DIALING HABITS OF THLKPHONE CUSTOMERS 65 



Table IV 



Message rate — residential 



— business 



— PBX 



— two-party 



Flat rate individual 



Coin 



* rjouRli extrapolated values 



Estimated Values of H in Seconds 



Table V 



Percentages of Subscribers Waiting for Dial Tone 



Service Observation 

 Figs. 17(a) to 19(b) 



5 sees 10 sees IS sees 



Sender Monitor Tests 

 Figs. 13 to 15 



S sees 10 sees IS sees 



Message rate 



Residential 



Business 



PBX 



Two party 



Flat rate individual 

 Coin 



34% 

 62 

 35 

 62 



74 

 68 



16% 



41 



22 



35 



34 



55 



10% 



16 



13 



11 



20 



47 



55% 



55 



67 



33% 



19 

 48 



19% 



14 

 35 



lU < 



A 



/ 



--t\. 



MESSAGE RATE i 



RESIDENTIAL 

 BUSINESS 



TWO-PARTY 

 FLAT RATE INDIVIDUAL 

 COIN 



214 

 127 

 144 

 211 

 79 

 888 



DIAL TONE DELAYED TO 0.5 SECONDS 

 CLASS INTERVAL = 0.5 SECOND 



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. 20 — Distributions of the start-to-dial times of subscribers who dial after 

 the receipt of dial tone. 



