1. doc.: IEEE 802.15-<doc#>
<month year>
doc.: IEEE <doc#>
January 2006
Project: IEEE P Working Group for Wireless Personal Area Networks (WPANs)
Submission Title: [Simple DAA Support]
Date Submitted: [17 January, 2006]
Sources:
[Joe Decuir] Company [MCCI]
Address [18814 SE 42nd St, Issaquah, WA 98027]
Voice:[ ], FAX: [ ],
Re: [Simple DAA Support]
Abstract: [Simple additions to draft a to support DAA, modeled on IEEE h]
Purpose: [Help accommodate anticipated world wide regulations and ballot comments]
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
Decuir
<author>, <company>

2. January 2006
Introduction & Scope
TG4a is resolving ballots on the first draft of IEEE a (LB33).
Some of those ballots call attention to proposed regulatory restrictions that require mitigation on the UWB PHY.
There are two kinds of mitigation:
Low Duty Cycle
Detect And Avoid (DAA)
This contribution is focused on a very simple implementation of DAA with the TG4a PHY.
Decuir

3. Goals of this presentation
January 2006
Goals of this presentation
Propose modifications to draft a so that it is possible for a system of compliant devices (piconet controller and simple devices) to implement DAA mitigation where it is required.
By doing so increase the chances that this standard can achieve acceptance by international regulators and by voters.
Decuir

4. Detect & Avoid Overview
January 2006
Detect & Avoid Overview
Three parts:
Detect signals of interest
Decide what signals to Avoid
Implement Avoidance
In this proposal:
Devices should help detection
Piconet controllers make decisions
Piconet controllers instruct devices on channel usage and avoidance
Decuir

5. 802.15.4a DAA would be simple The UWB PHY has very simple structure:
January 2006
a DAA would be simple
The UWB PHY has very simple structure:
Three 494 MHz channels in MHz
Eight 507 MHz channels in MHz
Four superset channels
Detection and Avoidance is in units of those channels:
Us the existing 500MHz granularity, not 4MHz
We don’t have the cost or flexibility of an OFDM radio with FFT and IFFT built in
We do need whatever flexibility the band plan has
Decuir

6. January 2006
Detection Support
Existing model: IEEE h provides an extension of a for detecting and avoiding signals in 5 – 6 GHz.
From h, use the concept of an STA asking another STA to make signal measurements and report results.
Assumptions:
a radios can only detect signals with the granularity of their UWB channels
a radios can recognize themselves
Decuir

7. Cooperative Detection in 802.15.4a
January 2006
Cooperative Detection in a
Define two new MAC frames, modeled on those in IEEE h:
Basic request ( /802.11h)
Basic report ( /802.11h)
Any device should support these frames if the system needs to support DAA
DAA support is subject to national and regional regulations; it is not a requirement of the standard.
Decuir

8. Suggested New MAC frame details
January 2006
Suggested New MAC frame details
Basic Request:
1 byte channel # (see Table 1b)
2 byte measurement time (units tbd)
[omit the ‘start time’ from h]
Basic Report:
1 byte channel #
2 byte measurement time
1 byte energy value (units tbd)
1 byte bit map of detected type:
Undetermined energy source
a UWB signals (e.g. preamble, MAC frame)
Optional but popular: other UWB like ECMA-368
Decuir

9. DAA Data Collection Methods
January 2006
DAA Data Collection Methods
This is difficult, because in principle victim receivers don’t transmit ‘I am a victim receiver’ messages. It helps if it transmits on the same channel that it receives on.
Detectors can listen for:
A local transmitter (easy to detect IFF it is on when you listen)
A remote transmitter (fainter signals are harder to detect, but false detection is a problem)
ETSI is working on DAA performance standards; perhaps also in Japan
The ETSI work might complete in summer 2006
Decuir

10. January 2006
DAA Decision Making
The definition of DAA decision logic is beyond the scope of the a PHY & MAC
The same is true for turning ranging data into location information, draft Annex D.
The logical place to implement DAA logic is in the piconet controller.
The standard should have information on example implementation (similar to material in section 10.3 and of h)
That logic might decide that reduced duty cycle would be appropriate mitigation in some conditions.
Decuir

11. Avoidance Implementation
January 2006
Avoidance Implementation
Avoidance is simple: which channel(s) to use and which to avoid.
Again, we don’t require an IFFT or banks of notch filters.
We would need more than one channel to choose from.
The piconet controller defined in the draft a already specifies the particular channel to use.
Nothing new needs to be defined
Decuir

12. January 2006
Operating Issues
Applications for high rate UWB PAN, like ECMA-368, may be really busy, so making time and frequency space to listen often enough is tricky.
Luckily, a systems are likely to have relatively low duty cycles, making it feasible to listen more often.
But: listening for signals costs power!
If the system duty cycles are low enough, DAA might not be necessary.
Decuir

13. January 2006
Recommendations
Detect & Avoid mitigation is tricky but possible for a system of a compliant devices.
Supporting that requires two MAC frames to be added, modeled on IEEE h.
The draft standard should have an informative Annex that illustrates how to use these features.
Suggested scenario: CEPT rules; ETSI compliance standard
TG4a should decide whether to use this approach.
TG4a may use ideas in this to draft additional material.
Including optional detection bit(s) for other UWB may help co-existence, for market acceptance and voter acceptance.
Decuir

14. January 2006
Credits
Andreas Molisch first mentioned the idea of using the simpler devices to be remote sensors for signals.
Colin Lanzl pointed out that there was already a model for this in IEEE h (which he participated in).
Decuir