Performance analysis of a packet-switched synchronous voice/data network

Abstract

This dissertation is devoted to the study of a packet-switched synchronous voice/data network. Particularly, we are concerned with synchronization of voice packets in a packet voice/data network. For synchronization of packetized voice, we utilize a master frame format of time division multiplexing (TDM). With the frame structure of fixed duration, packet are transmitted synchronously at the start of each frame time. This scheme has discrete delay characteristics of packetized voice, and provides a simple play-out method of voice signals. With two separate buffers for voice and data, we investigate the queueing behavior of voice and data traffics. For the performance analysis of the proposed system, we investigate the queueing behaviors of voice and data at the start of a frame. The results of analysis include the cumulative distribution of delay of voice, and mean voice an data delay. With the cumulative distribution of voice delay, we select the optimal target play-out time to reproduce voice signal acceptably at the receiver. When voice packets experiencing delay greater than the target play-out time are discarded, the number of voice packets lost are compared with the cut-off probability of voice in the circuit-switched system with time assignment speech interpolation (TASI). When the number of voice packets to be lost exceed 0.005 of the received voice packets new calls are blocked. The probability that new voice calls are blocked is compared with that of the traditional circuit-switched system, and is also compared with that of the circuit-switched system with TASI when the loss probability of voice packet in the proposed system is the same as the cut-off probability of voice source in the circuit-switched system. By getting voice loss probability and call blocking probability, we obtain the maximum allowable input voice channels for a given capacity of output trunk. With the results of performance analysis, we obtain the optimal design criteria, such as ...