WDM ring networks based on integrated group-search wavelength add/drop multiplexers

Abstract

Wavelength division multiplexing (WDM) has emerged as the most promising technique for exploiting the terabit capacity optical networks. The acceptability of WDM networks depends heavily on the availability and cost of optical components. A wavelength add-drop multiplexer is one of the key network components, which is used for selectively dropping and inserting optical signals into the WDM network. Reconfigurable add-drop multiplexers offer great flexibility in the design of new network architectures. Ring network architectures, utilizing WDM transmission, present an efficient means for implementing optical, high speed local and metropolitan area communication. Its implementation appears to be feasible with state of the art components. In this dissertation, three new architectures of WDM ring networks are introduced and discussed in detail. These architectures are based on an especially designed add/drop multiplexer; namely the Integrated Group-Search Wavelength Add/Drop Multiplexer (IGSWADM). First, a WDM ring with a physical topology based on a double-fiber ring is presented. Each network station is connected to the ring via an IGSWADM device and equipped with two transmitters and two receivers. A medium access protocol for fast circuit switched applications is proposed and the performance is evaluated. The second WDM ring architecture has the same physical topology, but has different node architecture. Each node is equipped with only one tunable transmitter and one fixed receiver. A medium access protocol with timeout mechanism is proposed for fast circuit switched applications and evaluated. The third WDM ring architecture considers the case where the number of channels is less than number of nodes. A medium access protocol with timeout mechanism is proposed for fast circuit switched applications. All the simulation models are built and executed using a software tool called UltraSAN. The results of the first architecture showed that the proposed ring has high performance at high arrival rates and long message lengths. For the second and third architectures, the results are affected heavily by the timeout duration. For a given set of network parameters, there exists an optimal timeout duration, which will maximize the network performance.