Communication system based on remote interrogation of terminal equipment

Apparatus including an input port and an output port responsive to an information-bearing input signal arriving at the input port, comprising:

• first means coupled to said input port for
• a) forming a received signal and a carrier signal, where the carrier signal comprises a portion of the information-bearing input signal and contains at least some of the information borne by the information-bearing input signal, and
• b) modulating the carrier signal with an applied upstream signal to form a modulated return signal;
• and
• second means for delivering the return signal to the output port.

Apparatus responsive to an optical information-bearing input signal comprising:

• a splitter responsive to the information-bearing input signal for forming a received signal and a carrier signal, where the carrier signal carries at least some of the information borne by the input signal;
• and
• a modulator, including a first port for receiving an applied upstream signal and a second port for receiving the carrier signal, for
• a) modulating the carrier signal with the upstream signal to form a modulated return signal, and
• b) applying the modulated return signal to thee second port,

A system comprising:

• a plurality of units, each unit including
• a) a splitter for receiving an applied optical information-bearing unit input signal to form a received signal and a carrier signal that contains at least some of the information borne by said information-bearing input signal, and
• b) a modulator for modulating the carrier signal with an applied upstream signal to form a modulated return signal and to output the return signal from the unit:
• and
• a wavelength division multiplexer/demultiplexer coupled to said plurality of units responsive to a composite incoming signal for
• a) forming a plurality of information-bearing unit input signals and distributing said unit input signals to the plurality of units, and
• b) accepting the return signals of the plurality of units and forming a composite return signal from the accepted return signals.

A system comprising:

• hub means for enabling transmission of an upstream information signal from a subscriber to the hub means by outputting a downstream light signal packet that carries information, when information is to be communicated to said subscriber;
• a router coupled to the hub means for routing the light signal packet to one of a plurality of output ports of the router based on the wavelength of the signal packet's wavelength:
• terminal means coupled to one of the output ports of the router for
• a) receiving the light signal packet,
• b) extracting a portion of the light signal packet, which portion contains at least some of the information carried by said light signal packet, and
• c) modulating said portion with an upstream signal to develop thereby the upstream information signal;
• and
• means for delivering said upstream information signal to said hub.

A system comprising:

• a multi-wavelength optical source for providing a wavelength division multiplexed signal;
• a router coupled to the multi-wavelength optical source for receiving the wavelength division multiplexed signal and for providing a plurality of information-bearing unit signals from the received wavelength division multiplexed signal, where the unit signals have wavelengths that are essentially mutually exclusive;
• and
• a plurality of terminal units coupled to the router, each including means for receiving one of the information-bearing unit signals and for modulating a portion of the received information-bearing unit signal with an upstream signal to thereby form a modulated return signal, where said portion carries at least some of the information carried by the received information-bearing unit signal.

System apparatus comprising:

• optical means for providing an optical wavelength division multiplexed downstream signal, at least one wavelength of which is modulated with downstream information;
• a router, responsive to the downstream signal, for directing different wavelengths of the downstream signal to different output ports of the router;
• and
• a plurality of units, each coupled to one of the output ports of the router and including means for receiving a unit signal from the coupled output port of the router and modulating a portion of the received unit signal with an upstream signal to thereby a remodulated return signal, where said portion of the received unit signal carries at least some of the information carried by the received information-bearing unit signal.