Space and Time Blocking versus Cost in All-Optical Banyan Networks

This paper analyzes possible Banyan network solutions as a multistage interconnection network exploiting time and space domains. The well-known approach to replicate a Banyan in space provides non- blocking property, meanwhile increasing the cost index to a great extent. In order to keep the cost function under control we investigate how a Banyan network can be built that maintains the blocking probability below acceptable thresholds. To this extent we first discuss the non-blocking conditions for multistage networks in the space domain with arbitrary size of the basic switching element. Then we evaluate how exploiting time division multiplexing in such a network can help relieving the cost issue while keeping the blocking probability under control. The study compares all-optical vs. electronic implementations and analyzes the cost index. The traffic performance results of Banyan with different sizes of the switching element, with replications and TDM are presented.