On Two Collision Protocols for High Speed Bus LANs

It is commonly believed that collision protocols are impractical for very fast bus networks, owing to the constraints on the minimum packet length. In this paper, we present two collision protocols that contradict this opinion. These protocols are two representatives of the so-called Piggyback Ethernet family. They incur no synchronisa-tion overhead under very light load, and under heavy traac conditions they perform no worse than collision-free protocols. Piggyback Eth-ernets are implementable on the basis of a simple, unsegmented, bidi-rectional, broadcast-type medium. Thus, they can be viewed as reene-ments of commercial Ethernet aimed at providing high-performance service in the environments when the packet length is small in comparison to the propagation length of the bus.