Multi-rate performance index for wireless LANs

The throughput per access point has been used as the main figure of merit in performance characterization of wireless LANs. The usefulness of throughput as a performance measure is limited because low throughput can be produced by either low offered traffic or by radio conditions that limit the data rates. We propose the multi-rate performance index as an additional figure of merit to characterize the performance of wireless LAN cells. It represents which bit rates are used in the cell, and therefore it identifies cells whose throughput is limited by radio conditions rather than offered traffic. We include several measurements in real cells to illustrate its utility in performance analysis.