Telephone circuit monitoring system

Apparatus for monitoring signals on a plurality of telephone circuits comprising:

• separate input means for connection to each of said telephone circuits and for receiving call-state signals on the associated telephone circuit;
• means responsive to different address signals respectively associated with said telephone circuits for sampling call-state signals on said input means associated with the addressed one of said telephone circuits, including means for producing corresponding signals representative of the sampled call-state signals;
• and means responsive to said representative signals and also responsive to seizure control signals on said telephone circuit for directing the generation of said address signals to control the operation of said sampling means;
• said address signal generating means including means for repeatedly directing the generation of address signals for sampling seizure control signals on said telephone circuits to identify those of said circuits having calls initiated and for repeatedly directing the generation of address signals for sampling other call-state signals on some of said telephone circuits having initiated calls identified;
• said means for producing signals representative of said sampled call-state signals including means for standardizing said sampled signals, and a plurality of separate means respectively responsive to a plurality of signals of different audio control frequencies associated with said telephone circuits for producing signals identifying the presence of said audio signals;
• and said means responsive to said representative signals including means responsive to said audio identifying signals for identifying said call-state signals.

Apparatus for monitoring signals on a plurality of telephone circuits comprising:

• separate input means for connection to each of said telephone circuits and for receiving call-state signals on the associated telephone circuit;
• means responsive to different address signals respectively associated with said telephone circuits for sampling call-state signals on said input means associated with the addressed one of said telephone circuits, including means for producing corresponding signals representative of the sampled call-state signals;
• and means responsive to said representative signals and also responsive to seizure control signals on said telephone circuit for directing the generation of said address signals to control the operation of said sampling means;
• said address signal generating means including means for repeatedly directing the generation of address signals for sampling seizure control signals on said telephone circuits to identify those of said circuits having calls initiated and for repeatedly directing the generation of address signals for sampling other call-stage signals on some of said telephone circuits having initiated calls identified;
• said means for producing signals representative of said sampled call-state signals including means for standardizing said sampled signals, and a plurality of separate means respectively responsive to a plurality of signals of different audio contol frequencies associated with said telephone circuits for producing signals identifying the presence of said audio signals;
• said telephone circuits including a pair of signal lines, and said representative signal producing means including means for obtaining signals in accordance with the difference between the control signals on the pair of lines of said telephone circuits, and said signal standardizing means including means for removing direct current signals, and means for developing uniform amplitudes for the remaining alternating current signals.

The process of monitoring control signals on a plurality of telephone circuits comprising:

• repeatedly sampling the seizure control signals of the telephone circuits to detect the initiation of calls on said circuits;
• after detecting the initiation of a call on one of said telephone circuits, repeatedly sampling other call-state signals and said seizure control signals on said one circuit having the detected call, and
• repeatedly sampling the seizure control signals of said telephone circuits to detect the initiation of calls on others of said telephone circuits;
• and
• identifying the sampled call-state signals, and comparing the identified call-state signals of one sample with the call-state signals of a preceding sample to determine if they are the same, and if not the same, obtaining another sample of said call-state signals.

The process of monitoring control signals on a plurality of telephone circuits comprising:

• repeatedly sampling the seizure control signals of the telephone circuits to detect the initiation of calls on said circuits;
• after detecting the initiation of a call on one of said telephone circuits, repeatedly sampling other call-state signals and said seizure control signals on said one circuit having the detected call, and
• repeatedly sampling the seizure control signals of said telephone circuits to detect the initiation of calls on others of said telephone circuits;
• and
• identifying the sampled control signals, and comparing the identified control signals of said samples with a predetermined set of criteria for valid control signals to determine consistency therewith.

The process of monitoring control signals on a plurality of telephone circuits comprising:

• repeatedly sampling the seizure control signals of the telephone circuits to detect the initiation of calls on said circuits;
• after detecting the initiation of a call on one of said telephone circuits, repeatedly sampling other call-state signals and said seizure control signals on said one circuit having the detected call, and
• repeatedly sampling the seizure control signals of said telephone circuits to detect the initiation of calls on others of said telephone circuits;
• and
• identifying the sampled control signals, and comparing the identified control signals with a predetermined set of criteria for call dispositions to determine the disposition of said call.

The process of monitoring control signals on a plurality of telephone circuits comprising:

• repeatedly sampling the seizure control signals of the telephone circuits to detect the initiation of calls on said circuits;
• after detecting the initiation of a call on one of said telephone circuits, repeatedly sampling other call-state signals and said seizure control signals on said one circuit having the detected call, comprising the sampling of signal elements including frequencies and direct signal characteristics associated with said telephone circuits, and
• repeatedly sampling the seizure control signals of said telephone circuits to detect the initiation of calls on others of said telephone circuits;
• and
• registering the states of the detected call with the development thereof, and
• selecting the next of said call-state signal elements to be sampled based on the registered call-states of said detected call.

The process of monitoring control signals, including seizure and other call-state signals on a plurality of telephone circuits comprising:

• repeatedly sampling the seizure control signals of the telephone circuits to detect the initiation of calls on said circuits,
• upon detecting the initiation of a call on one of said telephone circuits, repeatedly and discontinuously sampling other call-state signals and said seizure control signals on said one circuit having the detected call,
• identifying a sampled call-state signal from a plurality of discontinuous samples, and repeating the call-state signal sampling and signal identifying to identify the signals of a sequence of call-state signals, and
• comparing said sequence of identified signals with predetermined criteria for different sequences of call state signals to identify the sequence of sampled call-state signals.

Apparatus for monitoring linear signals on a plurality of telephone circuits comprising:

• separate input means for connection to each of said telephone circuits and for receiving call-state signals on the associated telephone circuit;
• means responsive to different address signals respectively associated with said telephone circuits for sampling and detecting call-state signals on said input means associated with the addressed one of said telephone circuits, including:
• means for standardizing said sampled signals,
• a plurality of separate means respectively responsive to a plurality of signals of different audio control frequencies associated with said telephone circuits for producing signals identifying said audio signals, and
• means for restoring said standardizing means and said plurality of means for producing identifying signals to a reference condition at the beginning of a sampling operation.