Throughput limitations in high speed networks

It is shown that the maximum channel utilization between two half-duplex terminals, each transmitting for T seconds and receiving for T seconds over a channel with propagation delay τ, varies as a function of τ/T between the values of 0.5 and 2. This compares to the classical case, where τT is considered to be equal to 0 and the maximum utilization is 1. Channel utilization is defined to be the percentage of time that the channel contains data that can be received by the receiver, and maximum utilization is utilization maximized over θ, the relative phase of the receive/transmit functions of the two terminals. It is also shown that for a system where τ/T>0, the buffer requirements are reduced if optimization is made with respect to θ. If the system is not optimized, the buffer requirements approach infinity as the channel utilization approaches 1