초록 ▼

A power transmission network which includes an input for the input of telecommunication signals having carrier frequencies greater than 1 MHz onto the network, and removing similar speech and/or data signals from the network. Preferably a network conditioning element is used which includes a low pas

A power transmission network which includes an input for the input of telecommunication signals having carrier frequencies greater than 1 MHz onto the network, and removing similar speech and/or data signals from the network. Preferably a network conditioning element is used which includes a low pass filter portion for filtering out a low frequency high amplitude mains power signal, and a coupling element for input and/or removal of telecommunication signals from the network. In this way both speech and data signals can be transmitted at carrier frequencies of greater than 1 MHz along a standard electricity distribution and/or transmission network which when conditioned provides a larger available spectrum per unit length of network and greater transmission capacity than previously known. The quiescent noise level of the conditioned network is also much reduced thus permitting lower signal injection levels for a given signal-to-noise ratio and a consequential reduction in spurious radiation from the network.

대표청구항 ▼

A polyphase electricity distribution and/or power transmission network comprising: a plurality of phase conductors; input means for input of a telecommunication signal having a carrier frequency greater than approximately 1 MHz onto at least one of the phase conductors of the network; and output mea

A polyphase electricity distribution and/or power transmission network comprising: a plurality of phase conductors; input means for input of a telecommunication signal having a carrier frequency greater than approximately 1 MHz onto at least one of the phase conductors of the network; and output means for removing the telecommunication signal from at least one other phase conductor of the network; the network further including communications apparatus, the communications apparatus including a low pass filter portion for allowing, in use, a low frequency high amplitude mains electricity power signal to pass along the network to a building and for preventing electrical noise from the building entering the portion of the network external to the building, and a coupling element for input and/or removal of the telecommunication signal from the network.