Glass Fibers Force Down Communication Power Consumption

In the course of the last 50 years the power required for transmitting one telephone call has been reduced considerably. Today a telephone call transmitted over several hundred kilometers on conventional copper cables requires only as much energy as a torch. The introduction of glass fibers as a new transmission medium promises further significant reduction in energy requirements. For the transmission of large channel blocks, glass fibers have an attenuation which is much lower than that for conventional copper cables. Distances of up to ten or twenty kilometers - these will be increased even further in the future - can be covered without line repeaters. Five or more line repeaters requiring electrical energy for operation must be used for equivalent connections on conventional copper cables. Because the repeaters for glass fiber cables and copper cables require approximately the same energy, power consumption on glass fiber routes is a fifth or less of that on copper cable routes. In contrast to copper wires, which can be used for two functions (transmission and power supply), glass fibers cannot be used for power feeding; this makes the use of solar generators for supplying the intermediate repeaters on longer routes especially attractive. If this solution is not possible, central power feeding via a standard power cable with dc current is an economical and energy-saving alternative.