GB1326626A - Apparatus and method for routing discrete telecommunication signals - Google Patents

Abstract

1326626 Automatic exchange systems AUSTRALIA COMMONWEALTH OF 18 Sept 1970 [25 Sept 1969] 44636/60 Heading H4K. A telecommunication exchange adapted for switching between TDM highways and arranged to transfer P.C.M. samples from a first time channel on one highway to a second channel on a second highway stores the samples at addresses independent of the particular time channels used on the highways. As shown the highways are arranged in groups SR1 to SRn of eight highways each group being associated with an input group speech memory such as GSM1 and an "output register memory" such as OPR1. Each highway is divided into 25 time slots, 24 of which are used for communication and the 25th for synchronization. Each time slot conveys an 8 bit serial word or sample. At the group speech memory each word is converted to parallel form and fed out on a super-highway HIM comprising 8 parallel conductors (one for each bit) and having 8 times as many time slots so as to be able to cope with all 8 highways of its group. Depending on whether a sample from a first highway is destined for the same or a different time slot on a second highway, the sample is routed via an interhighway HXJ or an intermediate storage interhighway of junctor such as H1J to a superhighway H1R-HNR leading to the group output register of the destination highway. Each junctor highway includes an associative store. A single storage location is used for both directions of transmission, one time slot being used for signals between the first highway and the location and a second time slot being used from the location to the second highway. The addressing arrangement for one highway stores a time address indicating the time slot of the incoming highway and the address of a storage location in which the sample from the incoming highway is to be stored. A comparator compares the time address with addresses successively generated by the exchange clock and on a match being detected the sample is gated from the location given by the storage location address to the highway and a sample is gated from the highway to the location to provide transmission in both directions. The address arrangement for the second highway works in similar fashion. The read in or read out can be inhibited until pre-arranged conditions are fulfilled but no reason for this is given. The junctor can be selected from those which are not involved in a read in or read out step and the storage location can be any which is free and not defective. The highways may be wire or radio links.