slide1 n.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) PowerPoint Presentation
Download Presentation
Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs)

Loading in 2 Seconds...

play fullscreen
1 / 21

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


  • 78 Views
  • Uploaded on

Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title: [ Adaptive Frequency Hopping - An Simple Instant Channel Replacement Approach for both ACL and SCO Links ] Date Submitted: [September, 2001]

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs)' - kyna


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
slide1

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

Submission Title: [Adaptive Frequency Hopping - An Simple Instant Channel Replacement Approach for both ACL and SCO Links]

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 Simple Approach for Adaptive Frequency Hopping, as a non-collaborative coexistence mechanism]

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.

H. Gan, V. Sapozhnykov, et. al.

adaptive frequency hopping afh a simple instant channel replacement approach for both acl and sco
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.

H. Gan, V. Sapozhnykov, et. al.

benefits of the simple afh approach mechanism
Benefits of the Simple AFH Approach Mechanism
  • Channel replacement on a per channel pair basis instantly, NO complicated ACL and SCO partition sequence generator is needed.
  • A simple AFH mechanism to cover all traffic types (ACL, SCO, Mixed ACL/SCO), high priority traffic such as SCO can get more good channels
  • A simple AFH to cover both low power and high power modes
  • Better backward compatibility with legacy devices
  • Master’s Transmitting channels are kept in the original positions in the hoping sequence, good for piconet synchronization, broadcast, Park mode, Sniff mode, beacon channel, etc.
  • Legacy devices also benefits from the new AFH approach
  • Random number generator seamlessly integrated
  • A harmonized simple AFH mechanism

H. Gan, V. Sapozhnykov, et. al.

definition of channel pair
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, i.e., Slave return channel, at odd-numbered timeslot

Channel Pair

Channel Pair

Master Tx Rx Tx Rx

f1

f3

f2

f4

Slave Rx Tx Rx Tx

Odd-numbered

Timeslot

Even-numbered

Timeslot

Odd-numbered

Timeslot

Even-numbered

Timeslot

H. Gan, V. Sapozhnykov, et. al.

definitions
Definitions
  • N: Total number of hopping channels
  • Nmin: Minimum number of channels to be used, set

by regulations such as FCC

  • G: Good channel
  • B: Bad channel
  • BN: Bad channel to be removed legally from the hopping sequence
  • BK: Bad channel to keep in the hopping sequence
  • NG, NB, NBN, NBK: Number of good channel, Number of bad channel, Number of bad channel to remove, Number of bad channel to keep, respectively
  • N = NG + NB
  • NB = NBK + NBN

H. Gan, V. Sapozhnykov, et. al.

afh covers all possible channel classification scenarios
AFH Covers All Possible Channel Classification Scenarios
  • Scenario 1: NBN > 0, NBK= 0 (Ideal scenario)
    • All Bad channels are replaced with Good channels in the new hopping sequence
    • (e.g., in lower power mode, all bad channels removed )
  • Scenario 2: NBN > 0, NBK > 0,
    • AFH removes BN , replaces it with randomly selected good channels G or BK (to maintain equal channel usage of G and BK),
    • AFH intelligently use BK in the new hoping sequence
    • (e.g., in high power mode, a maximum of 4 channels can be removed, the rest bad channels if any have to be kept)

H. Gan, V. Sapozhnykov, et. al.

afh covers all the traffic types
AFH Covers All the Traffic Types

H. Gan, V. Sapozhnykov, et. al.

afh approach
AFH Approach

- Standard Instant Channel Replacement (Standard ICR)

(Details in IEEE 802.15 Document 01/435r0, 01/438r0)

H. Gan, V. Sapozhnykov, et. al.

principle of standard icr

G

B

G

B

G

G

B

B

G

B

B

G

B

G

B

G

Principle of Standard ICR

Pass

Re-transmission

Blocked

Blocked

Original

New

Pass

Pass

Blocked

Blocked

  • 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

H. Gan, V. Sapozhnykov, et. al.

slide10

Flowchart A:

Used for Master Tx/Slave Rx timeslots, i.e., Even-numbered timeslot

H. Gan, V. Sapozhnykov, et. al.

slide11

Flowchart B:

Used for Slave Tx/Master Rx timeslots, i.e., Odd-numbered timeslot

H. Gan, V. Sapozhnykov, et. al.

standard icr processing table
Standard ICR Processing Table

In case Master TX BN

replaced with a G

In case Master TX BN

replaced with a BK

  • When NO BK, Case 1, 3 ,4, 6 are processed
  • When NO BN, Case 1, 2, 10, 11 are processed

H. Gan, V. Sapozhnykov, et. al.

example portion of original and afh hopping sequence

G

G

G

G

G

G

G

BN

BN

G

G

G

BK

G

BK

BN

G

BK

G

BK

G

BN

G

G

G

BN

BK

BK

BK

G

G

G

G

G

BK

G

G

G

G

BK

BK

G

BN

BN

BN

BK

BK

G

G

BK

BK

G

G

BK

G

G

Example Portion of Original and AFH Hopping Sequence

AFH

In this example, 7 more ‘Good Good’ channel pairs are created

H. Gan, V. Sapozhnykov, et. al.

afh approach1
AFH Approach

- ‘Fit Best’ Instant Channel Replacement (Fit Best ICR)

The only difference from Standard ICR is that higher priority traffic such as SCO voice link can have more good channels

H. Gan, V. Sapozhnykov, et. al.

how fit best icr works
How Fit Best ICR works
  • At higher priority timeslots such as reserved HV2 SCO 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.
  • At lower priority timeslots, if there is any GUD debt, it must be repaid
    • ‘Good Bad’ ‘Bad Bad’ , to repay the GUD by 1;
    • ‘Good Good’ ‘Bad Bad’, to repay the GUD by 2.
    • If No GUD debt, just do standard ICR.
  • GUD balance is always towards ZERO, to maintain equal channel usage

H. Gan, V. Sapozhnykov, et. al.

fit best icr processing table
Fit Best ICR Processing Table

At timeslots for higher priority traffic, such as voice HV2

Repay the debt

At timeslots for lower priority traffic

Repay the Good Channel Usage Debt (GUD)

H. Gan, V. Sapozhnykov, et. al.

general principle of fit best icr
General Principle of Fit Best ICR
  • For HV2 and HV3 link:
    • 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

H. Gan, V. Sapozhnykov, et. al.

mixed sco hv2 hv3 and acl links

T

T

T

T

T

T

T

T

T

T

T

T

R

R

R

R

R

R

R

R

R

R

R

R

Mixed SCO (HV2, HV3) and ACL Links

HV2

ACL

HV2

ACL

HV2

ACL

HV2 reserves half Timeslots, transmits every four Timeslots

HV3

ACL

ACL

HV3

ACL

ACL

HV3 reserves one third Timeslots, transmits every six Timeslots

H. Gan, V. Sapozhnykov, et. al.

how fit best icr works assuming hv2 has higher priority

G

G

BK

G

BK

BK

G

G

G

G

BK

G

G

BK

G

BK

BK

G

G

BK

G

BK

BK

BK

G

G

G

G

G

BK

BK

BK

G

G

G

BK

BK

G

G

G

BK

BK

G

G

BK

G

BK

G

G

BK

G

G

G

BK

G

G

How Fit Best ICR works(Assuming HV2 has higher priority)

ACL

HV2

ACL

HV2

ACL

HV2

HV2

1 2 3 4 5 6 7

ACL

HV2

ACL

HV2

ACL

HV2

ACL

8 9 10 11 12 13 14

AFH

ACL

HV2

ACL

HV2

ACL

HV2

HV2

1 2 3 4 5 6 7

ACL

HV2

ACL

HV2

ACL

HV2

ACL

8 9 10 11 12 13 14

H. Gan, V. Sapozhnykov, et. al.

summary afh approach v s traffic type
Summary: AFH Approach v.s. Traffic Type

H. Gan, V. Sapozhnykov, et. al.

conclusion
Conclusion
  • A simple AFH mechanism to cover all traffic types (ACL, SCO, Mixed ACL/SCO), high priority traffic such as SCO can get more good channels
  • A simple AFH to cover both low power and high power modes
  • AFH removes as many Bad channels as legally possible
  • Kept Bad channels are intelligently used in the hopping sequence
  • The AFH channel replacement works on a per channel pair basis instantly, NO complicated ACL and SCO partition sequence generator is needed.
  • Better backward compatibility with legacy devices. Master’s Tx channels are kept in the original positions in the hoping sequence, good for piconet synchronization, broadcast, Park mode, Sniff mode, beacon channel, etc.
  • Legacy devices also benefits from the new AFH approach
  • A harmonized simple AFH mechanism

H. Gan, V. Sapozhnykov, et. al.