FDM packet multiple access network using coherent fibre optic communication

The authors present the design of a fiber-optic packet multiple-access network which employs coherent detection over FDM optical channels. The network consists of a single-mode optical fiber arranged in the D configuration and clusters of stations attached via passive taps to the transmit and receive arms. Each station cluster is assigned one dedicated FDM channel for packet reception, and each station is equipped with a frequency agile transmitter for communication with any station in any cluster. Slotted access with collision detection is employed for nearly 100% channel utilization, but favours upstream over downstream stations. A window flow-control and acknowledgment scheme is incorporated to overcome this fairness problem