A 2-LEVEL PROCESS FOR DIAGNOSING CROSSTALK IN PHOTONIC DILATED BENES NETWORKS

A two-level process for diagnosing crosstalk in photonic Dilated Benes Networks (DBNs) is presented. At level one is the Test-All-Switches ( TAS) procedure, which obtains the crosstalk ratios of each and every s witch in an N x N DBN in 4N tests using O(N.log(2) N) calculations. On e of its applications is to identify single or multiple crosstalk-faul ty switches in the DBN which generate excessive crosstalk. To reduce t he number of tests and amount of computation when diagnosing only a fe w switches suspected of crosstalk-faulty along an arbitrary path, the Test-One-Path (TOP) procedure at level two is proposed. A recursive al gorithm applicable to both procedures is used to configure the DBN for each test such that the necessary power measurements of the signals c an be taken accurately An important feature of the proposed diagnostic process is its suitability for automated test generation. (C) 1997 Ac ademic Press.