ISDN trials on subscriber loops and customer premises wiring

The results and operation issues pertaining to the ISDN basic rate access trials are described. The trials were performed on both the subscriber loop and the customer premises wiring. The test results for the U-interface and the S/T-interface are presented. The S/T-interface field trial was completed in two office high-rise buildings located in the Ottawa region. The main objective was to test the passive bus operation at the S/T-interface. All CCITT (International Telegraph and Telephone Consultative Committee) proposed configurations, as well as a configuration which was considered better matched to the existing office wiring architecture, were tested. Certain configurations, such as the short passive bus and the extended passive bus, were not suited for deployment within the building when using the existing inside wiring. Conversely, the branched passive bus uses the existing wiring architecture in a practical manner in regions served by Bell Canada