Performance evaluation of cellular digital packet data (CDPD) systems

A computer simulation study is made on the performance of slotted non-persistent digital sense multiple access with collision detection (DSMA/CD), the medium access control (MAC) protocol used in CDPD. A purpose built hierarchical simulation model based on the CDPD System Specification 1.1 is used. The performance of DSMA/CD in a noiseless, non-fading channel is evaluated when collisions are the only cause of transmission failure. The investigation mainly falls on the performance indices such as the channel throughput, the data delivery time, and the service grade. The influence of user queue size on the performance of DSMA/CD is also studied.