Circuit arrangement for signal and information conversion between analog junction lines and digital terminal devices in communications exchanges
March 14, 2011. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent ReferencesCommunication apparatus Telephone subscriber line unit with sigma-delta digital to analog converter Telephone line circuit and system Analog telephone circuit for digital telephone system Channel unit interface circuit Interface circuit Combination interface circuit for coupling a digital loop carrier telephone system Interface means Patent #: 5151936 InventorsAssigneeApplicationNo. 669487 filed on 03/14/1991US Classes:379/402, Hybrid circuit379/339, With signal conversion (e.g., dial to DTMF, analog to PCM)379/399.02Circuitry to provide a coder and decoder functionExaminersPrimary: Dwyer, James L.Assistant: Shehata, M. Attorney, Agent or FirmForeign Patent References
International ClassH04M 003/00Foreign Application Priority Data1990-03-16 DEAbstractA circuit arrangement converts signals and information between analog junction lines and digital terminal devices in communications exchanges. A decentralized control device is provided in order to process and pass on switching criteria and codes received and sent to the respective analog junction line, inside and outside the audio frequency band, the circuit arrangement including a plurality of line interfaces, each coupled directly to a respective one of the decentralized control devices, for the switching criteria and codes to be exchanged outside of the audio frequency. At least one digital signal processor is provided for processing the codes to be exchanged within the audio frequency band, the digital signal processor being looped in via a hybrid connection and converter in a speech path which cooperates with the control device. A digital terminal interface is responsive to the control device and the signal processor, the digital terminal interface being modulated by the control device and the signal processor to provide a plurality of useful channels and at least one signaling channel. | |
