On the departure process of jitter buffer in TDMoIP

Abstract

This paper discusses the condition under which the jitter buffer at the receiver is to be operated for minimum output variance in a TDMoIP framework. The above study would be useful in the design of synchronization algorithms at the receiver of a TDMoIP network. This work uses the results derived in [1] to the above problem. We model the receiver jitter buffer as a M/G/1 queueing system with EARMA correlations between the inter-arrival times and the service times. The motivation for the above correlation structure is that, if the service intervals depend on the arrival rate and there is correlation within service times, we can achieve a constant bit rate at the receiver, that is, emulate the TDM stream as it was sent at the transmitter. Also, analysis of such a correlated queue is analytically tractable. We derived the variance of the inter departure times, of the above queue. The analysis of the departure process and the waiting times of incoming packets of this correlated queue and the relevant simulations show that if the variance of the inter departure time process constituting output TDM stream is to be less than that of the inter arrival time process of the jitter buffer, which is modeled as M/G/1 queue, then the mean waiting time of the packets in the jitter buffer would necessarily be greater than that of independent (M/M/1) case.