444 



THE BELL SYSTEM TECHNICAL JOURNAL, MARCH 1956 



of a erlangs is submitted to the x -\- y paths. The general state equation 

 for all possible call arrangements, is 



(a* + m + n)f{m, n) = (w + l)/(m + 1, n) 



+ (n + l)/(m, w + 1) + ajim — 1, n) + aj{x, n — 1)% 



(7) 



in which the term marked {%) is to be included only when m = x, and 

 * indicates that the a in this term is to be omitted when in -\- n = x -{- y. 

 m and n may take values only in the intervals, -^ m ^ x;Q -^ n -^ y. 

 As written, the equation represents the "lost calls cleared" situation. 



(a) RANDOM TRAFFIC 



10 00 AM 



< I 



if) Q. 



a. 



2 

 to 



10 00 A M 



10 30 

 TIME OF DAY 



(b) PEAKED OVERFLOW TRAFFIC 



10 30 

 TIME OF DAY 



Fig. 11 — Production of peakedness in overflow traffic. 



