ALOHA with Queue Sharing

Abstract

ALOHA with Queue Sharing (ALOHA-QS) maintains most of the simplicity of ALOHA with priority acknowledgments (ACK) and attains the high throughput of transmission scheduling methods that require clock synchronization. Channel access with ALOHA-QS consists of a sequence of queue cycles, with each cycle having one or multiple collision-free transmissions by nodes that have joined the transmission queue and a single request turn to join the queue. The signaling of ALOHA-QS entails adding to packet headers the size of the shared queue, the position of the sending node in the queue, a bit indicating the end of transmissions by the transmitting node, and a bit stating whether or not a new node joined the queue successfully. The throughput of ALOHA-QS is compared with the throughput of TDMA with a fixed transmission schedule, ALOHA with priority ACK’s, and CSMA with priority ACK’s analytically and by simulation.