Patent ID: 8055136

Claim:
A base station, operable to communicate data over a two-way communications channel established with a mobile terminal unit, by way of a plurality of antenna units operable to communicate wirelessly with the mobile terminal unit, wherein the base station is operable to communicate with said a plurality of antenna units over optical fibre links, the base station comprising: an optical transmitter for generating and transmitting downlink optical data signals to said antenna units; and an optical receiver for receiving uplink optical data signals generated by said antenna units in respect of said communications channel, wherein said optical transmitter comprises: a light source operable to generate an optical carrier; a first optical modulator operable to modulate said optical carrier with a radio frequency oscillator signal to generate an optical oscillator signal suitable for use by said at least one antenna unit in generating uplink optical data signals; and a second optical modulator, coupled optically to the first optical modulator, operable to receive the optical oscillator signal and to modulate the optical oscillator signal with an input data signal of a frequency allocated in respect of said communication channel and generate and to output a downlink optical data signal comprising the modulated optical oscillator signals, wherein the second optical modulator is directly coupled to the first optical modulator, and comprises an optical splitter for distributing the downlink optical data signal from the second optical modulator to the plurality of antenna units.