Combining Correlated Streams of Nonrandom Traffic

The Equivalent Random method1-- is used for engineering many of the telephone overflow-networks in the Bell System. However, the method is not directly applicable to the analysis of graded-multiple trunk-groups 1 which carry overflow traffic; e.g., gradings used as alternate routes in step-bv-step switching systems having common control and alternate-routing capability. Apparently, Lotze5-" is the only author with results for estimating load-loss relations for gradings t The reader should have some knowledge of graded multiples and the methods associated with the engineering of telephone overflow-networks. Some familiarity with the step-by-step switching system would also be helpful. Those not acquainted with these concepts may find it. worthwhile to consult Ref. 1 for a discussion of telephone overflow-networks. An introduction to graded multiples is given in Ref. 3. Reference 4 contains a description of the pertinent aspects of the step-by-step system. 2015 2016 T H E BELL SYSTEM TECHNICAL J O U R N A L , J U L Y - A U G U S T