A high performance LAN/MAN using a distributed dual mode control protocol

The authors propose a new dual-mode-control local area network/metropolitan area network, called DDMNET, based on a single-folded bus topology. Stations are connected to communication channels by means of three passive taps. At light loads, each station transmits packets on the outbound channel as long as the channel is sensed as being idle. As the load of the network increases, the occurrence of collisions will lead the network to be controlled under an implicit token-passing scheme. Transmissions at this mode are thus guaranteed collision-free and will be of bounded delay. It is shown that DDMNET differs from other dual-mode networks in several ways. Throughput superiority of DDMNET is demonstrated over four existing schemes through performance analysis and simulation results