mod

NG

.

.

.

.

fadp

XL

YL

bank of good channels1

0

Top path: the bad channels are replaced by good channels

Bottom path: bypass if original channel is already good

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

SG


Submission


Block diagram of mode H mapping

fgen NG

.SG..

fadp

XH bank of good channels

.

.

.

bank of bad channels kept

1 0

NBK

YH

1

0

pseq

The black parts have exactly the same

structure as mode L

Top path: the bad channels are replaced by good channels

Middle path: the good channels are replaced by bad channels

Mod

1

0

Bottom path: bypass if original channel is already in the desired set specified by pseq

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

SBK


Submission


When will mode H reduce to mode L? (1)

Mathematically, mode H reduces to mode L when three conditions holds:

1. pseq = 1• Do not select the middle path in mode H

2. XH=XL

• The two modes have the same shifting signal

3. YH=YL

• The two modes switch to the bypass path (bottom path) in the same way


Submission



Partition sequencepseq=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.

minNNG


Submission



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.


Submission



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.

otherwise

SfifY Ggen

L

0

1

otherwise

pandSforpandSfifY seqBKgenseqGgen

H

)]0()[()]1()[(

0

1


Submission


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.


Submission


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.

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