Dual test mode network interface unit for remote testing of transmission line and customer equipment
First Claim
1. A method of remotely testing customer equipment from a central office, the central office being connected to the customer equipment via a twisted pair transmission line and a network interface device including at least one xDSL filter, with the customer equipment being connected in electrical series with the at least one xDSL filter during normal operation, the method comprising:
- applying a request signal along the twisted pair transmission line to invoke a test mode;
in response to the request signal, automatically isolating from the twisted pair transmission line, the at least one xDSL filter, the customer equipment and a port connectable to an xDSL modem;
sending a first test signal via the twisted pair transmission line back to the central office to thereby test the twisted pair transmission line while it is disconnected from the at least one xDSL filter, the customer equipment and the port, during a line test phase; and
automatically bypassing the at least one xDSL filter such that the twisted pair transmission line remains connected to the customer equipment, and testing the customer equipment while the customer equipment is unaffected by the at least one xDSL filter and the port, during a customer equipment test phase.
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0 Petitions
Accused Products
Abstract
A network interface device intended to be placed approximate to the customers equipment and remote from a central office of a telephone company (“TELCO”). The purpose of the network interface device is to allow the twisted pair transmission line between the central office and the customer'"'"'s port to be selectively switched from a normal monitoring mode into a test mode. The test mode has two phases. In the first phase, the NIU transmits a signal back to the central office. This allows the central office to determine whether there are any problems with the transmission line, the potential bandwidth for the transmission line and related parameters concerning the efficacy and suitability of the transmission line for a variety of communication services. In the second phase, which is entered into upon completion of the first phase, the customer-end ADSL low pass filter is bypassed so that the central office can test the customer'"'"'s POTS equipment.
128 Citations
17 Claims
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1. A method of remotely testing customer equipment from a central office, the central office being connected to the customer equipment via a twisted pair transmission line and a network interface device including at least one xDSL filter, with the customer equipment being connected in electrical series with the at least one xDSL filter during normal operation, the method comprising:
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applying a request signal along the twisted pair transmission line to invoke a test mode;
in response to the request signal, automatically isolating from the twisted pair transmission line, the at least one xDSL filter, the customer equipment and a port connectable to an xDSL modem;
sending a first test signal via the twisted pair transmission line back to the central office to thereby test the twisted pair transmission line while it is disconnected from the at least one xDSL filter, the customer equipment and the port, during a line test phase; and
automatically bypassing the at least one xDSL filter such that the twisted pair transmission line remains connected to the customer equipment, and testing the customer equipment while the customer equipment is unaffected by the at least one xDSL filter and the port, during a customer equipment test phase. - View Dependent Claims (3, 4, 5)
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2. A network interface device operable in one of a normal monitor mode and a test mode having a line test phase and a customer equipment test phase, said network interface device configured to interface a twisted pair transmission line to customer equipment in a communication system, said network interface device comprising:
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a first port comprising first and second terminals establishing respective first and second voltage nodes;
a second port comprising third and fourth terminals selectively connected to respective first and second terminals via respective first and second switches, said second port being connected to the first port when the device is in the monitor mode and also in the customer equipment test phase, and being disconnected from the first port when the device is in the line test phase;
a third port connected to the first port when the device is in the monitor mode and being disconnected from the first port when the device is in the test mode;
at least one xDSL filter situated between the first and second switches, and the second port;
a detector circuit connected in electrical parallel across said first and second voltage nodes and configured to detect a request signal, said detector circuit being further configured to output a first control signal to said first and second switches upon detection of said request signal, to thereby place the de vice in the test mode;
a power supply circuit connected to said first port via said first and second switches, and arranged to output a DC supply voltage when the device is in the test mode, said power supply circuit being powered by a voltage applied across the first and second voltage nodes;
a signal generator circuit coupled to said first port via said first and second switches, and configured to output a predetermined test signal to said first port for a predetermined first period of time, when the device is in the line test phase, said signal generator circuit being powered by said DC supply voltage from said power supply circuit; and
a bypass circuit configured to allow a signal passing between the first and second ports to bypass the at least one xDSL filter during the customer equipment test phase. - View Dependent Claims (6, 7, 8, 9, 10, 16)
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11. A network interface device operable in one of a normal monitor mode and a test mode having a line test phase and a customer equipment test phase, said network interface device configured to interface a twisted pair transmission line to customer equipment in a communication system, said network interface device comprising:
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a first port comprising first and second terminals establishing respective first and second voltage nodes;
a second port comprising third and fourth terminals selectively connected to respective first and second terminals via respective first and second switches, said second port being connected to the first port when the device is in the monitor mode and also in the customer equipment test phase, and being disconnected from the first port when the device is in the line test phase;
a third port connected to the first port when the device is in the monitor mode and being disconnected from the first port when the device is in the test mode;
at least one xDSL filter situated between the first and second switches, and the second port;
a detector circuit connected in electrical parallel across said first and second voltage nodes and configured to detect a request signal, said detector circuit being further configured to output a first control signal to said first and second switches upon detection of said request signal, to thereby place the device in the test mode; and
a bypass circuit configured to allow a signal passing between the first and second ports to bypass the at least one xDSL filter during the customer equipment test phase.
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12. A network interface device operable in one of a normal monitor mode and a test mode having a line test phase and a customer equipment test phase, said network interface device configured to interface a twisted pair transmission line to customer equipment in a communication system, said network interface device comprising:
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a first port configured to connect to a twisted pair transmission line;
a second port connected to the first port when the device is in the monitor mode and also in the customer equipment test phase, and being disconnected from the first port when the device is in the line test phase;
a third port connected to the first port when the device is in the monitor mode and being disconnected from the first port when the device is in the test mode;
at least one xDSL filter situated between the first port and the second port;
a detector circuit connected to terminals of the first port and configured to detect a request signal sent along the twisted pair transmission line, said detector circuit being further configured to place the device in the test mode, in response to the request signal; and
a bypass circuit configured to allow a signal passing between the first and second ports to bypass the at least one xDSL filter during the customer equipment test phase. - View Dependent Claims (13, 14, 15, 17)
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Specification