Method and apparatus for providing an alternate telecommunications network

• US 5,912,963 A
• Filed: 03/03/1997
• Issued: 06/15/1999
• Est. Priority Date: 03/03/1997
• Status: Expired due to Fees

• Current Assignee: AT&T Corporation (AT&T, Inc.)
• Original Assignee: AT&T Corporation (AT&T, Inc.)
• Inventors: Greenspan, Steven Lloyd, Begeja, Lee
• Primary Examiner(s): Eisenzopf, Reinhard J.
• Assistant Examiner(s): APPIAH, CHARLES NANA
• Application Number:
  US08/811,435
• Time in Patent Office: 834 Days
• Field of Search: 379/272, 379/273, 379/279, 379/221, 379/93.14, 379/93.08, 379/909, 379/914, 379/911, 379/220, 379/102.01
• US Class Current: 379/221.01
• CPC Class Codes: H04M 3/12 Marking faulty circuits "busy"; Enabling equipment to disengage itself from faulty circuits ; Using redundant circuits; Response of a circuit, apparatus or system to an error
• CPC Class Codes: H04M 3/2254 in networks
• CPC Class Codes: H04M 7/00 Arrangements for interconnection between switching centres
• CPC Class Codes: H04Q 2213/1308 Power supply
• CPC Class Codes: H04Q 2213/1309 Apparatus individually associated with a subscriber line, line circuits
• CPC Class Codes: H04Q 2213/13103 Memory
• CPC Class Codes: H04Q 2213/13106 Microprocessor, CPU
• CPC Class Codes: H04Q 2213/13141 Hunting for free outlet, circuit or channel
• CPC Class Codes: H04Q 2213/13166 Fault prevention
• CPC Class Codes: H04Q 2213/1318 Ringing
• CPC Class Codes: H04Q 2213/13202 Network termination [NT]
• CPC Class Codes: H04Q 2213/1332 Logic circuits
• CPC Class Codes: H04Q 3/0016 Arrangements providing connection between exchanges

Abstract

A media selection device is in functional parallel with an alternate local telephone network and an existing local telephone network. Upon detecting a loss of local power, the device switches to the local exchange network based on the assumption that the local exchange network is operable, despite the loss of local power. While power is supplied to the device, originating calls are transmitted from the telephone to the device and to the alternate network. Incoming calls from the alternate network are transmitted to the device and to the telephone. Alternatively, incoming and outgoing calls are also selectably engageable on the local exchange network without disrupting telephone service on the alternate network. Differences in dial tone indicate which network is currently being used.

Claims

1. A method of switching between an alternate communications network and a local exchange network, comprising the steps of:

configuring said alternate communications network and said local exchange network in selectable engagement with a communications device;

switching between said alternate communications network and said local exchange network as a function of a state of available local power detected by a switch that performs said switching; and

reprogramming remotely a controller coupled to said switch said controller for calculating a delay time based on a time when an off-hook state occurs and a time when a dial-tone is received, and for controlling said switching as a function of said calculated delay time.

2. The method according to claim 1, further comprising the steps of:

detecting the state of available local power; and

switching from said alternate communications network to said local exchange network upon detecting that said available local power is insufficient.

3. The method according to claim 1, wherein the state of available local power comprises a loss of threshold operating power.

4. The method according to claim 1, wherein the state of available local power comprises a loss of local power.

5. The method according to claim 1, wherein the state of available local power comprises a reduction in threshold voltage to operate said switch.

6. The method according to claim 1, wherein the state of available local power comprises a reduction in threshold current to operate said switch.

7. The method according to claim 1, wherein said step of configuring said alternate communications network and said local exchange network comprises coupling said alternate communication network in parallel with said local exchange network.

8. The method according to claim 1, further comprising the steps of:

transmitting outgoing calls to the alternate communications network when said local power is active; and

switching all incoming calls from said alternate communications network and said local exchange network to said communications device.

9. The method according to claim 1, further comprising the steps of:

detecting said communications device in an off-hook state; and

detecting the reception of a dial-tone after said communications device is in an off-hook state.

10. The method according to claim 9, further comprising the steps of:

calculating a delay time between the time at which said communications device goes off-hook and the communications device receives a dial-tone; and

determining whether to switch between said networks in the event that the calculated delay time exceeds an acceptable range.

11. The method according to claim 8, wherein said step of transmitting outgoing calls compress switching all emergency related calls to said local exchange network.

12. A method for providing telecommunications services during a power outage to a communications device operates over an alternate communications network, comprising the steps of:

detecting a state of available local power by a switch that switches, in the event of an outage of said local power, the network over which said communications device operates from said alternate communications network to a local exchange;

switching telecommunications services in the event of a power outage from said alternate communications network to a remotely powered local exchange network; and

reprogramming remotely a controller coupled to said switch, said controller for calculating a delay time based on a time when an off-hook state occurs and a time when a dial-tone is received and for controlling said switch as a function of said calculated delay time.

13. An apparatus for coupling a communication device to two communications service providers, said apparatus comprising:

means for coupling said two communications service providers in a functionally parallel mode of operation with said communications device;

means for switching communications service from one of said two of said two communications service providers to the other communications service provider upon detection of a loss of power;

means for accepting remote reprogramming instructions to enable remote reprogramming of a means for controlling coupled to the means for switching, the means for controlling for calculating a delay time based on a time when an off-hook state occurs and a time when a dial-tone is received, and for controlling said means for switching as a function of said calculated delay time.

14. The apparatus according to claim 13, wherein the means for coupling comprises a media selection device comprising a first input/output connection for coupling to a first of said two communications service providers, a second input/output connection for coupling to a second of two communications service providers, an input connection for coupling to a local power source, and an input/output connection for coupling to said communications device.

15. The apparatus according to claim 13, wherein said means for switching comprises a means for detecting local power.

16. The apparatus according to claim 13, wherein said means for switching comprises a spring-loaded switch which maintains a first state when power is connected to said switch and switches to a second state when power is disconnected from said switch.

17. The apparatus according to claim 14, wherein the media selection device comprises two or more input/output connections for coupling to two or more communications devices.

18. A device for coupling to a telephone that communicates via an alternate communications network, and operates from a local power source, and for enabling the telephone to operate on a local exchange carrier during power outages, said device comprising:

a first interface to said local exchange carrier for sending and receiving telephone signals;

a power detector coupled to said local power source for detecting a change in state of the power from the local power source;

a second interface to the alternate communications network for sending and receiving telephone signals;

a third interface to said telephone for sending and receiving telephone signals;

a means of switching telephone signals from said second interface to said first interface upon the detection of a change in state of the local power from the local power source;

a remotely reprogrammable controller coupled to said means for switching an accepting programming instructions via a telephone call, said controller for calculating a delay time based on a time when an off-hook state occurs and a time when a dial-tone is received, and for controlling said means for switching as a function of said calculated delay time.

19. The device according to claim 18, further comprising a second input/output for coupling to a second telephone, and wherein said device can establish two telephone channels simultaneously.

20. The device according to claim 19, wherein said two simultaneous channels are established on both the alternate communications carrier and the local exchange carrier.

21. The device according to claim 18, further comprising an off-hook detector for detecting whether said telephone coupled to said device is off-hook and for disconnecting said telephone from said local exchange carrier if said telephone is off-hook and is being used on said alternate communications network.

22. The device according to claim 18, further comprising a voltage detector for detecting a ringing voltage, and for transmitting the ringing voltage to said telephone in the event said telephone is not off-hook and for transmitting a call waiting signal to said telephone in the event that said telephone is off-hook.

23. A media selection device for coupling between a communications device and at least two communications networks, comprising:

a switch activated by a loss of power to the media selection device, whereupon such activation, said switch decouples said communications device from one communications network and couples said communications switch to the other communications network; and

a remotely reprogrammable controller coupled to said switch and accepting new programming instructions remotely, said controller for calculating a delay time based on a time when an off-hook state occurs and a time when a dial-tone is received, and for controlling said switch as a function of said calculated delay time.

24. The device according to claim 23, further comprising a receiver/transmitter for coupling to one of said communications networks.

25. The device according to claim 24, wherein the receiver/transmitter comprises a wireless receiver/transmitter.

26. The device according to claim 23, wherein the receiver/transmitter comprises a cable modem.

27. The device according to claim 23, further comprising a manual override switch that enables a user to select the communications network.

28. The device according to claim 23, further comprising a call director that automatically directs emergency calls to a predetermined communications network.

29. The device according to claim 23, further comprising a call director that automatically directs specified telephone numbers to a predetermined communications networks.