# US 2025/0085441 A1 · Joint GNSS-Terrestrial AP Geolocating > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2025/0085441 A1 - Document ID: US20250085441A1 - Status: Published application - Kind: A1 - Application number: 18/466,659 - Filed: 2023-09-13 - Published: 2025-03-13 - Earliest claimed: 2023-09-13 - Assignees: Cisco Technology, Inc. - Applicants: Cisco Technology, Inc. - Inventors: Peiman Amini; Ardalan Alizadeh; Jerome Henry; Arya Fallahi; Navid Reyhanian - Web page: https://patentgrep.com/patent/US20250085441A1 ## CPC - G01S 19/09: providing processing capability normally carried out by the receiver - G01S 19/46: the supplementary measurement being of a radio-wave signal type - G01S 19/14: specially adapted for specific applications - G01S 5/0081: {Transmission between base stations} - G01S 5/0289: {of multiple transceivers, e.g. in ad hoc networks} - G01S 19/51: Relative positioning - G01S: RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES ## Abstract Described herein are devices, systems, methods, and processes for estimating the geolocation of network devices by jointly utilizing pseudorange measurements from global navigation satellite system (GNSS) satellites and terrestrial-based ranging measurements between network devices. Each network device is equipped with a GNSS receiver that collects pseudorange data from each satellite link at time intervals. Terrestrial-based ranging measurements between network devices can also be collected. The receiver clock error can be accounted for at least in part by over-the-air time synchronization of network devices. To mitigate the impact of multipath and improve accuracy, pseudorange measurements with less than satisfactory quality metrics can be filtered out. In some embodiments, the geolocation of anchor network devices can be estimated with high accuracy first, and then the rest of the non-anchor network devices may be localized in a second-stage localization process. ## Claims ### Claim 1 A network node, comprising: a processor; at least one network interface controller configured to provide access to a network; and a memory communicatively coupled to the processor, wherein the memory comprises a geolocation logic that is configured to: collect a plurality of pseudorange measurements from a first set of network devices, each network device in the first set of network devices including a respective global navigation satellite system (GNSS) receiver for obtaining one or more pseudorange measurements; collect one or more inter-network device ranging measurements from a second set of network devices, the second set of network devices sharing at least one network device with the first set of network devices; and determine, for each network device in a third set of network devices, a geo-position based at least in part on at least some of the plurality of pseudorange measurements and at least some of the one or more inter-network device ranging measurements, the third set of network devices including one or more first network devices in the first set of network devices and one or more second network devices in the second set of network devices. ### Claim 2 (depends on 1) The network node of claim 1, wherein at least one network device in the first set of network devices or the second set of network devices corresponds to an access point (AP). ### Claim 3 (depends on 1) The network node of claim 1, wherein the plurality of pseudorange measurements is collected during one or more time intervals. ### Claim 4 (depends on 1) The network node of claim 1, wherein each pseudorange measurement in the plurality of pseudorange measurements is associated with a timestamp. ### Claim 5 (depends on 1) The network node of claim 1, wherein each pseudorange measurement in the plurality of pseudorange measurements is associated with a satellite identifier (ID) or a constellation ID. ### Claim 6 (depends on 1) The network node of claim 1, wherein each pseudorange measurement in the plurality of pseudorange measurements is associated with a quality metric. ### Claim 7 (depends on 6) The network node of claim 6, wherein the geolocation logic is further configured to discard at least one pseudorange measurement based on the quality metric associated with the at least one pseudorange measurement being less than a threshold. ### Claim 8 (depends on 6) The network node of claim 6, wherein the quality metric includes a carrier-to-noise power density ratio (C/N0) metric or a code-minus-carrier (CMC) metric. ### Claim 9 (depends on 1) The network node of claim 1, wherein the geolocation logic is further configured to receive ephemeris data associated with the plurality of pseudorange measurements. ### Claim 10 (depends on 9) The network node of claim 9, wherein the ephemeris data is received via the first set of network devices. ### Claim 11 (depends on 9) The network node of claim 9, wherein the ephemeris data is received from a precise point positioning (PPP) server. ### Claim 12 (depends on 1) The network node of claim 1, wherein the plurality of pseudorange measurements is associated with synchronized GNSS receiver clocks at the first set of network devices, and the plurality of pseudorange measurements is associated with a same time-distance offset. ### Claim 13 (depends on 12) The network node of claim 12, wherein to determine the geo-position, the geolocation logic is further configured to estimate a GNSS receiver clock error associated with the plurality of pseudorange measurements. ### Claim 14 (depends on 1) The network node of claim 1, wherein each network device in the third set of network devices is an anchor network device, and the geolocation logic that is further configured to: collect one or more additional inter-network device ranging measurements from a fourth set of network devices, the fourth set of network devices sharing one or more network devices with the third set of network devices, the fourth set of network devices including one or more non-anchor network devices; and determine, for each non-anchor network device in the one or more non-anchor network devices, a non-anchor geo-position based at least in part on at least some of the one or more additional inter-network device ranging measurements. ### Claim 15 (depends on 14) The network node of claim 14, wherein a number of observable satellites associated with each anchor network device is greater than a first threshold. ### Claim 16 (depends on 14) The network node of claim 14, wherein a number of ranging links associated with each anchor network device is greater than a second threshold. ### Claim 17 (depends on 1) The network node of claim 1, wherein the one or more inter-network device ranging measurements are based on at least one of fine time measurement (FTM), ultra-wideband (UWB), or high-accuracy distance measurement (HADM). ### Claim 18 A network device, comprising: a processor; at least one network interface controller configured to provide access to a network; and a memory communicatively coupled to the processor, wherein the memory comprises a geolocation logic that is configured to: obtain one or more pseudorange measurements via a global navigation satellite system (GNSS) receiver; obtain one or more inter-network device ranging measurements to one or more other network devices; transmit an indication of the one or more pseudorange measurements and an indication of the one or more inter-network device ranging measurements to a network node; and receive an indication of a geo-position of the network device from the network node. ### Claim 19 (depends on 18) The network device of claim 18, wherein the geolocation logic is further configured to synchronize a GNSS receiver clock over-the-air with at least one other network device. ### Claim 20 A method for joint geolocating, comprising: collecting a plurality of pseudorange measurements from a first set of network devices, each network device in the first set of network devices including a respective global navigation satellite system (GNSS) receiver for obtaining one or more pseudorange measurements; collecting one or more inter-network device ranging measurements from a second set of network devices, the second set of network devices sharing at least one network device with the first set of network devices; and determining, for each network device in a third set of network devices, a geo-position based at least in part on at least some of the plurality of pseudorange measurements and at least some of the one or more inter-network device ranging measurements, the third set of network devices including one or more first network devices in the first set of network devices and one or more second network devices in the second set of network devices.