Developing Throughput Metric for VHTL6 Effort

1. VHTL6 Throughput Metric Thoughts Authors: Date: 2008-05-01 Darwin Engwer, Nortel Networks

2. Abstract A presentation of possible directions for the development of a throughput metric for the VHTL6 effort. Please view in slideshow mode to see animations. Darwin Engwer, Nortel Networks

3. Outline • Objectives • Throughput Metrics • M1 • M3 • M4 • Naming the Metric Darwin Engwer, Nortel Networks

4. VHTL6 Throughput Metric Objectives • From previous discussions: • A BSS peak aggregated throughput of at least 1Gbps as measured at the MAC data service access point (SAP). • Zero or more overlapping BSSs and Direct Links (DLs), with at most one infrastructure BSS. Darwin Engwer, Nortel Networks

5. VHTL6 Throughput Metric Objectives • From previous discussions: • A BSS peak aggregated throughput of at least 1Gbps as measured at the MAC data service access point (SAP). • Zero or more overlapping BSSs and Direct Links (DLs), with at most one infrastructure BSS. • The later is difficult to characterize as stated. • Since we are seeking a peak or maximum value the second requirement can be restated as: • One or more overlapping BSSs and Direct Links (DLs), together with one infrastructure BSS. Darwin Engwer, Nortel Networks

6. Analytical Scenario I • Consider a universe; a void with nothing in it. • In the middle of this void, place an AP with a set of associated STAs communicating with the AP. • The AP is a point of access to a non-802.11 LAN of infinite capacity (through a DS and portal, not shown). • A constellation of n STAs is associated with the AP. • Each STA is attempting to exchange a maximum amount of data with an entity x on the non-802.11 LAN. The entity x has infinite throughput capacity. Darwin Engwer, Nortel Networks

7. STA STA STA STA STA A single AP in a void AP Darwin Engwer, Nortel Networks

8. BSSThroughput Max 1 2 3 4 5 STAs Infrastructure BSS Maximum Throughput (M1) • Collectively the AP and the set of STAs are capable of some MAXIMUM throughput. Note: Data is for illustration purposes only. Darwin Engwer, Nortel Networks

9. Infrastructure BSS Maximum Throughput where, i = index of current STA n = number of associated and active STAs T = throughput at MAC SAP of STA i of n Darwin Engwer, Nortel Networks

10. Analytical Scenario II • Consider a universe; a void with nothing in it. • In the middle of this void, place an AP with a set of associated STAs communicating with the AP. • The AP is a point of access to a non-802.11 LAN of infinite capacity (through a DS and portal, not shown). • A constellation of n STAs is associated with the AP. • Each STA is attempting to exchange a maximum amount of data with an entity x on the non-802.11 LAN. The entity x has infinite throughput capacity. • Collocated with the above are one or more sets of directly communicating STAs (either IBSS or DL). Darwin Engwer, Nortel Networks

11. STA STA STA STA STA STA STA STA STA STA A single AP with multiple sets of DL STAs AP Darwin Engwer, Nortel Networks

12. DL Throughput Factor • Since we already have a metric for the infrastructure BSS throughput (M1), let’s consider the IBSS/DL throughput, M3: • Collocated with the above are one or more sets of directly communicating STAs (either IBSS or DL). Darwin Engwer, Nortel Networks

13. Multiple DL Maximum Throughput (M3) where, i = index of current STA n = number of associated and active STAs j = index of current DL/IBSS set m = number of DL/IBSS sets k = number of channels T = throughput at MAC SAP of STA i of n wrt DL/IBSS set j of m (j, m+1, k determine number of sets on current channel) Darwin Engwer, Nortel Networks

14. Combined Metric where, all infrastructure mode and DL/IBSS STAs are located in the same BSA. Darwin Engwer, Nortel Networks

15. Naming the Metric • “BSS Peak Aggregated Throughput” ? • “Max BSS Throughput” ? • But the M4 metric as refined doesn’t really have anything to do with a specific BSS. Instead the metric establishes the maximum throughput possible in a given area/volume. Thus it may be more appropriate to speak of the metric wrt the BSA: • “Maximum BSA Throughput” ? Darwin Engwer, Nortel Networks

16. BSA Definition (for 802.11-2007) • 3.15 basic service area (BSA): The area containing the members of a basic service set (BSS). It may contain members of other BSSs. Darwin Engwer, Nortel Networks

17. Can we • Agree on the metric? • Agree on the name for the metric? Darwin Engwer, Nortel Networks

18. References • “Mobile Cooperation Usage Models”, IEEE 802.11 submission, 2008-01-13, Marc de Courville (Motorola) et al.11-08-0081-02-0vht-mobile-cooperation.ppt • “Below 6 GHz 11VHT PAR&5C’s Proposal”, IEEE 802.11 submission, 2008-03-17, Marc de Courville, Darwin Engwer et al.11-08-0219-04-0vht-below-6ghz-11vht-par-5c-s-proposal.ppt • 11-08-0465-02-0vht-vht-metrics-considerations.ppt • 11-08-0464-01-0vht-below-6ghz-11vht-par-scope-and-purpose-discussion.ppt • IEEE Std. 802.11-2007 Darwin Engwer, Nortel Networks

19. Revisions • r0 – 2008-05-01 For first presentation to VHT SG. • r1 – 2008-05-12 s13: Corrected range of ‘n’ parameter to start at ‘2’ since an IBSS or DL by definition must include at least 2 STAs; channel factor depends on “m+1” rather than “m” (because the infrastructure BSS will use one channel). Darwin Engwer, Nortel Networks

20. Backup Slides Darwin Engwer, Nortel Networks