Asynchronous reservation protocol for variable-sized messages in a WDM-based local network

In this paper, we propose and analyse an asynchronous reservation protocol for a very high-speed optical LAN using a passive star topology. Each node is equipped with a single tunable transmitter and a single tunable receiver, both of which are tunable over a range of wavelengths. A separate channel, called the control channel, is used to coordinate message transmissions on the other channels, called data channels. We consider random and idle selection schemes for the data channel selection strategy. The proposed protocol can efficiently support variable-sized messages. It is operated asynchronously, i.e. data channels are not slotted and the control channel is slotted with the size of a control packet. Also, the protocol is scalable, hence the network can accommodate a variable number of nodes. Any new node can join the network without network reinitialization. Moreover, with the protocol one can avoid destination conflicts. We analyse its performance by using the equilibrium point analysis (EPA) method, and validate the results by simulation. According to the numerical results, the asynchronous protocol achieves higher throughput than the synchronous one.