Call progress capability for a switched channel data service unit

A method and apparatus is provided within an interface to data terminal equipment for obtaining call progress information. The call progress information provides relevant data as to the progress of a call initiated by the data terminal equipment. The interface is designed to be used in a portion of the telephone network that lacks byte alignment. Such portions of the telephone network do not currently receive call progress tones. The interface is preferably a data service unit that includes a receiving means processor and a display means. The data service unit interprets signals sent from the DDA/OCU that encode the presence or absence of call progress tones sent from the destination node of an initiated call.

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Claims

1. In a telephone network having a direct digital access/office channel unit (DDA/OCU), a method of obtaining call progress information for a call placed from a calling party data service unit to a called party node wherein a local loop to which the calling party data service unit is connected lacks byte alignment, comprising the steps of:

a) placing a call from the calling party data service unit to the called party node over the telephone network;
b) providing a bit sequence of digitally encoded tones that encode progress of the call from the called party node that travels across the network to the DDA/OCU;
c) issuing a first type of signal from the DDA/OCU to the calling party data service unit whenever there is an absence of digitally encoded tone in the sequence of tones received by the DDA/OCU from the called party node;
d) issuing a second type of signal from the DDA/OCU to the calling party data service unit whenever there is digitally encoded tone present in the sequence of tones received by the DDA/OCU from the called party node; and
e) interpreting a resulting sequence of first type signals and second type signals at the calling party data service unit to decode call progress information.

2. A method as recited in claim 1 wherein the local loop provides 56 kilobits per second service.

4. A method as recited in claim 1 wherein the sequence of first type signals and second type signals indicates that the called party node is busy, said sequence being comprised of an alternating sequence of a first type signal having a duration of approximately 0.5 seconds followed by a second type signal having a duration of approximately 0.5 seconds.

5. A method as recited in claim 1 wherein the sequence of first type signals and second type signals indicates that the called party node is ringing, said sequence being comprised of an alternating sequence of a first type signal having a duration of approximately four seconds followed by a second type signal having a duration of approximately two seconds.

6. A method as recited claim 1 wherein the sequence of first type signals and second type signals indicates that a trunk for the called party node is busy, said sequence being comprised of an alternating sequence of a first type signal having a duration of approximately 0.25 seconds followed by a second type signal having a duration of approximately 0.25 seconds.

7. In a telephone system having a digital voice network that includes a digital data access/office channel unit (DDA/OCU), a switched channel data service unit coupled to data terminal equipment and connected to the DDA/OCU via a local loop, comprising:

a) a receiver for receiving a sequence of digitally encoded signals from the DDA/OCU, wherein said sequence of digitally encoded signals is generated by the DDA/OCU unit in response to a sequence of digitally encoded call progress tones sent from a called party node over the network, said call progress tones encoding progress of a call initiated by the data service unit to the called party node;
b) a processor for processing the sequence of digitally encoded signals to discern call progress information concerning the call; and
c) an output means for outputting the call progress information.

8. A switched channel data service as recited in claim 7 wherein the output means comprises a display for displaying the call progress information to a user of the data terminal equipment.

9. A switched channel data service unit as recited in claim 7 wherein the output means comprises control means for generating activity in response to the call progress information.

10. A switched channel data service unit as recited in claim 7 wherein the output means comprises a data link for forwarding the call progress information to the data terminal equipment.

11. In a telephone network having a direct digital access/office channel unit (DDA/OCU), a method of obtaining call progress information for a call placed from a calling party data service unit to a called party node wherein a local loop to which the calling party data service unit is connected lacks byte alignment, comprising the steps of:

a) placing a call from the calling party data service unit to the called party node over the telephone network;
b) providing a bit sequence of digitally encoded tones that encode progress of the call from the called party node that travels across the network to the DDA/OCU;
c) issuing a control mode idle (CMI) signal from the DDA/OCU to the calling party data service unit whenever there is an absence of digitally encoded tone in the sequence of tones received by the DDA/OCU from the called party node;
d) issuing an alternative (ALT) signal from the DDA/OCU to the calling party data service unit whenever there is digitally encoded tone present in the sequence of tones received by the DDA/OCU from the called party node; and
e) determining the time duration of the CMI and ALT signals viewed in sequence at the calling party data service unit to decode call progress information.

12. A method as recited in claim 11 wherein the sequence of CMI and ALT signals indicates that the called party node is busy, said sequence being comprised of an alternating sequence of a CMI and ALT of approximately 0.5 seconds each.

13. A method as recited in claim 11 wherein the sequence of CMI and ALT signals indicates that the called party node is ringing, said sequence being comprised of an alternating sequence of a CMI of approximately four seconds followed by an ALT signal having a duration of approximately two seconds.

14. A method as recited claim 11 wherein the sequence of CMI and ALT signals indicates that a trunk for the called party node is busy, said sequence being comprised of an alternating sequence of a CMI and ALT of approximately 0.25 seconds each..Iadd.15. In a network for connecting a calling party data service unit (DSU) to a called party node wherein the calling party DSU is in a local loop that lacks byte alignment wherein the calling party DSU is in a local loop that lacks byte alignment, a direct digital access/office channel unit (DDA/OCU) comprising:

a receiver for receiving a bit sequence of digitally encoded status tones associated with the called party node;
a transmitter for transmitting a first type of signal to the calling party DSU whenever there is an absence of status digitally encoded tone in the received sequence of status tones and for transmitting a second type of signal to the calling party DSU whenever there is a digitally encoded tone present in the received sequence of status tones..Iaddend..Iadd.16. A DDA/OCU as claimed in claim 15 wherein the first type of signal is a control mode idle (CMI) signal..Iaddend..Iadd.17. A DDA/OCU as claimed in claim 15 wherein the second type of signal is an alternative (ALT) signal..Iaddend..Iadd.18. A DDA/OCU as claimed in claim 15 wherein the transmitter transmits a sequence of first type signals and second type signals to indicate that the called party node is busy, the sequence comprising an alternating sequence of a first type signal having a duration of approximately 0.5 seconds followed by a second type signal

having a duration of approximately 0.5 seconds..Iaddend..Iadd.19. A DDA/OCU as claimed in claim 15 wherein the transmitter transmits a sequence of first type signals and second type signals to indicate that the called party node is ringing, the sequence comprises an alternating sequence of a first type signal having a duration of approximately four seconds followed by a second type signal having a duration of approximately two seconds..Iaddend..Iadd.20. A DDA/OCU as claimed in claim 15 wherein the transmitter transmits a sequence of first type signals and second type signals to indicate that a trunk for the called party node is busy, the sequence comprises an alternating sequence of a first type signal having a duration of approximately 0.25 seconds followed by a second type signal having a duration of approximately 0.25 seconds..Iaddend..Iadd.21. A DDA/OCU as claimed in claim 15 wherein the transmitter comprises first means for transmitting the first type of signal and second means for transmitting the second type of signal..Iaddend..Iadd.22. A method of providing call progress information to a calling party data service unit (DSU) from a digital data access/office channel unit (DDA/OCU) comprising the steps of:

receiving a bit sequence of digitally encoded tones associated with a called party node;
transmitting a first type of signal to the calling party DSU whenever there is an absence of digitally encoded tone in the received sequence of tones; and
transmitting a second type of signal to the calling party DSU whenever there is a digitally encoded tone present in the received sequence of

tones..Iaddend..Iadd.23. A method as recited in claim 22 wherein the step of transmitting the first type of signal comprises transmitting a control mode idle (CMI) signal..Iaddend..Iadd.24. A method as recited in claim 22 wherein the step of transmitting the second type of signal comprises transmitting an alternative (ALT) signal..Iaddend..Iadd.25. A method as recited in claim 22 further comprising the step of transmitting a sequence of first type signals and second type signals to indicate that the called party node is busy, the sequence comprising an alternating sequence of a first type signal having a duration of approximately 0.5 seconds followed by a second type signal having a duration of approximately 0.5 seconds..Iaddend..Iadd.26. A method as recited in claim 22 further comprising the step of transmitting a sequence of first type signals and second type signals to indicate that the called party node is ringing, the sequence comprises an alternating sequence of a first type signal having a duration of approximately four seconds followed by a second type signal having a duration of approximately two seconds..Iaddend..Iadd.27. A method as recited in claim 22 further comprising the step of transmitting a sequence of first type signals and second type signals to indicate that a trunk for the called party node is busy, the sequence comprises an alternating sequence of a first type signal having a duration of approximately 0.25 seconds followed by a second type signal

having a duration of approximately 0.25 seconds..Iaddend..Iadd.28. In a network for connecting a calling party data service unit (DSU) to a called party node, a digital data access/office channel unit (DDA/OCU) comprising:

a receiver for receiving a bit sequence of digitally encoded tones from the direction of the called party node;
a transmitter for transmitting a control mode idle (CMI) signal to the calling party DSU whenever there is an absence of digitally encoded tone in the received sequence of tones and for transmitting an alternative (ALT) signal to the calling party DSU whenever there is a digitally encoded tone present in the received sequence of tones..Iaddend..Iadd.29. A DDA/OCU as claimed in claim 28 wherein the CMI signal is represented by the sequence BBBBXOV..Iaddend..Iadd.30. A DDA/OCU as claimed in claim 28 wherein the ALT signal is represented by the sequence NBOBXOV..Iaddend..Iadd.31. A DDA/OCU as claimed in claim 28 wherein the transmitter transmits a sequence of CMI signals and ALT signals to indicate that the called party node is busy, the sequence comprising an alternating sequence of a CMI signal having a duration of approximately 0.5 seconds followed by an ALT signal having a duration of approximately 0.5 seconds..Iaddend..Iadd.32. A DDA/OCU as claimed in claim 28 wherein the transmitter transmits a sequence of CMI signals and ALT signals to indicate that the called party node is ringing, the sequence comprises an alternating sequence of a CMI signal having a duration of approximately four seconds followed by an ALT signal having a duration of approximately

two seconds..Iaddend..Iadd.33. A DDA/OCU as claimed in claim 28 wherein the transmitter transmits a sequence of CMI signals and ALT signals to indicate that a trunk for the called party node is busy, the sequence comprises an alternating sequence of a CMI signal having a duration of approximately 0.25 seconds followed by an ALT signal having a duration of approximately 0.25 seconds..Iaddend..Iadd.34. A DDA/OCU as claimed in claim 28 wherein the transmitter comprises first means for transmitting the CMI signal and second means for transmitting the ALT signal..Iaddend..Iadd.35. A method of providing call progress information to a calling party data service unit (DSU) from a direct digital access/office channel unit (DDA/OCU) wherein the calling party DSU is connected to a local loop that lacks byte alignment, the method wherein the calling party DSU is connected to a local loop that lacks byte alignment, the method comprising the steps of:

receiving a bit sequence of digitally encoded status tones from the direction of a called party node;
transmitting a control mode idle (CMI) signal to the calling party (DSU) whenever there is an absence of digitally encoded tone in the received sequence of status tones; and
transmitting an alternative (ALT) signal to the calling party DSU whenever there is a digitally encoded tone present in the received sequence of status tones..Iaddend..Iadd.36. A method as recited in claim 35 wherein the step of transmitting the CMI signal comprises transmitting a BBBBXOV sequence..Iaddend..Iadd.37. A method as recited in claim 35 wherein the step of transmitting the ALT signal comprises transmitting an NBOBXOV

sequence..Iaddend..Iadd.38. A method as recited in claim 35 further comprising the step of transmitting a sequence of CMI signals and ALT signals to indicate that the called party node is busy, the sequence comprising an alternating sequence of a CMI signal having a duration of approximately 0.5 seconds followed by an ALT signal having a duration of approximately 0.5 seconds..Iaddend..Iadd.39. A method as recited in claim 35 further comprising the step of transmitting a sequence of CMI signals and ALT signals to indicate that the called party node is ringing, the sequence comprises an alternating sequence of a CMI signal having a duration of approximately four seconds followed by an ALT signal having a duration of approximately two seconds..Iaddend..Iadd.40. A method as recited in claim 35 further comprising the step of transmitting a sequence of CMI signals and ALT signals to indicate that a trunk for the called party node is busy, the sequence comprises an alternating sequence of a CMI signal having a duration of approximately 0.25 seconds followed by an ALT signal having a duration of approximately 0.25 seconds.

.Iaddend..Iadd.1. A DDA/OCU as claimed in claim 15 wherein the local loop is a switched 56 kilobits per second network..Iaddend..Iadd.42. A method as recited in claim 35 wherein the steps of transmitting comprise formatting the signal as a 56 kilobits per second signal..Iaddend.

Referenced Cited
U.S. Patent Documents
4028493 June 7, 1977 Brennemann et al.
4213201 July 1980 Gagnier et al.
4403119 September 6, 1983 Conklin et al.
4439637 March 27, 1984 Munter
4528664 July 9, 1985 Cheng et al.
4636584 January 13, 1987 Binkerd et al.
4667065 May 19, 1987 Bangerter
4689760 August 25, 1987 Lee et al.
4696031 September 22, 1987 Freudberg et al.
5046067 September 3, 1991 Kimbrough
Other references
  • AT&T Technical Reference PUB 62310, "Digital Data System Channel Interface Specification," (Nov. 1987, Jan. 1988, Oct. 1989, Dec. 1989). Bell System Technical Reference PUB 41450, "Digital Data System Data Service Unit Interface Specification," (Nov. 1981). AT&T Technical Reference PUB 41458, "Special Access Connections to the AT&T Communications Network for New Service Applications," (Oct. 1985, Feb. 1987). Bellcore Technical Advisory TA-TSY-000077, "Digital Channel Banks--Requirements for Dataport Channel Unit Functions," (Apr. 1986). J. Bellamy, "Digital Telephony," John Wiley & Sons, Appendix B (1982).
Patent History
Patent number: RE36228
Type: Grant
Filed: Oct 21, 1993
Date of Patent: Jun 15, 1999
Assignee: Integrated Network Corporation (Bridgewater, NJ)
Inventors: Daniel M. Joffe (North Plainfield, NJ), Charles R. Eberle, Jr. (Rockaway, NJ)
Primary Examiner: Curtis Kuntz
Assistant Examiner: Paul Loomis
Law Firm: Hamilton, Brook, Smith & Reynolds, P.C.
Application Number: 8/141,325
Classifications
Current U.S. Class: For Calling Station (e.g., Status Or Progress Tones) (379/257); Interexchange Signalling (379/229); Pulse Or Digital Signalling (379/237)
International Classification: H04M 126; H04M 322;