Optimum transmission ranges in multihop packet radio networks in the presence of fading

The evaluation of optimum transmission ranges in a packet radio network in a fading and shadowing environment is considered. It is shown that the optimal probability of transmission of each user is independent of the system model and is p/sub o//spl sime/0.271. The optimum range should be chosen so that on the average there are /spl chi/(G/b)/sup 2//spl eta// terminals closer to the transmitter than the receiver, where G is the spread spectrum processing gain, b is the outage signal-to-noise ratio threshold, /spl eta/ is the power loss factor and /spl chi/ depends on the system parameters and the propagation model. The performance index is given in terms of the optimal normalized expected progress per slot, given by /spl thetav/(G/b)/sup 1//spl eta// where /spl thetav/ is proportional to the square root of /spl chi/. A comparison with the results obtained by using deterministic propagation models shows, for typical values of fading and shadowing parameters, a reduction up to 40% of the performance index.<
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