An optical multiaccess network with optical collision detection and optical frequency addressing

An optical frequency addressing carrier sense multiaccess (CSMA) network with optical collision detection (CD) is proposed. In this network, traffic is routed through many optical frequency division multiplexing (FDM) virtual transmission lines to nodes defined by optical carrier wave frequencies, and collision between optical signals having a large power level difference can be monitored by optical signal processing. Numerical results on the packet transmission delay characteristics are presented and compared to those for a conventional TDM (time division multiplexing)-based CSMA/CD. It is shown that the FDM CSMA/CD scheme achieves a shorter transmission delay time, even with higher traffic loads. An optical collision detection circuit using self-delay homodyne detection is also proposed. This novel circuit is expected to obtain more than 15 dB and is suitable for large-area applications