NON BLOCKING SWITCHING SYSTEMS 



419 



were: 



C[{k + l)r?] 



C{kn) = (2n - l)(2n + 2/c + 1) 



C{kn + r + 1) - C(/cn + r) = 2(fc + 3n - 1) 

 C(kn +1) - C(/crz) = 2/cn + 1 



(18) 



(19) 



(19a) 



Equation (18) was derived from equation (7) with N being replaced by 

 {k + l)n and by kn as required. Equation (19) was derived from equa- 

 tion (17) with r being replaced by r + 1 as required. This equation 

 applies for all values of n greater than 3 and for the particular case of 

 n = 3 and r = 2. Equation (19a) was derived from Equations (16a) 

 and (7) and is for the particular case of r = 1, when n = 2 and n = 3. 



SEARCH FOR THE MINIMUM NUMBER OF CROSSPOINTS FOR N = 240 



For a case where A^' is large enough to require five-switching stages, 

 the search for the minimum number of crosspoints should be based on 

 equations (12) and (13) and on the use of Table VI. The method is sug- 

 gested by means of Table VII. The data in a previous section indicate 



Table VII — Crosspoints for N = 240 and Various 

 Values of n 



* See Table VI for minimum number of crosspoints. 



