# US 11,029,354 B1 · Systems and methods for distributed sensing of a powerline conductor > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,029,354 B1 - Document ID: US11029354B1 - Status: Granted - Kind: B1 - Application number: 16/745,025 - Filed: 2020-01-16 - Granted: 2021-06-08 - Earliest claimed: 2017-10-17 - Assignees: Facebook, Inc. - Applicants: Facebook, Inc. - Inventors: Karthik Yogeeswaran - Web page: https://patentgrep.com/patent/US11029354B1 ## CPC - G01R 31/11: using pulse reflection methods - G01R 31/085: {in power transmission or distribution lines, e.g. overhead} - G02B 6/483: {Installation of aerial type} - H04B 10/071: using a reflected signal, e.g. using optical time domain reflectometers [OTDR] - H04B 10/2575: Radio-over-fibre, e.g. radio frequency signal modulated onto an optical carrier - H04Q 9/00: Arrangements in telecontrol or telemetry systems for selectively calling a substation from a main station, in which substation desired apparatus is selected for applying a control signal thereto or for obtaining measured values therefrom - G02B 6/4422: {of the overhead type} - H04Q 2209/30: using a wired architecture - G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12) - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS - H04B: TRANSMISSION - H04Q: SELECTING (switches, relays, selectors H01H; wireless communication networks H04W) ## Abstract A system includes (1) a signal transmitter that includes (a) a radio frequency generator that generates a first radio frequency electromagnetic signal and (b) a first transducer that converts the first radio frequency electromagnetic signal to a surface wave mode signal imposed onto a powerline conductor at a first location in a first direction toward a second location along the powerline conductor, (2) a signal receiver that includes a second transducer located at the second location that converts the surface wave mode signal into a second radio frequency electromagnetic signal, and (3) an analysis subsystem that monitors a signal strength of the second radio frequency electromagnetic signal over time to determine whether a physical encroachment of the powerline conductor exists between the first location and the second location. ## Claims ### Claim 1 A system comprising: a signal transmitter comprising: a radio frequency generator that generates a first radio frequency electromagnetic signal; and a first transducer that converts the first radio frequency electromagnetic signal to a first surface wave mode signal imposed onto a powerline conductor at a first location in a first direction toward a second location along the powerline conductor; a signal receiver comprising a second transducer located at the second location along the powerline conductor that converts the first surface wave mode signal into a second radio frequency electromagnetic signal; and an analysis subsystem that monitors a signal strength of the second radio frequency electromagnetic signal over time to determine whether a physical encroachment of the powerline conductor exists between the first location and the second location. ### Claim 2 (depends on 1) The system of claim 1, wherein: at least one of the first radio frequency electromagnetic signal or the second radio frequency electromagnetic signal comprises a transverse electromagnetic mode signal; and the first surface wave mode signal comprises a transverse magnetic mode signal. ### Claim 3 (depends on 1) The system of claim 1, wherein the system further comprises: a first device at the first location and comprising the radio frequency generator and the first transducer; and a second device at the second location and comprising the second transducer. ### Claim 4 (depends on 3) The system of claim 3, wherein: the first device comprises a first clamping device that mechanically couples a fiber optic cable to the powerline conductor at the first location; and the second device comprises a second clamping device that mechanically couples the fiber optic cable to the powerline conductor at the second location. ### Claim 5 (depends on 3) The system of claim 3, wherein: at least one of the first radio frequency electromagnetic signal or the second radio frequency electromagnetic signal has a carrier frequency for a wireless local area network; and the first device transmits data to the second device using the carrier frequency for the wireless local area network. ### Claim 6 (depends on 5) The system of claim 5, wherein the wireless local area network comprises a Wi-Fi communication network. ### Claim 7 (depends on 5) The system of claim 5, wherein the analysis subsystem determines a received signal strength indication associated with the wireless local area network to monitor the signal strength of the second radio frequency electromagnetic signal. ### Claim 8 (depends on 5) The system of claim 5, wherein: the analysis subsystem, to monitor the signal strength of the second radio frequency electromagnetic signal, determines at least one of: a magnitude of at least one carrier signal of the wireless local area network; or a phase angle of the at least one carrier signal of the wireless local area network. ### Claim 9 (depends on 5) The system of claim 5, wherein the first device further comprises: a detection circuit that detects a characteristic of power carried on the powerline conductor; and a communication timing circuit that causes the first surface wave mode signal to be imposed onto the powerline conductor according to a timing that is based on the characteristic of power carried on the powerline conductor. ### Claim 10 (depends on 9) The system of claim 9, wherein the characteristic of power carried on the powerline conductor detected by the detection circuit comprises a zero-crossing of a voltage carried on the powerline conductor. ### Claim 11 (depends on 3) The system of claim 3, wherein: the first device further comprises a third transducer that converts the first radio frequency electromagnetic signal to a second surface wave mode signal imposed onto the powerline conductor at the first location in a second direction opposite the first direction along the powerline conductor; the system further comprises a third device that is located at a third location in the second direction from the first location and that comprises a fourth transducer that converts the second surface wave mode signal into a third radio frequency electromagnetic signal; and the analysis subsystem monitors a signal strength of the third radio frequency electromagnetic signal over time to determine whether a physical encroachment of the powerline conductor exists between the first location and the third location. ### Claim 12 (depends on 11) The system of claim 11, wherein the first device further comprises a radio frequency switch that directs the first radio frequency electromagnetic signal to at least one of: the first transducer; or the third transducer. ### Claim 13 (depends on 1) The system of claim 1, wherein at least one of the first transducer and the second transducer comprises a conically-shaped waveguide defining an axis aligned along the powerline conductor. ### Claim 14 (depends on 1) The system of claim 1, wherein the analysis subsystem determines whether a physical encroachment of the powerline conductor exists between the first location and the second location based on a rate of change of signal strength of the second radio frequency electromagnetic signal. ### Claim 15 A method comprising: transmitting a surface wave mode signal imposed on a powerline conductor at a first location along the powerline conductor toward a second location along the powerline conductor; receiving at least a portion of the transmitted surface wave mode signal at the second location along the powerline conductor; and monitoring a signal strength of the received portion of the transmitted surface wave mode signal over time to determine whether a physical encroachment of the powerline conductor exists between the first location and the second location. ### Claim 16 (depends on 15) The method of claim 15, wherein a determination whether a physical encroachment of the powerline conductor exists between the first location and the second location is based on a rate of change of the signal strength associated with the received portion of the transmitted surface wave mode signal. ### Claim 17 (depends on 15) The method of claim 15, wherein: the surface wave mode signal comprises a wireless network communication signal; and the signal strength associated with the received portion of the transmitted surface wave mode signal is indicated as a received signal strength indication associated with the wireless network communication signal. ### Claim 18 (depends on 15) The method of claim 15, wherein: the surface wave mode signal comprises a wireless network communication signal; and the signal strength associated with the received portion of the transmitted surface wave mode signal is indicated as at least one of a magnitude or a phase angle associated with the wireless network communication signal. ### Claim 19 A method comprising: installing a first device onto a powerline conductor at a first location along the powerline conductor, wherein the first device transmits a surface wave mode signal imposed on the powerline conductor at the first location for propagation along the powerline conductor toward a second location along the powerline conductor; installing a second device onto the powerline conductor at the second location along the powerline conductor, wherein the second device receives at least a portion of the transmitted surface wave mode signal at the second location; and providing an analysis subsystem, communicatively coupled to at least the second device, that monitors a signal strength of the received portion of the transmitted surface wave mode signal over time to determine whether a physical encroachment of the powerline conductor exists between the first location and the second location. ### Claim 20 (depends on 19) The method of claim 19, wherein at least one of the first device and the second device comprises a clamping device that secures a fiber optic cable to the powerline conductor.