Power supply systems for cellular communications repeaters

Cellular communications networks require the use of cellular repeaters (especially in mountainous areas) which are specifically designed to solve problems regarding insufficient cover age by the radio field in special situations. Thruway, railway and subway tunnels are some of the most common cases. Various repeater technologies such as leaky cables, antennas fed with coaxial cables and antennas fed with optical fibres are used, depending on the distances to be covered. A different type of power supply is used with each of these technologies. A central power cabinet is always included. The guidelines of project design include choice of voltages and type of current (continuous or alternating), degree of protection specified for the equipment, methods of handling ground potentials in the presence of surges that may cause malfunctions, and safety regulations. Diverse solutions are considered, and both currently operative systems and projects to be implemented in the future are presented for evaluation.