Transcript IEEE 802.11T March 2005 Tom Alexander VeriWave, Inc.

March 2005
IEEE 802.11T
March 2005
Tom Alexander
VeriWave, Inc.
Slide 1
Tom Alexander
March 2005
What is IEEE 802.11T?
• Task group within the IEEE 802.11 Wireless LANs group
• Formally created in August 2004 to recommend methods
for testing performance of 802.11 devices and systems
– Goal: establish a common framework, terminology and
methodology for the 802.11 Wireless LAN industry
Slide 2
Tom Alexander
March 2005
Objectives of 802.11T
• Scope and purpose
– Official scope: “to provide a set of performance metrics,
measurement methodologies, and test conditions to enable
measuring and predicting the performance of 802.11 WLAN
devices and networks at the component and application level”
– Official purpose: “to enable testing, comparison, and deployment
planning of 802.11 WLAN devices based on a common and
accepted set of performance metrics, measurement methodologies
and test conditions”
• Output will be IEEE 802.11.2, a “Recommended Practice”
– Uses the word “should”
Slide 3
Tom Alexander
March 2005
Vital Statistics
• Officers
– Chair: Charles Wright, Azimuth Systems
– Technical Editor: Tom Alexander, VeriWave Inc
– Secretary: none yet
• About 15 – 20 active members
– Sometimes up to 40 people attend
• Involvement from a broad cross-section of the WLAN industry
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System and chipset vendors: Dell, Intel, Broadcom, AMD, Atheros, …
Test equipment vendors: Spirent, Azimuth, Rohde & Schwarz, VeriWave, …
Installation tools & services vendors: Wireless Valley, …
Users: Microsoft, UBC, UNH-IOL, …
And some just plain interested folks
• Activity
– Meets during every 802.11 interim or Plenary for about 10 – 16 hours
– Weekly teleconferences (Thursday mornings, 9AM PST)
– Ad-hoc teleconferences
Slide 4
Tom Alexander
March 2005
Work To Date
•
Scope and framework
– What kind of metrics? What sort of approach to measurement? What layer(s) do we
include?
– Diverse group; these discussions help build common understanding
– General consensus on some key issues
• Both open-air and conducted metrics should be specified
• Metrics should be somehow tied to end-user experience
• Etc.
•
Draft structure
– Proposed templates for the overall draft and for individual measurement
descriptions have been created, plus proposals for the organization of the standard
•
Terminology
– Key discussion point in group to date (e.g., “What is a metric? What does
‘controlled environment’ imply?)
•
Lots of “this is how we did it” and “this is how we should do it” presentations
– Very useful in assessing what is possible and what is not
– Wireless measurement methodologies differ somewhat from wired
Slide 5
Tom Alexander
March 2005
Recent and Upcoming Work
• Convergence on some basic terminology
– Examples: ‘controlled test environment’, ‘conducted test’, ‘overthe-air test’, ‘interference’, etc.
– Most of these are specific to wireless testing (as opposed to
benchmarking in general)
• Not much disagreement (yet!) on terms such as latency, throughput,
loss, delay, etc.
• Adoption of ground rules before voting on formal
proposals
– Requirements for a proposal to be considered “complete”
– Format and content of formal metrics & methodology proposals
• Timeline for first draft standard: uncertain at the moment
Slide 6
Tom Alexander
March 2005
For Further Information …
• The 802.11 document server
– www.802wirelessworld.com – 802.11 document server with 802.11T
contributions
– Examples of interesting contributions:
• # 11-04-1160-00-000t Enabling Prediction of Wireless Performance
• # 11-04-1202-00-000t Proposed Metrics and TGT Call to Action
• # 11-04-1222-01-000t Measurement Methodology Proposal Based on
Approved Framework
• # 11-05-1582-00-000t Environment and Metrics: Laboratory vs. Real-world
• # 11-05-0002-00-000t Proposed TGT Document Structure
• # 11-05-0004-01-000t TGT Terminology and Concepts
• The 802.11T reflector
• March 802.11 Plenary
– March 14th to 18th, Atlanta, GA
Slide 7
Tom Alexander