Adaptive station grouping: a highly efficient protocol for optical LANs

A new medium access control protocol for wavelength division multiplexing (WDM) Star Networks, which is capable of achieving a high performance under bursty traffic conditions, is introduced. According to the proposed protocol, the access of stations to the wavelengths is based on their grouping. A separate set of groups is maintained for each wavelength within the traffic stream. All the groups are granted permission to transmit on the corresponding wavelength in a round-robin fashion. The main objective of the grouping algorithm is to have in each group exactly one station which is ready to transmit on the corresponding wavelength, at any given time. In this way, idle slots and collisions are minimized and a nearly optimal throughput-delay performance is achieved. The grouping of stations is dynamically modified at each time slot according to the network feedback information. Due to the dynamic nature of the grouping algorithm, the protocol is capable of being adapted to the sharp changes of the stations’ traffic. Extensive simulation results are presented which indicate that the proposed protocol achieves a significantly superior performance than other well-known medium access control protocols for WDM Star Networks.