project: ieee p802.15 working group for wireless personal area networks (wpans)
DESCRIPTION
Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title: [ CTA Advertisement for Overlapping Piconets ] Date Submitted: [ Mar. 2004] Source: [Song-Lin Young] Company [Sharp Labs. of America, Inc.] Address [5750 NW Pacific Rim Blvd, Camas, WA, 98607] - PowerPoint PPT PresentationTRANSCRIPT
Mar. 2004
Song-Lin Young[Sharp Labs.]Slide 1
doc.: 15-04-0091-00-003b
Submission
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: [CTA Advertisement for Overlapping Piconets]Date Submitted: [Mar. 2004]
Source: [Song-Lin Young] Company [Sharp Labs. of America, Inc.]Address [5750 NW Pacific Rim Blvd, Camas, WA, 98607]Voice:[+1 360 817 7509], FAX: [+1 360 834 8696], E-Mail [[email protected]]
Re: [15-04-0034-01-003b-SG3b-Closing-Report-Jan04.ppt]
Abstract: [This document provides the method for announcement of CTA by non-PNC devices to uncoordinated piconet.]
Purpose: [This contribution is a response to SG3b call for submission about proposed amendment of 802.15.3 MAC Standard.]
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.
Mar. 2004
Song-Lin Young[Sharp Labs.]Slide 2
doc.: 15-04-0091-00-003b
Submission
CTA Advertisement for Overlapping Piconets
Song-Lin YoungSharp Labs. of America, Inc.
Mar. 2004
Song-Lin Young[Sharp Labs.]Slide 3
doc.: 15-04-0091-00-003b
Submission
Contents
• Introduction
• Issues associated with PNC/beacon
• CTA announcement mechanism
• Conclusions and future work
Mar. 2004
Song-Lin Young[Sharp Labs.]Slide 4
doc.: 15-04-0091-00-003b
Submission
Introduction
• Operations of 15.3 WPAN require devices to find a PNC (and its beacons) in order to engage in piconet activities.
• Multiple piconet overlapping scenarios are expected to occur in a dynamic environment, such as home networking.– Device may start a piconet without knowing the existence of
a nearby PNC.– Piconet consisting of portable devices may be carried
around and brought into area of other piconets.– Changes of topology due to moving objects/people
Mar. 2004
Song-Lin Young[Sharp Labs.]Slide 5
doc.: 15-04-0091-00-003b
Submission
Simple Piconet Configuration
PNC
Device 1Beacon
Device 2
BeaconCTA 1
CTA 2
CTA 1 CTA 1
Superframe N Superframe N+1
Beacon BeaconCTA 2
PNC 1
Device 1
Device 2
Mar. 2004
Song-Lin Young[Sharp Labs.]Slide 6
doc.: 15-04-0091-00-003b
Submission
Overlapping Piconets
PNC 1
Device 1
PNC 2
Beacon PNCDevice 1
PNC 2Beacon
Device 2
A. PNC 2 is not able to hear beacons form PNC 1
B. Device 2 is not able to hear beacons from PNC 1
Mar. 2004
Song-Lin Young[Sharp Labs.]Slide 7
doc.: 15-04-0091-00-003b
Submission
Potential Interference Scenario
CTA CTA
Superframe Superframe
Beacon BeaconBeacon
PNC 1
Device 1
PNC 2 orDevice 2
Interference Interference
• Device 1 (PNC 1) is scheduled to transmit during the assigned CTA(s)
• PNC 2/Device 2 will be interfered during Device 1 CTA if two piconets are not coordinated
Mar. 2004
Song-Lin Young[Sharp Labs.]Slide 8
doc.: 15-04-0091-00-003b
Submission
Basic Concept
• A mechanism is needed to advertise piconet timing and CTA for those unassociated devices not covered by PNC
• Extending the coverage area of beacons such that superframe timing and CTA information is available for:– Making it possible for devices to be aware of
existing piconets via scan operation.– Better selection of channel/frequency usage.– Co-existence by sharing channel time
Mar. 2004
Song-Lin Young[Sharp Labs.]Slide 9
doc.: 15-04-0091-00-003b
Submission
Beacon Frame Format
Preamble Header SuperframeDuration
CTA # 1 CTA # 2 CTA # 3 CTA # n FCS
p0 (Superframe starts)
Dev AAddress
Dev BAddress
StreamIndex
CTADuration
CTALocation
Mar. 2004
Song-Lin Young[Sharp Labs.]Slide 10
doc.: 15-04-0091-00-003b
Submission
Quasi-Beacon Frame Format
• During transmission, the device advertises its CTA(s) containing duration and offset from beginning of superframe
• Only corresponding CTA of transmitting device are advertised.• Superframe duration can also be included.• Applicable to Data, command, and Ack frame types.
SuperframeDuration CTA # nFrame Control
Preamble Header Data FCS
p0 (Packet starts)
HCS
Mar. 2004
Song-Lin Young[Sharp Labs.]Slide 11
doc.: 15-04-0091-00-003b
Submission
Conclusions
CTA Advertisement
• Solve hidden node problem
• Facilitate the following operations:– Coexistence of multiple piconets– Coordination/synchronization of piconets– Device discovery
• Minimum overhead to each packet
Mar. 2004
Song-Lin Young[Sharp Labs.]Slide 12
doc.: 15-04-0091-00-003b
Submission
Future Work
• Asymmetric data transfer– Delay Ack frames which occur less
frequently
• Streaming applications– No Ack frame