Necessary and Sufficient Conditions for the Rearrangeability of WSW1 Switching Fabrics

Abstract

This paper considers the three-stage switching fabrics of the wavelength-space-wavelength architecture, called the WSW1 switching fabrics, for elastic optical nodes. Seven control algorithms for simultaneous connection routing are described. One algorithm is designed for the WSW1 switching fabric with two inputs and two outputs, four algorithms for the WSW1 switching fabric with three inputs and outputs, and two algorithms for nodes with a capacity greater than 3. We establish the necessary conditions for rearrangeability and prove sufficient rearrangeable conditions for the proposed algorithms. In cases where the switching fabric capacity is a multiple of 3, the sufficient conditions obtained for the proposed algorithms are the best known and close to the necessary conditions. INDEX TERMS Elastic optical networks, optical switches, rearrangeable switching fabrics, control algorithms.

Analytical Modeling of Switching Fabrics of Elastic Optical Networks

“…The values n j (n) and n k (n) in (29) and (30) express, in line with (6) and (8), the number of traffic sources of, respectively, class j and k that are serviced (occupied in state ON) in the occupancy state of n FSUs. It is proved in [55] that these values are equal to the average number y dir,j (n) of serviced Engset calls of class j and the average number y dir,k (n) of serviced Pascal calls of class k, respectively, in a given occupancy state n: n j (n) = y dir,j (n); n k (n) = y dir,k (n).…”

“…To use the resources of EONs effectively, it is necessary to make use of optical switching networks that are capable of converting and transmitting optical signals in different wavelengths of light. Research and studies on optical switching networks focus mainly on the development of new nonblocking [1]- [5] and rearrangeable [6], [7] optical structures for switching networks. The construction of such systems, however, involves a huge number of switching points or complex control algorithms for setting up connections.…”

“…These conditions are determined depending on the capacity of inter-stage links expressed in frequency slot units (FSUs) [1]- [3], [5]- [7]. In addition, the influence of the number of switches in individual stages on nonblocking [1]- [3], [5] or rearrangeable [6], [7] conditions in these networks is investigated. Several studies have proposed new non-blocking structures of switching networks, in which non-blocking conditions are chosen in such a way as to decrease the production costs of a given network as much as possible.…”

RoR: A low insertion loss design of rearrangeable hybrid photonic-plasmonic 6 × 6 non-blocking router for ONoCs

“…blocking, strictly non-blocking, rearrangeable non-blocking, repackable and wide sense non-blocking [23]. When all inputs-outputs permutations of optical router can be rearranged such that all information is transmitted at the same time, the condition is called rearrangeable non-blocking (RNB) [24].…”

New upper bound for a rearrangeable non‐blocking WSW architecture

“…Based on a matrix decomposition method, various routing algorithms, each of which is applied for a specific value of r, are proposed in [17] for RNB WSW architectures. Most sufficient conditions derived from [17] are equal to the results given in [16], i.e. k RNB , except the cases with 3|r.…”