Method and apparatus for testing remote communication systems
First Claim
1. In a telecommunication system comprising a communication line, a local interface connecting the communication line to a central office and a remote interface connecting the communication line to at least one continuous metallic subscriber line, there being no continuous metallic path from the subscriber line to the central office, and means connected to the central office side of the local interface for testing the subscriber line, apparatus for testing said subscriber line comprising:
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Accused Products
Abstract
A method and apparatus are described for testing a telecommunication line despite a gap in a metallic line between the testing system at a central office and the subscriber'"'"'s line. On the subscriber'"'"'s or remote end of the gap in the metallic line, apparatus is provided for performing certain desired tests on the continuous metallic portion of the subscriber'"'"'s line. This apparatus is connected to a testing system on the central office or local side of the gap with suitable communication equipment so that tests performed on the remote end may be reported back to the testing system. The remote end testing apparatus is similar to apparatus described in application Ser. No. 645,479. The testing system at the central office preferably is a conventional system, such as the MLT system which already is installed in many central offices throughout the United States, together with the necessary modifications to communicate with and control the remote end testing apparatus. The necessary modifications can be implemented in software by modifying the computer programs that run the MLT system. Alternatively, the necessary modifications are implemented in hardware by providing at the local end apparatus that can simulate certain operating parameters of the subscriber'"'"'s line and by providing communication between the remote end testing apparatus and the simulation equipment.
31 Citations
17 Claims
- 1. In a telecommunication system comprising a communication line, a local interface connecting the communication line to a central office and a remote interface connecting the communication line to at least one continuous metallic subscriber line, there being no continuous metallic path from the subscriber line to the central office, and means connected to the central office side of the local interface for testing the subscriber line, apparatus for testing said subscriber line comprising:
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2. means at the remote interface for measuring at least one of subscriber line resistance, DC current and DC voltage, said means being connected by continuous metallic leads to said subscriber line;
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means at the remote interface for applying to the subscriber line at least one AC signal to measure AC characteristics of the subscriber line; means at the local interface for simulating at least one of the subscriber line resistance, DC current and DC voltage and AC characteristics that are measured at the remote interface; means at the remote interface for transmitting to the simulating means measurements made by the measuring means and signals representative of said AC characteristics of the subscriber line; and means at the local interface for connecting said simulating means to said testing means, whereby said testing means measures circuit parameters generated by said simulating means that simulate measurements made on the subscriber line by the means located at the remote interface.
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5. Apparatus for testing a continuous metallic subscriber line from a controlling location that is not connected to said subscriber line by a continuous metallic line, said apparatus comprising:
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apparatus at said controlling location for measuring at least some of line resistance, DC current and DC voltage; a test circuit connected to said subscriber line by a continuous metallic line, said test circuit comprising; means for measuring at least some of subscriber line resistance, DC voltage and DC current, and means for transmitting said measurements to the controlling location; and a simulator at the controlling location comprising; means for receiving the measurements transmitted by the test circuit, a circuit comprising variable resistances, variable voltage sources and means for adjusting said resistances and voltage sources so that the output of the circuit represents the measurements received by said receiving means, and means for connecting said circuit to said measuring apparatus, whereby said measuring apparatus measures circuit parameters representing the measurements made on the subscriber line by the measurement performing means.
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6. In a telecommunication system comprising a communication line, a local interface connecting the communication line to a central office and a remote interface connecting the communication line to at least one continuous metallic subscriber line, there being no continuous metallic path from the subscriber line to the central office, means connected to the central office side of the local interface for testing the subscriber line, a method of testing said subscriber line comprising the steps of:
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measuring at the remote interface at least one of subscriber line resistance, DC current and DC voltage, said means being connected by continuous metallic leads to said subscriber line; applying to the subscriber line at the remote interface at least one AC signal to determine AC characteristics of the subscriber line; and transmitting from the remote interface to the local interface measurements made during the measuring step and signals representative of said AC characteristics of the subscriber line; simulating at the local interface at least one of the subscriber line resistance, DC current, DC voltage and AC characteristics; and measuring with said testing means connected to the central office side of the local interface the subscriber line resistance, DC current, DC voltage and AC characteristics that are simulated. - View Dependent Claims (8, 9, 10, 11, 12, 13, 15, 17)
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Specification