Performance evaluation of EDGE under S-ALOHA and adaptive traffic load S-ALOHA random access protocols

Abstract

We make a performance evaluation of the air interface system EDGE (enhanced data rate for GSM evolution) introducing the adaptive traffic load (ATL) S-ALOHA as the random access protocol. The EDGE system originally considers the S-ALOHA random access protocol to let users access the network for transmitting their data packets. However, S-ALOHA becomes unstable for high traffic loads, rendering very low throughput, and not allowing any user in the network to successfully transmit a packet. In this way, even if the EDGE system has sufficient capacity to give service to the users, system throughput would still be very low since no user can access the network. By introducing the ATL S-ALOHA protocol, we maintain the access throughput constant at the maximum value, allowing users to access the network to transmit their data packets even at very high traffic loads. We evaluate the performance of the EDGE system in terms of average data rate and packet delay for both S-ALOHA and ATL S-ALOHA as the random access protocol.