66 



THE BELL SYSTEM TECHNICAL JOURNAL, JANUARY 1952 



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5-120 



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MESSAGE RATE 

 RESIDENTIAL 

 BUSINESS 



TWO-PARTY 

 FLAT RATE INDIVIDUAL 145 

 COIN 237 



123 

 68 

 195 

 104 



DIAL TONE DELAYED 0.6 TO 0.9 SECONDS 

 CLASS INTERVAL = 0.5 SECOND 



'^ 5 



5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 



TIME,t, IN SECONDS AFTER THE RECEIPT OF DIAL TONE 



Fig. 21 — Distributions of the start-to-di;il times of subscribers wlio dial after 

 the receipt of dial tone. 



These results agree reasonably well when it is recalled that parts of 

 the individual line data were scanty and that the sender monitor tests 

 included the effects of observer reactions. 



Once dial tone is received, it appears that all types of subscribers 

 tend to follow a uniform dialing pattern. Figs. 20 to 23 show for a class 

 interval of 0.5 second the distribtitions of the per cent of subscribers who 

 dial at time t for the six types of subscribers studied. Figs. 20, 21 and 22 

 show the distributions when dial tone is received from 0.0 to 0.5, 0.6 to 

 0.9 and 1.0 to 1.9 seconds after dial tone, respectively. These curves 





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MESSAGE RATE 

 RESIDENTIAL 

 ' BUSINESS 

 PBX 



38 



19 

 31 

 19 



TWO-PARTY 



FLAT RATE INDIVIDUAL 27 



COIN 129 



DIAL TONE DELAYED 1.0 TO 1.9 SECONDS 

 CLASS INTERVAL = 0.5 SECOND 



0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 



TIME,t, IN SECONDS AFTER THE RECEIPT OF DIAL TONE 



Fig. 22 — Distril)utions of the start-to-dial times of subscribers who dial after 

 the receipt of dial tone. 



