1. “802.11 Radio Measurements in Support of WLAN Management”
Month 2000
doc.: IEEE /xxx
November 2001
“ Radio Measurements in Support of WLAN Management”
Byoung-Jo “J” Kim, Zoran Kostic, Mathew Sherman, Harry Worstell
AT&T Labs - Research
NJ, USA
Date: Nov. 12th, 2001
Z. Kostic and ”J” Kim, AT&T Labs - Research
John Doe, His Company

2. Motivation for Pursuing Support for Radio Measurement in 802.11
Month 2000
doc.: IEEE /xxx
November 2001
Motivation for Pursuing Support for Radio Measurement in
Fundamental enabler for automated WLAN management
Existence of unpredictable interference in unlicensed bands
Required for tools for Automatic Planning, Deployment, Maintenance
Simple versions are a de-facto Need for today’s products
Higher density, bigger coverage WLAN deployments are coming (Hong Kong, Singapore, Europe: Potential Operators Concerned about rapid deployment, interference management of Public WLAN)
Simple Proprietary solutions exist, but opening the interfaces, allowing the interoperability and third party solutions are beneficial
Needed for interoperability/radio resource management with other wireless technologies -Activities by 3G vendors in support of joint management of cellular/WLAN systems
Progress in TGh & TGf:
A good Starting point for RRM: DFS, TPC, IAPP
Z. Kostic and ”J” Kim, AT&T Labs - Research
John Doe, His Company

3. Thoughts on the Use of Radio Measurements
November 2001
Thoughts on the Use of Radio Measurements
Contained within a BSS
Measurement and Reporting methods between an AP & STA’s in a single BSS
Suitable for small deployment, unmanaged, Multi-dwelling, etc.
Coordinated between BSS
Involving multiple BSS’s
Communication between APs and/or external managers over wireline networks
Suitable for Large deployment, Enterprise, etc.
Needed for coordination with 3G services
Z. Kostic and ”J” Kim, AT&T Labs - Research

4. Measurements Contained Within a BSS
November 2001
Measurements Contained Within a BSS
Extend DCS to all Radio Interfaces
Measurements at STA’s and AP
What and How to measure
Where to measure (PHY/MAC)
How to trigger measurements
How to exchange results
in Support of Autonomous Radio Resource Management
Load Balancing
Power control
Interference management
Z. Kostic and ”J” Kim, AT&T Labs - Research

5. Sharing the Measurements, e.g., Extending the Published MIB
Month 2000
doc.: IEEE /xxx
November 2001
Sharing the Measurements, e.g., Extending the Published MIB
dot11CurrentChannel, dot11EDThreshold
Radio Measurement Results by STA’s and AP’
loading (number of STA’s associated, number of STA’s, frames transmit/received during last second/min, etc.)
Per STA statistics seen at AP’s
Beacon transmit power (extend dot11CurrentTxPowerLevel per STA & beacon, Keep a sliding window average)
Extend Counter objects to include /sec or /min averages, average number of retransmissions, etc., to reduce number of polling
Traps to detect changes in the network (New beacon heard, high load, new STA joined/left, etc.)
Z. Kostic and ”J” Kim, AT&T Labs - Research
John Doe, His Company

6. Communication Means for Exchanging Measurement Results
November 2001
Communication Means for Exchanging Measurement Results
Among AP’s
Extend IAPP to support Radio Measurement Result exchange among AP’s
Among AP’s or with External Entities
SNMP managers accessing MIB’s at AP’s
Limited Coordination among nearby WLAN’s owned by different entities: Over-the-air
Wired access is not assured.
Dynamic Channel Selection
Z. Kostic and ”J” Kim, AT&T Labs - Research

7. Extending the ideas from 802.11h
November 2001
Extending the ideas from h
For DFS:
Channel Monitoring
AP Channel Measurement Requests
Channel Measurement Process in STAs
Measurement reports from STAs to AP
MODIFICATION: Collecting inputs (via SNMP or IAPP) from other APs and/or central radio resource manager (Need standard Mapping of measurement report to IAPP, or MIB )
AP or Manager decision making
AP Channel Switch Announcement
The new channel switch !
Power control
Mobile decides everything, but AP can still provide SNR or Signal Strength to aid mobile to make better decisions.
SNR is asymmetric due to interference.
Z. Kostic and ”J” Kim, AT&T Labs - Research

8. Benefits of Radio Measurement Support
November 2001
Benefits of Radio Measurement Support
Enable Advanced Deployment, Management and Expansion Tools
Economic Deployment and Management of Large-scale Networks (airports, downtown, etc)
Better co-existence of independent WLAN’s
Enable Higher Capacity
Enable Better Load balancing
More Robustness to interference
Z. Kostic and ”J” Kim, AT&T Labs - Research

9. What to do now? Start an ad-hoc group to study the issues:
November 2001
What to do now?
Start an ad-hoc group to study the issues:
What measurements are needed to support current and future needs (such as radio resource management)
What are the basic mechanisms that need to be in standards for radio measurement - protocols, PHY, MAC changes, MIB extension
What can be done within existing TG’s to accommodate radio measurement? (MIB, TGe, TGf, TGh.)
Consider creating a study group and PAR for a TG if needed
We invite interested people to get involved – send s to and
Z. Kostic and ”J” Kim, AT&T Labs - Research