Determination of the optimum packet length and buffer sizes for the consumer electronics bus

Two issues related to the implementation of the consumer electronics bus (CEBus) on a power line medium are considered. These are the determination of (a) optimum packet length and (b) optimum buffer size. The delay-throughput characteristics of each of the three priority classes of messages, i.e., HIGH, STANDARD, and DEFERRED, have been measured by simulation experiments for various packet lengths and buffer sizes. This way optimum packet length and buffer sizes have been deduced. The optimum buffer size at a node corresponds to the best overall performance for messages of all priorities in terms of overflow rates at the buffers of the nodes with respect to increasing offered loads. The optimum packet length has been found to be between 276 and 400 USTs (unit symbol times), i.e., 184 and 286 b. If 276 USTs is assigned as the optimum packet length, the optimum buffer size at each node is found to be between 150 and 200 packets, i.e., approximately 28 to 37 kb