An efficient diagnostic procedure based on recursive configuration of Dilated Benes Networks

Crosstalk is a major concern in switching networks such as dilated Benes networks (DBNs) consisting of electro-optical switches. There are many practical constraints which make efficient diagnosis of a DBN difficult. These constraints include (a) only the inputs and outputs of the network are accessible and (b) the crosstalk is both nonuniform among different switches as well as asymmetric for a given switch. We propose a diagnostic procedure that is amendable to automatic test generation. At its heart is a set of recursively defined network configurations that enable us to collect the power measurements at the outputs of the network in an accurate and yet efficient way. Based on these measurements, one may obtain the crosstalk measurements of each switch, which can in turn be used to calculate the signal-to-crosstalk ratio (SXR) of the network and identify switches having excessive crosstalk.