1. VHTL6 Throughput Metric Thoughts
May 2008
doc.: IEEE /0499r0
May 2008
VHTL6 Throughput Metric Thoughts
Date:
Authors:
Darwin Engwer, Nortel Networks
Darwin Engwer, Nortel Networks

2. May 2008
doc.: IEEE /0499r0
May 2008
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
Darwin Engwer, Nortel Networks

3. Outline Objectives Throughput Metrics Naming the Metric M1 M3 M4
May 2008
Outline
Objectives
Throughput Metrics M1 M3 M4
Naming the Metric
Darwin Engwer, Nortel Networks

4. VHTL6 Throughput Metric Objectives
May 2008
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
May 2008
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.
May 2008
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 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 LAN. The entity x has infinite throughput capacity.
Darwin Engwer, Nortel Networks

7. A single AP in a void May 2008 May 2008 doc.: IEEE 802.11-08/0499r0 AP
STA AP
With a constellation of associated and active MUs.
Darwin Engwer, Nortel Networks
Darwin Engwer, Nortel Networks

8. Infrastructure BSS Maximum Throughput (M1)
May 2008
Infrastructure BSS Maximum Throughput (M1)
Collectively the AP and the set of STAs are capable of some MAXIMUM throughput.
STAs
BSS Throughput
Max 1 2 3 4 5
Note: Data is for illustration purposes only.
Darwin Engwer, Nortel Networks

9. Infrastructure BSS Maximum Throughput
May 2008
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
May 2008
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 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 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. A single AP with multiple sets of DL STAs
May 2008
doc.: IEEE /0499r0
May 2008
A single AP with multiple sets of DL STAs
STA
STA AP
With a constellation of associated and active MUs.
STA
Darwin Engwer, Nortel Networks
Darwin Engwer, Nortel Networks

12. May 2008
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)
May 2008
doc.: IEEE /0499r0
May 2008
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)
Note that a given *system* might employ multiple bands, e.g. dual concurrent 11b + 11a.
Darwin Engwer, Nortel Networks
Darwin Engwer, Nortel Networks

14. May 2008
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” ?
May 2008
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. May 2008
BSA Definition (for )
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? May 2008
Darwin Engwer, Nortel Networks

18. May 2008
References
“Mobile Cooperation Usage Models”, IEEE submission, , Marc de Courville (Motorola) et al vht-mobile-cooperation.ppt
“Below 6 GHz 11VHT PAR&5C’s Proposal”, IEEE submission, , Marc de Courville, Darwin Engwer et al vht-below-6ghz-11vht-par-5c-s-proposal.ppt
vht-vht-metrics-considerations.ppt
vht-below-6ghz-11vht-par-scope-and-purpose-discussion.ppt
IEEE Std
Darwin Engwer, Nortel Networks

19. Revisions r0 – 2008-05-01 For first presentation to VHT SG.
May 2008
Revisions
r0 – For first presentation to VHT SG.
r1 – 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. May 2008
Backup Slides
Darwin Engwer, Nortel Networks