1. Project: IEEE 802.15 Working Group for Wireless Personal Area Networks (WPANs)
Submission Title: [Merged AFH Proposal]
Date Submitted: [7 August 01]
Source: [Hong Bing Gan, Vitaliy Sapozhnykov, Efstratios Skafidas, Bijan Treister]
Company [Bandspeed]
Address [7000 West William Cannon Dr. Suite 2220 Austin, TX 78735]
Voice: [ ], FAX: [ ],
[{h.gan, v.sapozhnykov, e.skafidas,
Re: [AFH Merging of systems]
Abstract: [Method of merging of AFH systems]
Purpose: [Merge AFH proposal to one unified system while maintaining flexibility]
Notice: This document has been prepared to assist the IEEE 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

2. AFH Merge overview (1) 1) Proposal for AFH merge (Mechanism)
Block diagram
Justification
Comparison and Evaluation
2) Proposal for LMP commands
Use only ‘good’ / ‘bad’ channels in LMP command instead of ‘good’/’bad’/’unused’

3. 3. Use remaining ‘bad’ channels in intelligent manner.
AFH Merge overview (2)
Logical segmentation:
3. Use remaining ‘bad’ channels in intelligent manner.
Selection
Box 27
UAP/LAP
CLOCK
fgen
23/79 Mode
Frequency Replacement
fadp
AM_ADDR
CLKE12-1 / CLKN12-1 12
Figure 6: AFH System Overview. 28
Grouping / paring
fout
2. Remove as many ‘bad’ channels as required / legally possible.
1. Bluetooth Hopping Sequence generator

4. Definitions
Nmin = minimum number of good channels which must be used under FCC
NB = number of bad channels
NBR = number of bad channels to be replaced
NBP = number of bad channels to be grouped/paired
NG = number of good channels

5. Frequency replacement
RANDW 12 7
Mod NG .
fgen
fadp
Good channel bank
Used in all circumstances
bypass if NB = 0 (no bad channels)

6. Grouping / Pairing Only used if NG < Nmin
fadp
fout
Only used if NG < Nmin
bypass block completely otherwise

7. Integration Proposal TG2_382r0 shows merge is possible Why modular?
integration is definitely possible;
however, design should keep modularity of systems
Why modular?
allows for implementation of Frequency Replacement only under low power mode (reduced complexity of systems);
allows vendor to choose if to implement both or one of the blocks;
current FCC restrictions on high power require grouping/pairing, future changes may occur;
simplifies block diagram for readability;
splits OPNET simulation work between groups appropriately;

8. Gain scenarios The following slides show:
Gain of the merged scheme under
Low Power (FCC )
High Power (FCC with NPRM)

9. Definitions Normally: Grouping/Paring:
Transaction #1
Transaction #2
Transaction #3
M  S
S  M
M  S
S  M
M  S
S  M f1 f2 f3 f4 f5 f6
Probability of erroneous transaction
Normally:
Grouping/Paring:
P (Bad,Bad)
P (Bad,Good) + P (Good,Bad)
Simple binomial distribution
(see /082r1)
Assumed: Uniform pseudo-random sequence (as in Bluetooth)
Interference due only to bad channels
79 Channel mode

10. Additional complexity under FCC 15.249 or 15.247 with NPRM
Nmin = 15 (under FCC NPRM)
Example for 23 bad channels (100% duty)
Frequency Replacement (replace 23 channels)
before: P (erroneous transaction) ~ 48%
after: P (erroneous transaction) ~ 0%
decrease error probability by 48%
Grouping/Pairing (remaining 0 channels)
not needed

11. Additional complexity under FCC 15.249 or 15.247 with NPRM
Nmin = 15 (under FCC NPRM)
Example for 70 bad channels (100% duty)
Frequency Replacement (replace 64 channels)
before: P (erroneous transaction) ~ 98%
after: P (erroneous transaction) ~ 32%
decrease error probability by 66%
Grouping/Pairing (remaining 6 channels)
before: P (erroneous transaction) ~ 32%
after: P (erroneous transaction) ~ 19%
decrease error probability by 13%
what gain justifies implementation of the scheme? P.T.O...

12. Summary of modular merge
Allow vendor to choose if they want to implement both or one of either sub-block;
Both modules have value depending on:
FCC situation
power mode and
vendor’s requirements

13. 79 bits for LMP commands
Only transmit ‘good’/’bad’ channel information, not ‘good’/’bad’/’unused’
Fits into a normal LMP data unit;
doesn’t require special LMP packets to be defined;
only requires a new op-code to be defined;
More logical.
Solution
Use replacement for first (N-Nmin) bad channels in LMP command
Use grouping/pairing for remaining bad channels

14. LMP Example Assume 70 ‘bad’ channels, 9 ‘good’ channels: HD
1,1,1,1,1,1,1,1,1,1,1,1,0,1,0,0,1,1,1,1,1, ,1,0,0,1,0,0,1,0,0,1,1,0
Replace first (N - Nmin) = 64 channels
Group/pair remaining 6 channels
Assume Nmin = 15