A reservation based medium access control protocol with multicast support for optical star networks

In this paper, we propose a reservation based multicast protocol for the single-hop passive optical star network. Of the available wavelengths (channels), one channel is designated as a control channel, and the remaining channels are used for data transmission. A node accesses the control channel using a fixed transmitter and a fixed receiver. A node sends data packets using a fixed transmitter and receives packets through a tunable receiver (filter). All the channels are viewed as sequences of frames. In addition, frames of the control channel are further divided into mini slots. Corresponding to each node in the network, there is a mini slot in a control frame. A node puts its multicast request in its designated mini slot in a control frame. At the end of a control frame, all nodes receive the multicast requests of all other nodes, and decide which nodes are going to transmit and/or receive during the following data slot. An easily implementable way of resolving destination and source conflicts is presented. We simulate the protocol to study its throughput behavior, and presentits analytic model. Simulation results show that our protocol delivers maximum unicast throughput, and the protocol's multicast throughput is much better than existing protocols using a control channel.