# US 11,122,573 B2 · Robust beam tracking and data communication in millimeter-wave mobile networks > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,122,573 B2 - Document ID: US11122573B2 - Status: Granted - Kind: B2 - Application number: 16/515,249 - Filed: 2019-07-18 - Published: 2020-01-30 - Granted: 2021-09-14 - Earliest claimed: 2018-07-30 - Assignees: NEC Corporation - Applicants: NEC Laboratories America, Inc. - Inventors: Mohammad Khojastepour; Shahram Shahsavari - Web page: https://patentgrep.com/patent/US11122573B2 ## CPC - H04B 7/0617: {for beam forming} - H04W 72/51: based on terminal or device properties - H04B 7/0619: {using feedback from receiving side (feedback signaling for adaptive modulation/coding H04L1/0001)} - H04W 4/029: Location-based management or tracking services - H04W 48/16: Discovering, processing access restriction or access information - H04B: TRANSMISSION - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) ## Abstract Systems and methods for robust beam tracking and data communication data are provided. The method includes dividing, by a base station, time into frames each having two phases, a location probing phase and a data communication phase. In the location probing phase, the base station uses a fractional search policy to localize a mobile device by transmitting multiple probing packets over different time-slots and updates information about a location of the mobile device. In the data communication phase, the base station communicates with the mobile device while expanding a beamwidth to compensate for possible mobility of the mobile device. ## Claims ### Claim 1 A method for robust beam tracking and data communication, comprising: dividing, by a base station, time into frames each having two phases, a location probing phase and a data communication phase; determining a steady state analysis of the performance of beam tracking by the base station; formulating an optimization problem to obtain optimal frame structure maximizing steady state average throughput; in the location probing phase, using a fractional search policy to localize at least one mobile device by transmitting multiple probing packets over different time-slots and updating information about a location of the at least one mobile device; and in the data communication phase, communicating with the at least one mobile device while expanding a beamwidth to compensate for possible mobility of the at least one mobile device. ### Claim 2 (depends on 1) The method as recited in claim 1, wherein details of a mobility model of the at least one mobile device are not available to the base station. ### Claim 3 (depends on 1) The method as recited in claim 1, wherein updating the information about the location of the at least one mobile device comprises updating the information about the location of the at least one mobile device based on the feedback from the at least one mobile device. ### Claim 4 (depends on 1) The method as recited in claim 1, further comprising obtaining an optimal data communication duration using quasi-concave programming. ### Claim 5 (depends on 1) The method as recited in claim 1, wherein an optimal location probing duration of one timeslot is used for location probing. ### Claim 6 (depends on 1) The method as recited in claim 1, further comprising: estimating a maximum user velocity and a distance between the at least one mobile device and the base station using at least one of global positioning system (GPS) or low frequency channels. ### Claim 7 (depends on 1) The method as recited in claim 1, further comprising: determining an angular uncertainty region (AUR) on a location of the at least one mobile device; and matching a transmission pattern to the AUR. ### Claim 8 (depends on 1) The method as recited in claim 1, further comprising: localizing the at least one mobile user intermittently to enable use of predetermined narrow beams while maintaining a connection to a predetermined reliability. ### Claim 9 (depends on 1) The method as recited in claim 1, further comprising: in the location probing phase, at a beginning of each time-slot, transmitting a probing packet while matching an angular coverage region to a fraction of an angular uncertainty region (AUR) at an end of the each time-slot. ### Claim 10 (depends on 9) The method as recited in claim 9, wherein the AUR is updated based on feedback which is either an acknowledgement packet (ACK) that identifies that the at least one mobile device has been in the angular coverage region or no packet (NACK) is interpreted as the at least one mobile device not having been in the angular coverage region. ### Claim 11 A computer system for robust beam tracking and data communication, comprising: a processor device operatively coupled to a memory device, the processor device being configured to: divide, by a base station, time into frames each having two phases, a location probing phase and a data communication phase; determine a steady state analysis of the performance of beam tracking by the base station; formulate an optimization problem to obtain optimal frame structure maximizing steady state average throughput; in the location probing phase, use a fractional search policy to localize at least one mobile device by transmitting multiple probing packets over different time-slots and update information about a location of the at least one mobile device; and in the data communication phase, communicate with the at least one mobile device while expanding a beamwidth to compensate for possible mobility of the at least one mobile device. ### Claim 12 (depends on 11) The system as recited in claim 11, wherein, when updating the information about the location of the at least one mobile device, the processor device is further configured to: update the information about the location of the at least one mobile device based on the feedback from the at least one mobile device. ### Claim 13 (depends on 11) The system as recited in claim 11, wherein the processor device is further configured to: obtain an optimal data communication duration using quasi-concave programming. ### Claim 14 (depends on 11) The system as recited in claim 11, wherein an optimal location probing duration of one timeslot is used for location probing. ### Claim 15 (depends on 11) The system as recited in claim 11, wherein the processor device is further configured to: estimate a maximum user velocity and a distance between the at least one mobile device and the base station using at least one of global positioning system (GPS) or low frequency channels. ### Claim 16 (depends on 11) The system as recited in claim 11, wherein the processor device is further configured to: determine an angular uncertainty region (AUR) on a location of the at least one mobile device; and match a transmission pattern to the AUR. ### Claim 17 (depends on 11) The system as recited in claim 11, wherein the processor device is further configured to: transmit to the at least one mobile device with an average throughput of: R ~ = 1 D + K ⁢ ∑ m = K D + K ⁢ log 2 ⁡ ( 1 + A u K + 2 ⁢ Δ ⁡ ( m - K ) ) , wherein {circumflex over (R)} is an average throughput in steady state, D is a unit of time for data communication, K is a unit of time for location probing, m is a desgn parameter, and uk is a function of K and D. ### Claim 18 A computer program product for robust beam tracking and data communication, the computer program product comprising a non-transitory computer readable storage medium having program instructions embodied therewith, the program instructions executable by a computing device to cause the computing device to perform the method comprising: divide, by a base station, time into frames each having two phases, a location probing phase and a data communication phase; determine a steady state analysis of the performance of beam tracking by the base station; formulate an optimization problem to obtain optimal frame structure maximizing steady state average throughput; in the location probing phase, use a fractional search policy to localize at least one mobile device by transmitting multiple probing packets over different time-slots and update information about a location of the at least one mobile device; and in the data communication phase, communicate with the at least one mobile device while expanding a beamwidth to compensate for possible mobility of the at least one mobile device.