Call progress decoder for multiple cadenced tones on telephone lines

• US 5,483,593 A
• Filed: 11/01/1993
• Issued: 01/09/1996
• Est. Priority Date: 12/21/1990
• Status: Expired due to Fees

• Current Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Gupta, Sanjay, Lis, Timothy
• Primary Examiner(s): Hofsass, Jeffery A.
• Assistant Examiner(s): Wolinsky, Scott
• Application Number:
  US08/146,772
• Time in Patent Office: 799 Days
• Field of Search: 379/372, 379/377, 379/381, 379/382, 379/386
• US Class Current: 379/386
• CPC Class Codes: H04Q 1/30 Signalling arrangements; Manipulation of signalling currents multiplex systems providing for calling or supervisory signals H04J1/14, H04J3/12

Abstract

Apparatus for detecting single and/or multiple cadenced tone progress status of a telephone call in any one of a plurality of telephone networks is disclosed. A set of parameters for each of a multiplicity of predetermined single and/or cadenced tones in which some call progress status having multiple different sets of parameters for the same call progress status are stored in memory. Parameters of the cadence (s) of a valid tone present on the telephone line are measured and compared with the multiplicity of sets of parameters stored in the memory to establish the presence of the call progress status represented by the corresponding cadenced valid tone. For tones having multiple cadences, the measured parameters of each cadence is compared with a corresponding set of cadence parameters of the memory to establish the presence of the call progress status represented by the multiple cadenced tone.

Claims

1. An apparatus for detecting progress status of cadenced tones of a telephone call in any one of a plurality of telephone networks by comparing measured parameters of the cadenced tones with a multiplicity of sets of predetermined parameters, said apparatus comprising:

means for detecting valid tones being generated over a telephone line of one of the telephone networks;

means for measuring parameters of at least one cadence of said valid tones, said measured parameters of the cadenced valid tones being representative of the call progress status present on said telephone line;

means for storing a set of parameters for each of a multiplicity of predetermined cadenced tones, some call progress status having multiple different sets of parameters for the same call progress status; and

multiple cadence comparing means for comparing the measured parameters with the multiplicity of sets of predetermined parameters of said storing means to establish the presence of the call progress status represented by the corresponding cadenced valid tones,

wherein the comparing means includes a comparing element corresponding to each different call progress status of a predetermined plurality of call progress status, each said comparing element for comparing the measured cadence parameters of said valid tone with only the sets of parameters representing the call progress status corresponding to said comparing element to establish if the measured cadence parameters represent the corresponding call progress status,

and wherein each comparing element includes at least one cadence detect element for comparing measured parameters of at least one cadence of said valid tone with at least one corresponding set of parameters representing at least one cadenced tone of the associated call progress status,

and wherein the cadence detect element includes means for comparing the measured parameters of each cadence of a multiple cadenced tone sequentially with its corresponding set of parameters of each corresponding cadence of the multiple cadenced tone of the associated call progress status to establish whether or not there is agreement sequentially with each comparison,

wherein the stored set of parameters for a predetermined single cadenced tone includes a maximum and minimum on time and a maximum and minimum off time of the single cadence thereof;

wherein the stored set of parameters for a predetermined multiple cadenced tone includes a maximum and minimum on time and a maximum and minimum off time for each cadence of the multiple cadences thereof; and

wherein the measured parameters of each cadence of the valid tone include a measured on time and a measured off time,

wherein for each cadence comparison, the corresponding measured on time is window compared with its corresponding maximum and minimum on times and the corresponding measured off time is window compared with its corresponding maximum and minimum off times; and

wherein agreement is established when both the measured on time and measured off time falls within their respective comparison windows,

wherein the cadence detect element further includes means for detecting disagreement in a cadence comparison and for resetting the comparison sequence to an initial state in response to said detected disagreement, and

wherein the cadence detect element further includes means for counting each period of multiple cadences for which there is no comparison disagreement and for generating a signal representing the presence of the corresponding call progress status when said counting means reaches a predetermined count.

2. An apparatus for detecting progress status tones of multiple cadences of a telephone call in a telephone network, said apparatus comprising:

means for detecting each valid tone of multiple cadences being generated over a telephone line of the telephone network;

means for measuring parameters of each cadence of said multiple cadenced tones, said measured parameters of the multiple cadenced tone being representative of the call progress status present on said telephone line;

means for storing a set of parameters for each cadence of said multiple cadenced tones; and

multiple cadence comparing means for comparing the measured parameters of each cadence with a corresponding set of cadence parameters of said storing means to establish the presence of the call progress status represented by said multiple cadenced tones,

wherein the comparing means includes a comparing element corresponding to each different call progress status of a predetermined plurality of call progress status, each said comparing element for comparing the measured cadence parameters of said valid tone with only the sets of parameters representing the call progress status corresponding to said comparing element to establish if the measured cadence parameters represent the corresponding call progress status,

and wherein each comparing element includes at least one cadence detect element for comparing the measured parameters of the multiple cadences of said valid tone with corresponding multiple sets of parameters representing the multiple cadences of the cadenced tone of the associated call progress status,

wherein the cadence detect element includes means for comparing the measured parameters of each cadence of the multiple cadenced tone sequentially with its corresponding set of parameters of each corresponding cadence of the multiple cadenced tone of the associated call progress status to establish whether or not there is agreement sequentially with each comparison,

wherein the stored set of parameters for a predetermined multiple cadenced tone includes a maximum and minimum on time and maximum and minimum off time for each cadence of the multiple cadences thereof; and

;

wherein the measured parameters of each cadence of the valid tone include a measured on time and a measured off time,

wherein for each cadence comparison, the corresponding measured on time is window compared with its corresponding maximum and minimum on times and the corresponding measured off time is window compared with its corresponding maximum and minimum off times; and

wherein agreement is established when both the measured on time and measured off time falls within their respective comparison windows,

wherein the cadence detect element further includes means for detecting disagreement in a cadence comparison and for resetting the comparison sequence to an initial state in response to said detected disagreement, and

wherein the cadence detect element further includes means for counting each period of multiple cadences for which there is no comparison disagreement and for generating a signal representing the presence of the corresponding call progress status when said counting means reaches a predetermined count.