Cell proximity triggered ho

Abstract

A method performed at a User equipment (UE) is provided. The method comprises receiving at a user equipment,UE, from a serving network access node a femto cell proximity assistance information. The method further comprises starting to obtain measurements by the UE of at least one cell in neighborhood of the serving network access node cell based on the femto cell proximity assistance information. The method further comprises selecting the obtained measurements by the UE based on the femto cell proximity assistance information. The method further comprises reporting the selected measurements of the at least one cell in the neighborhood of the serving network access node cell in a measurement report from the UE to the serving network access node for handover decision.

Description

CELL PROXIMITY TRIGGERED HOFIELD

[0001] Various example embodiments generally relate to mobile / wireless communication networks, and more particularly to cell proximity triggered Handover (HO).BACKGROUND

[0002] Various example embodiments relate to considerations in a (e.g. mobile / wireless) communication system or network, such as a 5G / NR system, and a next-generation system beyond 5G. For example, various example embodiments are applicable in a 3rd Generation Partnership Project (3 GPP) standardized mobile / wireless communication system or network.LIST OF ABBREVIATIONS

[0003] In the present disclosure, the following abbreviations are used and should be understood in accordance with the given definitions:3 GPP 3rdGeneration Partnership Project5G 5thGeneration (Mobile Communication Network)BS Base StationCHO Conditional HandoverCN Core NetworkCPA Conditional PSCell AdditionCPC Conditional PSCell ChangeCSI Channel State InformationCU Central UnitDL DownlinkDU Distributed Unit eNB Evolved NodeBEPS Evolved Packet System / 4G gNB Next Generation Node B / 5G Base StationHO HandoverID IdentifierLI Layer 1 / Physical LayerL3 Layer 3 / Network LayerLTE Long Term EvolutionLTM Lower Layer Triggered Mobility MAC Medium Access Control MAC CE MAC Control Element MN Main Node NR New Radio / 5G NW Network PDCCH Physical Downlink Control Channel PDN Packet Data Network PDU Protocol Data Unit PLMN Public Land Mobile Network PRACH Physical Random Access Channel QoS Quality of Service RACH Random Access Channel RAN Radio Access Network RAT Radio Access Technology RRC Radio Resource Control RRM Radio Resource Management RS SI Received Signal Strength Indicator. RSRP Reference Signal Received Power RSRQ Reference Signal Received Quality SAPC Service Application PLMN Code SD Sidelink Discovery SINR Signal-to-Interference-plus-Noise Ratio SL Sidelink SN Secondary Node SRB Signaling Radio Bearer ss Synchronization Signal TA Timing Advance TCI Transmission Configuration Indicator U2N UE to Network UE User Equipment / Mobile Terminal UL UplinkSUMMARY

[0004] According to a first aspect, a method performed at a User equipment (UE) is provided. The method comprises receiving at a user equipment ,UE, from a serving network access node a femto cell proximity assistance information. The method further comprises starting to obtain measurements by the UE of at least one cell in neighborhood of the serving network access node cell based on the femto cell proximity assistance information. The method further comprises selecting the obtained measurements by the UE based on the femto cell proximity assistance information. The method further comprises reporting the selected measurements of the at least one cell in the neighborhood of the serving network access node cell in a measurement report from the UE to the serving network access node for handover decision.

[0005] In some embodiments, the method further comprises receiving at the UE a handover command from the serving network access node to perform a handover from the serving network access node cell to a target cell in the neighborhood of the serving network access node cell, wherein the selection of the target cell is based on a match between the selected measurements that are reported and a list of allowed cells in the neighborhood of the serving network access node cell for the UE determined by the serving network access node from a list of at least one allowed identification tag received from a core network node.

[0006] In some embodiments, the method further comprises that the femto cell proximity assistance information is received in an RRC reconfiguration message including measurement configuration associated with the measuring of the at least one cell in the neighborhood of the serving network access node cell.

[0007] In some embodiments, the method further comprises that the femto cell proximity assistance information comprises at least one of a proximity indicator, a list of CAG IDs wherein each CAG ID corresponds to a femto cell or CAG cell, in the neighborhood of the serving network access node cell, a list of PCIs wherein each PCI corresponds to a femto cell or CAG cell, in the neighborhood of the serving network access node cell, a list of reference signal received power signal of a downlink signal (DL RSRP) or reference signal received power signal (RSRP) ranges, a list of one or more geographical coordinates of neighbor femto cells or closed access groups CAG cells.

[0008] In some embodiments, the method further comprises starting measurements by the UE of the at least one cell in the neighborhood of the serving network access node cell based on the receiving of the proximity indicator that is part of the femto cell proximity assistance information.

[0009] In some embodiments, the method further comprises that starting measurements by the UE of the at least one cell in the neighborhood of the serving network access node cell isbased on receiving a coarse location of the at least one cell in the neighborhood of the serving network access node cell that is part of the femto cell proximity assistance information.

[0010] In some embodiments, the method further comprises that the coarse location of the at least one cell in the neighborhood of the serving network access node cell is defined by a range of reference signal received power signals of a downlink signal (DL RSRP) of the serving cell of the serving network access node.

[0011] In some embodiments, the method further comprises receiving one or more range(s) of DL RSRP in the coarse location; measuring the DL RSRP of the serving network access node cell, determining that the measured DL RSRP of the serving network access node cell matches at least one of the received one or more range(s) of DL RSRP, starting the measurements by the UE of the at least one cell in the neighborhood of the serving network access node cell based on the determining.

[0012] In some embodiments, the method further comprises that the coarse location of the at least one cell in the neighborhood of the serving network access node cell is defined by geographical coordinates.

[0013] In some embodiments, the method further comprises receiving one or more geographical coordinates in the coarse location, determining that the position of the UE matches at least one of the received one or more geographical coordinates. The method further comprises starting the measurements of the at least one cell in the neighborhood of the serving network access node cell based on the determining.

[0014] In some embodiments, the method further comprises starting measurements by the UE of at least one cell in the neighborhood of the serving network access node cell is performed regardless of the radio condition with the serving network access node cell.

[0015] In some embodiments, the method further comprises that selecting the obtained measurements by the UE further comprising, receiving, within the femto cell proximity assistance information, a list of one or more physical cell identities, PCIs, associated with cells in the neighborhood of the serving network access node cell, reading the PCI of the at least one cell in the neighborhood of the serving network access node cell, selecting the obtained measurements by the UE to be the ones which correspond to cells in the neighborhood of the serving network access node cell whose PCI match at least one PCI of the received list.

[0016] In some embodiments, the method further comprises that selecting the obtained measurements by the UE further comprising, receiving from a core network or within the femto proximity assistance information a list of allowed closed access group IDs ,CAG IDs, storing the received list of CAG IDs, reading the system information block 1 ,SIB1, of the cells in the neighborhood of the serving network access node cell, selecting the obtained measurements bythe UE to be the ones which correspond to the cells in neighborhood of the serving network access node cell which broadcast in SIB1 at least one of the CAG IDs of the received list.

[0017] In some embodiments, the method further comprises receiving from the serving network access node, prior to the reception of the femto cell proximity assistance information at the UE, a request to measure and report identification tags of at least one cell in the neighborhood of the serving network access node cell and corresponding DL RSRP of the serving network access node cell. The method further comprises starting measurements by the UE to determine identification tags of the at least one cell in the neighborhood of the serving network access node cell and corresponding DL RSRP of the serving network access node cell, reporting measurements of determined identification tags of the at least one cell in the neighborhood of the serving network access node cell together with DL RSRP of the serving network access node cell from the UE to the serving network access node.

[0018] In some embodiments, the method further comprises that the identification tag of the at least one cell in the neighborhood of the serving network access node cell is a physical cell identity (PCI).

[0019] In some embodiments, the method further comprises that the identification tag of the at least one cell in the neighborhood of the serving network access node cell is a closed access group ID (CAG ID).

[0020] In some embodiments, the method further comprises that the at least one cell in the neighborhood of the serving network access node cell is a femto cell.

[0021] In some embodiments, the method further comprises that the at least one cell in the neighborhood of the serving network access node cell is a CAG cell.

[0022] According to a second aspect, an apparatus is provided. The apparatus comprises at least one processor; and at least one memory including instructions that, when executed by the at least one processor, cause the apparatus at least to perform the method according to the first aspect.

[0023] According to a third aspect, a method performed at a serving network access node is provided. The method comprises receiving at a serving network access node at least one identification tag from at least one cell in the neighborhood of the serving network access node. The method further comprises receiving at the serving network access node a connection request of a user equipment (UE). The method further comprises receiving from a core network a list of at least one allowed identification tag for the UE. The method further comprises transmitting the femto proximity assistance information to the UE.

[0024] In some embodiments, the method further comprises that the transmitting is based on determining a match between the at least one identification tag from the at least one cell inthe neighborhood of a serving network access node cell and the list of the at least one allowed identification tag for the UE.

[0025] In some embodiments, the method further comprises receiving a measurement report from the UE, wherein the measurement report comprises at least one selected measurement by the UE of a target cell in the neighborhood of the serving network access node cell, wherein the at least one selected measurement by the UE is based on the transmitted femto proximity assistance information. The method further comprises evaluating a handover decision to a target cell in the neighborhood of the serving network access node cell based on the received measurement report.

[0026] In some embodiments, the method further comprises transmitting to the network access node of the target cell a request to hand over the UE to the target cell based on the received measurement report. The method further comprises receiving from the network access node of the target cell an acceptance of the handover. The method further comprises transmitting a handover command to the UE to perform a handover to the target cell in the neighborhood of the serving network access node based on the acceptance.

[0027] In some embodiments, the method further comprises that the femto cell proximity assistance information is transmitted in an RRC reconfiguration message to the UE, including measurement configuration associated with the measuring of the at least one cell in the neighborhood of the serving network access node cell.

[0028] In some embodiments, the method further comprises that the femto proximity assistance information comprises at least one of: a proximity indicator, a list of identification tags, wherein each identification tag correspond to a femto cell or closed access group cell (CAG) cell, in the neighborhood of the serving network access node cell, a list of physical cell identities (PCIs) wherein each PCI correspond to a femto cell or closed access group cell cell, in the neighborhood of the serving network access node cell, a list of reference signal received power signal of a downlink signal (DL RSRP) or reference signal received power signal (RSRP) ranges, a list of one or more geographical coordinates of neighbor femto cells or closed access groups CAG cells.

[0029] In some embodiments, the method further comprises that transmitting to the UE, prior to transmitting the proximity assistance information to the UE, a request to measure and report by the UE at least one identification tag of the at least one cell in the neighborhood of the serving network access node cell and at least one corresponding reference signal received power signal of a downlink signal ,DL RSRP, of the serving network access node cell. The method further comprises receiving a pre-measurement report from the UE, comprising the at least one identification tag of at least one cell in the neighborhood of the serving network access node cell and the at least one corresponding DL RSRP of the serving network access node cell.The method further comprises configuring a database based on the received pre-measurement report from the UE.

[0030] In some embodiments, the method further comprises that the at least one identification tag of at least one cell in the neighborhood of the serving network access node cell associated with the at least one corresponding DL RSRP of the serving network access node cell.

[0031] In some embodiments, the method further comprises receiving at the serving network access node, prior to transmitting the femto proximity assistance information, at least one of, geographical coordinate of at least one cell in neighborhood of the serving network access node; or at least one corresponding identification tag of at least one cell in neighborhood of the serving network access node. The method further comprises configuring a database based on the received information.

[0032] In some embodiments, the method further comprises that the cell identifies of at least one cell in the neighborhood of the serving network access node; or at least one geographical coordinate of at least one cell in the neighborhood of the serving network access node; or at least one corresponding identification tag of at least one cell in the neighborhood of the serving network access node.

[0033] In some embodiments, the method further comprises that the at least one geographical coordinate or the at least one corresponding identification tag of the at least one cell in the neighborhood of the serving network access node are transmitted from an operation and management system (O&M) to the serving network access node.

[0034] In some embodiments, the method further comprises that the at least one geographical coordinate or the at least one corresponding identification tag of the at least one cell in the neighborhood of the serving network access node are transmitted from the neighbor network access node hosting the at least one cell in the neighborhood of the serving network access node.

[0035] In some embodiments, the method further comprises that the received information are transmitted in one of an Xn Setup Request message or a Xn Setup Response message to the serving network access node.

[0036] In some embodiments, the method further comprises that the geographical coordinates are GPS coordinates, GLONASS coordinates, GALILEO coordinates or BEIDO coordinates.

[0037] In some embodiments, the method further comprises that the geographical coordinates are sent with an associated accuracy value, uncertainty circle or confidence level.

[0038] In some embodiments, the method further comprises that the identification tag of the at least one cell in the neighborhood of the serving network access node cell is a physical cell identity (PCI).

[0039] In some embodiments, the method further comprises that the identification tag of the at least one cell in the neighborhood of the serving network access node cell is a closed access group ID (CAG ID).

[0040] In some embodiments, the method further comprises that the at least one cell in the neighborhood of the serving network access node cell is a femto cell.

[0041] In some embodiments, the method further comprises that the at least one cell in the neighborhood of the serving network access node cell is a CAG cell.

[0042] According to a fourth aspect, an apparatus is provided. The apparatus comprises at least one processor; and at least one memory including instructions that, when executed by the at least one processor, cause the apparatus at least to perform the method according to the third aspect.

[0043] According to a fifth aspect, a method performed at a User equipment (UE) is provided. The method comprises receiving at a user equipment ,UE, from a serving network access node a conditional handover request comprising femto cell proximity assistance information. The method further comprises starting to obtain measurements by the UE of at least one cell in neighborhood of the serving network access node cell based on the femto cell proximity assistance information. The method further comprises selecting the obtained measurements by the UE based on the femto cell proximity assistance information. The method further comprises selecting a target cell in the neighborhood of the serving network access node cell, wherein the selection of the target cell is based on a match between the selected measurements and the femto cell proximity assistance information. The method further comprises completing the conditional handover by transmitting a handover complete message to the network access node of the selected target cell.

[0044] In some embodiments, the method further comprises that the femto cell proximity assistance information is a closed access group ,CAG, cell proximity assistance information.

[0045] In some embodiments, the method further comprises that the femto cell proximity assistance information comprises a list of at least one allowed identification tag of the at least one cell in the neighborhood of the serving network access node cell.

[0046] In some embodiments, the method further comprises that the femto cell proximity assistance information comprises at least one of, a proximity indicator, a list of physical cell identities ,PCIs, wherein each PCI corresponds to a femto cell or closed access group cell ,CAG cell, in the neighborhood of the serving network access node, a list of reference signal receivedpower signal of a downlink signal ,DL RSRP, or reference signal received power signal ,RSRP, ranges, a list of one or more geographical coordinates of neighbor femto cells or closed access groups CAG cells.

[0047] In some embodiments, the method further comprises starting measurements by the UE of the at least one cell in the neighborhood of the serving network access node cell based on the receiving of the proximity indicator that is part of the femto cell proximity assistance information.

[0048] In some embodiments, the method further comprises that starting measurements by the UE of the at least one cell in the neighborhood of the serving network access node cell is based on receiving a coarse location of the at least one cell in the neighborhood of the serving network access node cell that is part of the femto cell proximity assistance information.

[0049] In some embodiments, the method further comprises that the coarse location of the at least one cell in the neighborhood of the serving network access node cell is defined by a range of reference signal received power signals of a downlink signal ,DL RSRP, of a serving cell of the serving network access node.

[0050] In some embodiments, the method further comprises receiving one or more range(s) of DL RSRP in the coarse location, measuring the DL RSRP of the serving network access node cell, determining that the measured DL RSRP of the serving network access node cell matches at least one of the received one or more range(s) of DL RSRP, starting the measurements by the UE of the at least one cell in the neighborhood of the serving network access node cell based on the determining.

[0051] In some embodiments, the method further comprises that the coarse location of the at least one cell in the neighborhood of the serving network access node cell is defined by geographical coordinates.

[0052] In some embodiments, the method further comprises receiving one or more geographical coordinates in the coarse location. The method further comprises determining that the position of the UE matches at least one of the received one or more geographical coordinates. The method further comprises starting the measurements of the at least one cell in the neighborhood of the serving network access node cell based on the determining.

[0053] In some embodiments, the method further comprises that starting measurements by the UE of the at least one cell in the neighborhood of the serving network access node cell is performed regardless of the radio condition with the serving cell.

[0054] In some embodiments, the method further comprises that selecting the obtained measurements by the UE further comprising, receiving, within the femto cell proximity assistance information, a list of one or more physical cell identities, PCIs, associated with cellsin the neighborhood of the serving network access node cell. The method further comprises reading the PCI of the at least one cell in the neighborhood of the serving network access node cell. The method further comprises selecting the obtained measurements by the UE to be the ones which correspond to cells in the neighborhood of the serving network access node whose PCI match at least one PCI of the received list.

[0055] In some embodiments, the method further comprises that selecting the obtained measurements by the UE further comprising receiving from a core network a list of allowed closed access group IDs ,CAG IDs,. The method further comprises storing the received list of CAG IDs. The method further comprises reading the system information block 1 ,SIB1, of the cells the neighborhood of the serving network access node cell. The method further comprises selecting the obtained measurements by the UE to be the ones which correspond to the cells in neighborhood of the serving network access node cell which broadcast in SIB1 at least one of the CAG IDs of the received list.

[0056] In some embodiments, the method further comprises receiving from the serving network access node, prior to the reception of the femto cell proximity assistance information at the UE, a request to measure and report identification tags of at least one cell in the neighborhood of the serving network access node cell and corresponding DL RSRP of the serving network access node cell. The method further comprises starting measurements by the UE to determine identification tags of the at least one cell in the neighborhood of the serving network access node cell and corresponding DL RSRP of the serving network access node cell. The method further comprises reporting measurements of determined identification tags of the at least one cell in the neighborhood of the serving network access node cell together with DL RSRP of the serving network access node cell from the UE to serving network access node.

[0057] In some embodiments, the method further comprises that the identification tag of the at least one cell in the neighborhood of the serving network access node cell is a physical cell identity (PCI).

[0058] In some embodiments, the method further comprises the identification tag of the at least one cell in the neighborhood of the serving network access node cell is a closed access group ID ,CAG ID,.

[0059] In some embodiments, the method further comprises the at least one cell in the neighborhood of the serving network access node cell is a femto cell.

[0060] In some embodiments, the method further comprises the at least one cell in the neighborhood of the serving network access node cell is a CAG cell.

[0061] According to a sixth aspect, an apparatus is provided. The apparatus comprises at least one processor; and at least one memory including instructions that, when executed by theat least one processor, cause the apparatus at least to perform the method according to the fifth aspect.

[0062] According to a seventh aspect, a method performed at a serving network access node is provided. The method comprises receiving at a serving network access node at least one identification tag from at least one cell in neighborhood of the serving network access node. The method further comprises receiving from a core network a list of at least one allowed identification tag for a user equipment (UE). The method further comprises determining at least one match between the at least one identification tag from the at least one cell in the neighborhood of the serving network access node and the list of at least one allowed identification tag for the UE. The method further comprises transmitting a handover request to the network access node of the at least one cell in the neighborhood of the serving network access node based on the determining. The method further comprises transmitting based on the determining a conditional handover request which comprises a femto cell proximity assistance information to the UE.

[0063] In some embodiments, the method further comprises the femto cell proximity assistance information is a closed access group (CAG) cell proximity assistance information.

[0064] In some embodiments, the method further comprises receiving from the network access node of the at least one cell in the neighborhood of the serving network access node a completion message of the handover of the UE.

[0065] In some embodiments, the method further comprises that the transmitted conditional handover request to the UE further comprises at least one of a list of candidate target cells or legacy conditional handover criteria.

[0066] In some embodiments, the method further comprises that the femto proximity assistance information comprises at least one of, a proximity indicator, a list of identification tags, wherein each identification tag correspond to a femto cell or closed access group cell in the neighborhood of the serving network access node cell. The method further comprises a list of physical cell identities (PCIs) wherein each PCI correspond to a femto cell or closed access group cell (CAG cell) in the neighborhood of the serving network access node cell. The method further comprises a list of reference signal received power signal of a downlink signal (DL RSRP) or reference signal received power signal (RSRP) ranges. The method further comprises a list of one or more geographical coordinates of neighbor femto cells or closed access groups CAG cells.

[0067] In some embodiments, the method further comprises transmitting to the UE, prior to transmitting the femto proximity assistance information to the UE, a request to measure and report by the UE the at least one identification tag of the at least one cell in the neighborhood of the serving network access node and at least one corresponding reference signal receivedpower signal of a downlink signal (DL RSRP) of the serving network access node cell. The method further comprises receiving a pre-measurement report from the UE, comprising the at least one identification tag of the at least one cell in the neighborhood of the serving network access node cell and the at least one corresponding DL RSRP of the serving network access node call. The method further comprises configuring a database based on the received premeasurement report from the UE.

[0068] In some embodiments, the method further comprises that the configured database comprises: at least one identification tag of at least one cell in the neighborhood of the serving network access node cell associated with the at least one corresponding DL RSRP of the serving network access node cell.

[0069] In some embodiments, the method further comprises receiving at the serving network access node, prior to transmitting the femto proximity assistance information, at least one of: geographical coordinate of the at least one cell in neighborhood of the serving network access node; or at least one corresponding identification tag of the at least one cell in neighborhood of the serving network access node. The method further comprises configuring a database based on the received information.

[0070] In some embodiments, the method further comprises that the configured database comprises at least one of the cell identify of at least one cell in the neighborhood of the serving network access node; or, the at least one geographical coordinate of the at least one cell in the neighborhood of the serving network access node; or and the at least one corresponding identification tag of the at least one cell in the neighborhood of the serving network access node.

[0071] In some embodiments, the method further comprises that the at least one geographical coordinate or the at least one corresponding identification tag of the at least one cell in the neighborhood of the serving network access node are transmitted from the operation and management system (O&M) to the serving network access node.

[0072] In some embodiments, the method further comprises that the at least one geographical coordinate or the at least one corresponding identification tag of the at least one cell in the neighborhood of the serving network access node are transmitted from the neighbor network access node hosting the at least one cell in the neighborhood of serving network access node.

[0073] In some embodiments, the method further comprises that the received information is transmitted in one of an Xn Setup Request message or a Xn Setup Response message to the serving network access node.

[0074] In some embodiments, the method further comprises that, wherein the geographical coordinates are GPS coordinates, GLONASS coordinates, GALILEO coordinates or BEIDO coordinates.

[0075] In some embodiments, the method further comprises that the geographical coordinates are sent with an associated accuracy value, uncertainty circle or confidence level.

[0076] In some embodiments, the method further comprises that the identification tag of the at least one cell in the neighborhood of the serving network access node cell is a physical cell identity (PCI).

[0077] In some embodiments, the method further comprises that the identification tag of the at least one cell in the neighborhood of the serving network access node cell is a closed access group ID (CAG ID).

[0078] In some embodiments, the method further comprises that the at least one cell in the neighborhood of the serving network access node cell is a femto cell.

[0079] In some embodiments, the method further comprises that the at least one cell in the neighborhood of the serving network access node cell is a CAG cell.

[0080] According to an eighth aspect, an apparatus is provided. The apparatus comprises at least one processor; and at least one memory including instructions that, when executed by the at least one processor, cause the apparatus at least to perform the method according to the seventh aspect.BRIEF DESCRIPTION OF THE FIGURES

[0081] In the following embodiments will be described in greater detail with reference to the attached drawings, in which:

[0082] FIG. 1 shows a schematic diagram of an example (mobile / wireless) communication system or network;

[0083] FIG. 2 shows a schematic diagram of an example wireless device or entity;

[0084] FIG. 3 shows a schematic diagram of an example network node or entity;

[0085] FIGs. 4A-4B show a flow diagram of a method according to an example embodiment.

[0086] More particularly, Fig. 4A-4B illustrates a triggered handover to a cell in the neighborhood of the serving cell of the UE.

[0087] Figs. 5A-5B show a flow diagram of a method according to another example embodiment.

[0088] More particularly, Fig. 5A-5B illustrates a triggered conditional handover (CHO) completion based on cell proximity detection.

[0089] FIG. 6 shows an embodiment for building a database for cell proximity detection.

[0090] FIG. 7 shows another embodiment for building a database for cell proximity detection.DETAILED DESCRIPTION

[0091] The examples and embodiments set forth below represent information to enable those skilled in the art to practice the subject disclosure. Upon reading the following description in light of the accompanying drawing figures, those skilled in the art will understand the concepts of the description and will recognize applications of these concepts not particularly addressed herein. It should be understood that these concepts and applications fall within the scope of the description.

[0092] References in the specification to "one embodiment," "an embodiment," "an example embodiment," etc., indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to implement such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.

[0093] It is to be noted that the detailed description, at times, refers to one or more specifications being used as non-limiting and illustrative examples for certain architectures, network configurations and system deployments. More specifically, the detailed description refers to 3GPP standards, being used as non-limiting and illustrative examples. As such, the example embodiments provided herein can specifically employ terminology which is directly related thereto. Such terminology is only used in the context of the non-limiting and illustrative examples and is not intended to limit the example embodiments in any way. Rather, any other system configuration or deployment may be utilized while complying with what is described herein and / or example embodiments are applicable to it.

[0094] For example, various example embodiments are applicable in any (e.g., mobile / wireless) communication system, such as a 5G / NR system and a next-generation system beyond 5G. For example, various example embodiments are applicable in a 3 GPP-standardized mobile / wireless communication system of Release 18 onwards.

[0095] Hereinafter, various example embodiments are described using several variants and / or alternatives. It is generally to be noted that, according to certain implementations or constraints, all the described variants and / or alternatives may be provided alone or in anyconceivable combination (e.g., also including combinations of individual features of these various variants and / or alternatives).

[0096] As used herein, the words "comprising" and "including" should be understood as not limiting the example embodiments to consist of only those features that have been mentioned, and example embodiments may also contain, among other things, e.g., features, structures, units, modules, or the like, that have not been specifically mentioned.

[0097] As used herein, "at least one of the following: " and "at least one of " and similar wording, like "one or more of, where the list of two or more elements are joined by "and" or "or", mean at least any one of the elements, or at least any two or more of the elements, or at least all the elements.

[0098] As used herein, the term “circuitry” may refer to one or more or all of the following: (a) hardware-only circuit implementations (such as implementations in only analog and / or digital circuitry), and (b) combinations of hardware circuits and software, such as: (i) a combination of analog and / or digital hardware circuit(s) with software / firmware, and (ii) any portions of hardware processor(s) with software (including digital signal processor(s)), software, and memory(ies) that work together to cause an apparatus, such as a mobile phone or server, to perform various functions) and hardware circuit(s) and or processor(s), such as a microprocessor s) or a portion of a microprocessor s), that requires software (e.g., firmware) for operation, but the software may not be present when it is not needed for operation.

[0099] This definition of circuitry applies to all uses of this term in this application, including in any claims. As a further example, as used in this application, the term circuitry also covers an implementation of merely a hardware circuit or processor (or multiple processors) or portion of a hardware circuit or processor and its (or their) accompanying software and / or firmware. The term circuitry also covers, for example and if applicable to the particular claim element, a baseband integrated circuit or processor integrated circuit for a mobile device or a similar integrated circuit in server, a cellular network device, or other computing or network device.

[0100] In the drawings, it is to be noted that lines / arrows interconnecting individual blocks or entities are generally meant to illustrate an operational coupling there-b etween, which may be a physical and / or logical coupling, which on the one hand is implementation-independent (e.g., wired, or wireless) and on the other hand may also comprise an arbitrary number of intermediary functional blocks or entities not shown. In flowcharts or sequence diagrams, the illustrated order of operations or actions is generally non-limiting and illustrative, and any other order of respective operations or actions is conceivable, if feasible.

[0101] Before explaining example embodiments in detail, certain general principles of a (mobile / wireless) communication system or network are briefly explained with reference toFIGS. 1 to 3 to assist in understanding the technology underlying the described example embodiments.

[0102] FIG. 1 illustrates an example of a (mobile / wireless) communication system or network 100, for example a fifth generation (5G) new radio (NR) network, that may be used for wireless communications. Communication system or network 100 includes wireless communication devices or entities 110, such as UEs (e.g., UEs 110A-110C), and network nodes or entities, such as radio access nodes 120 (e.g., 120A-120B) (e.g., eNBs, gNBs, etc.), connected to one or more network nodes or entities 130 via an interconnecting network 125. Communication system or network 100 may use any suitable deployment scenarios. UEs 110 within coverage area 115 may each be capable of communicating directly with radio access nodes 120 over a wireless interface.

[0103] As an example, UE 110A may communicate with radio access node 120A over a wireless interface. That is, UE 110A may transmit wireless signals to and / or receive wireless signals from radio access node 120A. The wireless signals may contain voice traffic, data traffic, control signals, and / or any other suitable information.

[0104] As used herein, the term "user equipment" (UE) has the full breadth of its ordinary meaning and may refer to any type of wireless device or entity which can communicate with a network node or entity and / or with another UE in a cellular or mobile or wireless / mobile communication system. Examples of UE are target device, personal digital assistant (PDA), tablet, mobile terminal, smartphone, laptop embedded equipped (LEE), laptop mounted equipment (LME), vehicle-to-vehicle (V2V) UE, narrow band loT (NB-IoT) UE, etc. Example embodiments of a UE are described in more detail below with respect to FIG. 2.

[0105] In some embodiments, an area of wireless signal coverage 115 associated with a radio access node 120 may be referred to as a cell. However, particularly with respect to the fifth generation (5G) / New Radio (NR) mobile communication concepts, beams may be used instead of cells and, as such, it is important to note that concepts described herein are equally applicable to both cells and beams.

[0106] The interconnecting network 125 may refer to any interconnecting system capable of transmitting audio, video, signals, data, messages, etc., or any combination of the preceding. The interconnecting network 125 may include all or a portion of a public switched telephone network (PSTN), a public or private data network, a local area network (LAN), a metropolitan area network (MAN), a wide area network (WAN), a local, regional, or global communication or computer network such as the Internet, a wireline or wireless network, an enterprise intranet, or any other suitable communication link, including combinations thereof.

[0107] In some embodiments, the network node 130 may be a core network node, managing the establishment of communication sessions and other various other functionalitiesfor UEs 110. Examples of network node 130 may include mobile switching center (MSC), MME, serving gateway (SGW), packet data network gateway (PGW), operation and maintenance (O&M), operations support system (OSS), SON, positioning node (e.g., Enhanced Serving Mobile Location Center, E-SMLC), location server node, MDT node, etc. UEs 110 may exchange certain signals with the network node 130 using the non-access stratum (NAS) layer. In non-access stratum signaling, signals between UEs 110 and the network node 130 may be transparently passed through the radio access network. In some embodiments, radio access nodes 120 may interface with one or more network nodes 130 over an internode interface.

[0108] In some embodiments, radio access node 120 may be a distributed radio access node. The components of the radio access node 120, and their associated functions, may be separated into two main units (or sub-radio network nodes) which may be referred to as the central unit (CU) and the distributed unit (DU). Different distributed radio network node architectures are possible. For instance, in some architectures, a DU may be connected to a CU via dedicated wired or wireless link (e.g., an optical fiber cable) while in other architectures, a DU may be connected a CU via a transport network. Also, how the various functions of the radio access node 120 are separated between the CU(s) and DU(s) may vary depending on the chosen architecture.

[0109] Exemplary wireless communication systems are architectures standardized by the 3rd Generation Partnership Project (3GPP). A latest 3GPP based development is often referred to as the long-term evolution (LTE) of the Universal Mobile Telecommunications System (UMTS) radio-access technology (RAT). The various development stages of the 3GPP specifications are referred to as releases. More recent developments of the LTE are often referred to as LTE Advanced (LTE-A). The LTE (LTE-A) employs a radio mobile architecture known as the Evolved Universal Terrestrial Radio Access Network (E-UTRAN) and a core network known as the Evolved Packet Core (EPC). Base stations of such systems are known as evolved or enhanced Node Bs (eNBs) and provide E-UTRAN features such as user plane Packet Data Convergence / Radio Link Control / Medium Access Control / Physical layer protocol (PDCP / RLC / MAC / PHY) and control plane Radio Resource Control (RRC) protocol terminations towards the communication devices.

[0110] An example of a suitable communications system is the 5G or NR concept. Network architecture in NR may be similar to that of LTE-A. Base stations of NR systems may be known as next generation Node Bs (gNBs). An example 5G core network (CN) comprises functional entities. The CN is connected to a UE via the radio access network (RAN). At least in some embodiments, the 5G NR network 100 may comprise one or more massive machine-to-machine (M2M) network(s), massive machine type communications (mMTC) network(s), internet of things (loT) network(s), industrial internet-of-things (IIoT) network(s), enhanced mobile broadband (eMBB) network(s), ultra-reliable low-latency communication (URLLC)network(s), and / or the like. In other words, the 5G NR network 100 may be configured to serve diverse service types and / or use cases, and may logically be seen as comprising one or more networks.

[0111] An example 5G core network (CN) comprises functional entities. The CN is connected to a UE via the radio access network (RAN). An UPF (User Plane Function) whose role is called PSA (PDU Session Anchor) may be responsible for forwarding frames back and forth between the DN (data network) and the tunnels established over the 5G towards the UEs exchanging traffic with the data network (DN). The UPF is controlled by an SMF (Session Management Function) that receives policies from a PCF (Policy Control Function). The CN may also include an AMF (Access & Mobility Function).

[0112] Generally, all concepts disclosed herein may be applicable to different communication networks, comprising but not limited to LTE, LTE-A, 5G, 5G advanced, 6G, and other future or already implemented networks.

[0113] FIG. 2 is a schematic diagram of an example wireless communication device 110 according to certain example embodiments. Such a wireless communication device 110 is often referred to as User Equipment (UE), user device or terminal device. An appropriate wireless communication device 110 may be provided by any device capable of sending and receiving radio signals. Non-limiting examples comprise a mobile station (MS) or mobile device, such as a mobile phone (e.g., smartphone), a computer provided with a wireless interface card or other wireless interface facility (e.g., USB dongle), or any combinations of these or the like.

[0114] UE 110 may also or alternatively be configured to communicate using one or more Global Navigational Satellite Systems (GNSS such as, e.g., GPS), one or more mobile television broadcasting standards (e.g., ATSC-M / H or DVB-H), and / or any other wireless communication protocol, if desired. Other combinations of wireless communication standards (including more than two wireless communication standards) are also possible.

[0115] UE 110 may include one or more of at least one transceiver 210, at least one processor 220, at least one memory 230, and at least one network interface 240. In certain example embodiments, the transceiver 210 facilitates transmitting wireless signals to and receiving wireless signals from radio access node 120 (e.g., via transmitted s) (Tx), received s) (Rx) and antenna(s)). The processor 220 executes instructions to provide some or all of the functionalities described herein as being provided by a wireless device / entity or UE, and the memory 230 stores the instructions executed by the processor 220. In some embodiments, the processor 220 and the memory 230 form processing circuitry

[0116] The processor 220 may include any suitable combination of hardware to execute instructions and manipulate data to perform some or all the described functions of a wireless device or entity, such as the functions of UE 110 described herein. In some embodiments, theprocessor 220 may include, for example, one or more computers, one or more central processing units (CPUs), one or more microprocessors, one or more application specific integrated circuits (ASICs), one or more field programmable gate arrays (FPGAs) and / or other logic.

[0117] Generally, the wireless communication device 110 illustrated in FIG. 2 includes a set of components configured to perform core functions. For example, this set of components may be implemented as a system on chip (SoC), which may include portions for various purposes. Alternatively, this set of components may be implemented as separate components or groups of components for the various purposes. The set of components may be (communicatively) coupled (e.g., directly or indirectly) to various other circuits of the wireless communication device 110.

[0118] The memory 230 is generally operable to store instructions, such as a computer program, software, an application including one or more of logic, rules, algorithms, code, tables, etc. and / or other instructions capable of being executed by a processor 220. Examples of memory 230 include computer memory (for example, Random Access Memory (RAM) or Read Only Memory (ROM)), mass storage media (for example, a hard disk), removable storage media (for example, a Compact Disk (CD) or a Digital Video Disk (DVD)), and / or or any other volatile or non-volatile, non- transitory computer-readable and / or computer-executable memory devices that store information, data, and / or instructions that may be used by the processor 220 of UE 110. For example, the memory 230 includes instructions causing the processor 220 to perform processing according to any corresponding methods described herein.

[0119] The network interface 240 is communicatively coupled to the processor 220 and may refer to any suitable device operable to receive input for UE 110, send output from UE 110, perform suitable processing of the input or output or both, communicate to other devices, or any combination thereof. The network interface 240 may include appropriate hardware (e.g., port, modem, network interface card, etc.) and software, including protocol conversion and data processing capabilities, to communicate through a network.

[0120] Other embodiments of UE 110 may include additional components beyond those shown in FIG. 2 that may be responsible for providing certain aspects of the wireless device’s functionalities, including any of the functionalities described herein and / or any additional functionalities (including any functionality necessary to support the mechanisms according to the subject disclosure). As an example, UE 110 may include input devices and circuits, output devices, and one or more synchronization units or circuits, which may be part of the processor 220. Input devices include mechanisms for entry of data into UE 110. For example, input devices may include input mechanisms, such as a microphone, input elements, a display, etc. Output devices may include mechanisms for outputting data in audio, video and / or hard copy format. For example, output devices may include a speaker, a display, etc.

[0121] In certain example embodiments, the wireless device UE 110 may comprise a series of modules configured to implement the functionalities of the wireless device described herein.

[0122] It will be appreciated that the various modules may be implemented as combination of hardware and software, for instance, the processor, memory, and transceiver(s) of UE 110 shown in FIG. 2. Certain example embodiments may also include additional modules to support additional and / or optional functionalities.

[0123] UE 110 may also include one or more mechanisms for sharing and / or obtaining data. For example, UE 110 may include a short-range radio frequency (RF) transceiver and / or interrogator, so data may be shared with and / or obtained from electronic devices in accordance with RF techniques. UE 110 may include other short-range transceivers, such as an infrared (IR) transceiver, a Bluetooth™ (BT) transceiver operating using Bluetooth™ wireless technology, a wireless Universal Serial Bus (USB) transceiver, a Bluetooth™ Low Energy transceiver, a ZigBee transceiver, an ANT transceiver, a cellular device-to-device transceiver, a wireless local area link transceiver, and / or any other short-range radio technology. UE 110 and more specifically, the short-range transceiver may be capable of transmitting data to and / or receiving data from electronic devices within the proximity of the apparatus, such as within 10 meters, for example. UE 110 including the Wi-Fi or WLAN modem may also be capable of transmitting and / or receiving data from electronic devices according to various wireless networking techniques, including 6L0WPAN, Wi-Fi, Wi-Fi low power, WLAN techniques such as IEEE 802.11 techniques, IEEE 802.15 techniques, IEEE 802.16 techniques, and / or the like.

[0124] Some of the embodiments disclosed herein may be implemented in software, hardware, application logic, or a combination of software, hardware, and application logic. The software, application logic, and / or hardware may reside on the memory, the processor, or electronic components, for example. In some example embodiment, the application logic, software or an instruction set is maintained on any one of various conventional computer- readable media. In the context of this document, a "computer-readable medium" may be any non-transitory media that can contain, store, communicate, propagate or transport the instructions for use by or in connection with an instruction execution system, apparatus, or device, such as a computer or data processor circuitry, with examples depicted at FIG. 3, computer-readable medium may comprise a non-transitory computer-readable storage medium that may be any media that can contain or store the instructions for use by or in connection with an instruction execution system, apparatus, or device, such as a computer.

[0125] FIG. 3 is a schematic diagram of an example radio access node 120 or network node or entity 130 according to certain example embodiments. Radio access node 120 or network node or entity 130 may include one or more of at least one transceiver 310, at least one processor 320, at least one memory 330, and at least one network interface 340. In certain exampleembodiments, the transceiver 310 facilitates transmitting wireless signals to and receiving wireless signals from wireless devices, such as UE 110 (e.g., via transmitter(s) (Tx), receiver(s) (Rx), and antenna(s)). The processor 320 executes instructions to provide some or all the functionalities described herein as being provided by the radio access node 120 or the network node or entity 130, the memory 330 stores the instructions executed by the processor 320. In some embodiments, the processor 320 and the memory 330 form processing circuitry. The network interface 340 can communicate signals to backend network components, such as a gateway, switch, router, Internet, Public Switched Telephone Network (PSTN), core network nodes or radio network controllers, etc.

[0126] The processor 320 can include any suitable combination of hardware to execute instructions and manipulate data to perform some or all the described functions of the radio access node 120 or the network node or entity 130, such as those described herein. In some embodiments, the processor 320 may include, for example, one or more computers, one or more central processing units (CPUs), one or more microprocessors, one or more application specific integrated circuits (ASICs), one or more field programmable gate arrays (FPGAs) and / or other logic.

[0127] The memory 330 is generally operable to store instructions, such as a computer program, software, an application including one or more of logic, rules, algorithms, code, tables, etc. and / or other instructions capable of being executed by a processor 320. Examples of memory 330 include computer memory (for example, Random Access Memory (RAM) or Read Only Memory (ROM)), mass storage media (for example, a hard disk), removable storage media (for example, a Compact Disk (CD) or a Digital Video Disk (DVD)), and / or or any other volatile or non-volatile, non- transitory computer-readable and / or computer-executable memory devices that store information. For example, the memory 330 includes instructions causing the processor 320 to perform processing according to any corresponding methods described herein.

[0128] In certain example embodiments, the network interface 340 is communicatively coupled to the processor 320 and may refer to any suitable device operable to receive input for the radio access node 120 or the network node or entity 130, send output from the radio access node 120 or the network node or entity 130, perform suitable processing of the input or output or both, communicate to other devices, or any combination of the preceding. The network interface 340 may include appropriate hardware (e.g., port, modem, network interface card, etc.) and software, including protocol conversion and data processing capabilities, to communicate through a network.

[0129] Other example embodiments of the radio access node 120 or the network node or entity 130 can include additional components beyond those shown in FIG. 3 that may be responsible for providing certain aspects of the node’s functionalities, including any of thefunctionalities described herein and / or any additional functionalities (including any functionality necessary to support the solutions described herein). The various different types of radio access nodes or network nodes may include components having the same physical hardware but configured (e.g., via programming) to support different radio access technologies, or may represent partly or entirely different physical components.

[0130] Processors, interfaces, and memory similar to those described with respect to FIG. 3 may be included in other nodes or entities (such as UE 110, radio access node 120, etc.). Other nodes or entities may optionally include or not include a wireless interface (such as the transceiver described in FIG. 3).

[0131] In certain example embodiments, the radio access node 120 or the network node or entity 130 may comprise a series of modules configured to implement the functionalities of the radio access node 120 or the network node or entity 130 described herein.

[0132] It will be appreciated that the various modules may be implemented as combination of hardware and software, for instance, the processor, memory, and transceiver(s) of the radio access node 120 or the network node or entity 130 shown in FIG. 3. Certain example embodiments may also include additional modules to support additional and / or optional functionalities.).

[0133] Having thus introduced a suitable but non-limiting technical context for the practice of the example embodiments, the example embodiments are now described with greater specificity.

[0134] In general, the present disclosure is related to triggered handover to a cell in the neighborhood of serving network access node of the UE.

[0135] In general, the present disclosure is related to a procedure for proximity detection triggered handover (HO) or conditional handover (CHO) of a User Equipment (UE) from a cell of a serving network access node (open cell) to a closed group cell (e.g. CAG or femto cell).

[0136] During mobility of the UE in different serving network access node cells (e.g. serving cells) of a serving network access node (=gNodeB) UEs may come across closed access (CAG) cells for which the UE is member of. In such scenarios it is preferred to handover the UEs to the CAG cell to which the UE is member of, as a CAG cell is a closed cell. The reason to do this is that the service provided by the closed cell is better guaranteed for the member UEs in comparison to service of general serving cells (open cells) of the serving network access node (=gNodeB). The same is valid during the mobility of UEs from open cell to a hybrid cell, based on the resource availability for the UEs. Hybrid cells allowing both members and nonmembers to access the femto cell, balancing open and closed access models. In hybrid cells, the member UE may be prioritized over non-member UEs (non-CAG UEs) without impacting the service to non-member UEs.

[0137] When UE is approaching a closed cell or a cell in the neighborhood of the open cell, (e.g. a femto cell or a CAG cell), the channel condition towards to the serving open cell may be good enough so that UE is not be triggered for a conventional handover related measurement report or for any other type of handover.. Consequently, there is a need for a proximity detection triggered hand over procedure of the UEs which are member of closed cells to switch from the open cell to a closed cell.

[0138] A cell in the neighborhood of a serving network access node (open cell) also means cells that are fully within the coverage area of the serving network access node cell (e.g. serving cell) of the serving network access node (e.g. serving node).

[0139] Currently, in LTE / 4G Communication Services Group (CSG) proximity indication procedure relies on the autonomous search procedure in the UE to make the proximity estimation and indicate to the NW the proximity indication, which may trigger the NW to configure the UE to make CSG neighboring cell measurement to perform the HO. This approach leads to less network control and assistance for proximity estimation from the UE, and also has longer delay of triggering HO as more interactions between UE and NW are necessary. Thus, corresponding proximity detection triggered hand over of UEs is needed to enable more deterministic UE behavior on proximity detection of closed cells (e.g. CAG cells, Femto cells) and quicker HO to the CAG cell when UE move to the CAG cell coverage.

[0140] Fig. 4A-4B show a flow diagram of a method according to an example embodiment including the following steps.

[0141] More particularly, Fig. 4A-4B illustrates a triggered handover to a cell in the neighborhood of the serving network access node cell of the UE.

[0142] At 501, a serving network access node (e.g. a gNB) and cells (e.g. femto cell and CAG cell) in the neighborhood of the serving network access node set up an Xn interface together. As part of the Xn setup procedure, the gNB receives one or more identification tags, e.g. closed access group (CAG) IDs and physical cell identities (PCIs) of the cell(s) in the neighborhood of the serving network access node.

[0143] In an example, the neighbor Femto cell(s) and the gNB cell set up Xn interface together. As part of the Xn setup procedure the gNB cell receives the CAG ID and the PCI of the Femto cell(s).

[0144] At 502a, a UE enters the coverage of the gNB cell (e.g. a macro gNB cell). For example, later at 502b, 502c the UE transmits an RRC Reconnection setup message request and the gNB cell transmits an RRC acknowledgment message. In addition, the UE sets up connection in the gNB service cell towards AMF.

[0145] At 503, the gNB (e.g. a serving network access node) receives from the AMF a list of at least one allowed identification tag (e.g. an allowed CAG list, an allowed PCI list) for the UE. The list(s) may be delivered in a NGAP (Next Generation Application Protocol) Initial Context Setup Request message. NGAP handles signaling between the gNB and the AMF in the 5G core network.

[0146] At 504, the gNB determines that the list of at least one allowed identification tag (e.g. an allowed list of CAG IDs, an allowed list of PCIs) of the UE (received at step 503) contains an identification tag matching the identification tag of a cell (e.g. neighboring Femto cell, neighboring CAG cell) in neighborhood of the serving network access node (e.g. gNB) received at step 501.

[0147] Based on the determined match, a serving network access node cell (serving cell of gNB) sends a measurement configuration to the UE including femto cell proximity assistance information. The femto cell proximity assistance information comprises at least one of: a coarse location of the one or more cells in the neighborhood the serving network access node cell of whose identification tag matches the identification tag of the list of allowed cells for the UE;- the physical cell identities ,PCI(s), of the one or more cells in the neighborhood of the serving network access node cell whose identification tag matched the UE allowed identification tag list of this UE; a proximity bit indicator.

[0148] In an example, the gNB cell determines that a CAG ID of the neighbour Femto cell matches the UE allowed CAG List of the UE. Based on this determination, the gNB configures measurements with the femto cell proximity assistance information.

[0149] In one embodiment, the proximity bit indicator (e.g. a one bit proximity bit indicator) is part of the femto cell proximity assistance information. The proximity bit indicator triggers the UE to start obtaining measurements of at least one cell in the neighborhood of the serving network access node cell unconditionally of the radio condition of the serving network access node cell.

[0150] At 505, the gNB transmits an RRC reconfiguration message to the UE including measurement configuration associated with the measuring of the at least one cell in the neighborhood of the serving network access node cell. The RRC reconfiguration message also includes the femto cell proximity assistance information.

[0151] At 506, upon receiving the femto cell proximity assistance information of step 505, the UE performs the following method steps. The UE starts to obtain measurements of at least one cell in the neighborhood of the serving network access node cell based on the femto cellproximity assistance information. The UE selects the obtained measurements by the UE based on the femto cell proximity assistance information.

[0152] At 507a, the UE transmits a measurements report of neighbor cells (e.g. at least one femto cell) only if the PCI of the measured neighbor cell matches one of the identifications tags (e.g. PCI) received in the femto cell proximity assistance information. By this the UE reports the selected measurements of the at least one cell in the neighborhood of the serving network access node cell in a measurement report from the UE to the serving network access node for handover decision.

[0153] In another embodiment, at 507b the UE transmits a measurement report of neighbor Femto cells only if the determined CAG ID (read over SIB 1) matches to the allowed CAG List of the UE.

[0154] In an example, upon receiving with the femto cell proximity assistance information a coarse location of the at least one cell in the neighborhood of the serving network access node cell whose CAG ID matches with UE's allowed CAG list, the UE determines to transmit measurements reports of the measured neighboring cells (femto cell, CAG cell) based on UE determining that it is within or near this coarse location.

[0155] In another example, upon receiving with the femto cell proximity assistance information the PCI(s) of the at least one cell (e.g. a femto cell) in the neighborhood of the serving network access node and the CAG ID matches the UE's allowed CAG List, the UE determines to select the measurements (e.g. filter out at least some of the measurements) aand send measurement reports on the measured neighboring cells only if the identification tag (e.g. PCI) of the at least one cell (e.g. a femto cell) in the neighborhood of the serving network access node matches the received identification tag (e.g. PCI, CAG).

[0156] In another example, upon receiving the femto cell proximity assistance information, the UE may also starts receiving (e.g. reading) system information block 1 (SIB1) broadcast by the at least one cell in the neighborhood of the serving network access node cell and send measurements reports only if the broadcast CAG ID of SIB1 matches a CAG ID of the allowed CAG list of this UE.

[0157] Using identification tags (e.g. CAG IDs) from the SIB1 block instead of PCIs of the at least one cell in the neighborhood of the serving network access node is advantageous in view of the known “PCI Confusion” in 5G. PCI Confusion corresponds to the possibility that two neighboring cells, which are located close to each other, may transmit the same PCI, because in 5G only a defined number of PCIs are available. This may result in the “PCI Confusion” for the UE in the cellular network, if two cell have the same PCI. To provide a solution to the PCI confusion problem, the so-called closed access group ID (CAG ID) is used for the identification of the closed cell (e.g. Femto cell). The CAG ID is determined by receiving(e.g. reading) the System Information Block 1 (SIB1) of different cells (e.g. femto cells). The SIB1 is used to broadcast the CAG ID of the corresponding femto cell. Consequently, the UE is able to determine the correct femto cell.

[0158] At 508, the serving network access node (e.g. the serving gNB) receives a measurement report which is considered as suitable for handover, and also the list of at least one allowed identification tag (e.g. CAG ID) which matches the list of at least one allowed identification tag of the UE. The serving network access node then decides on the target cell to trigger hand over.

[0159] At 509, the serving network access node triggers handover to the target cell by transmitting to the target network access node hosting the cell in the neighborhood of the serving network access node a request to hand over the UE based on the decisioning at step 508.

[0160] At 510, in response to the request, the serving network access node receives from the target network access node hosting the cell in the neighborhood of the serving network access node an acceptance of the handover.

[0161] At 511, in response to the acceptance of the handover, the serving network access node transmits a handover command to the UE to perform a handover to the target cell in the neighborhood of the serving network access node based on the acceptance in step 510.

[0162] Fig. 5A-5B show a flow diagram of a method according to another example embodiment including the following steps.

[0163] More particularly, Fig. 5A-5B illustrates a triggered conditional handover (CHO) completion based on cell proximity detection.

[0164] At 601, a serving network access node (e.g. a gNB) and network access node hosting cells (e.g. femto cell and CAG cell) in the neighborhood of the serving network access node set up an Xn interface together. As part of the Xn setup procedure the gNB receives identification tags, e.g. closed access group (CAG) IDs and physical cell identities (PCIs) of the cell(s) (e.g. Femto, CAG Cells) in the neighborhood of the serving network access node.

[0165] In one example, the neighbor Femto cell(s) and gNB cell set up an Xn interface together. As part of the Xn setup procedure the gNB cell receives the CAG ID and the PCI of the Femto cell(s).

[0166] At 602, a UE enters the coverage of the gNB cell (e.g. a macro gNB cell). For example, the UE transmits an RRC Reconnection setup request message and the gNB cell transmits an RRC acknowledgment message. In addition, the UE sets up the connection in the gNB service cell towards AMF.

[0167] At 603, the serving network access node (e.g. gNB) receives from the AMF a list of at least one allowed identification tag for the UE (e.g. an allowed CAG list, an allowed PCI list) in a NGAP (Next Generation Application Protocol) Initial Context Setup Request message. NGAP handles signaling between the gNB and the AMF in the 5G core network.

[0168] At 604, the gNB determines that the list of at least one allowed identification tag (e.g. an allowed list of CAG IDs, an allowed list of PCIs) of the UE (received at step 603) contains an identification tag matching the identification tag of a cell (e.g. neighboring Femto cell, neighboring CAG cell) in the neighborhood of the serving network access node cell received at step 601.

[0169] At 605, the gNB transmits a handover request to the network access node hosting theat least one of the determined candidate target cells in the neighborhood of the serving network access node cell based on the determined match in step 604. In one embodiment, the gNB receives an acknowledgement message from he network access node hosting the at least one of the candidate target cells.

[0170] At 606, the gNB transmits based on the determined match in step 604 a conditional handover request comprising a femto cell proximity assistance information to the UE. In one embodiment the femto cell proximity assistance is included in an RRC reconfiguration message or handover command message, wherein the femto cell proximity assistance is added in addition to the legacy CHO evaluation criteria.

[0171] The femto cell proximity assistance information comprises at least one of: a coarse location of the one or more cells in the neighborhood the serving network access node cell of whose identification tag matches the identification tag of the list of allowed cells for the UE;- the physical cell identities ,PCI(s), of the one or more cells (e.g. Femto cells) in the neighborhood the serving network access node cell whose identification tag matched the allowed identification tag list of the UE; a proximity bit indicator.

[0172] In another embodiment, the conditional handover request with the femto cell proximity assistance information may also comprises a list of candidate target cells and legacy conditional handover criteria.

[0173] In one embodiment, the proximity bit indicator (e.g. a one-bit proximity bit indicator) is part of the femto cell proximity assistance information transmitted to the UE as described above. The proximity bit indicator triggers the UE to start obtaining measurementsof the at least one cell in the neighborhood of the serving network access node cell unconditionally of the radio condition of the serving network access node cell.

[0174] At 607, upon receiving the femto cell proximity assistance information of step 606, the UE performs the following method steps. The UE starts to obtain measurements by the UE of at least one cell in neighborhood of the serving network access node based on the femto cell proximity assistance information and selects the obtained measurements by the UE based on the received femto cell proximity assistance information.

[0175] In an example, upon receiving a coarse location of the one or more neighbor cell (e.g. Femto cells) whose CAG ID matches the UE's allowed CAG list, the UE determines to evaluate the CHO handover criteria only if the UE is within or near the coarse location.

[0176] In another example, upon receiving the PCI(s) of the one or more neighbor cells (e.g. Femto cells) whose CAG ID matches the UE's allowed CAG list, the UE filters out in the CHO handover evaluation the cells in the neighborhood which do not match the received PCI(s).

[0177] In another example, upon receiving the femto cell proximity assistance information, the UE may also starts reading the system information block ,SIB1, where the CAG IDs of any neighbor cells are broadcasted, and decide to select and complete the CHO towards a target cell (e.g. candidate neighbor cell) only if the broadcast CAG ID matches a CAG ID of its UE's allowed CAG List.

[0178] At 608, the UE transmits a handover complete message to the target node hosting the selected target cell in the neighborhood of the serving network access node cell based on the selected measurement by the UE, wherein the selection of the target cell is based on a match between the selected measurements and a list of allowed cells in the neighborhood of the serving network access node for the UE determined by the serving network access node from a list of at least one allowed identification tag received from a core network node.

[0179] At 609, the target cell (e.g. Femto cell) transmits a handover success message to the serving network access node that the conditional handover is performed.

[0180] FIG. 6 shows an embodiment for building a database for cell proximity detection.

[0181] In the following it is described how a coarse location which is included in femto cell proximity assistance information may be generated by the gNB and included in the messages towards the UE as described in view of the embodiments of Fig. 4a and 4b and Fig. 5a and 5b.

[0182] At 700, the UE is in the coverage of a cell (e.g. a Femto cell) in the neighborhood of the serving network access node cell. The UE receives from the cell in the neighborhood ofthe serving network node cell a broadcast signal including a Synchronization Signal (SS), a Master Information Block (MIB) and physical cell identities (PCIs).

[0183] As an optional step, at 701, the serving network access node (e.g. macro gNB) cell configures the UE for measurement and reporting of cells in the neighborhood of the serving network access node cell. The serving network access node requests in the measurement configuration that whenever the UE reports PCI of detected neighbor cell and especially neighbor femto cell, the UE also includes the measured signal strength (RSRP) the serving network access node cell in same measurement report.

[0184] At 702, whenever the UE reports identification tags (e.g. PCIs, CAGs) of detected cells in the neighborhood of the serving network access node and especially neighbor femto cell, the UE also includes the measured signal strength (RSRP) of the serving network access node cell (e.g. served macro cell) in the same measurement report. This measurement may optionally be triggered by step 701.

[0185] At 703, the gNB may build an internal database based on UE measurement reports and store, for each early reporting of further identifications tags (e.g. PCI, CAG ID), that UEs start to measure the corresponding / mapped DL RSRP level of the serving macro gNB macro cell.

[0186] FIG. 7 shows another embodiment for building a database for cell proximity detection.

[0187] At 800, the serving network access node is configured via an operation and management system (O&M) with the position and / or position accuracy of the at least one cell in the neighborhood of the serving network access node, the neighbor cells of the serving network access node (gNB). The position may be in geographical coordinates. In further embodiments, the geographical coordinates are GPS coordinates, GLONASS coordinates, GALILEO coordinates, BEIDO coordinates or any other coordiantes. It may also be configured at the same time whether the at least one cell in the neighborhood of the serving network access node is a femto cell, and in case the access mode of femto cell between open, hybrid or closed.

[0188] At 801, in an alternative embodiment, the serving network access node (gNB) may directly receive from neighbor network access node hosting the at least one cell in the neighborhood of the serving network access node over an Xn interface together with existing identification tags (e.g. CAG IDs and PCIs) of the at least one cell 11 (identified by e.g. CGI or PCI) in the neighborhood of the serving network access the cell position and / or position accuracy. This information is received for example in the Xn interface setup equest / response messages or RAN configuration update messages.. It may also be configured at the same time whether the at least one cell in the neighborhood of the serving network access node is a femtocell, and in case the access mode of the fem to cell. The access mode of the femto cell may be open, hybrid or closed.

[0189] The cell (e.g. a femto cell) may either infer itself its position / position accuracy (e.g. internal GPS) or receive it from an O&M system.

[0190] At 803, the serving network access node (gNB) builds a database based on steps 800 or 801. The database stores per neighbor cell (identified by PCI or CGI) the identification tags (PCIs or CAG IDs) and the position / position accuracy of the cell, and optionally, whether the cell is a femto cell. The access mode of the femto cell may be open, hybrid or closed.

[0191] In another embodiment, step 802 may be applied to the embodiment of Fig. 6 in such way that the UE is connected to neighbor cells and measures RSRP of neighboring / overlay macro cell and report it to the femto nodes. The Femto node over Xn interface indicate to the macro cell the RSRP of macro cell to help the gNB of macro cell to build the internal database of the embodiment of Fig. 6.

[0192] It is noted that whilst embodiments have been described in relation to 5G NR, similar principles can be applied in relation to other networks and communication systems, particularly next-generation systems beyond 5G. Therefore, although certain embodiments were described above by way of example with reference to certain example architectures for wireless networks, technologies and standards, embodiments may be applied to any other suitable forms of communication systems than those illustrated and described herein.

[0193] It is also noted herein that while the above describes exemplary embodiments, there are several variations and modifications which may be made to the disclosed solution without departing from the scope of the subject disclosure.

[0194] In general, the various exemplary embodiments may be implemented in hardware or special purpose circuits, software, logic or any combination thereof. Some aspects of the subject disclosure may be implemented in hardware, while other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device, although the subject disclosure is not limited thereto. While various aspects of the subject disclosure may be illustrated and described as block diagrams, flow charts, or using some other pictorial representation, it is well understood that these blocks, apparatus, systems, techniques or methods described herein may be implemented in, as non-limiting examples, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof.

[0195] Example embodiments of the subject disclosure may be implemented by computer software executable by a data processor of the mobile device, such as in the processor entity, or by hardware, or by a combination of software and hardware. Computer software or program, also called program product, including software routines, applets and / or macros, may be storedin any apparatus-readable data storage medium and they comprise program instructions to perform particular tasks. A computer program product may comprise one or more computerexecutable components which, when the program is run, are configured to carry out embodiments. The one or more computer-executable components may be at least one software code or portions of it.

[0196] Further in this regard it should be noted that any blocks of the logic flow as in the figures may represent program steps, or interconnected logic circuits, blocks and functions, or a combination of program steps and logic circuits, blocks and functions. The software may be stored on such physical media as memory chips, or memory blocks implemented within the processor, magnetic media such as hard disk or floppy disks, and optical media such as for example DVD and the data variants thereof, CD. The physical media is a non-transitory media.

[0197] The memory may be of any type suitable to the local technical environment and may be implemented using any suitable data storage technology, such as semiconductor-based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory and removable memory. The data processors may be of any type suitable to the local technical environment, and may comprise one or more of general-purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs), application specific integrated circuits (ASICs), FPGA, gate level circuits and processors based on multicore processor architecture, as non-limiting examples.

[0198] Example embodiments of the subject disclosure may be practiced in various components such as integrated circuit modules. The design of integrated circuits is by and large a highly automated process. Complex and powerful software tools are available for converting a logic level design into a semiconductor circuit design ready to be etched and formed on a semiconductor substrate.

[0199] The foregoing description has provided by way of non-limiting examples a full and informative description of the exemplary embodiment of the subject disclosure. However, various modifications and adaptations may become apparent to those skilled in the relevant arts in view of the foregoing description, when read in conjunction with the accompanying drawings and the appended claims. However, all such and similar modifications of the teachings of this disclosure will still fall within the scope of the subject disclosure as defined in the appended claims. Indeed, there is a further embodiment comprising a combination of one or more embodiments with any of the other embodiments previously discussed.

Claims

WE CLAIM:

1. A method, comprising: receiving at a user equipment ,UE, from a serving network access node a femto cell proximity assistance information; starting to obtain measurements by the UE of at least one cell in neighborhood of the serving network access node cell based on the femto cell proximity assistance information; selecting the obtained measurements by the UE based on the femto cell proximity assistance information; reporting the selected measurements of the at least one cell in the neighborhood of the serving network access node cell in a measurement report from the UE to the serving network access node for handover decision.

2. Method according to claim 1, further comprising: receiving at the UE a handover command from the serving network access node to perform a handover from the serving network access node cell to a target cell in the neighborhood of the serving network access node cell, wherein the selection of the target cell is based on a match between the selected measurements that are reported and a list of allowed cells in the neighborhood of the serving network access node cell for the UE determined by the serving network access node from a list of at least one allowed identification tag received from a core network node.

3. Method according to claim 1, wherein the femto cell proximity assistance information is received in an RRC reconfiguration message including measurement configuration associated with the measuring of the at least one cell in the neighborhood of the serving network access node cell.

4. Method according to claims 1 to 3 wherein the femto cell proximity assistance information comprises at least one of: a proximity indicator,a list of CAG IDs wherein each CAG ID corresponds to a femto cell or CAG cell, in the neighborhood of the serving network access node cell, a list of PCIs wherein each PCI corresponds to a femto cell or CAG cell, in the neighborhood of the serving network access node cell, a list of reference signal received power signal of a downlink signal ,DL RSRP, or reference signal received power signal ,RSRP, ranges, a list of one or more geographical coordinates of neighbor femto cells or closed access groups CAG cells.

5. Method according to claims 1 to 4, further comprising: starting measurements by the UE of the at least one cell in the neighborhood of the serving network access node cell based on the receiving of the proximity indicator that is part of the femto cell proximity assistance information.

6. Method according to claims 1 to 5, wherein starting measurements by the UE of the at least one cell in the neighborhood of the serving network access node cell is based on receiving a coarse location of the at least one cell in the neighborhood of the serving network access node cell that is part of the femto cell proximity assistance information.

7. Method according to claim 6, wherein the coarse location of the at least one cell in the neighborhood of the serving network access node cell is defined by a range of reference signal received power signals of a downlink signal ,DL RSRP, of the serving cell of the serving network access node.

8. Method according to claim 6 to 7, further comprising: receiving one or more range(s) of DL RSRP in the coarse location; measuring the DL RSRP of the serving network access node cell; determining that the measured DL RSRP of the serving network access node cell matches at least one of the received one or more range(s) of DL RSRP; starting the measurements by the UE of the at least one cell in the neighborhood of the serving network access node cell based on the determining.

9. Method according to claim 6, wherein the coarse location of the at least one cell in the neighborhood of the serving network access node cell is defined by geographical coordinates.

10. Method according to claim 6 and 9, further comprising: receiving one or more geographical coordinates in the coarse location, determining that the position of the UE matches at least one of the received one or more geographical coordinates, starting the measurements of the at least one cell in the neighborhood of the serving network access node cell based on the determining.11 Method according to any of claims 1 to 10, wherein starting measurements by the UE of at least one cell in the neighborhood of the serving network access node cell is performed regardless of the radio condition with the serving network access node cell.

12. Method according to claims 1 to 11, wherein selecting the obtained measurements by the UE further comprising: receiving, within the femto cell proximity assistance information, a list of one or more physical cell identities, PCIs, associated with cells in the neighborhood of the serving network access node cell; reading the PCI of the at least one cell in the neighborhood of the serving network access node cell; selecting the obtained measurements by the UE to be the ones which correspond to cells in the neighborhood of the serving network access node cell whose PCI match at least one PCI of the received list.

13. Method according to claims 1 to 11, wherein selecting the obtained measurements by the UE further comprising: receiving from a core network or within the femto proximity assistance information a list of allowed closed access group IDs ,CAG IDs,, storing the received list of CAG IDs, reading the system information block 1 ,SIB1, of the cells in the neighborhood of the serving network access node cell,selecting the obtained measurements by the UE to be the ones which correspond to the cells in neighborhood of the serving network access node cell which broadcast in SIB1 at least one of the CAG IDs of the received list.

14. Method according to claim 6, further comprising: receiving from the serving network access node, prior to the reception of the femto cell proximity assistance information at the UE, a request to measure and report identification tags of at least one cell in the neighborhood of the serving network access node cell and corresponding DL RSRP of the serving network access node cell, starting measurements by the UE to determine identification tags of the at least one cell in the neighborhood of the serving network access node cell and corresponding DL RSRP of the serving network access node cell; reporting measurements of determined identification tags of the at least one cell in the neighborhood of the serving network access node cell together with DL RSRP of the serving network access node cell from the UE to the serving network access node.

15. Method according to claims 1-14, wherein: the identification tag of the at least one cell in the neighborhood of the serving network access node cell is a physical cell identity ,PCI.

16. Method according to claim 1-14, wherein: the identification tag of the at least one cell in the neighborhood of the serving network access node cell is a closed access group ID ,CAG ID,.

17. Method according to claims 1 to 14 wherein the at least one cell in the neighborhood of the serving network access node cell is a femto cell.

18. Method according to claims 1 to 14 wherein the at least one cell in the neighborhood of the serving network access node cell is a CAG cell.

19. An apparatus, comprisingat least one processor; and at least one memory including instructions that, when executed by the at least one processor, cause the apparatus at least to perform: receiving at a serving network access node at least one identification tag from at least one cell in the neighborhood of the serving network access node; receiving at the serving network access node a connection request of a user equipment ,UE; receiving from a core network a list of at least one allowed identification tag for the UE; transmitting the femto cell proximity assistance information to the UE.

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