Subscriber loop testing in a fiber-to-the-curb communications network

• US 5,301,050 A
• Filed: 06/25/1993
• Issued: 04/05/1994
• Est. Priority Date: 07/30/1991
• Status: Expired due to Term

• Current Assignee: Alcatel Network Systems India Limited (Nokia Corporation)
• Original Assignee: Alcatel Network Systems India Limited (Nokia Corporation)
• Inventors: Czerwiec, Richard M., Sutherland, Joseph E.
• Primary Examiner(s): Chilcot, Jr., Richard E.
• Assistant Examiner(s): BACARES, RAFAEL D
• Application Number:
  US08/083,787
• Time in Patent Office: 284 Days
• Field of Search: 359/110, 359/125, 359/152, 359/113, 359/154, 359/155, 359/173, 379/2, 379/23, 379/24, 379/26, 379/27, 379/29, 379/30, 379/379, 371/2.1, 371/15, 370/13
• US Class Current: 398/30
• CPC Class Codes: H04B 10/272 Star-type networks or tree-type networks
• CPC Class Codes: H04M 3/30 for subscriber's lines , for the local loop
• CPC Class Codes: H04M 3/301 Circuit arrangements at the subscriber's side of the line
• CPC Class Codes: H04M 3/303 and using PCM multiplexers, e.g. pair gain systems

Abstract

In fiber telecommunications network where an optical fiber is extended to the subscriber'"'"'s neighborhood, mechanized loop testing is performed by a test unit located in a network unit in the subscriber'"'"'s neighborhood. The test unit is responsive to commands from a controller located in the network unit to perform metallic line tests on the lines extending to the subscriber. Test results are stored in a memory associated with the controller in the network unit. Upon receipt of a test request from a central test controller, the controller within the network unit determines if there is sufficient time to perform the test; if so, a new test is performed and the results are conveyed back to the central test controller controller. If sufficient time is not available, the results of the last performed routine test contained in the memory are transmitted back to the central test controller. The test results sent back to the central test controller are conveyed firstly in the form of a particular four-digit code, which code is interpreted at a remote terminal and converted to a specific resistive signature which is conveyed back to the central test controller. The specific resistive signature is interpreted by the standard remote measurement unit located in a remote terminal.

Claims

1. An apparatus for performing mechanized loop testing in a optical fiber telecommunications network having optical transmission lines extending from a central office test controller to a remote terminal and from the remote terminal to a network unit located in the neighborhood of the subscribers, said apparatus comprising:

test means in the network unit, responsive to a start test command signal, for performing selected mechanized loop tests on subscriber lines at the network unit and for providing a test results signal;

controller means located in the network unit for starting the selected tests by providing the start test command signal to said test means and responsive to the test results signal from the test means for storing the test result signals, said controller means being responsive to test request signals transmitted from the central office test controller for providing a specific code identifying the stored test results to the remote terminal; and

means located within the remote terminal responsive to the code received from the controller means in the network unit for providing a specific resistive signature indicative of the stored test results to the central office test controller, where the specific resistive signals is recognized in the central office test controller as a specific test result.

2. An apparatus as described in claim 1, wherein the remote control terminal includes:

a dual network controller for receiving the code from the controller means;

a remote measurement unit interface responsive to a signal from the dual network controller for placing the specific resistive signature on a test line; and

a remote measurement unit monitoring the test line to identify the specific resistive signature and convey the test results to the central office test controller.

3. A method for performing mechanized loop testing in an optical fiber telecommunications network having optical transmission lines extending from a remote terminal to the subscriber'"'"'s neighborhood, said method comprising the steps of:

at a network unit located in the neighborhood, routinely conducting tests on the subscriber lines and storing said test results in a processor memory;

in response to a central office requested test, transmitting the routinely conducted, stored test results from the memory to the remote terminal;

in response to a craft request to initiate a test, running the craft requested test and providing the test results at the network unit for craft use.

4. A method as described in claim 3, wherein the stored test results are conveyed to the remote terminal as a specific coded test result and additionally comprising the steps of:

interpreting code received for the network unit, in the remote terminal, and in response thereto placing a specific resistive signal on a test line in the remote terminal; and

monitoring the test line, in the remote terminal, to recognize the specific resistive test results and forwarding said test results to a central office test controller.

5. A method for performing mechanized loop testing in an optical fiber telecommunications network having optical transmission lines extending to the subscriber'"'"'s neighborhood, said method comprising the steps of:

at a network unit located in the neighborhood, routinely conducting tests on the subscriber lines and storing said test results in a processor memory;

in response to a request to initiate a test, transmitting stored test results from the memory to the remote terminal,

wherein the test results are conveyed to the remote terminal as a specific coded test result and additionally comprising the steps of;

interpreting the code received from the network unit and, in response thereto, placing a specific resistive signature on a test line; and

monitoring the test line to recognize the specific resistive test results and forwarding said test results to a central test controller.

6. The method of claim 5, further comprising the steps of:

at the network unit, in response to a craft request to initiate a test, performing the craft requested test; and

providing a test results signal at the network unit for craft display.