Adaptive algorithms for improving the throughput of CDMA packet radio networks

The authors present two adaptive techniques, involving route selection and channel access, which significantly improve the throughput and delay performance of a multihop, receiver-directed CDMA (code-division multiple-access) packet radio network. Routing is accomplished by choosing among potential next nodes in a distribution fashion, based on the simple metric of queue length. De facto preference is given to congested nodes by the channel access protocol, based on queue length ratios, in order to increase their (outbound) throughput without increasing the number of channel collisions. These algorithms have the effect of spreading network traffic more evenly across the network, thereby alleviating the congestion at bottleneck nodes, so that network throughput approaches that analytically predicted using a homogeneity assumption. Simulation results are presented which quantify the achieved improvement for networks with varying connectivity fractions