PLANNING AND OVER-ALL PERFORMANCE 23 



Repeater Test Frequencies 



In each submarine cable link, test freciuency bands were required for 

 monitoring repeater performance; and these are indicated in Fig. 4. 



Pilot Frequencies 



It was agreed to provide pilot facilities throughout the route for line-up 

 maintenance and regulation purposes. In addition to the usual pilots on 

 the inland networks, there would be provided: 



(a) a 92-kc pilot in each 12-channel group, continuous only in a par- 

 ticular section of the route and fitted with a recording voltmeter at the 

 receiving end of that section, and 



(b) an 84.08-kc overall pilot in each 12-channel group as recommended 

 by the C.C.I.F. This would transmit continuously over the entire route 

 and would be monitored and recorded at every main station. 



Connections between Component Links 



At the time that the objectives were being established, a far-reaching 

 decision was made to employ channel equipment at London, New York, 

 and Montreal only, and to adopt the frequency band 60-108 kc as the 

 standard frequency for connecting the various parts of the over-all 

 system. By adopting this band as standard for the transatlantic system, 

 it also became possible to interconnect readily with land systems at each 

 end. 



This agreement also facilitated decisions on responsibihty for design 

 and manufacture of equipment. For example, it became logical to define 

 each submarine system as the equipment between points where the 

 60-108-kc band appeared, i.e., the group connecting frames. Thus, these 

 systems would include not only the cable, repeaters, and power supplies, 

 but also the terminal gear to translate between 60-108 kc and line 

 frequency of the submarine sj^stem. It also became logical to assign 

 responsibility for manufacture of all of this equipment to the administra- 

 tion responsible for the specific system design, i.e., responsibility for the 

 Oban-Clarenville Hnk to the Bell System and the Clarenville-Sydney 

 Mines link to the Post Office. 



THE REALIZATION OF THE SYSTEM 



With decisions reached on the system objectives and interconnecting 

 arrangements, it became possible to lay out jointly a detailed over-all 

 plan and for each administration to proceed with developing and engi- 

 neering the links under its jurisdiction. 



