A two level optical star WDM metropolitan area network

We propose a metropolitan area network which is a two level optical star network. The stations are grouped into clusters based on geographical proximity and communication demands. The stations within a cluster communicate using a local WDM star network and a station in one cluster communicates to a station in another cluster through a remote star in a single hop. The multiwavelength filtering capability of acoustooptic tunable filters is used to isolate the wavelengths of one cluster from the wavelengths used in another cluster. Hence, the wavelengths used for local communication in a cluster can be completely reused in another cluster. We present three media access protocols for this network based on group time division multiplexing (GTDM). We present analytical models for these protocols for the uniform traffic case and obtain the system performance in terms of the average delay