The Effect of Acknowledgment Traffic on the Capacity of Packet-Switched Radio Channels

We consider a population of terminals communicating with each other or with a central station over a packet-switched multiple access radio channel. To ensure the integrity of the transmitted data over the multi-access channel, we consider a reliable method using an error detecting block code in conjunction with a positive acknowledgment of each correct message. In this paper, we study the effect on channel capacity of the overhead created by the error-control traffic for both slotted ALOHA [1] and carrier sense multiple access (CSMA) [2]. For this we consider several implementation schemes for the two channel configurations: the common-channel configuration (a single channel for both information traffic and error-control traffic); and the split-channel configuration. The packet delay analysis will be treated in a forthcoming companion paper.