Multi-hop Radio Networks in Rough Terrain: Some Traffic Sensitive MAC Algorithms

An exciting application of Multi-hop Packet Radio Networks (MPRNet) is to provide communication services in environments without suitable infrastructure. One key design issue in MPRNet is the formulation of Medium Access Control (MAC) protocols. In this paper, the performance of two MAC protocols, Slotted ALOHA (S-ALOHA) and Spatial TDMA (S-TDMA), are investigated. A finite number of buffered nodes were used in the evaluation of these MAC protocols. By definition, optimum network performance is achieved when the average packet delay is minimized. For S-ALOHA, nodes transmit at random with some given probability q. We investigate the selection of q. Finding an assignment in terms of the traffic load and the connectivity, which yields a near optimal packet delay performance. A novel systematic procedure to find transmission schedules in S-TDMA based on the connectivity is also described. The traffic-sensitive schedules show better performance in comparison to the classical S-TDMA.