transatlantic voice communications was carried out using wireless technologies. These were unreliable as short wave radio signals were suscep- tible to signal fading and noise. To increase received signal power from coaxial cables repeater devices needed to be installed at intervals of some 70 km. These required power which had to be supplied from both ends. The technology for such repeaters needed for submarine cable telephony was not developed until the 1950s. The first transatlantic cable (TAT-1), connecting the UK, Canada and the US was commissioned in 1954 and started operation in 1956. TAT-1's useful bandwidth was 144 kHz and could provide 3 groups of 12 voice chan- nels (36 in total). The cost of manufacturing and laying the cable down was $36 million in 1954, or the equivalent of some $320 million today (2014), which averaged over its 22 years of operation cost some $34 000 per channel per year. The cost of a phone call needed to be set in the order of $3 per minute to pay back the initial investment and operating costs [or $27 today (2014)]. This was still a major improvement over the radio calls which had inferior voice quality, and cost some $9 per minute [7]. The transatlantic telephony link became very popular and traffic grew at an annual rate of 20%. Soon extra capacity was needed, and therefore link capacity had to be increased by reducing the bandwidth required for voice communication from 4 to 3 kHz. This increased the number of circuits by 33% to 48 channels at a reduced voice quality. Even at this quality, 48 circuits could only support 36 E of traffic. To maximise the links' usage transatlantic calls were handled by booking through operators. With the popularity of the link, more submarine cable systems were commissioned and laid around the world. Seven generations of coaxial cable-based transatlantic cables were laid before optical fibre technology was developed. Table 3.1 shows these seven transatlantic cables and their respective capacities, and cost per speech channel per year. Table 3.1 