Diagnosing crosstalk-faulty switches in photonic networks

A procedure for diagnosing crosstalk and crosstalk-faulty switches in photonic dilated Benes networks (DBNs) is presented. It obtains the crosstalk ratios of each and every switch in an N/spl times/N DBN in 4N tests, along with O(N/spl middot/log/sup 2/N) calculations. One of its applications is to identify single or multiple switches in the DBN which are generating excessive crosstalk, or crosstalk-faulty. A recursive algorithm is used to configure the DBN for each test such that the necessary power measurements of the signals can be taken accurately. An important feature of the proposed diagnostic procedure is its suitability for automated test generation.