Device and method for detecting presence of service on telephone line
AssigneeThomson Licensing
InventorsBlaine Edward Ramey, Brian Albert Wittman
Life of this patent
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Abstract
A device and a method for detecting presence of service on a telephone line prior to and during activation of alternative service on the line. The method comprises performing a first voltage detection on a subscriber line (S20), activating a subscriber line interface circuit (SLIC) if no pre-existing service is detected (S30), the SLIC providing an interface between the subscriber line and a service provider, and performing a second voltage detection on the subscriber line after a usage-dependent time has elapsed (S60), the time being determined by heuristics which consider several factors, including usage history of the line and time of day.
Claims18
A method for detecting presence of service on a subscriber line in a communications network, comprising the steps of:
- performing a first voltage detection on a subscriber line (S20);
- activating a subscriber line interface circuit (SLIC) if no other service is detected on the subscriber line (S30), the SLIC providing an interface between the subscriber line and a service provider;
- and
- performing a second voltage detection on the subscriber line after a usage-dependent time has elapsed (S60).
A method for detecting presence of a foreign voltage on a telephone line, comprising the steps of:
- detecting a voltage on a telephone line and comparing the voltage with a predetermined voltage;
- activating a subscriber line interface circuit (SLIC) when the voltage on the telephone line is less than the predetermined voltage, wherein the SLIC provides interface between the telephone line and a central office of a communications system;
- deactivating the SLIC after a usage-dependent time has elapsed;
- and
- detecting a foreign voltage greater than the predetermined voltage on the telephone line.
A device for detecting presence of service on a subscriber line in a communications network, comprising:
- means for detecting a voltage on a subscriber line and for comparing the voltage with a predetermined voltage;
- means for selectively activating the device in response to the detected voltage on the subscriber line;
- and
- means for using heuristics to determine when to perform test of presence of another service,
- wherein presence of another service is detected when the device is deactivated after the usage-dependent time has elapsed.
Dependencies are inferred from the claim text.