Rapid collision resolution in slotted Aloha without retransmission delays

Abstract

A simple collision resolution algorithm is presented wherein a set of contending packets transmit randomly into a frame of n slots. Those packets involved in collisions retransmit in another n-slot frame, and so on till all originally contending packets achieve successful transmission. It is shown via a state space model that the algorithm attains a maximal throughput of 0.304 for the optimal frame length n=6. Delay analysis indicates reduction of average delays by a factor of seven or more relative to comparable Aloha systems.