Adaptive satellite hybrid access (ASHA) protocols: a simulation study

A general class of broadband protocols called ART is proposed. It consists of adaptive hybrid multiple-access protocols applicable to communication networks that share a single transmission medium and behave like Aloha-type, reservation, and TDMA (thus ART) basic protocols at low, medium, and high throughput respectively. For satellite communication networks, a subclass of ART protocols called adaptive satellite hybrid access (ASHA) is proposed. Two ASHA protocols, named ASHA1 and ASHA2, that combine the features of S-Aloha TDMA-reservation and TDMA basic multiple-access protocols are described. The ASHA protocols are simulated using a fairly sophisticated simulator, modeled basically as a three-state finite-state machine. Simulation results are presented which provide a large amount of practical and valuable insight into the workings of adaptive hybrid multiple-access protocols in general and of ASHA and SRUC protocols in particular. Moreover, ASHA protocols provide better delay versus throughput than to any of their individual constituent protocols and extend the channel capacity to unity