Design of mutiwavelength ATM switches with multicast capabilities

Abstract

In the future, photonic ATM (or packet) switching technology is expected to play an essential role in both routing and switching because electronic switching technology has several limitations in large-capacity switches owing to speed bottleneck of electronic devices and physical constraints in packaging. However, the application of purely optical technology to switching systems is very limited due to a difficulty in processing cell headers in the photonic domain. Therefore, hybrid-type photonic switches have been proposed to take advantage of an optical layer for high-speed transport and an electrical layer for routing control. These approaches utilize electronic buffers or optical buffers at input or output interface and electronic processing of cell header signals in the switch controllers. In this dissertation, we design the architectures of photonic ATM switches with multicast capabilities, which take advantage of the characteristics of both optical transport and electronic control. We also design multicast cell scheduling schemes with input reservation algorithm operating at a switch controller. Two cell scheduling schemes for multicast switches have been introduced; 1) a one-shot scheduling scheme - transmission of all replicated cells in a cell time and 2) a cell splitting scheme - transmission of replicated cells over several cell times. Another issue in multicast switches is the input reservation method. In this dissertation, a new parameter for input reservation is introduced. This parameter is the number of rejected copy cells occurring only in multicast switches. Using this parameter an enhanced priority reservation algorithm for ATM multicast switches is proposed. Priority for input reservation is selected among input ports considering the number of rejected copy cells and the blocked age of head-of-line (HOL) cells. One significant point of the proposed algorithm is to achieve high throughput with proper fairness according to the design factor, ...