Architectures of 2-to-1 COD multiplexers for asynchronous packet arrivals

Optically time-based 2-to-1 statistical multiplexers for packets of constant length without slot-aligned synchronization at inputs are studied. Two issues are presented: First, the fundamental building block in a class of Cascaded Optical Delay (COD) multiplexers for wide-area optical networks is designed to `look ahead' at inputs for traffic and to change switch states on an appropriate instant when the entity of a packet in transit remains intact. Such functionality is fulfilled by the use of optical delay lines and simple electronic control logic; Second, performance of packet loss probabilities of the architecture is analyzed, given two independent continuous time on-off arrival processes each with exponential idle intervals and fixed busy times of packet transmissions. Simulations are also conducted at high link utilization. It is shown that as long as total link utilization is less than 50%, an acceptable packet loss probability can be achieved by increasing the number of cascaded stages in the architecture.