Traffic smoothing effects of bit dropping in a packet voice multiplexer

The authors examine the performance of a packet voice multiplexer queue in which the less significant bits on voice packets are dropped during states of congestion in the multiplexer. Using the results of simulation and analytical modeling, it is illustrated that bit dropping on voice packets significantly smoothes the superposition packet voice traffic by speeding up the packet service rate during critical periods of congestion in the queue. This phenomenon renders it possible to approximate the superposition process by a Poisson process for analyzing a packet voice multiplexer with bit dropping. The multiplexer is modeled using an M/D/1/K model in which D denotes the deterministic but state-dependent nature of service. By comparison with a simulation, this model is shown to produce quite accurate performance predictions.<>