doc.: IEEE /0867r1 Submission July 2008 Darwin Engwer, Nortel NetworksSlide 1 MAC Component Breakdown Topics for Discussion Date: Authors:
doc.: IEEE /0867r1 Submission July 2008 Darwin Engwer, Nortel NetworksSlide 2 Abstract This presentation enumerates some MAC component breakdown topics for discussion and shows some examples breakdowns for the purpose of initiating deeper discussions.
doc.: IEEE /0867r1 Submission July 2008 Darwin Engwer, Nortel NetworksSlide 3 Logistics Please view in slideshow mode to see the animations, which are an important part of the presentation.
doc.: IEEE /0867r1 Submission July 2008 Darwin Engwer, Nortel NetworksSlide 4 Outline Introduction/ Caveats Component Breakdown vs. Function Breakdown WLAN System Architecture Example Breakdowns –Access Unit Device Breakdown Top level Component detail (drill down sequence) –802.11u_D3.0 STA Breakdown –AP Component Breakdown –Possible VHT Work Breakdown –Single Breakdown Step Terms Real-time MAC Breakdown Work References
doc.: IEEE /0867r1 Submission July 2008 Darwin Engwer, Nortel NetworksSlide 5 Introduction/ Caveats An illustration – for discussion catalyst purposes only. An example to demonstrate the architectural framework result that is desired. Represents a sample component breakdown. Not the only component breakdown approach or the best approach, just an approach. Purpose is to show the components within and the relationship between those components in a consistent architectural framework.
doc.: IEEE /0867r1 Submission July 2008 Darwin Engwer, Nortel NetworksSlide 6 Component Breakdown Approach functional view vs. component view –functional view describes the functions without regard to any given component or architecture view (i.e. architecture independent) –component view is architecture dependent and can easily become device specific; therefore must strive to create an architectural component view Ultimately both views are required for a complete understanding.
doc.: IEEE /0867r1 Submission July 2008 Darwin Engwer, Nortel NetworksSlide WLAN System [1]
doc.: IEEE /0867r1 Submission July 2008 Darwin Engwer, Nortel NetworksSlide 8 Remember Equivalent AP Syntax [1]
doc.: IEEE /0867r1 Submission July 2008 Darwin Engwer, Nortel NetworksSlide 9 Non LAN / AN Access Unit (device) STA 1 Access Unit component breakdown sequence from [3], 8/496r1
doc.: IEEE /0867r1 Submission July 2008 Darwin Engwer, Nortel NetworksSlide 10 2 Non LAN / AN STA Access Unit Portal DS AP ACM_STA Access Unit component breakdown sequence from [3], 8/496r1
doc.: IEEE /0867r1 Submission July 2008 Darwin Engwer, Nortel NetworksSlide 11 3 Non LAN / AN STA Access Unit Portal DS AP ACM_STA ACM_MAC PHY Access Unit component breakdown sequence from [3], 8/496r1
doc.: IEEE /0867r1 Submission July 2008 Darwin Engwer, Nortel NetworksSlide 12 4 Non LAN / AN STA ACM_MAC Access Unit Portal DS AP ACM STA PHY Data Handling Mgmt (inc. SSID) Data fwd Beacons/Probes Authen. CA/NAV CSMA MPDU CTRL MMPDU MLME/ SME MAC SAP PHY SAP Access Unit component breakdown sequence from [3], 8/496r1
doc.: IEEE /0867r1 Submission July 2008 Darwin Engwer, Nortel NetworksSlide 13 5 Non LAN / AN STA ACM_MAC Access Unit Portal DS AP ACM STA PHY Data Handling Mgmt (inc. SSID) Data fwd Beacons/Probes Authen. CA/NAV CSMA MPDU CTRL MMPDU MLME/ SME MAC SAP PHY SAP Data Movement: -Queues -Filters/Gating BSS Mgmt: -Association -SSID Medium Access and Control Access Unit component breakdown sequence from [3], 8/496r1
doc.: IEEE /0867r1 Submission July 2008 Darwin Engwer, Nortel NetworksSlide 14 6 Non LAN / AN STA ACM_MAC Access Unit Portal DS AP ACM STA PHY Data Handling Mgmt (inc. SSID) Data fwd Beacons/Probes Authen. CA/NAV CSMA MPDU CTRL MMPDU MLME/ SME MAC SAP PHY SAP Data Movement: -Queues -Filters/Gating BSS Mgmt: -Association -SSID Medium Access and Control BSS Identity = SSID MAC Identity = BSSID Access Unit component breakdown sequence from [3], 8/496r1
doc.: IEEE /0867r1 Submission July 2008 Darwin Engwer, Nortel NetworksSlide 15 7 Non LAN / AN STA ACM_MAC Access Unit Portal DS AP ACM STA PHY Data Handling Mgmt (inc. SSID) Data fwd Beacons/Probes Authen. CA/NAV CSMA MPDU CTRL MMPDU MLME/ SME MAC SAP PHY SAP Data Movement: -Queues -Filters/Gating BSS Mgmt: -Association -SSID Medium Access and Control BSS Identity = SSID Addressable (BSSID) Non-addressable Access Unit component breakdown sequence from [3], 8/496r1
doc.: IEEE /0867r1 Submission July 2008 Darwin Engwer, Nortel NetworksSlide 16 STA Breakdown from u_D3.0
doc.: IEEE /0867r1 Submission July 2008 Darwin Engwer, Nortel NetworksSlide 17 FilteringBridging Encapsulation (integration) Decapsulation (integration) Queuing: -fairness -unfairness -bcst BWM Frag Data Scheduler: -normal -MOM Queuing: -fairness -unfairness BridgingFiltering DeFrag Net Mgmt Entity IAPP Mgmt Frame Processor Air Access Scheduler -CCA -NAV DSWM Buffer Aging Buffer Aging Address Table (w/ mobile STA context info) Aging Data Frame Tx Data Frame Rx Mgmt Frames AP Component Breakdown Example (from [6], 5/1606r0)
doc.: IEEE /0867r1 Submission July 2008 Darwin Engwer, Nortel NetworksSlide 18 Possible VHT Work Breakdown 60 GHz PHY 60 GHz Lower MAC Upper MAC (management) <6 GHz PHY <6 GHz Lower MAC VHT60 scope VHTL6 scope Legend: Legacy Upper MAC modification for VHT60 and VHTL6 Legacy Lower MAC Legacy PHY Link-mgmt & session switch Link-mgmt & session switch The majority of the work between VHTL6 and VHT60 can be independent (since the PHY and lower MAC is tightly coupled per band). There will be some overlapping MAC work between VHT60 and VHTL6. Illustrative example only, non-binding.
doc.: IEEE /0867r1 Submission July 2008 Darwin Engwer, Nortel NetworksSlide 19 Terms Upper/Lower/Middle are all relative terms and should be avoided. We need a scheme that allows for continuous stratification, division and relation of the various components. –Suggestion = a Dewey Decimal like system –Allows for infinite subdivision and specification
doc.: IEEE /0867r1 Submission July 2008 Darwin Engwer, Nortel NetworksSlide 20 Example of a Single Breakdown Step The figure at the right shows 3 types of frames that cross the PHY-SAP: MPDUs, Ctrl, MMPDUs. This is a common view. But, Stnd. defines that all frames at the PHY-SAP are MPDUs. Therefore we need a new name for the data laden MPDUs, say “n1”. n1 MPDUs
doc.: IEEE /0867r1 Submission July 2008 Darwin Engwer, Nortel NetworksSlide 21 Process ARC SC Mission: The ARC group is tasked to discover, analyze, codify, and promote a common understanding of architecture. –Discover: To notice or learn, especially by making an effort; Archaic To reveal or expose; –Analyze: To separate (a material or abstract entity) into constituent parts or elements; determine the elements or essential features of; –Codify: To arrange or systematize; –Promote: To help or encourage to exist or flourish; MAC Breakdown is an example of Discover, Analyze, Codify.
doc.: IEEE /0867r1 Submission July 2008 Darwin Engwer, Nortel NetworksSlide 22 MAC Component Breakdown MAC/MLME distinction is not so important right now. MLME-SME SAP is well defined, so ought not to include SME components.
doc.: IEEE /0867r1 Submission July 2008 Darwin Engwer, Nortel NetworksSlide 23 Real-time Breakdown Work To the Bat-Easel …
doc.: IEEE /0867r1 Submission July 2008 Darwin Engwer, Nortel NetworksSlide 24 Summary of Work at the Easel Clarified nature of diagrams on slides –Represents composite data flow/control flow diagram –Although control flows not called out – ought to be dashed lines Added fragmentation component to the diagram Reviewed doc 5/1606 AP Breakdown diagram as an additional example
doc.: IEEE /0867r1 Submission July 2008 Darwin Engwer, Nortel NetworksSlide 25 ACM_MAC MPDU. ACM STA PHY Data Handling Mgmt (inc. SSID) Data fwd Beacons/Probes Authen. CA/NAV CSMA MSDU MMSDU MLME/ SME Data Movement: -Queues -Filters/Gating BSS Mgmt: -Association -SSID Medium Contention and Access Frag/Defrag MSDU mux/demux & address matching Frame Tx/Rx Non-ctrl CTRL MSDU-MPDU Conversion STA-STA discovery & data xfer Addressable MAC MSDU MAC-SAP PHY-SAP
doc.: IEEE /0867r1 Submission July 2008 Darwin Engwer, Nortel NetworksSlide 26 References 1. IEEE Std –Cl. 5 General Description Integration with non 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) AP Function Summary v-merged-access-unit-framework.ppt, Engwer, April wng-need-ap-functional-descriptions.ppt, Engwer/O’Hara, May VHT Task Group Organization Approaches.ppt, Engwer/Yang, May apf-ap-functions-diagram.ppt, Engwer, Jan frfh-measurement roaming-intervals.pp, Engwer, Jan 2004
doc.: IEEE /0867r1 Submission July 2008 Darwin Engwer, Nortel NetworksSlide 27 Revisions r0 – For first presentation to ARC SC. r1 – Added AP breakdown diagram from 5/1606r0. Added summary of work at the easel. Added new MAC breakdown diagram based on reflections after the easel work (see slide 25). Added session switch illustrative slides from 4/86r3 to the backup slides for initiating discussion on that topic.
doc.: IEEE /0867r1 Submission July 2008 Darwin Engwer, Nortel NetworksSlide 28 Backup Slides
doc.: IEEE /0867r1 Submission July 2008 Darwin Engwer, Nortel NetworksSlide 29 Abstract Systems Analysis “A [system] may be divided for purposes of classical rational analysis by means of its component assemblies and by means of its functions.” - Pirsig From that it follows...
doc.: IEEE /0867r1 Submission July 2008 Darwin Engwer, Nortel NetworksSlide 30 WLAN System Analysis An WLAN infrastructure system may be divided for purposes of classical rational analysis by means of its component assemblies and by means of its functions. –If divided by means of its component assemblies, its most basic division is into a PHY, a MAC, an AP, a distribution system and a management entity. –To know what the components are for, a division according to functions is necessary.
doc.: IEEE /0867r1 Submission July 2008 Darwin Engwer, Nortel NetworksSlide 31 Multi-band “Session Switch” VHT has discussed the need to include multi-band “session switch” within the VHT60 specification. VHT60 PAR: –Scope: Enables fast session transfer between PHYs –Dependencies?: Yes, n (for fast session transfer between PHYs) –Additional Explanatory Notes: Fast session transfer between 60 GHz and 2.4/5 GHz bands will enable typical WLAN coverage for multi-band devices. However, this does not imply that devices must be multi-band. The amendment will specify a mechanism for multi-band devices. Multi-band transition in a single device is commonly supported within many current device implementations. However, the Std. does NOT currently define such a mechanism. Hence VHT60 might look to formalize the commonly implemented session switch mechanism by adding corresponding specifications to the standard, especially wrt transitions to/from VHT60 links. There are many considerations, see some examples on the following slide.
doc.: IEEE /0867r1 Submission July 2008 Darwin Engwer, Nortel NetworksSlide 32 Multi-PHY STAs 11a PHY MAC 11b/g PHY MAC 5 GHz Radio 2.4 GHz Radio 0x … x … 1235 (adapted from [7], 4/86r3) Case 1 Case 2 MAC 11a PHY11b/g PHY 5 GHz Radio 2.4 GHz Radio 0x … 1234
doc.: IEEE /0867r1 Submission July 2008 Darwin Engwer, Nortel NetworksSlide 33