Backoff Strategies for CSMA/CD with Real-Time Applications

Contention-based access strategies have the principal advantage of being distributed and probabilistic, which is good insurance against system failure; however, the resulting access waiting times normally have an exponential distribution, showing maxima about ten times above the average. In a recent paper /4/, we proposed an Ethernet-compatible contention protocol with an access queueing mechanism that achieves nearly deterministic behaviour. In the present paper, compatibility is abandoned for shorter contention times, e.g. better throughput. An algorithm is developed to adapt the contention behaviour of nodes to the present network traffic. It is shown how distributed access queueing control can be added to this without increasing contention times.