Performance analysis of new wide-sense nonblocking photonic switching system

The deployment of optical fibers as a transmission medium aroused the problem of speed mismatching between transmission and switching. To build a large IP router with capacity of 1 Tb/s and beyond, either electronic or optical switching can be used. Optical communications with photonic switching are promising to provide high bandwidth and low error probability. The major obstacle in this regard is suitable switching systems that can efficiently route optical signals. An all-optical switch network, in which data remains in the optical domain throughout its journey from source to destination, is central to such switching systems. Existing switching systems do not scale well for large number of ports when optics is considered as the carrier of information. There are two major problems, namely cross talk and path-dependent-signal loss that needs to be addressed while designing a switch network with guided-wave technology. Because of stringent bit errorrate requirement of optical transmission facilities, elimination of cross talk has become an important issue for making optical networks work properly. It is also difficult to handle the path-dependent-signal loss and delay in the optical domain with such a high bit rate especially if the variation is large. In this paper, new switch architecture is proposed for nonblocking photonic switching. The switch is a space division multistage network using 2 × 2 optical switching elements. The switch network is constructed by using independent building blocks recursively. Thus, by choosing appropriate building blocks, it can be customized according to the costperformance requirement of a system. The proposed architecture is presented and properties of the switch are derived, analyzed and compared with other well-known design.