Link Metric for High Throughput Mesh Month Year doc.: IEEE 802.11-yy/xxxxr0 September 2008 Link Metric for High Throughput Mesh Date: 2008-09-11 Authors: Yongho Seok, LG Electronics John Doe, Some Company

Abstract Suggested resolution for CID 4240 September 2008 Month Year doc.: IEEE 802.11-yy/xxxxr0 September 2008 Abstract Suggested resolution for CID 4240 Yongho Seok, LG Electronics John Doe, Some Company

CID 4240 (LB93) Comment Proposed Resolution Resolution Month Year doc.: IEEE 802.11-yy/xxxxr0 September 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

CID 11 and CID 1152 in LB126 Comment Proposed Resolution Month Year doc.: IEEE 802.11-yy/xxxxr0 September 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

Month Year doc.: IEEE 802.11-yy/xxxxr0 September 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

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

Suggested Enhancement Month Year doc.: IEEE 802.11-yy/xxxxr0 September 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 B-ACK Yongho Seok, LG Electronics John Doe, Some Company

Airtime cost parameters Month Year doc.: IEEE 802.11-yy/xxxxr0 September 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

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