THE BELL SYSTEM TECHNICAL JOURNAL, MARCH 1956 



GROUP N0.1 



17 TRUNKS, a = 13.t6 



GROUP NO. 2 

 14 TRUNKS, a: 



10 15 20 5 10 15 



r = NUMBER OF SIMULTANEOUS CALLS OFFERED TO THE DIRECT TRUNKS 



0.15 



0.10 



f(r) 



ao5 



I- 

 z 



ui 



BC 



a. 



Ill 



S 

 1- 



z 

 o 



o 



o 

 a. 

 a. 



10 



GROUP NO. 3 



13 TRUNKS, a = 10.24 



20 



GROUP N0.4 ' 

 14 TRUNKS,; 



GROUP N0.6 

 10 TRUNKS, i 



8 10 12 14 16 18 



0.15 r 



0.10 



F(n) 



0.05 



DISTRIBUTION OF OVERFLOW CALLS FROM 8 DIR 

 GROUPS OFFERED TO 1ST ALTERNATE ROUTE 



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 



n = NUMBER OF SIMULTANEOUS CALLS OFFERED TO THE ALTERNATE ROUTE 



17 



Fig. 21 — Comparison of theoretical and throwdown dis(ril)utions of simul- 

 taneous calls offered to direct groups and to tlieir first alternate route (OST No. 1). 



