# US 10,320,539 B2 · Methods and apparatuses for reference signal adaptation based on incoming user mobility information > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,320,539 B2 - Document ID: US10320539B2 - Status: Granted - Kind: B2 - Application number: 15/161,669 - Filed: 2016-05-23 - Published: 2017-11-23 - Granted: 2019-06-11 - Earliest claimed: 2016-05-23 - Assignees: Nokia Technologies Oy - Applicants: Nokia Technologies Oy - Inventors: Athul Prasad; Ankit Bhamri; Petteri Lunden - Web page: https://patentgrep.com/patent/US10320539B2 ## CPC - H04L 5/0048: {Allocation of pilot signals, i.e. of signals known to the receiver (allocation of control signalling H04L5/0053; use of control signalling H04L5/0091)} - H04L 5/0023: {Time-frequency-space} - H04L 5/0078: {Timing of allocation} - H04L 5/0091: {Signalling for the administration of the divided path, e.g. signalling of configuration information} - H04W 8/02: Processing of mobility data, e.g. registration information at HLR [Home Location Register] or VLR [Visitor Location Register]; Transfer of mobility data, e.g. between HLR, VLR or external networks - H04W 36/0058: {Transmission of hand-off measurement information, e.g. measurement reports} - H04W 36/00837: {Determination of triggering parameters for hand-off} - H04W 36/0085: {Hand-off measurements} - H04W 36/302: {due to low signal strength} - H04L 5/001: {the frequencies being arranged in component carriers} - H04L 5/0035: {Resource allocation in a cooperative multipoint environment} - H04W 92/20: between access points - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) ## Abstract Systems, methods, apparatuses, and computer program products for reference signal adaptation based on incoming user mobility information are provided. One method includes receiving, by a target base station, a request to begin transmitting reference signals for mobility measurements. The request may be received from a source base station serving a user equipment. In addition, the request may be received when a handover of the user equipment is impending. ## Claims ### Claim 1 A method, comprising: receiving, by a target base station, a request to begin transmitting reference signals for mobility measurements, the request being received from a source base station serving a user equipment; and in response to the request, deciding whether or not to configure reference signal density and/or reference signal periodicity and transmit the reference signals for mobility measurements to the user equipment, wherein the receiving of the request further comprises receiving, by the target base station, at least one of reference signal density or reference signal periodicity information from the source base station. ### Claim 2 (depends on 1) The method according to claim 1, wherein the receiving comprises receiving the request when a handover of the user equipment is impending. ### Claim 3 (depends on 1) The method according to claim 1, wherein the reference signal density and/or periodicity is dependent upon at least one of user equipment speed, channel conditions, probability of non-line of sight, or quality of service (QoS) requirements of service flow that the user equipment receives. ### Claim 4 (depends on 1) The method according to claim 1, wherein the configuring further comprises: reducing the reference signal density and/or reference signal periodicity for user equipment moving at a speed that is below a threshold; and increasing the reference signal density and/or reference signal periodicity for user equipment moving at a speed that is above a threshold. ### Claim 5 (depends on 1) The method according to claim 1, wherein said deciding is based on load or mobility support that the target base station would like to provide. ### Claim 6 An apparatus, comprising: at least one processor; and at least one memory including computer program code, wherein the at least one memory and computer program code are configured, with the at least one processor, to cause the apparatus at least to receive a request to begin transmitting reference signals for mobility measurements, the request being received from a source base station serving a user equipment; and in response to the request, decide whether or not to configure reference signal density and/or reference signal periodicity and transmit the reference signals for mobility measurements to the user equipment, wherein the request further comprises at least one of reference signal density or reference signal periodicity information from the source base station. ### Claim 7 (depends on 6) The apparatus according to claim 6, wherein the request is received when a handover of the user equipment is impending. ### Claim 8 (depends on 6) The apparatus according to claim 6, wherein the at least one memory and computer program code are further configured, with the at least one processor, to cause the apparatus at least to, after receiving the at least one of reference signal density or reference signal periodicity information, determine a candidate beam set to enable discovery of the apparatus. ### Claim 9 (depends on 8) The apparatus according to claim 8, wherein the at least one memory and computer program code are further configured, with the at least one processor, to cause the apparatus at least to increase the at least one of reference signal density or reference signal periodicity information in the candidate beam set in the apparatus for service flows serving traffic requiring reliability. ### Claim 10 (depends on 8) The apparatus according to claim 8, wherein the at least one memory and computer program code are further configured, with the at least one processor, to cause the apparatus at least to change the at least one of reference signal density or reference signal periodicity information depending on mobility state alone for default service flows. ### Claim 11 (depends on 6) The apparatus according to claim 6, wherein the reference signal density and/or periodicity is dependent upon at least one of user equipment speed, channel conditions, probability of non-line of sight, or quality of service (QoS) requirements of service flow that the user equipment receives. ### Claim 12 (depends on 6) The apparatus according to claim 6, wherein the at least one memory and computer program code are further configured, with the at least one processor, to cause the apparatus at least to: reduce the reference signal density and/or reference signal periodicity for user equipment moving at a speed below a threshold; and increase the reference signal density and/or reference signal periodicity for user equipment moving at a speed above a threshold. ### Claim 13 (depends on 6) The apparatus according to claim 6, wherein the at least one memory and computer program code are further configured, with the at least one processor, to cause the apparatus at least to, when the apparatus does not want to serve new user equipment, send a non-acknowledgement message to reject the request from the source base station so that user equipment do not detect the target base station. ### Claim 14 (depends on 6) The apparatus according to claim 6, wherein said deciding is based on load or mobility support that the apparatus would like to provide. ### Claim 15 An apparatus, comprising: at least one processor; and at least one memory including computer program code, wherein the at least one memory and computer program code are configured, with the at least one processor, to cause the apparatus at least to determine that a target base station should be informed about a need for reference signals for mobility measurements; and send a request to the target base station to begin transmitting reference signals for mobility measurements to a user equipment; wherein the apparatus comprises a source base station serving the user equipment, wherein the request further comprises at least one of reference signal density or reference signal periodicity information from the source base station. ### Claim 16 (depends on 15) The apparatus according to claim 15, wherein the at least one of reference signal density or reference signal periodicity information is also dependent upon at least one of user equipment speed, channel conditions, probability of non-line of sight, or quality of service (QoS) requirements of service flow that the user equipment receives. ### Claim 17 (depends on 15) The apparatus according to claim 15, wherein the at least one memory and computer program code are further configured, with the at least one processor, to cause the apparatus at least to send a notification, to the target base station, of a potentially impending handover of the user equipment. ### Claim 18 (depends on 15) The apparatus according to claim 15, wherein the request is sent when a handover of a user equipment is impending, and wherein it is determined that the handover of the user equipment is impending when the user equipment starts moving or when the user equipment's signal quality decreases. ### Claim 19 (depends on 15) The apparatus according to claim 15, wherein the at least one memory and computer program code are further configured, with the at least one processor, to cause the apparatus at least to receive a non-acknowledgement message, from the target base station, rejecting the request when the target base station does not wish to change reference signal configuration.