s. In Proceedings of INTELEC, Toronto, of sight, out of mind services (tended by latter day troglodytes) can Feder, D.O. and Kiehne, H.E. (1987). Changes and progress in negate the whole integrity of high technology communications battery technologies during the last decade. In Proceedings of IN- networks. The lessons of the infamous widespread losses of power TELEC, Stockholm. supplies; in the north-eastern United States, including New York, in Fry, M.G.J. (1982) A switched mode power supply. In Proceed- late 1965; the British power workers' strike in 1971; or the coal ings of INTELEC, Washington. miners' strike of 1973 in the U.K.; all represent examples of major Gahrn, V., Mueller, M.P., and Schlosser, H.G. (1987) Power events which in the absence of adequate standby power supplies supply systems for remote, unmanned microwave repeater stations caused major disruptions to entire communities or even nations. in Greenland. In Proceedings of INTELEC, Stockholm. And how much worse would the situation be today, where every Grant, W.T., Attwood, R. (1983) Autonomous multi-source power other service comes to a halt when the mains supply fails or even systems for telecommunications. In Proceedings of INTELEC, has a transient blip. It has been eloquently summed up that such Tokyo. events 'can disrupt whole societies, very much like a collective loss Gropper, J. and Christopher, N. (1985) Experience with hybrid of breath (Roberts, 1989). It is appropriate therefore, to finish on power systems using closed cycle vapour turbogenerators the same note as at the beginning of this Section. Power is the (CCVT's). In Proceedings of INTELEC, Munich. lifeblood of any communications system, large or small, and is one Gumhalter, H. (1983) Power supply systems in communications of the few elements capable of causing a total failure or malfunction engineering, Wiley and Sons. of even the most sophisticated network. It is neglected at one's peril. Habock, A. and Schmalzl, F. (1979) Power supplies for telecom- munications in remote are