# US 9,521,597 B2 · System and method of supporting softer handover in a cell using adaptive antenna in enabling narrow beam operation > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,521,597 B2 - Document ID: US9521597B2 - Status: Granted - Kind: B2 - Application number: 12/282,590 - Filed: 2006-08-30 - Published: 2009-04-16 - Granted: 2016-12-13 - Earliest claimed: 2006-03-13 - Assignees: Telefonaktiebolaget LM Ericsson (publ) - Applicants: Bo Göransson; Bo Hagerman - Inventors: Bo Göransson; Bo Hagerman - Web page: https://patentgrep.com/patent/US9521597B2 ## CPC - H04W 72/046: {the resource being in the space domain, e.g. beams} - H04W 36/0085: {Hand-off measurements} - H04W 16/28: using beam steering - H04W 36/00835: {Determination of neighbour cell lists} - H04W 36/0094: {Definition of hand-off measurement parameters} - H04W 36/302: {due to low signal strength} - H04W 72/21: in the uplink direction of a wireless link, i.e. towards the network - H04W 72/542: using measured or perceived quality - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) ## Abstract Handover is a main function that is used to support mobility in the network. In a cellular communication network having adaptive antennas for enabling narrow beam operation, a network control unit sends a radio link setup request to a selected cell-serving network unit for configuration of a new serving radio link. Before responding to the radio link setup request the cell-serving network unit performs uplink measurements with respect to the mobile unit, and a narrow target beam is selected within a cell served by the cell-serving network unit based on these measurements. The cell-serving network unit then configures the new serving radio link for the considered mobile unit directly with the selected narrow target beam. Consequently the system can perform the handover procedure using narrow beams only, without first establishing the radio link with a cell-wide beam and then reconfiguring the radio link onto a narrow beam. ## Claims ### Claim 1 A method for supporting handover between cells in a cellular radio communication system having adaptive antennas for enabling narrow beam operation, wherein a mobile unit is served by an active cell set of at least one cell in said cellular radio communication system, wherein said method comprises the steps of: upon a determination, by a network control unit in said cellular communication system, that a new serving radio link in a neighboring cell, for said mobile unit is needed, wherein the determination is based on downlink quality measurements, receiving, by a radio base station, a radio link setup request from the network control unit in said cellular communication system for configuration of the new serving radio link for said mobile unit; performing, by said radio base station, upon receiving said radio link setup request and before responding to said radio link setup request, uplink measurements with respect to said mobile unit and selecting, based on said uplink measurements, a narrow target beam within the neighboring cell served by said radio base station; configuring, by said radio base station, said new serving radio link for said mobile unit directly with the selected narrow target beam while said radio link setup request is pending, wherein said radio link setup request is incomplete with respect to the setup of said new serving radio link, and information of the selected narrow target beam constitutes complementary information for setup of said new radio link directly with the selected narrow target beam; and sending, by said radio base station, information representative of the selected narrow target beam to said network control unit in a radio link setup response. ### Claim 2 (depends on 1) The method of claim 1, wherein said information representative of the selected narrow target beam is appended to said radio link setup response by said radio base station. ### Claim 3 (depends on 1) The method of claim 1, wherein information on a cell portion corresponding to the selected narrow target beam is provided in a cell portion field in said radio link setup response. ### Claim 4 (depends on 3) The method of claim 3, wherein said cell portion field is a S-CPICH field. ### Claim 5 (depends on 1) The method of claim 1, wherein said method further comprises a step of said network control unit informing said mobile unit that said new serving radio link is associated with said selected radio base station and with a reference signal related to the selected narrow target beam. ### Claim 6 (depends on 1) The method of claim 1, wherein said method further comprises a step of informing, by said network control unit, said mobile unit that said new serving radio link is associated with said selected radio base station and with said selected narrow target beam. ### Claim 7 (depends on 1) The method of claim 1, wherein said network control unit is one selected from a group consisting of a radio network controller, a mobility server and an access gateway. ### Claim 8 (depends on 1) The method of claim 1, wherein said radio base station is one selected from a group consisting of a radio access node and a Node B. ### Claim 9 (depends on 1) The method of claim 1, wherein said new serving radio link is configured for said mobile unit directly with the selected narrow target beam independent of a cell-wide beam within the neighboring cell. ### Claim 10 (depends on 1) The method of claim 1, wherein said new serving radio link from the neighboring cell is added to an active cell set by the network control unit based on said new serving radio link being configured for said mobile unit directly with the selected narrow target beam. ### Claim 11 A radio base station in a cellular radio communication system, said-radio base station being operable for serving at least one mobile unit and having adaptive antennas for enabling narrow beam operation, wherein said radio base station comprises: a processing circuitry configured to receive a radio link setup request from a network control unit for configuration of a new serving radio link in a neighboring cell for a selected mobile unit, wherein the network control unit has determined that the new serving radio link is needed based on downlink quality measurements; the processing circuitry further configured to perform, upon receiving said radio link setup request and before responding to said radio link setup request, uplink measurements with respect to said mobile unit and for selecting, based on said uplink measurements, a narrow target beam within the neighboring cell served by said radio base station; the processing circuitry further configured to configure said new serving radio link for said mobile unit directly with the selected narrow target beam while said radio link setup request is pending, wherein said radio link setup request is incomplete with respect to the setup of said new serving radio link, and information of the selected narrow target beam constitutes complementary information for setup of said new radio link directly with the selected narrow target beam; and the processing circuitry further configured to send information representative of the selected narrow target beam to said network control unit in a radio link setup response. ### Claim 12 (depends on 11) The radio base station of claim 11, wherein said information representative of the selected narrow target beam is appended to said radio link setup response by the processing circuitry. ### Claim 13 (depends on 11) The radio base station of claim 11, wherein information on a cell portion corresponding to the selected narrow target beam is provided in a cell portion field in said radio link setup response. ### Claim 14 (depends on 13) The radio base station of claim 13, wherein said cell portion field is a S-CPICH field. ### Claim 15 (depends on 11) The radio base station of claim 11, wherein said radio base station is one of a radio access node and a Node B. ### Claim 16 (depends on 11) The radio base station of claim 11, is in combination with a cellular communication network. ### Claim 17 (depends on 11) The radio base station of claim 11, wherein said new serving radio link is configured for said mobile unit directly with the selected narrow target beam independent of a cell-wide beam within the neighboring cell. ### Claim 18 (depends on 11) The radio base station of claim 11, wherein said new serving radio link from the neighboring cell is added to an active cell set by the network control unit based on said new serving radio link being configured for said mobile unit directly with the selected narrow target beam. ### Claim 19 A network control unit for supporting handover between cells in a cellular radio communication system, said cellular radio communication system having adaptive antennas for enabling narrow beam operation, wherein a mobile unit is served by an active cell set of at least one cell in said cellular radio communication system, wherein said network control unit comprises: a processing circuitry configured to send a radio link setup request from the network control unit to a selected radio base station for configuration of a new serving radio link in a neighboring cell for said mobile unit, wherein the network control unit has determined that the new serving radio link is needed based on downlink quality measurements; the processing circuitry further configured to receive, in a radio link setup response from said radio base station, information representative of a narrow target beam selected for said new radio link by said radio base station based on uplink measurements with respect to said mobile unit; wherein said radio link setup request is incomplete with respect to the setup of said new serving radio link, and information of the selected narrow target beam constitutes complementary information for setup of said new radio link directly with the selected narrow target beam while said radio link setup request is pending with said selected radio base station; and the processing circuitry further configured to inform said mobile unit that said new serving radio link is associated with said radio base station and said selected narrow target beam. ### Claim 20 (depends on 19) The network control unit of claim 19, wherein said new serving radio link is configured for said mobile unit directly with the selected narrow target beam independent of a cell-wide beam within the neighboring cell.