1. Link Metric for High Throughput Mesh
Month Year
doc.: IEEE yy/xxxxr0
May 2008
Link Metric for High Throughput Mesh
Date:
Authors:
Yongho Seok, LG Electronics
John Doe, Some Company

2. Abstract Suggested resolution for CID 4240 May 2008 Month Year
doc.: IEEE yy/xxxxr0
May 2008
Abstract
Suggested resolution for CID 4240
Yongho Seok, LG Electronics
John Doe, Some Company

3. CID 4240 (LB93) Comment Proposed Resolution Resolution
Month Year
doc.: IEEE yy/xxxxr0
May 2008
CID 4240 (LB93)
Comment
The link metric assumes a packet of standard size. When TGn is used the overhead cost of the PHY is spread across potentially multiple frames.
Proposed Resolution
Indicate how the metric should be used in a TGn envionment. Note, another useful metric that you might want to consider is post-detection capacity which is relatively easy to measure and correlates well with an optimal mcs/rate selection. The issue you have with using a rate in the measurement is how the rate is selected - i.e. it typically requires a number of frames to stabilize. A measurement based on a single packet is more indicative of the starting state of a link adaptation algorithm than anything else.
Resolution
Reject
Resolution Notes
The comment is true but no solution can be provided.
Yongho Seok, LG Electronics
John Doe, Some Company

4. CID 11 and CID 1152 in LB126 Comment Proposed Resolution
Month Year
doc.: IEEE yy/xxxxr0
May 2008
CID 11 and CID 1152 in LB126
Comment
How does the airtime for HT STA is calculated? The airtime for Legacy STA may be less than that for HT STA, because the block ACK overhead of HT STA is much larger than the normal ACK overhead of legacy STA.
Proposed Resolution
Instead of the airtime for one test frame, uses the airtime for multiple test frames. The new airtime metric for legacy STA is Ca*N, where N is the number of test frames. The new airtime metric for HT STA is [O+(Bt*N)/r]*1/(1-ef), when A-MSDU is used. It seems that the new airtime metric is not change the concept of the current airtime metric.
Yongho Seok, LG Electronics
John Doe, Some Company

5. Month Year
doc.: IEEE yy/xxxxr0
May 2008
Motivation
The Airtime Link Metric should consider High Throughput Mesh Point (HT MP)
HT MP supports an aggregation mechanism such as A-MSDU and A-MPDU
When frames are aggregated, the MAC and PHY overhead is spread across potentially multiple frames
Yongho Seok, LG Electronics
John Doe, Some Company

6. Current Metric May 2008 Month Year doc.: IEEE 802.11-yy/xxxxr0
Yongho Seok, LG Electronics
John Doe, Some Company

7. Suggested Enhancement
Month Year
doc.: IEEE yy/xxxxr0
May 2008
Suggested Enhancement
Extended Airtime Link Metric (N = 2)
Airtime Link Metric
MAC
Header
MAC
Header
DIFS
SIFS
DIFS
SIFS
No Aggregation
Test Frame
ACK
Test Frame
ACK
Airtime Link Metric
A-MSDU
Header
A-MSDU
Header
DIFS
MSDU Aggregation
Test Frame
Test Frame
ACK
Airtime Link Metric
A-MPDU
Delimiter
A-MPDU
Delimiter
DIFS
MPDU Aggregation
Test Frame
Test Frame
ACK
Yongho Seok, LG Electronics
John Doe, Some Company

8. Airtime cost parameters
Month Year
doc.: IEEE yy/xxxxr0
May 2008
Proposed metric
Airtime cost parameters
Parameter
No Aggregation
MSDU Aggregation
MPDU Aggregation
Description Oc
Channel access overhead
Channel access overhead, which varies depending on PHY and includes frame headers, training sequences, access protocol frames Oa
A-MSDU subframe header
MPDU delimiter
Aggregation overhead Nt 1
variable
Number of aggregated frames Bt
8192
Number of bits in test frame Ef ef
e f
Frame error rate for single MSDU, or A-SDU , or Aggregated MPDU, respectively
Yongho Seok, LG Electronics
John Doe, Some Company

9. References Normative text: doc.: IEEE 802.11-08/0639r1 May 2008
Month Year
doc.: IEEE yy/xxxxr0
May 2008
References
Normative text: doc.: IEEE /0639r1
Yongho Seok, LG Electronics
John Doe, Some Company