Contention-based reservation protocol using a counter for detecting a source conflict in WDM single-hop optical network with non-equivalent distance

We propose a new channel reservation protocol which can reduce message delay by using a counter for detection of a source conflict in a WDM single-hop network with non-equivalent propagation delay. A source conflict occurs when a source node has the right to transmit more than or equal to two messages simultaneously, which are transmitted using different wavelengths. In such a case, the source node has to newly obtain the right to transmit the message. In the proposed protocol, by using a source conflict counter a source node can detect a source conflict before a wavelength assignment is performed. Therefore, the source node can start a procedure to newly obtain the right to transmit the message which cannot be transmitted due to a source conflict. We analyze the throughput performance by taking the effect of a source conflict into account, and show that the approximate analysis and the computer simulated results are close. Also, from computer simulated results, we show that our proposed protocol can reduce mean message delay dramatically without degrading throughput performance as the offered load becomes large.