On the spatial capacity of packet radio networks

Point-to-point network can achieve much higher performance levels due to the ability to spatially reuse the channel. Optimum transmission ranges and retransmission policies (maximizing capacity) for various configurations of ALOHA networks are derived. For one dimensional random networks (i.e., random topologies) with random traffic matrices, satisfied by exactly adjusted transmission range, allowing communication in one hop, a capacity proportional to the logarithm of the number of nodes in the network was obtained. For regular (topology) networks using fixed transmission ranges and multi-hop communication to support uniform traffic matrices, a throughput of 2/e was obtained. For two dimensional networks, throughput proportional to the square root of the number of nodes in the network was obtained for both regular and random topologies. The best regular design is a hexagonal tesselation. The optimum average degree for random networks in which each node uses the same (fixed) transmission radius is shown to be about 6. Several routing algorithms are presented and the best performanced. it is shown that the routing algorithm which balances traffic flow, seems to produce the best performance.