Performance Analysis of S-ALOHA Protocol Under Pareto Distributed Packet Arrival

Abstract

This article presents a medium access control mechanism based on the very well-known Slotted ALOHA, using Adaptive Traffic Load (ATL) to stabilize the throughput and access delay under long range dependent traffic and Poisson traffic. We consider a system in which users request a data channel for packet data transmission, where arrivals follow a Poisson distribution, if the request is successful, they transmit their data and release the channel at the end of the transmission. If after the first transmission, users have more packets to transmit, they request a data channel again, but the packet inter-arrival times follow a Pareto distribution. At high traffic loads, the basic idea of ATL is to limit the number of packet transmission for both new and retransmitted users, to avoid collisions and keeping the system stability. We show that S-ALOHA, in spite of its simplicity and low throughput, can provide low delay and latency in the second access channel even in high traffic loads by using the ATL scheme limiting the access to the second access channel. Also, a Pareto-based traffic entails lower transmissions compared to the Poisson traffic.