Ringback tone apparatus and telephone metering system

Claim 2

A MESSAGE METERING APPARATUS FOR OPERATION WITH A TELEPHONE SYSTEM HAVING LOCAL STATIONS AND TRUNK LINES, HAVING A SWITCHING EXCHANGE FOR CONNECTING THE STATIONS TO THE TRUNK LINES, AND HAVING TONE SIGNALS OF PREDETERMINED DURATION FOR SIGNALING IN THE TELEPHONE SYSTEM, SAID APPARATUS COMPRISING, ANALOG-TO-DIGITAL CONVERTER MEANS FOR CONVERTING SAID TONE SIGNALS TO RECTANGULAR WAVE SIGNALS HAVING PULSE WIDTHS REPRESENTING THE DURATION OF SAID TONE SIGNALS, FIRST DETECTOR MEANS INCLUDING LOWER LIMIT FIRST MEANS FOR SENSING PULSE WIDTHS OF SAID RECTANGULAR WAVE SIGNALS LESS THAN A FIRST LOWER LIMIT, UPPER LIMIT FIRST MEANS FOR SENSING PULSE WIDTHS OF SAID RECTANGULAR WAVE SIGNALS GREATER THAN A FIRST UPPER LIMIT, AND MEANS, RESPONSIVE TO BOTH SAID FIRST MEANS FOR SENSING, FOR INDICATING WHEN TONE SIGNALS HAVE A PULSE DURATION BETWEEN SAID FIRST LOWER LIMIT AND SAID FIRST UPPER LIMIT.

Claim 3

The apparatus of claim 1 including timing means responsive to said detector means for sensing for a timed duration the presence of said tone signals having a pulse duration between said first upper and lower limits.

Claim 4

The apparatus of Claim 1 including second detector means including lower limit second means for sensing pulse widths of said rectangular wave signals less than a second lower limit, upper limit second means for sensing pulse widths of said rectangular wave signals greater than a second upper limit, and means, responsive to both said second means for sensing, for indicating when tone signals have a pulse duration between said second lower limit and said second upper limit.

Claim 5

The apparatus of claim 3 including busy interlock means connected to said first and second detector means for inhibiting the detection by one of said first and second detector means after the other of said first and second detector means detects the presence of a tone signal.

Claim 6

The apparatus of claim 3 including third detector means including lower limit third means for sensing pulse widths of said rectangular wave signals less than a third lower limit, upper limit third means for sensing pulse widths of said rectangular wave signals greater than a third upper limit, and means, responsive to both said third means for sensing, for indicating when tone signals have a pulse duration between said third lower limit and said third upper limit.

Claim 7

The apparatus of claim 1 wherein one of said means for sensing includes lower limit timing means and the other of said means for sensing includes upper limit timing means, said lower and upper limit timing means responsive to leading edges of said rectangular wave signals for commencing timed operations, said lower limit timing means operative to terminate the timed operations when said first lower limit is reached and said upper limit timing means operative to terminate the timed operation when said first upper limit is reached and where said means for sensing includes flip-flop means for responsively storing an indication that said rectangular wave signal includes a pulse having a pulse width between said lower limit and said upper limit.

Claim 8

The apparatus of claim 6 wherein said flip-flop means includes a flip-flop receiving an input from both said lower limit means and said upper limit means whereby said flip-flop is set only when said rectangular wave signal has a pulse width between said upper limit and said lower limit.

Claim 9

The apparatus of claim 6 wherein said flip-flop means includes a first flip-flop set whenever said rectangular wave signal has a pulse width greater than said upper limit and includes a second flip-flop set whenever said rectangular wave pulse has a pulse width less than said lower limit and where said apparatus includes gate means connected to said first and second flip-flops for providing an output whenever said first flip-flop or said second flip-flop is set thereby indicating that said rectangular wave signal has a pulse width outside the range between said upper limit and said lower limit.

Claim 10

The apparatus of claim 8 including second timing means connected to said gate means operative in response to said gate means for sensing for a timed duration the absence of outputs from said gate means thereby indicating for a timed duration the presence of pulses in said rectangular wave signal having pulse widths between said first upper and lower limits.

Claim 11

The apparatus of claim 9 including storage means connected to said second timing means for storing an indication that said pulses have been present for a timed duration.

Claim 12

A message metering apparatus for operation with a telephone system having local stations and trunk lines, having a switching exchange for coNnecting stations to the trunk lines, and having rectangular wave control signals of predetermined pulse width for signaling in the telephone system, said apparatus comprising, first detector means including lower limit first means for sensing pulse widths of said rectangular wave signals less than a first lower limit, upper limit first means for sensing pulse widths of said rectangular wave signals greater than a first upper limit, and means,responsive to both said first means for sensing, for indicating when control signals have a predetermined pulse width between said first lower limit and said first upper limit.

Claim 13

A message metering apparatus for operation with a telephone system having local stations and trunk lines, having a switching exchange for coNnecting stations to the trunk lines, and having rectangular wave control signals of predetermined pulse width for signaling in the telephone system, said apparatus comprising, first detector means including lower limit first means for sensing pulse widths of said rectangular wave signals less than a first lower limit, upper limit first means for sensing pulse widths of said rectangular wave signals greater than a first upper limit, and means,responsive to both said first means for sensing, for indicating when control signals have a predetermined pulse width between said first lower limit and said first upper limit.

Claim 14

A message metering apparatus for operation with a telelphone system having local stations and trunk lines, having a switching exchange for connecting local stations to remote stations over the trunk lines, and having tone signals of predetermined duration for signaling in the telephone system, said tone signals including a ringback tone for signaling the absence of a called-party answer after the calling party has completed dialing, said apparatus comprising, analog-to-digital means for converting said tone signals to rectangular wave signals having pulse widths representing the duration of said tone signals, first detector means for detecting the presence of said ringback tone signals, said first detector means including lower limit first means for sensing pulse widths of said rectangular wave signals less than a first lower limit, upper limit first means for sensing pulse widths of said rectangular wave signals greater than a first upper limit, and means, responsive to both said first means for sensing, to indicate the pulse duration of said ringback tone signals.

Claim 15

A message metering apparatus for operation with a telelphone system having local stations and trunk lines, having a switching exchange for connecting local stations to remote stations over the trunk lines, and having tone signals of predetermined duration for signaling in the telephone system, said tone signals including a ringback tone for signaling the absence of a called-party answer after the calling party has completed dialing, said apparatus comprising, analog-to-digital means for converting said tone signals to rectangular wave signals having pulse widths representing the duration of said tone signals, first detector means for detecting the presence of said ringback tone signals, said first detector means including lower limit first means for sensing pulse widths of said rectangular wave signals less than a first lower limit, upper limit first means for sensing pulse widths of said rectangular wave signals greater than a first upper limit, and means, responsive to both said first means for sensing, to indicate the pulse duration of said ringback tone signals.

Claim 16

The apparatus of said claim 12 including timing means, initiated by said first detector means, for timing the duration of calls between the local station and a remote station.

Claim 17

A message metering apparatus for operation with a telelphone system havng local stations and trunk lines, having a switching exchange for connecting local stations to remote stations over the trunk lines, and having a plurality of tone signals of predetermined duration for signaling in the telephone system, said tone signals including a ringback tone for signaling the absence of a called-party answer after the calling party has completed dialing, a trunk busy tone signal for signaling a trunk busy condition, and a line busy tone signal for signaling the busy condition of a line to a called-party station, said apparatus comprising, analog-to-digital means for converting said tone signals to rectangular wave signals having pulse widths representing the duration of said tone signals, first detector means for detecting the presence of said ringback tone signals, said first detector means including lower limit first means for sensing pulse widths of said rectangular wave signals less than a first lower limit, upper limit first means for sensing pulse widths of said rectangular wave signals greater than a first upper limit, and means, responsive to both said first means for sensing, to indicate the pulse duration of said ringback tone signals, second detector means for detecting the presence of said trunk busy tone signals, said second detector means including lower limit second means for sensing pulse widths of said rectangular wave signals less than a second lower limit, upper limit second means for sensing pulse widths of said rectangular wave signals greater than a second upper limit, and means, responsive to both said second means for sensing, to indicate the pulse duration of said trunk busy tone signals, and third detector means for detecting the presence of said line busy tone signals, said third detector means including lower limit third means for sensing pulse widths of said rectangular wave signals less than a third lower limit, upper limit third means for sensing pulse widths of said rectangular wave signals greater than a third upper limit, and means, responsive to both said third means for sensing, to indicate the pulse duration of said line busy tone signals.

Claim 18

A message metering apparatus for operation with a telelphone system havng local stations and trunk lines, having a switching exchange for connecting local stations to remote stations over the trunk lines, and having a plurality of tone signals of predetermined duration for signaling in the telephone system, said tone signals including a ringback tone for signaling the absence of a called-party answer after the calling party has completed dialing, a trunk busy tone signal for signaling a trunk busy condition, and a line busy tone signal for signaling the busy condition of a line to a called-party station, said apparatus comprising, analog-to-digital means for converting said tone signals to rectangular wave signals having pulse widths representing the duration of said tone signals, first detector means for detecting the presence of said ringback tone signals, said first detector means including lower limit first means for sensing pulse widths of said rectangular wave signals less than a first lower limit, upper limit first means for sensing pulse widths of said rectangular wave signals greater than a first upper limit, and means, responsive to both said first means for sensing, to indicate the pulse duration of said ringback tone signals, second detector means for detecting the presence of said trunk busy tone signals, said second detector means including lower limit second means for sensing pulse widths of said rectangular wave signals less than a second lower limit, upper limit second means for sensing pulse widths of said rectangular wave signals greater than a second upper limit, and means, responsive to both said second means for sensing, to indicate the pulse duration of said trunk busy tone signals, and third detector means for detecting the presence of said line busy tone signals, said third detector means including lower limit third means for sensing pulse widths of said rectangular wave signals less than a third lower limit, upper limit third means for sensing pulse widths of said rectangular wave signals greater than a third upper limit, and means, responsive to both said third means for sensing, to indicate the pulse duration of said line busy tone signals.

Claim 19

The apparatus of claim 14 including busy interlock means connected to said first, second and third detector means for inhibiting the detection by first and second ones of said first, second and third detector means after the third one of said detector means detects the presence of a tone signal.

Claim 20

The apparatus of claim 14 including timing means, initiated by said first detector means, for timing the duration of calls between a local station and a remote station.