Analysis of integrated voice and data communication network

This thesis studies the performance of an integrated voice and data communication network. Different characteristics from other communication networks and a different set of key parameters for its performance are addressed. The relationship of and the trade-off between the key parameters are also discussed. Voice communication requires slow but continuous information e×change while data communication requires burst type of information exchange. A new integrated switch is designed to support both type of communications_ line switch for voice and packet switch for data. Class ] traffic, voice or video, is modeled as an M/M/n queue and Class lI traffic, data or bulk, is modeled as an M/M/Y queue. A wild distribution of Class [I queue length is discovered and a significant trade-off between communication and ccmputer facilities is implied. The study shows that the queue length grows very rapidly when the Class ]/Class ]] job size ratio increases. A small integrated switch with relatively small job size ratio is studied in details. However large switches with realistcal job size ratio are only approximated and detail quantitative results for such system require further study. The longer the queue is, the larg;er the memory will be required to store the data packets. However though the integrated switch has a very long queue, the number of buffer for the switch to operate efficiently is rather limited as shown by the network queueing model. In order to increase the memory utilization and to lower the system cost, several memory management and buffer assignment schemes are discussed, An unconventional secondary storage for switching processor is modeled and the advantages and disadvantages are thoroughly discussed. A special delay of integrated switch is introduced by its frame structure. In, order to minimize the through network delay, the design problem of how to share the . communication link capacities between voice and data and how to assign the frame skew on each link are discussed. Because of discrete delay incremented by the frame period, the frame skew assignment problem is investil]ated as a mixed integer linear program. A speeding algorithm using k-tree concept is developed to speed up the ordinary branch and bound algorithm. However the speedin_ algorithm does not show much improvement in computation time and is thus limited useful. A heuristic algorithm is then developed to find a local optimal assis;nment in relatively short computation time.