Persistent reservation protocol for variable-length messages in WDM-based local networks

The author proposes a persistent reservation protocol in a wavelength division multiplexing (WDM)-based local network using a passive star topology. With this protocol, once a node reserves a data channel, the node persistently uses the channel until its message is completely transmitted. Therefore, the protocol needs only one tuning time for a node to begin to transmit its message, which reduces deterioration of the throughput due to tuning overhead. The proposed protocol can efficiently support variable-length messages. The network can accommodate a variable number of nodes and can operate independently of any change of the number of nodes. Hence, any `new´ node can join the network at anytime without network re-initialisation. Moreover, with the protocol, data channel and destination conflicts can be avoided. Throughput-delay characteristics are analysed with a finite population model, and are verified by simulation results