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January 2009
Darwin Engwer, Nortel Networks
Slide 1
doc.: IEEE 802.11-09/0118r0
Submission
MAC Breakdown Update
Date: 2009-01-19
Name Company Address Phone email Darwin Engwer Nortel
Networks 4655 Great America Pkwy, Santa Clara CA 95054
+1-408-495-2588
dengwer at nortel.com
Authors:
January 2009
Darwin Engwer, Nortel Networks
Slide 2
doc.: IEEE 802.11-09/0118r0
Submission
Abstract
This submission provides an update on the MAC breakdown work accomplished during the 2008-12-16 and 2009-01-13 conference calls.
January 2009
Darwin Engwer, Nortel Networks
Slide 3
doc.: IEEE 802.11-09/0118r0
Submission
Outline
• Recap of MAC Component Breakdown WIP
• BSS Management Analysis for 2008-12-16
• Insights from the 2008-12-16 analysis
• Intro to Functional Analysis
• WLAN Functional Breakdown
• Next Steps
• References
• References for conf calls
• F.A.S.T. References
January 2009
Darwin Engwer, Nortel Networks
Slide 4
doc.: IEEE 802.11-09/0118r0
Submission
Recap of MAC Component Breakdown work-in-progress (WIP)
• In previous meetings and conf calls we made progress on construction of a MAC component breakdown.
• The result after the Nov 2008 meeting:– 11-08-1298-01-0arc-MAC-component-breakdown.doc
• The work continued in two recent conference calls: 2008-12-16 and 2009-01-13.– The agenda for those calls was to continue the incremental work
on the MAC component breakdown diagram and descriptions.– The objective was to delve deeper into Block 10, "MLME", on the
top level diagram and codify the aspects of the MLME that relate to formation and management of the BSS, including establishment, advertising, discovery and “membership” updates.
January 2009
Darwin Engwer, Nortel Networks
Slide 5
doc.: IEEE 802.11-09/0118r0
Submission
BSS Management Analysis for 2008-12-16
http://tinyurl.com/bss-manage-1 This is a hierarchical analysis diagram showing the components of BSS Mgmt,but it highlights the need for a functional breakdown.
January 2009
Darwin Engwer, Nortel Networks
Slide 6
doc.: IEEE 802.11-09/0118r0
Submission
Insights from the 2008-12-16 analysis
• The discussion led to a meta discussion on the nature of the MAC breakdown work since the BSS Management block is difficult to decompose from a component perspective but easy from functional perspective. This is because a component breakdown becomes more complicated as finer levels of detail are sought because state must be indicated and there are always exceptions.
• Past discussions have revealed that everyone knows how to do component breakdown – the difficulty is that everyone does it differently.
• This is understandable since the participants come from different backgrounds (e.g. chip mfgr, systems engineer, architect, ...), work in different engineering environments, and operate at different levels of analysis and implementation. i.e. the components are arbitrary.
• A full MAC analysis requires both a component and a functional breakdown. Thus, pursuing a functional breakdown of the MLME block is not counter to the current MAC analysis efforts.
• In particular, a functional analysis might add insight and meaning to the analysis of BSS Management.
• Functional analysis leads to a deeper understanding of the reasons behind and the relations between the most important functions. This outcome is aligned the goals of the ARC SC work.
January 2009
Darwin Engwer, Nortel Networks
Slide 7
doc.: IEEE 802.11-09/0118r0
Submission
Intro to Functional Analysis
• Function Analysis Systems Technique (F.A.S.T.) is a formal method of functional analysis.
• FAST is “a means of explicitly representing something, a means of analyzing a system”
• Knowing the components, a FAST analysis proceeds by asking a series of WHY, HOW questions to uncover the corresponding functions and the relations between those functions.– The functions are arranged as entries or blocks on a diagram with
WHY answers on the left and HOW answers on the right.– Functions are described using simple verb-noun phrases.– Relationship lines connect the functional blocks together in a way
that captures the relations between the functions.
January 2009
Darwin Engwer, Nortel Networks
Slide 8
doc.: IEEE 802.11-09/0118r0
Submission
FAST Example
• Lightbulb components:– Filament
– Glass bulb
– Support wires
– Lead-in wires
– Heat deflecting disc
– Stem
– Stem press
– Base rim
– Insulation
– Center contact
January 2009
Darwin Engwer, Nortel Networks
Slide 9
doc.: IEEE 802.11-09/0118r0
Submission
FAST Example - Light Bulb Functions
ProvideLuminousEnergy
Product Light
ConvertEnergy
HeatFilament
Prevent Oxidation
ConfineFilament
HOW WHY
Exclude Oxygen
SupplyPower
ConductCurrent
ConnectWires
January 2009
Darwin Engwer, Nortel Networks
Slide 10
doc.: IEEE 802.11-09/0118r0
Submission
The Mindomo Tool
• A mind map tool is not idea for drawing FAST diagrams, but it’s close and quick and easy to use, with capable online versions available that allow for effective collaborative work efforts.
• Mindomo is one such mind map tool.See www.mindomo.com
January 2009
Darwin Engwer, Nortel Networks
Slide 11
doc.: IEEE 802.11-09/0118r0
Submission
WLAN Functional Breakdown rev 1
http://tinyurl.com/bss-manage-2This is an analysis diagram in transition to a FAST diagram, beginning to examine the underlying functions of the MAC and the relationships between those functions.
HOW WHY
January 2009
Darwin Engwer, Nortel Networks
Slide 12
doc.: IEEE 802.11-09/0118r0
Submission
WLAN Functional Breakdown rev 2
This is an analysis diagram in transition to a FAST diagram, beginning to examine the underlying functions of the MAC and the relationships between those functions.
HOW WHY
January 2009
Darwin Engwer, Nortel Networks
Slide 13
doc.: IEEE 802.11-09/0118r0
Submission
WLAN Functional Breakdown rev 3
This is an analysis diagram in transition to a FAST diagram, beginning to examine the underlying functions of the MAC and the relationships between those functions.
HOW WHY
January 2009
Darwin Engwer, Nortel Networks
Slide 14
doc.: IEEE 802.11-09/0118r0
Submission
Next Steps
• Construct a MAC functional breakdown to argument our component level breakdown since ultimately both are needed.– We have the necessary subject matter experts (SMEs).
– Functional analysis is well suited to a collaborative team effort.
– The functional breakdown will be useful to our ongoing ARC efforts and those of other groups.
January 2009
Darwin Engwer, Nortel Networks
Slide 15
doc.: IEEE 802.11-09/0118r0
Submission
References
• 1. IEEE Std. 802.11-2007– Cl. 5 General Description
• 5.2.5 Integration with non-802.11 LANs• Figure 5.6 Connecting to other IEEE 802 LANs [shows portal]
– Annex N AP Functional Description• Figure N.4 High-level UML entity diagram for the WLAN system• Figure N.5 AP UML composition diagram (alternate syntax)
• 2. 11-04-1225-08 AP Function Summary• 3. 11-08-0496-01-000v-merged-access-unit-framework.ppt, Engwer,
April 2008• 4. 11-05-1606-00-0apf-ap-functions-diagram.ppt, Engwer, Jan 2005• 5. 11-08-0867-01-0arc-MAC-Component-Breakdown-Topics-for-
Discussion.ppt• 6. 11-08-0869-00-0arc-minutes-arc-sc-July-2008.doc• 7. 11-08-0949-04-0arc-MAC-Component-Breakdown-WIP.ppt• 8. 11-08-1298-01-0arc-MAC-component-breakdown.doc
January 2009
Darwin Engwer, Nortel Networks
Slide 16
doc.: IEEE 802.11-09/0118r0
Submission
References for 2008-12-16 and 2009-01-13 conference calls
• 2008-12-16:– JPG image of MLME component breakdown of BSS Management
• http://tinyurl.com/bss-manage-1
• 2008-01-13:– JPG image of WLAN functional breakdown map rev1 2009-01-12
• http://tinyurl.com/bss-manage-2
– Mindomo map of WLAN functional breakdown• http://tinyurl.com/7eksy2
January 2009
Darwin Engwer, Nortel Networks
Slide 17
doc.: IEEE 802.11-09/0118r0
Submission
Function Analysis Systems Technique (F.A.S.T.) References
• “Function Analysis As A General Design Dicipline”, Dan A. Seni, P.Eng., Ph.D. Professor, Department of the Management of Technology. School of Management, University of Quebec at Montreal, 2004, www.value-eng.org/knowledge_bank/attachments/200441.pdf
• “Genesis of FAST”, Charles W. Bytheway, 2005, http://www.value-eng.org/knowledge_bank/attachments/Genesis%20of%20FAST.pdf
• “Function Analysis and Decomposition Using Function Analysis Systems Technique”, Charles W. Bytheway, 1999-06-10, www.osti.gov/bridge/servlets/purl/8929-OkjsUp/native/8929.PDF
• “Functional Analysis System Technique (F.A.S.T.) as a Group Knowledge Elicitation Method for Model Building”, J.E. Bartolomei, T. Miller, 2001, http://www.systemdynamics.org/conferences/2001/papers/Bartolomei_2.pdf
• “Value: Its Measurement, Design, and Management”, M. Larry Shillito, David J. De Marle, 1992, (Google Books), http://books.google.com/books?id=e01LfamiCpUC&pg=PA153&lpg=PA153&dq=charles+bytheway+%22light+bulb%22&source=web&ots=nfrS-5o7nM&sig=whr5YhytmTz8JnmRqVOnlJbSbxE&hl=en&sa=X&oi=book_result&resnum=3&ct=result
January 2009
Darwin Engwer, Nortel Networks
Slide 18
doc.: IEEE 802.11-09/0118r0
Submission
Revisions
• r0: 2009-01-19 Created.
