Subscriber terminal and method for passing control signals between a first and second signal processing units

A subscriber terminal for communicating over a wireless link with a central terminal of a wireless telecommunications system, the subscriber terminal comprising:

• a first signal processing unit associated with an antenna to transmit and receive signals over the wireless link at first frequencies within an operating frequency band, the first signal processing unit comprising a frequency converter for converting signals between said first frequencies and a second frequency;
• a second signal processing unit remote from the first signal processing unit and associated with an item of telecommunications equipment to pass signals between said item of telecommunications equipment and the first signal processing unit, the second signal processing unit being formed from signal processing circuitry which is independent of the operating frequency band, the signals being passed between the first signal processing unit and the second signal processing unit at the second frequency via a connection medium connecting the first and second signal processing units;
• and
• a communication link to allow control signals to be passed between the first and second signal processing units, said communications link being established over the connection medium, and the control signals being issued at a predetermined frequency distinct from said second frequency, wherein the second frequency is an intermediate frequency, the second signal processing unit comprising a radio modem circuit arranged to process a signal received via the connection medium at the intermediate frequency to generate a baseband signal for passing to the item of telecommunications equipment, and to process a baseband signal from the item of telecommunications equipment to generate a signal at the intermediate frequency for outputting to the first signal processing unit via the connection medium.

A method of communicating over a wireless link with a central terminal of a wireless telecommunications system, comprising the steps of:

• providing a first signal processing unit associated with an antenna to transmit and receive signals over the wireless link at first frequencies within an operating frequency band;
• converting, within the first signal processing unit, signals between said first frequencies and a second frequency;
• providing a second signal processing unit remote from the first signal processing unit and associated with an item of telecommunications equipment to pass signals between said item of telecommunications equipment and the first signal processing unit;
• forming the second signal processing unit from signal processing circuitry which is independent of the operating frequency band;
• passing the signals between the first signal processing unit and the second signal processing unit at the second frequency via a connection medium connecting the first and second signal processing units;
• and
• passing control signals between the first and second signal processing units over the connection medium at a predetermined frequency distinct from the second frequency, wherein the second frequency comprises a downlink second frequency for signals passed from the first signal processing unit to the second signal processing unit and an uplink second frequency for signals passed from the second signal processing unit to the first signal processing unit.