Simulation performance study of Aloha network

A simulation-based performance study of an Aloha network is presented. It is shown that the results obtained using analytical techniques are good approximations when lost packets are not retransmitted. However, when a retry protocol is used, the throughput of the system drops to less than the well-known figure of 0.184 (=1/2e ) obtained analytically. Two models have been built using SLAM (Simulation Language for Alternative Modeling). The first model is for the no-retry case. The second model allows the network to be studied under various retry protocols. The first model gives a maximum throughput of 0.188, which is close to the analytical result. The second model gives a maximum throughput that is less than that of the first model. Graphs of delay figures of this model are presented for the protocols tested