Symmetric Rearrangeable Networks: Algorithms and Rearrangement Limits

Symmetric rearrangeable networks have been a topic of research interest for a long time in the communication community. In recent years these networks have been suggested for use in high speed communications such as in optical cross connects, because of their unique feature of being able to rearrange the state of the network to unblock a blocked request. Although these networks have been studied extensively, yet there are issue have not been addressed. One open question is the softbound required rearrangements. This paper presents a non-blocking routing algorithm for symmetric rearrangeable networks and goes on to determine softbound for the rearrangements. Along with a new routing algorithm, another major contribution of this work is to determine the soft bound of the number of rearrangements for different sizes of networks and compare them with theoretical results on hardbound available in the literature. Ours is a much simpler solution for routing than other available techniques because it exploits the softbound. Each switching stage has been represented by a set of sub-matrices and hence a conflict free routing is found. This algorithm can provide much simpler hardware implementation than other commonly known algorithms because of its simple approach.