1. Mar. 2004
Project: IEEE P 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:[ ], FAX: [ ],
Re: [ b-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 MAC Standard.]
Notice: This document has been prepared to assist the IEEE P 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 P
Song-Lin Young[Sharp Labs.]

2. Mar. 2004
CTA Advertisement for Overlapping Piconets Song-Lin Young Sharp Labs. of America, Inc.
Song-Lin Young[Sharp Labs.]

3. Contents Introduction Issues associated with PNC/beacon
Mar. 2004
Contents
Introduction
Issues associated with PNC/beacon
CTA announcement mechanism
Conclusions and future work
Song-Lin Young[Sharp Labs.]

4. Mar. 2004
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
Song-Lin Young[Sharp Labs.]

5. Simple Piconet Configuration
Mar. 2004
Simple Piconet Configuration
Device 1
Beacon
PNC
Beacon
CTA 1
CTA 2
Device 2
Superframe N
Superframe N+1
CTA 2
Beacon
Beacon
PNC 1
CTA 1
CTA 1
Device 1
Device 2
Song-Lin Young[Sharp Labs.]

6. Overlapping Piconets PNC 2 is not able to hear beacons form PNC 1
Mar. 2004
Overlapping Piconets
PNC 1
Device 1
PNC 2
Beacon
PNC
Device 1
PNC 2
Beacon
Device 2
PNC 2 is not able to hear beacons form PNC 1
Device 2 is not able to hear beacons from PNC 1
Song-Lin Young[Sharp Labs.]

7. Potential Interference Scenario
Mar. 2004
Potential Interference Scenario
CTA
Superframe
Beacon
PNC 1
Device 1
PNC 2 or
Device 2
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
Song-Lin Young[Sharp Labs.]

8. Mar. 2004
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
Song-Lin Young[Sharp Labs.]

9. Beacon Frame Format Mar. 2004 p0 (Superframe starts) Superframe
Duration
Preamble
Header
CTA # 1
CTA # 2
CTA # 3
CTA # n
FCS
Dev A
Address
Dev B
Address
Stream
Index
CTA
Location
CTA
Duration
Song-Lin Young[Sharp Labs.]

10. Quasi-Beacon Frame Format
Mar. 2004
Quasi-Beacon Frame Format
p0 (Packet starts)
Preamble
Header
Data
FCS
Superframe
Duration
Frame Control
CTA # n
HCS
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.
Song-Lin Young[Sharp Labs.]

11. Conclusions CTA Advertisement Solve hidden node problem
Mar. 2004
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
Song-Lin Young[Sharp Labs.]

12. Future Work Asymmetric data transfer Streaming applications
Mar. 2004
Future Work
Asymmetric data transfer
Delay Ack frames which occur less frequently
Streaming applications
No Ack frame
Song-Lin Young[Sharp Labs.]