DIALING HAHITS OF TELEPHONE CUSTOMERS 



39 



2 34 5 6 7 8 9 10 11 12 



TIME, t, IN SECONDS FROM START OF DIAL TONE TEST 



Fig. 4 — Results of dial tone tests. 



trunking formulae and a large field of intermediate assumptions regard- 

 ing the disposition of calls which fail to obtain immediate service. These 

 assumptions are given in Table II on page 42. 



One method for developing the generalized trunking formula^ is to 

 consider the probabilities of the existence of certain states and to de- 

 termine the number of transitions during some convenient interval of 



^ In this article only the unlimited sources trunking formula is considered. 



