Communication network terminating device, communication system, signal jamming method and signal jamming program

A communication system comprising:

• a transmitter configured to send a transmission signal generated in accordance with a frequency division multiplexed signal to a wired communication network;
• a receiver configured to receive the frequency division multiplexed signal, and select and demodulate a carrier signal included in the frequency division multiplexed signal;
• a communication network termination apparatus connecting to the wired communication network and the receiver;
• and
• a control server apparatus configured to transmit apparatus identifying data and signal specifying data to the communication network termination apparatus, the apparatus identifying data specifying an apparatus to be requested to perform signal quality degradation, the signal specifying data specifying a signal requesting signal quality degradation among a plurality of carrier signals included in the frequency division multiplexed signal,
• wherein the communication network termination apparatus includes
• a reception processor configured to output the frequency division multiplexed signal obtained from the transmission signal transmitted over the wired communication network,
• an output controller configured to output, in a case that the apparatus identifying data transmitted by the control server apparatus matches an apparatus identifying data stored in a storage of the communication network termination apparatus, frequency band specifying data indicating a frequency band corresponding to the signal specifying data,
• a disturbing signal generator configured to generate a disturbing signal in a frequency band corresponding to the frequency band specifying data output by the output controller, and
• a multiplexer configured to multiplex the frequency division multiplexed signal and the disturbing signal to output,
• the output controller, in a case that the apparatus identifying data, the signal specifying data specifying each of the plurality of carrier signals included in the frequency division multiplexed signal and the frequency band specifying data in association with each other, and the apparatus identifying data acquired matches, refers to the storage to detect the frequency band specifying data corresponding to the signal specifying data, and outputs the detected frequency band specifying data,
• the output controller, in a case the signal specifying data is the frequency band specifying data and apparatus identifying data acquired matches the apparatus identifying data stored in the storage, outputs the signal specifying data as the frequency band specifying data.

A signal disturbing method comprising:

• outputting a frequency division multiplexed signal obtained from a transmission signal transmitted over a wired communication network;
• outputting, in a case that apparatus identifying data matches an apparatus identifying data stored in a storage of a communication network termination apparatus, a frequency band specifying data indicating a frequency band corresponding to signal specifying data, the apparatus identifying data being for requesting signal quality degradation, and the signal specifying data being for specifying a carrier signal requesting signal quality degradation among a plurality of carrier signals included in the frequency division multiplexed signal;
• generating a disturbing signal in a frequency band corresponding to the frequency band specifying data output;
• and
• multiplexing the frequency division multiplexed signal and the disturbing signal to output,
• the outputting, in a case that the apparatus identifying data the signal specifying data specifying each of the plurality of carrier signals included in the frequency division multiplexed signal and the frequency band specifying data in association with each other, and the apparatus identifying data acquired matches, refers to the storage to detect the frequency band specifying data corresponding to the signal specifying data, and outputs the detected frequency band specifying data,
• the outputting, in a case the signal specifying data is the frequency band specifying data and apparatus identifying data acquired matches the apparatus identifying data stored in the storage, outputs the signal specifying data as the frequency band specifying data.