High speed data links using power line carrier equipment

In high voltage networks various communications bearers may be utilised. Data signalling has been slow, particularly where power line carrier communications have been used. The authors describe a system using high speed data signalling power line carrier (PLC) bearer channels in a rapidly developing country. Restrictions at the time of design were imposed by the licensing authorities with regard to available high frequency bandwidth and limited transmitter output power. Due to the length of the 275 kV lines, double transpositions were included which, together with high corona noise under adverse weather, gave potentially onerous signal to noise ratio (SNR) conditions