will be clear to those skilled in the art how to determine and use the collision fraction the average duration d a of a first ieee 802 11 message sequence comprising a clear_to_send frame followed by a data frame followed by an acknowledgement frame is equal to d a 1 u2212 f d cts d data d ack f d cts d data eq 1 wherein f is the collision threshold and d cts d data and d ack refer to the lengths of time required to transmit the clear_to_send data and acknowledgement frames respectively accounting for the intermediate time intervals contributed by interframe spaces e g short interframe space etc similarly the average duration d b of a second ieee 802 11 message sequence comprising a request_to_send frame followed by a clear_to_send frame followed by a data frame followed by an acknowledgement frame is equal to d b 1 u2212 f d rts d cts d data d ack f d rts eq 2 wherein f is the collision threshold and d rts d cts d data and d ack refer to the lengths of time required to transmit the request_to_send clear_to_send data and acknowledgement frames respectively accounting for the intermediate time intervals contributed by interframe spaces by setting d a and d b equal to each other and solving for d data the value for d data at which the use of either message sequence results in equal levels of optimization is determined to be equal to d.