US-20260128789-A1 - MULTI-PATH, SMART OPTICAL TIME-DOMAIN REFLECTOMETER

Abstract

Aspects of the subject disclosure may include, for example, determining distinct timing offsets between an input port and output ports of a multiport optical device. An optical signal is injected at an input port of the device to obtain output signals at the output ports, which are injected into downstream fibers. An optical multipath return signal is received via the input port of the device, including a combination of measured events including reflections, backscatter, or both. A number of similar events expected in the number of downstream optical fibers is calculated to obtain an expected multipath signature based on configuration data. Results of the optical multipath return signal are then compared to the expected multipath signature to obtain comparison results. One of the measured events is distinguished from the others based on the first comparison results and the distinct timing offsets. Other embodiments are disclosed.

Inventors

• Ricky Perry

Assignees

• AT&T INTELLECTUAL PROPERTY I, L.P.

Dates

Publication Date

20260507

Application Date

20260106

Claims (20)

1. 1 . A device, comprising: a processing system including a processor; and a memory that stores executable instructions that, when executed by the processing system, facilitate performance of operations, the operations comprising: initiating, over a network, an optical time-domain reflectometry (OTDR) measurement at one of a plurality of OTDR devices respectively coupled to optical distribution networks; receiving, from the OTDR device, OTDR trace data representing reflections, backscatter, or both, from the corresponding optical distribution network; performing a multipath analysis of the OTDR trace data to identify, for each of a plurality of detected reflection and/or backscatter events, a corresponding output port of a multiport optical device within the optical distribution network; and performing, for each of the plurality of detected reflection and/or backscatter events, one or both of storing an association with the corresponding output port and presenting, via a user interface, an indication of the corresponding output port.
2. 2 . The device of claim 1 , wherein the performing the multipath analysis of the OTDR trace data comprises: determining a plurality of distinct timing offsets between an input port of the multiport optical device and each output port of the multiport optical device; and identifying the corresponding output port for a detected reflection and/or backscatter event based on a comparison between the determined timing offsets and a timing of a corresponding detected event within the OTDR trace data.
3. 3 . The device of claim 1 , wherein the performing the multipath analysis of the OTDR trace data comprises: calculating an expected multipath signature based on predetermined optical fiber lengths and device parameters of the optical distribution network; and comparing the OTDR trace data to the expected multipath signature to identify the corresponding output port.
4. 4 . The device of claim 3 , wherein: the performing the multipath analysis of the OTDR trace data comprises determining a plurality of distinct timing offsets between an input port of the multiport optical device and each output port of the multiport optical device; the expected multipath signature is calculated without applying timing offsets of the multiport optical device; and identifying the corresponding output port comprises matching a difference between an observed event and an expected event to one of the plurality of distinct timing offsets.
5. 5 . The device of claim 1 , wherein the performing the multipath analysis of the OTDR trace data comprises iteratively eliminating candidate output ports based on distances of detected reflection and/or backscatter events relative to known fiber terminations until a remaining output port is identified.
6. 6 . The device of claim 1 , wherein the OTDR measurement employs at least one of optical pulses of a first width and optical pulses of a second width, the second width being greater than the first width, the first width being configured to resolve timing offsets between output ports, the second width being configured to increase sensitivity over longer optical fiber lengths.
7. 7 . The device of claim 1 , wherein the storing the association comprises updating a record that maps output ports of the multiport optical device to downstream optical fiber segments.
8. 8 . A non-transitory machine-readable medium, comprising executable instructions that, when executed by a processing system including a processor, facilitate performance of operations, the operations comprising: initiating, over a network, an optical time-domain reflectometry (OTDR) measurement at one of a plurality of OTDR devices respectively coupled to optical distribution networks; receiving, from the OTDR device, OTDR trace data representing reflections, backscatter, or both, from the corresponding optical distribution network; performing a multipath analysis of the OTDR trace data to identify, for each of a plurality of detected reflection and/or backscatter events, a corresponding output port of a multiport optical device within the optical distribution network; and performing, for each of the plurality of detected reflection and/or backscatter events, one or both of storing an association with the corresponding output port and presenting, via a user interface, an indication of the corresponding output port.
9. 9 . The non-transitory machine-readable medium of claim 8 , wherein the performing the multipath analysis of the OTDR trace data comprises: determining a plurality of distinct timing offsets between an input port of the multiport optical device and each output port of the multiport optical device; and identifying the corresponding output port for a detected reflection and/or backscatter event based on a comparison between the determined timing offsets and a timing of a corresponding detected event within the OTDR trace data.
10. 10 . The non-transitory machine-readable medium of claim 8 , wherein the performing the multipath analysis of the OTDR trace data comprises: calculating an expected multipath signature based on predetermined optical fiber lengths and device parameters of the optical distribution network; and comparing the OTDR trace data to the expected multipath signature to identify the corresponding output port.
11. 11 . The non-transitory machine-readable medium of claim 10 , wherein: the performing the multipath analysis of the OTDR trace data comprises determining a plurality of distinct timing offsets between an input port of the multiport optical device and each output port of the multiport optical device; the expected multipath signature is calculated without applying timing offsets of the multiport optical device; and identifying the corresponding output port comprises matching a difference between an observed event and an expected event to one of the plurality of distinct timing offsets.
12. 12 . The non-transitory machine-readable medium of claim 8 , wherein the performing the multipath analysis of the OTDR trace data comprises iteratively eliminating candidate output ports based on distances of detected reflection and/or backscatter events relative to known fiber terminations until a remaining output port is identified.
13. 13 . The non-transitory machine-readable medium of claim 8 , wherein the OTDR measurement employs at least one of optical pulses of a first width and optical pulses of a second width, the second width being greater than the first width, the first width being configured to resolve timing offsets between output ports, the second width being configured to increase sensitivity over longer optical fiber lengths.
14. 14 . The non-transitory machine-readable medium of claim 8 , wherein the storing the association comprises updating a record that maps output ports of the multiport optical device to downstream optical fiber segments.
15. 15 . A method, comprising: initiating, over a network, by a processing system comprising a processor, an optical time-domain reflectometry (OTDR) measurement at one of a plurality of OTDR devices respectively coupled to optical distribution networks; receiving, from the OTDR device, by the processing system, OTDR trace data representing reflections, backscatter, or both, from the corresponding optical distribution network; performing, by the processing system, a multipath analysis of the OTDR trace data to identify, for each of a plurality of detected reflection and/or backscatter events, a corresponding output port of a multiport optical device within the optical distribution network, wherein the performing the multipath analysis of the OTDR trace data comprises determining a plurality of distinct timing offsets between an input port of the multiport optical device and each output port of the multiport optical device; and performing, by the processing system, for each of the plurality of detected reflection and/or backscatter events, one or both of storing an association with the corresponding output port and presenting, via a user interface, an indication of the corresponding output port.
16. 16 . The method of claim 15 , wherein the performing the multipath analysis of the OTDR trace data further comprises: identifying the corresponding output port for a detected reflection and/or backscatter event based on a comparison between the determined timing offsets and a timing of a corresponding detected event within the OTDR trace data.
17. 17 . The method of claim 15 , wherein the performing the multipath analysis of the OTDR trace data further comprises: calculating an expected multipath signature based on predetermined optical fiber lengths and device parameters of the optical distribution network; and comparing the OTDR trace data to the expected multipath signature to identify the corresponding output port.
18. 18 . The method of claim 17 , wherein: the expected multipath signature is calculated without applying timing offsets of the multiport optical device; and identifying the corresponding output port comprises matching a difference between an observed event and an expected event to one of the plurality of distinct timing offsets.
19. 19 . The method of claim 15 , wherein the OTDR measurement employs at least one of optical pulses of a first width and optical pulses of a second width, the second width being greater than the first width, the first width being configured to resolve timing offsets between output ports, the second width being configured to increase sensitivity over longer optical fiber lengths.
20. 20 . The method of claim 15 , wherein the storing the association comprises updating a record that maps output ports of the multiport optical device to downstream optical fiber segments.

Description

CROSS REFERENCE TO RELATED APPLICATIONS This application is a continuation of U.S. patent application Ser. No. 18/166,281 filed on Feb. 8, 2023, now U.S. Pat. No. 11,606,139, which is a continuation of U.S. patent application Ser. No. 17/195,160 filed on Mar. 8, 2021. All sections of the aforementioned application(s) and/or patent(s) are incorporated herein by reference in their entirety. FIELD OF THE DISCLOSURE The subject disclosure relates to a multi-path, smart optical time-domain reflectometer. BACKGROUND Digital telecommunications, such as networks that facilitate a communication of data, voice, video, etc., between parties or between a content distribution service and subscribers, may utilize a passive optical network (PON) between a central office or exchange and equipment of one or more subscribers. A PON includes an optical fiber and/or other passive components along a path between the central office and equipment of subscribers. For example, a single fiber may run from the central office to a passive splitter located near a group of subscribers, such as a neighborhood or office complex. Individual fibers may run from the splitter to equipment of individual subscribers or sub-groups of subscribers. In at least some applications, splitters may be cascaded to reach a greater number of subscribers. A PON typically includes an optical line termination or terminal (OLT), located at the central office, and a number of optical network terminations or terminals (ONTs) located at the subscriber's premises (e.g., home, office building, etc.). The PON also includes optical fibers with one or more optical signal splitters between the OLT and the ONTs. In a downstream direction, i.e., data transmitted from the OLT to an ONT, data may be broadcast from the OLT to all of the ONTs on the PON. An ONT may select the data to receive by matching an address embedded in the data units to a previously provisioned or learned address. In an upstream direction, i.e., data transmitted from an ONT to the OLT, the data units may be time-domain multiplexed. An Optical Time-Domain Reflectometer (OTDR) is an instrument that may be used to characterize an optical waveguide system, such as an optical fiber cable or network, by injecting a series of optical pulses into an optical fiber system under test and extracting any light returned at the same end of the fiber as may result from scattering (Rayleigh backscatter) and/or reflections from discontinuities along the fiber, such as connectors, splices, breaks and the like. Data produced by the OTDR are typically used to create a picture, e.g., a graph, typically referred to as a “trace” or “signature” that provides valuable information about the system under test. In fiber, light is scattered in all directions, including some scattered back toward the source as shown here. The OTDR uses this “backscattered light” to make measurements along with reflected light from connectors or cleaved fiber ends. Since the measurements are performed from one end of the fiber, the light injected by the OTDR goes out and comes back. Accordingly, OTDR takes this into account by dividing time delays in half. BRIEF DESCRIPTION OF THE DRAWINGS Reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and wherein: FIG. 1 is a block diagram illustrating an exemplary, non-limiting embodiment of a communications network in accordance with various aspects described herein. FIG. 2A is a block diagram illustrating an example, non-limiting embodiment of a multi-path OTDR system functioning within the communication network of FIG. 1 in accordance with various aspects described herein. FIG. 2B is an OTDR results graph illustrating an example, non-limiting embodiment of an OTDR return trace obtained using a multi-path OTDR system functioning within the communication network of FIG. 1, the multipath OTDR system of FIG. 2A, or the multi-path OTDR of FIG. 2B in accordance with various aspects described herein. FIG. 2C is an OTDR results graph illustrating an example, non-limiting embodiment of another OTDR return trace obtained using a multi-path OTDR system functioning within the communication network of FIG. 1, the multipath OTDR system of FIG. 2A, or the multi-path OTDR of FIG. 2B in accordance with various aspects described herein. FIG. 2D is a block diagram illustrating an example, non-limiting embodiment of a multi-path OTDR functioning within the communication network of FIG. 1 and the multi-path OTDR system of FIG. 2A in accordance with various aspects described herein. FIG. 2E depicts an illustrative embodiment of a multipath OTDR process in accordance with various aspects described herein. FIG. 3 is a block diagram illustrating an example, non-limiting embodiment of a virtualized communication network in accordance with various aspects described herein. FIG. 4 is a block diagram of an example, non-limiting embodiment of a computing environment in accordance with vari