The effects of multiplexing on a computer-communications system

A study is made of the way in which asynchronous time division multiplexing changes the stochastic nature of the arrival process from a user to the computer and, consequently, affects the performance of a time-shared computer-communications system. It is concluded that while, for certain values of system parameters, there is noticeable improvement in the performance of the computer (model), in the sense that time-shared scheduling delays are reduced, these improvements are offset by the transmission delays imposed by multiplexing so that there may be little or no change in the computer-communications system performance. Analytical and simulation results are based on the model of the computer-communications system being an M/D/1 queue (the multiplexor) in tandem with a single exponential server (the computer). Analytical results include a general description of the output process of an M/D/1 queue and the conditions under which this output process is approximately Poisson.