CSMA/CD/TDMA: a dynamic combination for voice and data integration

摘要

A hybrid decentralized packet switching protocol for integrated real-time voice and data services on a bus topology local area network is presented. The bus has two states. State transitions depend on the existence of active voice users. Voice follows a modified version of time-division multiple-access (TDMA), whereas carrier-sense multiple-access with collision detection (CSMA/CD) is adopted for the channel access policy for data. The real-time requirement for voice is satisfied and a loss will not occur if the maximum number of calls is set properly. A fraction of the bandwidth is always reserved for data. Silence periods are detected and saved for data. Analytical results are derived by steady-state equivalent queuing models. Simulation results are close to analytical results.