Apparatus for interfacing analog telephones and digital data terminals to an ISDN line

• US 5,305,312 A
• Filed: 02/07/1992
• Issued: 04/19/1994
• Est. Priority Date: 02/07/1992
• Status: Expired due to Term

• Current Assignee: American Telephone & Telegraph Company (AT&T, Inc.)
• Original Assignee: AT&T, Inc.
• Inventors: Kinn, Dennis R., Meade, Steven P., Fornek, Martin J., Welman, Blaine E.
• Primary Examiner(s): Safourek, Benedict V.
• Assistant Examiner(s): HSU, ALPUS
• Application Number:
  US07/832,269
• Time in Patent Office: 802 Days
• Field of Search: 370/55, 370/58.1, 370/58.2, 370/58.3, 370/62, 370/79, 370/110.1, 370/110.2, 370/110.3, 379/88, 379/89, 379/93, 379/94, 379/97, 379/98, 379/387, 379/399, 379/413, 379/201
• US Class Current: 370/264
• CPC Class Codes: H04Q 11/0428 Integrated services digital network, i.e. systems for transmission of different types of digitised signals, e.g. speech, data, telecentral, television signals
• CPC Class Codes: H04Q 11/0471 Terminal access circuits
• CPC Class Codes: H04Q 2213/09 Subscriber related equipment; Analog terminal
• CPC Class Codes: H04Q 2213/096 Digital subscriber terminal
• CPC Class Codes: H04Q 2213/106 Microcomputer; Microprocessor
• CPC Class Codes: H04Q 2213/1309 Apparatus individually associated with a subscriber line, line circuits
• CPC Class Codes: H04Q 2213/13093 Personal computer, PC
• CPC Class Codes: H04Q 2213/13096 Digital apparatus individually associated with a subscriber line, digital line circuits
• CPC Class Codes: H04Q 2213/13106 Microprocessor, CPU
• CPC Class Codes: H04Q 2213/13173 Busy signals
• CPC Class Codes: H04Q 2213/13176 Common channel signaling, CCS7
• CPC Class Codes: H04Q 2213/13204 Protocols
• CPC Class Codes: H04Q 2213/13209 ISDN
• CPC Class Codes: H04Q 2213/1326 Consultation call, broker's call, call hold, toggling
• CPC Class Codes: H04Q 2213/13299 Bus
• CPC Class Codes: H04Q 2213/299 Bus

Abstract

An interface to an integrated service, digital network (ISDN) line for up to two analog dual tone, multifrequency telephones and up to four personal computers or data terminals. A stored program-controlled processor controls access to the ISDN line for the analog and digital interface circuits. The processor also provides access to switch-controlled ISDN features for the analog telephones (e.g., call waiting, call hold, etc.).

Claims

1. A customer premises apparatus capable of interfacing more than one analog telephone and more than one digital data terminal to a single integrated services digital network (ISDN) line connected to a telephone switching system switch that provides ISDN services, said ISDN line comprising two B-channels and a D-channel, said apparatus comprising:

a stored program control processor;

a communications controller, said communications controller communicating with said processor;

analog interface means for interfacing said more than one analog telephone to said B-channel under the control of said processor, said analog interface means receiving analog signaling indicative of requests for ISDN services from said analog telephones and forwarding said requests to said processor;

digital interface means for interfacing said more than one digital data terminal to said D-channel and said B-channels under the control of said processor, said digital interface means receiving digital signaling indicative of requests for ISDN services from said digital data terminals and forwarding said requests for ISDN services to said processor; and

bus means for connecting said analog interface means, said digital interface means and said communications controller to said ISDN line,

wherein said communications controller receives ISDN control messages from said switch on said ISDN line, translates said control messages and sends said translated control messages to said processor, and wherein said processor configures said analog and digital interface means responsive to said translated control messages, and wherein said communications controller receives request messages from said processor pursuant to requests for ISDN services from said analog interface means and said digital interface means, translates said messages and sends said messages on said ISDN line to said switch, thus providing ISDN services to said more than one analog telephone and said more than one digital data terminals.

2. An apparatus according to claim 1 further including a U-interface for interfacing said bus means to said ISDN line.

3. An apparatus according to claim 1 further including memory means for storing a control program for controlling said processor.

4. An apparatus according to claim 3 further including update means connected to said memory means for changing the contents of said memory means.

5. An apparatus according to claim 4 wherein said update means comprises a card reader for reading electronically encoded memory cards.

6. An apparatus according to claim 1 wherein said analog interface means comprises

coding and decoding means for converting digital data from said B-channels into analog signals for said analog telephones and analog signals from said analog telephone into digital data for said B-channels.

7. An apparatus according to claim 1 wherein said analog interface means comprises:

means for detecting on-hook and off-hook transitions of said analog telephone; and

means for providing electricity to said analog telephone.

8. An apparatus according to claim 1 wherein said analog interface means comprises

means for detecting dual-tone, multi-frequency (DTMF) signals from said analog telephone and reporting detected DTMF signals to said processor.

9. An apparatus according to claim 1 wherein said analog interface means comprises

means for generating audible tones for said analog telephone.

10. An apparatus according to claim 1 wherein said digital interface means comprises a serial communications controller for interfacing to a serial port of said digital data terminals.

11. An apparatus according to claim 1 wherein said digital interface means comprises two data ports for connecting to said digital data terminals.

12. An apparatus according to claim 1 further including means for providing electrical power to said analog telephones when local power supply is interrupted.

13. An apparatus according to claim 12 wherein said means for providing electrical power comprises a rechargeable battery.

14. A customer premises apparatus capable of interfacing more than one analog telephone and more than one digital data terminal to a single integrated services digital network (ISDN) line connected to a telephone switching system that provides ISDN services, said apparatus comprising:

a stored program control processor;

a system bus connected to said processor;

an ISDN bus connected to said ISDN line;

analog interface means, connected to said system bus and to said ISDN bus, for interfacing said more than one analog telephone to said ISDN bus and being configurable by said processor via commands sent over said system bus, said analog interface means adapted to receive analog signaling indicative of requests for ISDN service from said analog telephones and forward said requests to said processor via said system bus, said analog interface means also adapted to receive digital data from said ISDN bus, translate said data into analog signals, and deliver said analog signals to said more than one analog telephone, and further adapted to receive analog signals from said more than one analog telephone, translate said analog signals into data and deliver said data to said ISDN bus;

digital interface means, connected to said system bus and to said ISDN bus, for interfacing said more than one digital data terminal to said ISDN bus and being configurable by said processor via commands sent over said system bus, said digital interface means adapted to receive digital signaling indicative of requests for ISDN services from said digital data terminals and forward said requests for ISDN services to said processor over said system bus, said digital interface means also adapted to receive digital data from said ISDN bus and deliver said data to said more than one digital data terminal, and further adapted to receive data from said more than one digital data terminal and deliver said data to said ISDN bus; and

a communications controller connected to said ISDN bus and to said system bus for receiving ISDN control messages from said switch on said ISDN bus, translating said control messages and sending said translated control messages to said processor over said system bus, wherein said processor configures said analog interface means and said digital interface means responsively to said control messages, and for receiving request messages from said processor over said system bus pursuant to requests for ISDN services from said analog interface means and said digital interface means, translating said messages and sending said messages on said ISDN line, thus providing ISDN services to said more than one analog telephone and said more than one digital data terminals.