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 po ≃ 0.271. The optimum range should be chosen so that on the average there are χ(G/b)2/n 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, η is the power loss factor and χ 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 ϑ(G/b)1/n, where ϑ is proportional to the square root of χ. 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. © 1995 IEEE