To monitor the PHY rate between an 802.11 AP and STA do the following


  1. Enable packet trace and run the simulation
    • Set a short simulation time because logging this file takes time
  2. After simulation open the packet trace In Excel
  3. Under transmitted ID column filter to the Access point
  4. Add a new column 
    • Set the value of each cell equal to PHY_LAYER_PAYLOAD(Bytes)*8 /  (PHY_LAYER_END_TIME-PHY_LAYER_ARRIVAL_TIME). Since the times are in microseconds, this will give you the approximate PHY Rate in Mbps. 
  5. The precise formulas would be


PHY_RATE (802.11a) = PHY_LAYER_PAYLOAD * 8 /(PHY_LAYER_END_TIME - PHY_LAYER_ARRIVAL_TIME - 20)

PHY_RATE (802.11b) = PHY_LAYER_PAYLOAD * 8 /(PHY_LAYER_END_TIME - PHY_LAYER_ARRIVAL_TIME - 192)

PHY_RATE (802.11g) = PHY_LAYER_PAYLOAD * 8 /(PHY_LAYER_END_TIME - PHY_LAYER_ARRIVAL_TIME - 20)     

PHY_RATE (802.11n) = PHY_LAYER_PAYLOAD * 8 /(PHY_LAYER_END_TIME - PHY_LAYER_ARRIVAL_TIME - 40)

PHY_RATE (802.11ac) = PHY_LAYER_PAYLOAD * 8 /(PHY_LAYER_END_TIME - PHY_LAYER_ARRIVAL_TIME - 44)