A Terminal-Assisted Bayesian Broadcasting Algorithm for S-ALOHA Systems with Finite Population of Multi-Buffered Terminals

Abstract

This letter proposes a backoff algorithm for slotted ALOHA (S-ALOHA) systems with multi-buffered terminals. According to the proposed algorithm, a base station (BS) broadcasts a retransmission probability based on estimated backlog size, while the terminals help the BS to estimate the backlog size by sending a one-bit backlog indication piggybacked on the information packet upon a successful random access. We present the performance of the proposed algorithm in terms of mean and variance of system response time, and compare them against existing algorithms and the optimal one. Results show that the proposed algorithm can improve the performance significantly especially for high packet arrival rates, small population size and asymmetric traffic cases.