1. Radio Resource Measurements : Timing and Scheduling Considerations
September 2002
Radio Resource Measurements : Timing and Scheduling Considerations
Dr. Mehul Mehta
Synad Technologies, Ltd.
Reading. U.K
Dr. Mehul Mehta, Synad Technologies Ltd. UK

2. Introduction Initiate discussion on
June 2002
doc.: IEEE /xxxr0
September 2002
Introduction
Initiate discussion on
Signalling issues concerning Radio Resource Measurement (RRM)
Possible formats and types
Confidence in measurements
Systems Issues
Dr. Mehul Mehta, Synad Technologies Ltd. UK
Mike Moreton, Synad Technologies Ltd.

3. June 2002
doc.: IEEE /xxxr0
September 2002
The Aim of RRM is…
To reliably measure and report radio link measurements
Within a BSS, ESS, or beyond
Request/Response Protocol
Signal _request
Perform measurement
Signal _response
When to measure
Random RRM request
Pseudo-Periodic RRM request
Periodic RRM request
Periodic RRM without individual request
How to measure
Need to define common understanding and methods for calculating each entity
Dr. Mehul Mehta, Synad Technologies Ltd. UK
Mike Moreton, Synad Technologies Ltd.

4. RRM Request Types Random RRM request Pseudo-Periodic RRM request
June 2002
doc.: IEEE /xxxr0
September 2002
RRM Request Types
Random RRM request
Occasional
Fixed or Event based measurement period
Pseudo-Periodic RRM request
Intermittent
Fixed number of requests over a given time interval
Periodic RRM request
Regular
Fixed number of requests at specific intervals over a given time period
Predefined measurement period (a priori)
Periodic RRM without individual request
Single initial request, subsequent periodic responses
Dr. Mehul Mehta, Synad Technologies Ltd. UK
Mike Moreton, Synad Technologies Ltd.

5. RRM Response Types High priority response Rapid response
June 2002
doc.: IEEE /xxxr0
September 2002
RRM Response Types
High priority response
else measurement is timed out and hence invalid
Rapid response
takes priority over data traffic
Best effort response
takes same priority as data traffic
Low/Medium priority response
relatively long response time interval
Dr. Mehul Mehta, Synad Technologies Ltd. UK
Mike Moreton, Synad Technologies Ltd.

6. Possible RRM Signalling
June 2002
doc.: IEEE /xxxr0
September 2002
Possible RRM Signalling
_request(parameters)
Point-to-point, Multicast, Broadcast
One or more RRM with a single request
Initiated by AP or STA
Parameters could include
Identifier, confidence rating, and validity time stamp
Desired response type and time period
Single response
Multiple responses at regular intervals
_ack() fields
accept, reject, revised offer
_response()
Return one or more RRMs
Combine one or more responses
e.g. AP
e.g., STA
_request(parameters)
_ack()
_response(measurement(s))
Dr. Mehul Mehta, Synad Technologies Ltd. UK
Mike Moreton, Synad Technologies Ltd.

7. Confidence in Measurements
June 2002
doc.: IEEE /xxxr0
September 2002
Confidence in Measurements
Packet Networks exhibit bursty traffic conditions
Lack of regular uninterrupted transmission period
RRM will have to be over spasmodic transmission intervals
Overall measurement duration may be extended to meet accuracy
Statistical estimates can degrade significantly
Will affect decisions made with potentially inaccurate measurements
Measurement accuracy varies
Type of measurement, response duration, traffic conditions
Need to define how each RRM is calculated
Identify frame types best suited for each measurement
Suggest duration (time and events) for statistical confidence
RRMs must each have a time stamp
Valid (e.g., most recent) or Invalid (e.g., previously recorded)
Dr. Mehul Mehta, Synad Technologies Ltd. UK
Mike Moreton, Synad Technologies Ltd.

8. System Issues Scheduling of measurement requests may vary
June 2002
doc.: IEEE /xxxr0
September 2002
System Issues
Scheduling of measurement requests may vary
Rival policies may issue measurement requests at different times and at different rates
Depends on network density
Number of APs, STAs
Traffic mix (real-time, Non real-time, QoS stamps etc.)
Cost of measurement requests may vary
Bandwidth consumption and effect on throughput
Vary between BSSs of different traffic mix with time
RMM signals will compete for the medium
Need to resolve radio access conflicts
Priority queuing of RMM frames
Dr. Mehul Mehta, Synad Technologies Ltd. UK
Mike Moreton, Synad Technologies Ltd.

9. In summary… Requirements for RRM…
June 2002
doc.: IEEE /xxxr0
September 2002
In summary…
Requirements for RRM…
Types of radio link attributes needed
Accuracy, Confidence, Validity
List the different RRM and organise them
Occasionally, Intermittently, Regularly, Frequently
…will depend on entities that will use RRMs
Target deployment type
Public WLAN access, Enterprise, Home, SOHO, others
Complexity and ‘Sophistication’ of the incumbent policies
…and would also help structure the measurements
Database type ‘key’ access
Interface with minimal complexity
Dr. Mehul Mehta, Synad Technologies Ltd. UK
Mike Moreton, Synad Technologies Ltd.