# US 11,115,898 B2 · Method and apparatus for determining line of sight (LOS) > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,115,898 B2 - Document ID: US11115898B2 - Status: Granted - Kind: B2 - Application number: 16/600,008 - Filed: 2019-10-11 - Published: 2020-02-06 - Granted: 2021-09-07 - Earliest claimed: 2017-10-16 - Assignees: Futurewei Technologies, Inc. - Applicants: Futurewei Technologies, Inc. - Inventors: George Calcev - Web page: https://patentgrep.com/patent/US11115898B2 ## CPC - H04W 40/205: {using topographical information, e.g. hills, high rise buildings} - H04B 7/0617: {for beam forming} - H04B 7/10: Polarisation diversity; Directional diversity - H04W 40/02: Communication route or path selection, e.g. power-based or shortest path routing - H04W 40/28: for reactive routing - H04W 40/20: based on geographic position or location - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) - H04B: TRANSMISSION ## Abstract A method performed by a first device is disclosed that includes sending a light of sight, LOS, determination request to a second device which communicates with the first device, wherein the LOS determination request includes an indication of a dual polarization procedure for Line of Sight (LOS), with the indication of the dual polarization procedure for LOS is used indicating that a same sequence of bits is sent at two polarizations to the same direction; a channel measurement for each of the two received sequences at the two polarizations is compared to determine whether a transmission between the first device and the second is LOS or NLOS. ## Claims ### Claim 1 A method comprising: sending, by a first device, a line of sight (LOS) determination request to a second device, the LOS determination request including an indication that a dual polarization procedure is supported for LOS determination; and performing, by the first device, the dual polarization procedure to determine whether a LOS channel exists between the first device and the second device, wherein performing the dual polarization procedure includes communicating wave signals carrying the same sequence of bits using two different polarizations in the same direction between the first device and the second device to determine whether the LOS channel exists between the first device and the second device. ### Claim 2 (depends on 1) The method of claim 1, wherein the LOS determination request is an enhanced directional multi-gigabit (EDMG) beam refinement protocol (BRP) request. ### Claim 3 (depends on 2) The method of claim 2, wherein the indication of the dual polarization procedure for LOS determination is carried in a body or header part of the EDMG BRP request. ### Claim 4 (depends on 2) The method of claim 2, wherein the indication of the dual polarization procedure for LOS determination is included in RXVECTOR parameters or TXVECTOR parameters of the EDMG BRP request. ### Claim 5 (depends on 2) The method of claim 2, wherein the indication of the dual polarization procedure for LOS determination is carried in an EMDG-Header-A field of the EDMG BRP request. ### Claim 6 (depends on 2) The method of claim 2, wherein the indication of the dual polarization procedure for LOS determination is carried in an EMDG-Header-A2 subfield the EDMG BRP request. ### Claim 7 (depends on 2) The method of claim 2, wherein the indication of the dual polarization procedure for LOS determination is carried in a beamforming capability subfield of the EDMG BRP request. ### Claim 8 (depends on 2) The method of claim 2, wherein the indication of the dual polarization procedure for LOS determination is carried in a directional multi-gigabyte (DMG) Beam Refinement element of the EDMG BRP request. ### Claim 9 (depends on 1) The method of claim 1, wherein the first device transmits the wave signals carrying the same sequence of bits using the two different polarizations from the second device. ### Claim 10 (depends on 9) The method of claim 9, wherein performing the dual polarization procedure for LOS determination comprises: transmitting, by the first device, the wave signals carrying the same sequence of bits using the two different polarizations. ### Claim 11 (depends on 10) The method of claim 10, wherein performing the dual polarization procedure for LOS determination further comprises: receiving, by the first device, channel measurements for each of the wave signals from the second device; and comparing the channel measurements of the wave signals to determine whether the LOS channel exists between the first device and the second device. ### Claim 12 (depends on 1) The method of claim 1, wherein the first device receives the wave signals carrying the same sequence of bits using the two different polarizations from the second device. ### Claim 13 (depends on 12) The method of claim 12, wherein performing the dual polarization procedure for LOS determination further comprises: receiving, by the first device, the wave signals carrying the same sequence of bits using the two different polarizations from the second device; obtaining, by the first device, channel measurements for each of the wave signals; and comparing, by the first device, the channel measurements for each of the wave signals to determine whether the LOS channel exists between the first device and the second device. ### Claim 14 (depends on 12) The method of claim 12, wherein performing the dual polarization procedure for LOS determination further comprises: receiving, by the first device, the wave signals carrying the same sequence of bits using the two different polarizations from the second device; obtaining, by the first device, channel measurements for each of the wave signals; and sending, by the first device, the channel measurements for each of the wave signals to the second device. ### Claim 15 (depends on 14) The method of claim 14, wherein the second device compares the channel measurements for each of the wave signals to determine whether the LOS channel exists between the first device and the second device. ### Claim 16 A first device comprising: a processor; and a non-transitory computer readable storage medium storing programming for execution by the processor, the programming including instructions to: send a line of sight (LOS) determination request to a second device, the LOS determination request including an indication that a dual polarization procedure is supported for LOS determination; and perform the dual polarization procedure to determine whether a LOS channel exists between the first device and the second device, wherein the instructions to perform the dual polarization procedure includes instructions to communicate wave signals carrying the same sequence of bits using two different polarizations in the same direction between the first device and the second device to determine whether the LOS channel exists between the first device and the second device. ### Claim 17 A method comprising: sending, by a first device, a message to a second device, the message including a field indicating that the first device supports a dual polarization procedure for line of sight (LOS) determination, wherein the dual polarization procedure for LOS determination includes communicating wave signals carrying the same sequence of bits using two different polarizations in the same direction between the first device and the second device to determine whether a LOS path exists between the first device and the second device. ### Claim 18 (depends on 17) The method of claim 17, wherein the message further includes a first path training indication indicating that the first device is capable of determining a shortest path from a plurality of paths. ### Claim 19 (depends on 17) The method of claim 17, wherein the message is an enhanced directional multi-gigabit (EDMG) beam refinement protocol (BRP) request. ### Claim 20 (depends on 19) The method of claim 19, wherein the indication of the dual polarization procedure for LOS determination is carried in a body or header part of the EDMG BRP request. ### Claim 21 (depends on 19) The method of claim 19, wherein the EDMG BRP request is broadcast to multiple devices including the second device. ### Claim 22 (depends on 17) The method of claim 17, further comprising performing the dual polarization procedure for LOS determination. ### Claim 23 (depends on 22) The method of claim 22, wherein performing the dual polarization procedure for LOS determination comprises: transmitting, by the first device, the wave signals carrying the same sequence of bits using the two different polarizations. ### Claim 24 (depends on 22) The method of claim 22, wherein performing the dual polarization procedure for LOS determination further comprises: receiving, by the first device, channel measurements for each of the wave signals from the second device; and comparing the channel measurements of the wave signals to determine whether the LOS channel exists between the first device and the second device. ### Claim 25 (depends on 22) The method of claim 22, wherein performing the dual polarization procedure for LOS determination comprises: receiving, by the first device, the wave signals carrying the same sequence of bits using the two different polarizations from the second device; obtaining, by the first device, channel measurements for each of the wave signals; and comparing, by the first device, the channel measurements for each of the wave signals to determine whether the LOS channel exists between the first device and the second device. ### Claim 26 (depends on 22) The method of claim 22, wherein performing the dual polarization procedure for LOS determination comprises: receiving, by the first device, the wave signals carrying the same sequence of bits using the two different polarizations from the second device; obtaining, by the first device, channel measurements for each of the wave signals; and sending, by the first device, the channel measurements for each of the wave signals to the second device. ### Claim 27 (depends on 22) The method of claim 22, wherein performing the dual polarization procedure for LOS determination comprises: receiving, by the first device, three or more wave signals carrying the same sequence of bits using different polarizations from the second device, wherein each polarization corresponds to one copy of the wave signal; and determining whether the LOS path exists between the first device and the second device based on intensities of the three or more wave signals. ### Claim 28 (depends on 27) The method of claim 27, wherein determining whether the LOS path exists between the first device and the second device based on intensities of the three or more wave signals comprises determining that the LOS path exists when the intensities of the three or more wave signals are within a threshold of one another. ### Claim 29 A first device comprising: a processor; and a non-transitory computer readable storage medium storing programming for execution by the processor, the programming including instructions to: send a message to a second device, the message including a field indicating that the first device supports a dual polarization procedure for line of sight (LOS) determination, wherein the dual polarization procedure for LOS determination includes communicating wave signals carrying the same sequence of bits using two different polarizations in the same direction between the first device and the second device to determine whether a LOS path exists between the first device and the second device. ### Claim 30 (depends on 29) The first device of claim 29, wherein the message further includes a first path training indication indicating that the first device is capable of determining a shortest path from a plurality of paths.