S. Gorn

Task Group X3.3.51 is working to develop proposals for standards relating to the performance of systems used for digital data transmission. It has published two tutorial papers which were submitted by the U.S.A. to the International Organization for Standardization. In the first paper—ISO/TC97/SC6(USA-7)30,2 May, 1964—the general area of system performance was discussed. In the second paper, ISO/TC97/SC6 (USA-11)60,3 March, 1965, discussed in some detail were two characteristics of system performance, namely, Transfer Rate of Information Bits (TRIB) and Residual Error Rate. The present paper, the task group's third tutorial paper, is devoted to “System Description” insofar as that topic relates to system performance. Reported are the results of some 14 discussions that have occurred in about 1 3/4 years (June 1964 through March 1966). Including normal turnover of personnel in the group, some 14 people have been involved in these discussions. At present, the members of the task group are associated with business equipment manufacturers, users groups, and suppliers of communication facilities and services in the proportions 5 to 3 to 1. Other groups have published papers which discuss system description. In April, 1965, a paper from Italy4 was published in which system description was discussed in relation to line control and communication system techniques. In May, 1965, a paper from France5 was published in which system description was discussed in relation to system performance. These papers have been an interesting source of information to X3.3.5. While considering system performance, X3.3.5 concluded that system performance standards cannot be developed and used fully without having an organized way of describing the hardware and conditions to which performance applies. While this may not be quite t