Planning Aspects of Globe-Circling Communications System of High Capacity, Reliability, and Performance Quality

The need for very long-haul circuits of high-quality has developed considerably over the last few years. Recent developments in the under-seas cable field indicate that a global cable network might be devised to solve much of this traffic problem. A review is made of the basic considerations which enter into the planning of such a network, and it is pointed out that political difficulties may today pose far greater problems than any other single factor. Present and planned world cable systems are disclosed and it is pointed out that if advantage is taken of the alternate routing capabilities so offered, the required network can be reduced to a single globe-circling trunk. The factors which definitize the routing, such as economics, logistics, international agreements, presence of volcanic zones, and other inhospitable environments, are briefly discussed. It is shown that a 2-Mc cable, providing a 1-Mc band in each direction of transmission, is feasible. Performance capability may be based on a 10,000-nantical-mile section, and preliminary calculations indicate that toll-quality circuits over this length are possible. Preferred location of switching, centers is also given. Traffic from areas surrounding the global trunk can be readily fed in by spur circuits using tropospheric-scatter or microwave relay, submarine cable, or radio relays utilizing special long-endurance aircraft, according to requirements and terrain. It is suggested that the trans-African route should be a nine-link tropospheric-scatter system rather than a cable round the Cape. It is then shown that by these means, toll interconnections may be made between any two points over most of the globe, including most of the habitable part of the earth, and the major seaways and airways. It is concluded that this basic trunk could readily integrate with satellite trunks when these ultimately become operational.