Patent ID: 6980561

Claim:
A method for performing initial ranging in conjunction with a contention-based Medium Access Control (MAC) protocol in a shared-medium communication network, the method comprising the steps of: taking a first system performance measurement to obtain a first probability of success outcomes using a first backoff window size; taking a second system performance measurement to obtain a second, probability of success outcomes using a second backoff window size different than the first backoff window size; and determining a third backoff window size based on the first and second system performance measurements, wherein the step of taking the first system performance measurement comprises: providing ranging opportunities and specifying the first backoff window size for collision resolution; counting a first number of success outcomes in a first sample of N ranging opportunity slots; and determining the first probability of success outcomes equal to the first number of success outcomes divided by N; and the step of taking the second system performance measurement comprises: providing additional ranging opportunities and specifying the second backoff window size for collision resolution; skipping a number of ranging opportunity slots at least equal to the first backoff window size; counting a second number of success outcomes in a second sample of N ranging opportunity slots; and determining the second probability of success outcomes equal to the second number of success outcomes divided by N: and wherein the step of determining the third backoff window size comprises: determining a ratio R having a numerator equal to the second probability of success outcomes minus the first probability of success outcomes and a denominator equal to the second backoff window size minus the first backoff window size; setting the third backoff window size greater than the second backoff window size, if the ratio R is a positive value: and setting the third backoff window size less than the second backoff window size, if the ratio R is a negative value, and wherein the step of setting the third backoff window size greater than the second backoff window size comprises setting the third backoff window size equal to twice the second backoff window size: and the step of setting the third backoff window size less than the second backoff window size comprises setting the third backoff window size equal to half the second backoff window size.