Patent ID: 7567550
Filing Date: 2009-07-28
Classification: H04M,H04Q

Abstract:
1. A communications network comprising: a communications station; electrical transmission lines connecting the communications station to user terminations; data transmission means; optical carriers connecting the data transmission means to at least one interface, located between the communications station and user terminations, for converting optical signals from an optical carrier into electrical signals for transmission over one at least of the electrical transmission lines; wherein, in respect of at least downstream transport, and for each of a plurality of user terminations requiring data service: (a) a dedicated one of said optical carriers is provided; (b) the data transmission means comprises modulation means for converting input data signals into output signals suitable for transmission over the electrical transmission lines, followed by means for modulating the output signals onto an optical signal; (c) the interface has optoelectrical conversion means arranged to recover said output signals and feed them to the electrical transmission line serving the relevant user termination; and wherein, at least in respect of upstream transmission: (d) the communication station has associated therewith a light source for generating a plurality of optical seed signals at different respective wavelengths; and (e) there is provided, for each of the user terminations, a light generating device capable of predominantly generating light at a selected one of a plurality of predetermined wavelengths, the light generating devices each being arranged to receive a respective seed signal such that the wavelength of the light generated by a given light generating device is determined by the received seed signal wherein the light generating devices are each connected to a respective electrical transmission line serving the relevant user terminal such that data from a given user terminal can be transmitted upstream by the light emitting device connected to that user terminal, and the light generating devices are fed with DC power over the electrical transmission lines.