RATO-Net: A Random-Access Protocol for Unidirectional Ultra-High-speed Optical Fiber Network

The local network medium is a pair of unidirectional fiber optic busses to which stations are conneted via passive taps. For this configuration, a new random-access protocol called RATO (randomaccess, time-out) is presented in this paper. This RATO provides random-access, fairness, and bounded delay access to all stations, and is particularly suited for ultra-high-speed transmission when the performance of the popular Ethernet becomes unattractive. Simplicity and ease of hardware implementation of RATO under ultra-high-speed environment is emphasized because the only control requirements are the sensing of activity in the bus and a fixed time delay between consecutive transmissions from the same station. Simulation and performance comparison of RATO with other schemes have been carried out. In ultra-high-speed wide-area networks, RATO outperforms all these other schemes. RATO was tested in a three station pilot network: Excellent agreement was found between predicted and measured perfor-