## Info

k with inlets of10% busy, the switch size of N with n = 8, h = 5, P = 0.625 requires 2560 crosspoints. The merits of this method are

(i) It provide accurate results

(ii) Its formulaes are directly relate to the network structures

(iii) It provides insight of the network and thus provides ideas to change the structure for high performance.

Jacobaeus. The Lee's graph approach is not much accurate. Because the probability graphs entail several simplifying assumptions. The important one which gives erroneous values of blocking is the assumption that the individual probabilities are independent. In fact the probabilities not independent and highly dependent when significant amounts of expansion are not present. According to C. Jacobaeus the blocking probability of a three stage switch is

B=kfep*(2 - p)2n- * -..<5-23> where n = number of inlets (outlets) per first (third) stage array * = number of second stage array p = inlet utilization.

More accurate techniques can be used for systems with high concentrations and high blocking. As the high blocking probabilities not having much practical value, those techniques are not considered here.