Enhancements for beam management

Abstract

Described herein is a UE configured for supporting an ICBM involving a plurality of cells, comprising a source cell serving the UE and at least one neighboring target cell, where the UE comprises: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the UE to at least: transmit, to a first network node supporting at least one of a CU-CP function or a Layer 3 protocol of a radio access network, a measurement report comprising information indicating a target cell of at least one neighboring target cell; and receiving a configuration message from the first network node, the configuration message comprising information indicating a channel state information (CSI) measurement related configuration, the CSI measurement related configuration comprising a CSI resource related configuration typically used for measurement at the cells involved in the ICBM and a cell-specific CSI report related configuration for a subset of the cells, wherein the subset is determined according to the source cell, the subset comprising the source cell and at least one target cell.

Description

Technical Field

[0001] The present disclosure relates to beam management, and more particularly to enhancements to beam measurement and / or beam management configuration for inter-cell mobility. Background Art

[0002] Any discussion of the background art throughout the specification should not be considered as an admission that this art is widely known or forms part of the common general knowledge in the field.

[0003] Broadly speaking, in some existing mobile communication technologies, beam switching / changing may include the following steps: CSI (channel state information) reporting from UE (user equipment) regarding configured CSI resources; and TCI (transmission configuration indication) state changes for control channels (such as physical downlink control channel or PDCCH for short) and data channels (such as physical downlink shared channel or PDSCH for short) based on the CSI report configuration.

[0004] Beam measurement reports can generally be categorized into two main categories, namely:

[0005] CSI reporting related to PMI (precoding matrix index) and PDSCH specific RS (reference signal), which is meant for beam refinement and MIMO (multiple input multiple output)

[0006] (out) operation, and only CSI-RS resources are used for this purpose; and

[0007] CSI reporting for beam switching, which typically involves CSI resource indicator and RSRP (reference signal received power) reporting for the selected resource, and may also be applicable to the SSB (synchronization signal block) of the beam.

[0008] In addition, beam switching is usually triggered by a TCI state change operation. In addition, beam switching for control channels and beam switching / refinement for PDSCH also occur based on TCI state changes. These two types are generally summarized as follows:

[0009] PDCCH TCI state changes:

[0010] Switching of control channel beams due to UE mobility,

[0011] A MAC command (e.g., MAC Control Element (CE)) indicating switching of the TCI state for a CORESET (Control Resource Set); and

[0012] PDSCH TCI state changes:

[0013] · TCI state set for PDSCH configured for beam refinement and MIMO operation,

[0014] The TCI set is selected via the MAC CE, and

[0015] The TCI status within a set is indicated via PDCCH.

[0016] As technology develops, beam management operations can be extended to multiple cells, and in some cases, beam management operations are also referred to as inter-cell beam management (ICBM). Therefore, it is necessary to support such beam management (e.g., dynamic beam switching or ICBM) in an efficient and flexible manner. Summary of the invention

[0017] According to one aspect of the present disclosure, there is provided a user equipment (UE), configured to support inter-cell beam management (ICBM) involving multiple cells, the multiple cells including a source cell serving the UE and at least one neighboring target cell, wherein the UE includes:

[0018] at least one processor; and

[0019] At least one memory stores instructions, which, when executed by at least one processor, cause the UE to at least:

[0020] sending a measurement report including information of a target cell indicating at least one neighboring target cell to a first network node supporting at least one of a central unit control plane (CU-CP) function or a layer 3 (L3) protocol of a radio access network; and

[0021] A configuration message is received from a first network node, the configuration message including information indicating a channel state information (CSI) measurement related configuration, wherein the CSI measurement related configuration includes: a CSI resource related configuration typically used for measurement at a cell involved in ICBM, and a cell-specific CSI report related configuration for a subset of cells, wherein the subset is determined based on a source cell, and wherein the subset includes the source cell and at least one target cell.

[0022] In some examples, the UE is also caused to:

[0023] Perform measurement based on the CSI measurement related configuration; and

[0024] Based on the CSI reporting related configuration corresponding to the source cell, the measurement result is reported to a second network node of the source cell supporting at least one of a distributed unit (DU) function or a layer 2 (L2) protocol of the radio access network.

[0025] In some examples, the UE is also caused to receive a message from a second network node of the source cell indicating a transmission configuration indication (TCI) state corresponding to the target cell, for switching the UE to a beam of the target cell indicated by the TCI state.

[0026] In some examples, the UE is also caused to switch control channel monitoring from the source cell to the target cell.

[0027] In some examples, the UE is also caused to perform measurements based on the CSI measurement-related configuration, and report the results thereof to a second network node of the target cell supporting at least one of a distributed unit (DU) function or a layer 2 (L2) protocol of the radio access network based on the CSI reporting-related configuration corresponding to the target cell.

[0028] In some examples, the UE is also caused to receive a message from a second network node of the target cell indicating a TCI state corresponding to the source cell, for switching the UE back to the beam of the source cell indicated by the TCI state.

[0029] In some examples, the second network node of the source cell and the second network node of the target cell are different network nodes.

[0030] In some examples, a CSI resource-related configuration that is typically used for measurements at a cell is used for beam switching; and wherein the CSI measurement-related configuration also includes a cell-specific CSI resource-related configuration for beam refinement for a subset of cells.

[0031] In some examples, the configuration message also includes a control channel-related TCI state configuration commonly referenced in the cells involved in the ICBM, and a cell-specific data channel-related TCI state configuration for a subset of cells.

[0032] In some examples, the configuration message also includes a cell-specific bitmap associated with a cell-specific CSI reporting-related configuration for a subset of cells.

[0033] In some examples, the configuration message is a radio resource control (RRC) reconfiguration message.

[0034] According to another aspect of the present disclosure, there is provided a first network node, the first network node supporting at least one of a Central Unit Control Plane (CU-CP) function or a Layer 3 (L3) protocol of a radio access network, the first network node being configured to support Inter-Cell Beam Management (ICBM) involving a plurality of cells, the plurality of cells including a source cell serving a user equipment (UE) and at least one neighboring target cell, wherein the first network node comprises:

[0035] at least one processor; and

[0036] At least one memory storing instructions, which when executed by at least one processor, cause the first network node to at least:

[0037] receiving a measurement report from the UE, the measurement report including information of a target cell indicating at least one neighboring target cell;

[0038] generating a configuration message, the configuration message including information indicating a channel state information (CSI) measurement related configuration, wherein the CSI measurement related configuration includes: a CSI resource related configuration commonly used for measurement at a cell involved in ICBM, and a cell-specific CSI report related configuration for a subset of cells, wherein the subset is determined according to a source cell, and wherein the subset includes the source cell and at least one target cell; and

[0039] Send a configuration message to the UE.

[0040] In some examples, the first network node is further caused to:

[0041] sending a first request message including information indicating the ICBM to a second network node of a source cell, the source cell supporting at least one of a distributed unit (DU) function or a layer 2 (L2) protocol of a radio access network; and

[0042] A first response message including information indicating a CSI resource related configuration is received from a second network node of the source cell.

[0043] In some examples, the first network node is further caused to:

[0044] sending a second request message including information indicating the ICBM and information indicating a CSI resource related configuration to a second network node of a target cell, the target cell supporting at least one of a distributed unit (DU) function or a layer 2 protocol of a radio access network; and

[0045] A second response message is received from the second network node of the target cell, the second response message including information indicating a CSI measurement related configuration for the target cell.

[0046] In some examples, the first network node is further caused to:

[0047] sending a third request message to the second network node of the source cell, the third request message including information indicating a CSI measurement related configuration for the target cell; and

[0048] A third response message is received from the second network node of the source cell, the third response message including information indicating a CSI measurement related configuration modified based on the information indicating the CSI measurement related configuration for the target cell.

[0049] In some examples, each of the first request message and the second request message is a respective UE context setup request message; and each of the first response message and the second response message is a respective UE context setup response message.

[0050] In some examples, the third request message is a UE context modification request message; and the third response message is a UE context modification response message.

[0051] In some examples, a CSI resource-related configuration commonly used for measurements at a cell is used for beam switching; and wherein the CSI measurement-related configuration also includes a cell-specific CSI resource-related configuration for beam refinement of a subset of cells.

[0052] In some examples, the configuration message also includes a control channel-related transmission configuration indication TCI state configuration commonly referenced in the cells involved in the ICBM, and a cell-specific data channel-related TCI state configuration for a subset of cells.

[0053] In some examples, the configuration message also includes a cell-specific bitmap associated with a cell-specific CSI reporting-related configuration for a subset of cells.

[0054] In some examples, the configuration message is a radio resource control (RRC) reconfiguration message.

[0055] According to yet another aspect of the present disclosure, there is provided a second network node, the second network node supporting at least one of a distributed unit (DU) function or a layer 2 (L2) protocol of a radio access network, the second network node being configured to support inter-cell beam management (ICBM) involving a plurality of cells, the plurality of cells including a source cell of the second network node serving a user equipment (UE) and at least one neighboring target cell, wherein the second network node comprises:

[0056] at least one processor; and

[0057] At least one memory storing instructions, which when executed by at least one processor, cause the second network node to at least:

[0058] receiving a first request message from a first network node supporting at least one of a Central Unit Control Plane (CU-CP) function or a Layer 3 (L3) protocol of a radio access network, the first request message comprising: information indicating a channel state information (CSI) measurement related configuration of a target cell for at least one neighboring target cell;

[0059] generating a first response message, the first response message comprising: information indicating a CSI measurement related configuration modified based on received information indicating a CSI measurement related configuration for a target cell, wherein the CSI measurement related configuration comprises: a CSI resource related configuration commonly used for measurement at a cell involved in ICBM, and a cell-specific CSI report related configuration for a subset of cells, wherein the subset is determined according to a source cell, and wherein the subset comprises the source cell and at least one target cell; and

[0060] A first response message is sent to the first network node.

[0061] In some examples, the second network node is further caused to:

[0062] receiving, from the first network node, a second request message including information indicating the ICBM; and

[0063] A second response message including information indicating CSI resource related configuration is sent to the first network node.

[0064] In some examples, the second network node is further caused to send a configuration message including information indicating transmission configuration indication (TCI) state information for cells involving ICBM.

[0065] In some examples, the second network node is further caused to:

[0066] receiving, from the UE, a report of measurements performed based on a CSI reporting related configuration corresponding to the source cell; and

[0067] A configuration message is sent, the configuration message including information indicating TCI state information for another subset of cells involved in the ICBM, wherein the another subset of cells is determined based on the target cell.

[0068] In some examples, the second network node is further caused to send a message to the UE indicating a transmission configuration indication (TCI) state corresponding to the target cell, for switching the UE to a beam of the target cell indicated by the TCI state.

[0069] In some examples, the first request message is a UE context modification request message; and the first response message is a UE context modification response message.

[0070] In some examples, the second request message is a UE context setup request message; and the first response message is a UE context setup response message.

[0071] According to yet another aspect of the present disclosure, there is provided a method of a user equipment (UE), configured to support inter-cell beam management (ICBM) involving multiple cells, the multiple cells including a source cell serving the UE and at least one neighboring target cell, the method comprising:

[0072] sending a measurement report including information of a target cell indicating at least one neighboring target cell to a first network node supporting at least one of a central unit control plane (CU-CP) function or a layer 3 (L3) protocol of a radio access network; and

[0073] A configuration message is received from a first network node, the configuration message including information indicating a channel state information (CSI) measurement related configuration, wherein the CSI measurement related configuration includes a CSI resource related configuration generally used for measurement at a cell involved in ICBM, and a cell-specific CSI report related configuration for a subset of cells, wherein the subset is determined based on a source cell, and wherein the subset includes the source cell and at least one target cell.

[0074] According to yet another aspect of the present disclosure, there is provided a method of a first network node supporting at least one of a Central Unit Control Plane (CU-CP) function or a Layer 3 (L3) protocol of a radio access network, the first network node being configured to support Inter-Cell Beam Management (ICBM) involving a plurality of cells, the plurality of cells including a source cell serving a user equipment (UE) and at least one neighboring target cell, the method comprising:

[0075] receiving a measurement report from the UE, the measurement report including information of a target cell indicating at least one neighboring target cell;

[0076] generating a configuration message including information indicating a channel state information (CSI) measurement related configuration, wherein the CSI measurement related configuration includes a CSI resource related configuration commonly used for measurement at a cell involved in ICBM, and a cell-specific CSI report related configuration for a subset of cells, wherein the subset is determined according to a source cell, and wherein the subset includes the source cell and at least one target cell; and

[0077] Send a configuration message to the UE.

[0078] According to yet another aspect of the present disclosure, a method of a second network node supporting at least one of a distributed unit (DU) function or a layer 2 (L2) protocol of a radio access network is provided, the second network node being configured to support inter-cell beam management (ICBM) involving a plurality of cells, the plurality of cells including a source cell of the second network node serving a user equipment (UE) and at least one neighboring target cell, the method comprising:

[0079] receiving a first request message from a first network node supporting at least one of a central unit control plane (CU-CP) function or a layer 3 (L3) protocol of a radio access network, the first request message including information indicating a channel state information (CSI) measurement related configuration of a target cell for at least one neighbor target cell;

[0080] generating a first response message, the first response message comprising: information indicating a CSI measurement related configuration modified based on received information indicating a CSI measurement related configuration for a target cell, wherein the CSI measurement related configuration comprises a CSI resource related configuration commonly used for measurement at a cell involved in ICBM, and a cell-specific CSI report related configuration for a subset of cells, wherein the subset is determined according to a source cell, and wherein the subset comprises the source cell and at least one target cell; and

[0081] A first response message is sent to the first network node.

[0082] Furthermore, according to some example embodiments, a UE is provided, comprising corresponding suitable components configured to perform corresponding steps disclosed in the present disclosure.

[0083] Similarly, according to some example embodiments, there is also provided a CU and a DU, comprising corresponding suitable components configured to perform the corresponding steps as disclosed in the present disclosure.

[0084] In addition, according to some other example embodiments, for example, a computer program product for a wireless communication device is provided, the wireless communication device comprising at least one processor, comprising a software code portion for performing the corresponding steps disclosed in the present disclosure when the product is run on the device. The computer program product may include a computer-readable medium, and the software code portion is stored on the medium. In addition, the computer program product can be directly loaded into the internal memory of the computer and / or can be sent via a network through at least one of an upload, download and push process.

[0085] Although some example embodiments will be described herein with particular reference to the above-mentioned applications, it will be appreciated that the present disclosure is not limited to such fields of use and is applicable in a wider context.

[0086] It is worth noting that it should be understood that the method according to the present disclosure relates to a method of operating an apparatus according to the above-described example embodiments and variations thereof, and that corresponding statements made about the apparatus are equally applicable to the corresponding method, and vice versa, such that similar descriptions may be omitted for the sake of brevity. In addition, even if not explicitly disclosed, the above aspects may be combined in a variety of ways. Those skilled in the art will appreciate that the combination of these aspects and features / steps is possible unless it produces a contradiction that is explicitly excluded.

[0087] Implementation of the disclosed apparatus may include the use of, but is not limited to, one or more processors, one or more application specific integrated circuits (ASICs), and / or one or more field programmable gate arrays (FPGAs). Implementation of the apparatus may also include the use of other conventional and / or custom hardware, such as a software programmable processor, such as a graphics processing unit (GPU) processor.

[0088] Other and further example embodiments of the present disclosure will become apparent during the course of the following discussion and with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0089] Example embodiments of the present disclosure will now be described, by way of example only, with reference to the accompanying drawings, in which:

[0090] Figure 1 schematically illustrates an example of a high level block diagram of a CSI (channel state information) measurement (correlation) configuration according to an example embodiment of the present disclosure;

[0091] Figure 2 schematically illustrates an example of a signaling / message flow diagram according to an example embodiment of the present disclosure;

[0092] Figure 3 schematically illustrates an example of a high level block diagram of a CSI (channel state information) measurement (correlation) configuration according to another example embodiment of the present disclosure;

[0093] Figure 4 schematically illustrates an example of a high level block diagram of a modified TCI (Transmission Configuration Indication) state configuration according to an example embodiment of the present disclosure; and

[0094] Figure 5 An example of a signaling / message flow diagram according to another example embodiment of the present disclosure is schematically shown. DETAILED DESCRIPTION

[0095] In the following, different exemplary embodiments will be described using a communication network architecture based on 3GPP standards (such as 5G / NR) as an example of a communication network to which the embodiments can be applied, but the embodiments are not limited to such an architecture. It is obvious to those skilled in the art that these embodiments can also be applied to other types of communication networks in which the mobile communication principles are integrated with D2D (device to device) or V2X (vehicle to everything) configurations, such as SL (side link). Wi-Fi, Worldwide Interoperability for Microwave Access (WiMAX), Personal Communications Service (PCS), Wideband Code Division Multiple Access (WCDMA), systems using ultra-wideband (UWB) technology, mobile ad hoc networks (MANET), wired access, etc. In addition, without loss of generality, the description of examples of some embodiments is related to mobile communication networks, but the principles of the present disclosure can be extended and applied to any other type of communication network, such as a wired communication network.

[0096] The following examples and embodiments should be understood as illustrative examples only. Although the specification may refer to "an", "one" or "some" examples or embodiments in multiple places, this does not necessarily mean that each such reference is related to the same (multiple) examples or (multiple) embodiments, or that the feature applies only to a single example or embodiment. Individual features of different embodiments may also be combined to provide other embodiments. In addition, the terms "comprising" and "including" should be understood as not limiting the embodiments to only the features mentioned; these examples and embodiments may also include features, structures, units, modules, etc. that are not specifically mentioned.

[0097] The basic system architecture of a (telecommunication) communication network including a mobile communication system to which examples of some embodiments are applicable may include the architecture of one or more communication networks, including (multiple) radio access network subsystems and (multiple) core networks. Such an architecture may include one or more communication network control elements or functions, access network elements, radio access network elements, access service network gateways or base station transceiver stations, such as base stations (BS), access points (AP), NodeBs (NBs), eNBs or gNBs, distributed units (DUs) or centralized / central units (CUs), which control the corresponding coverage area or (multiple) cells, and one or more communication stations (such as communication elements or functions, such as user equipment or terminal equipment, such as user equipment (UE), or another device with similar functions, such as a modem chipset, chip, module, etc., which may also be part of a station, element, function or application capable of communication, such as a UE, an element or function that can be used for a machine-to-machine communication architecture, or as a separate element attached to such an element, function or application capable of communication, etc.) utilizing its ability to communicate via one or more communication beams via one or more channels to send several types of data in multiple access domains. Furthermore, core network elements or network functions such as gateway network elements / functions, mobility management entities, mobile switching centers, servers, databases, etc. may be included.

[0098] The following description may provide further details of alternatives, modifications and variants: The gNB includes, for example, a node that provides NR user plane and control plane protocol terminations towards the UE and is connected to the 5GC via an NG interface, for example in accordance with 3GPP TS 38.300 V16.6.0 (2021-06) section 3.2 incorporated by reference.

[0099] The gNB Central Unit (gNB-CU) includes, for example, logical nodes hosting, for example, RRC, SDAP and PDCP protocols of the gNB or RRC and PDCP protocols of the en-gNB, which controls the operation of one or more gNB-DUs. The gNB-CU terminates the F1 interface connected to the gNB-DU.

[0100] The gNB distributed unit (gNB-DU) includes logical nodes such as the RLC, MAC, and PHY layers that host the gNB or en-gNB, and its operation is partially controlled by the gNB-CU. One gNB-DU supports one or more cells. One cell is supported by only one gNB-DU. The gNB-DU terminates the F1 interface connected to the gNB-CU.

[0101] The gNB-CU control plane (gNB-CU-CP) includes logical nodes that host, for example, the control plane part of the RRC and PDCP protocols of the gNB-CU of an en-gNB or gNB. The gNB-CU-CP terminates the E1 interface with the gNB-CU-UP and the F1-C interface with the gNB-DU.

[0102] The gNB-CU-User Plane (gNB-CU-UP) includes, for example, a logical node hosting, for example, the user plane part of the PDCP protocol of the gNB-CU of the en-gNB and the user plane parts of the PDCP protocol and the SDAP protocol of the gNB-CU of the gNB. The gNB-CU-UP terminates the E1 interface connected to the gNB-CU-CP and the F1-U interface connected to the gNB-DU, for example according to section 3.1 of 3GPP TS 38.401 V16.6.0 (2021-07) incorporated by reference.

[0103] Different functional splits between central and distributed units are possible, for example, known as options:

[0104] Option 1 (similar split to 1A):

[0105] The functional split in this option is similar to the 1A architecture in DC. RRC is located in the central unit. PDCP, RLC, MAC, physical layer, and RF are located in the distributed unit.

[0106] Option 2 (similar to 3C split):

[0107] The functional split in this option is similar to the 3C architecture in DC. RRC and PDCP are located in the central unit. RLC, MAC, physical layer, and RF are located in the distributed unit.

[0108] Option 3 (RLC internal split):

[0109] • Low RLC (part of the RLC functions), MAC, physical layer and RF are located in the distributed unit. PDCP and High RLC (another part of the RLC functions) are located in the central unit.

[0110] Option 4 (RLC-MAC Split):

[0111] MAC, physical layer and RF are located in the distributed unit. PDCP and RLC are located in the central unit.

[0112] Or, for example, according to 3GPP TR 38.801 V14.0.0 (2017-03) section 11, incorporated by reference.

[0113] gNB supports different protocol layers, such as Layer 1 (L1) - physical layer.

[0114] Layer 2 (L2) of NR is divided into the following sublayers: Medium Access Control (MAC), Radio Link Control (RLC), Packet Data Convergence Protocol (PDCP), and Service Data Adaptation Protocol (SDAP), where for example:

[0115] The physical layer provides transport channels for the MAC sublayer;

[0116] The MAC sublayer supplies logical channels to the RLC sublayer;

[0117] The RLC sublayer supplies RLC channels to the PDCP sublayer;

[0118] The PDCP sublayer supplies radio bearers to the SDAP sublayer;

[0119] The SDAP sublayer provides 5GC QoS flows;

[0120] Comp. refers to header compression and Segm. refers to segmentation;

[0121] Control channels include (BCCH, PCCH).

[0122] Layer 3 (L3) includes, for example, Radio Resource Control (RRC), for example according to 3GPP TS 38.300 V16.6.0 (2021-06) part 6, incorporated by reference.

[0123] A RAN (Radio Access Network) node or network node, such as, for example, a gNB, a base station, a gNB CU or a gNB DU or a part thereof, may be implemented using, for example, a device having at least one processor and / or at least one memory with computer-readable instructions (computer program) configured to support and / or provide and / or process CU and / or DU related functions and / or features, and / or at least one protocol (sub)layer of a RAN (Radio Access Network), such as layer 2 and / or layer 3.

[0124] The gNB CU and gNB DU parts may, for example, be co-located or physically separated. The gNB DU may even be further split, for example, into two parts, for example, one part including a processing device and one part including an antenna. The central unit (CU) may also be referred to as BBU / REC / RCC / C-RAN / V-RAN, O-RAN or a part thereof. The distributed unit (DU) may also be referred to as RRH / RRU / RE / RU or a part thereof. Hereinafter, in various example embodiments of the present disclosure, the CU-CP (or more generally CU) may also be referred to as a (first) network node supporting at least one of the central unit control plane functions or the layer 3 protocols of the radio access network; similarly, the DU may be referred to as a (second) network node supporting at least one of the distributed unit functions or the layer 2 protocols of the radio access network.

[0125] A gNB-DU supports one or more cells and can thus be used, for example, as a serving cell for a user equipment (UE).

[0126] User equipment (UE) may include a wireless or mobile device, a device with a radio interface to interact with a RAN (Radio Access Network), a smartphone, an in-vehicle device, an IoT device, an M2M device, etc. Such a UE or device may include: at least one processor; and at least one memory, including computer program code; wherein the at least one memory and the computer program code are configured to, together with the at least one processor, cause the device to perform at least certain operations, such as, for example, an RRC connection with the RAN. The UE is configured to generate a message (e.g., including a cell ID) to be sent to the RAN via radio (e.g., to arrive at a serving cell and communicate with it). The UE may generate, send and receive an RRC message containing one or more RRC PDUs (packet data units).

[0127] The UE may have different states (e.g., according to 3GPP TS 38.331 V16.5.0 (2021-06) sections 42.1 and 4.4, incorporated by reference).

[0128] When the RRC connection has been established, the UE is in, for example, the RRC_CONNECTED state or the RRC_INACTIVE state.

[0129] In the RRC_CONNECTED state, the UE can:

[0130] Store AS context;

[0131] ·Transmit unicast data to / from UE;

[0132] · monitoring a control channel associated with a shared data channel to determine whether data is scheduled for the data channel;

[0133] Provide channel quality and feedback information;

[0134] Perform neighbor cell measurements and measurement reporting.

[0135] The RRC protocol includes the following main functions:

[0136] RRC connection control;

[0137] Measurement configuration and reporting;

[0138] Establishment / modification / release of measurement configurations (e.g. intra-frequency, inter-frequency and inter-RAT measurements);

[0139] ·Measure the establishment and release of the gap;

[0140] Measurement report.

[0141] The general functionality and interconnection of the elements and functions (also depending on the actual network type) are known to those skilled in the art and are described in the corresponding specifications, and therefore, for the sake of brevity, their detailed description may be omitted herein. However, it should be noted that in addition to the elements, functions or applications described in detail below, several additional network elements and signaling links may be employed for communication to or from the elements, functions or applications, such as communication endpoints, communication network control elements (such as servers, gateways, radio network controllers) and other elements of the same or other communication networks.

[0142] The communication network architecture as considered in the example embodiments may also be able to communicate with other networks such as a public switched telephone network or the Internet. The communication network may also support the use of cloud services for virtual network elements or their functions, wherein it should be noted that the virtual network portion of the telecommunications network may also be provided by non-cloud resources (e.g., an internal network, etc.). It should be understood that the network elements and / or corresponding functions of the access system, core network, etc. may be implemented using any node, host, server, access node or entity, etc. suitable for such use. Typically, the network functions may be implemented as network elements on dedicated hardware, as software instances running on dedicated hardware, or as virtualized functions instantiated on an appropriate platform (e.g., a cloud infrastructure).

[0143] In addition, network elements (such as communication elements, such as UE, terminal equipment), control elements or functions (such as access network elements, such as base stations / BS, gNB, radio network controllers), core network control elements or functions (such as gateway elements) or other network elements or functions (as described herein) and any other elements, functions or applications may be implemented by software (e.g., by a computer program product for a computer) and / or by hardware. In order to perform their corresponding processing, the correspondingly used devices, nodes, functions or network elements may include several components, modules, units, components, etc. (not shown) required for control, processing and / or communication / signaling functions. Such components, modules, units and components may include, for example, one or more processors or processor units, including one or more processing parts for executing instructions and / or programs and / or for processing data, storage or memory units or components for storing instructions, programs and / or data, for use as a work area of ​​a processor or processing part, etc. (e.g. ROM, RAM, EEPROM, etc.), input or interface components for inputting data and instructions by software (e.g. floppy disk, CD-ROM, EEPROM, etc.), user interfaces for providing monitoring and operation possibilities for users (e.g. screen, keyboard, etc.), other interfaces or components for establishing links and / or connections under the control of the processor unit or part (e.g. wired and wireless interface components, radio interface components including, for example, antenna units, etc., components for forming a radio communication part, etc.), etc., wherein the corresponding components forming the interface (such as the radio communication part) may also be located at a remote site (e.g. a radio head or a radio station, etc.). It should be noted that in this specification, a processing part should not be regarded as representing only a physical part of one or more processors, but should be regarded as a logical division of the indicated processing tasks performed by one or more processors. It should be understood that according to some examples, a so-called "fluid" or flexible network concept may be adopted, wherein the operations and functions of a network element, a network function, or another entity of the network may be performed in a flexible manner in different entities or functions (such as nodes, hosts, or servers). In other words, the "division of labor" between the network elements, functions, or entities involved may vary from case to case.

[0144] As mentioned above, the present disclosure generally seeks to provide an efficient and flexible beam management mechanism to support, for example, (dynamic) beam switching or ICBM use cases.

[0145] According to a broad aspect, the idea of ​​ICBM can generally be understood as utilizing a so-called "borrowed" beam of a (target) cell that is different from the source / serving cell. The (target) cell can be the same serving DU of (operated by) the source / serving cell or a different DU other than the serving DU, so in some cases they can be referred to as intra-DU ICBM or inter-DU ICBM respectively. In some possible cases, the UE can be connected to the serving DU, and while traversing the cell, it may experience good measurements from another cell (e.g., of another DU), which may be a coverage island within the serving cell or an area overlapping with the serving cell (e.g., at the edge of the serving cell). The connection with the serving cell may, for example, still be good, but the connection with the other cell is / becomes better. In this case, the UE can be served by a borrowed beam of a non-serving DU ("borrowed" means that the UE can be instructed to communicate with a beam from another cell without a serving cell change) without performing a complete (conventional) handover to another cell, so no additional RRC signaling overhead and interruption time are observed compared to a (conventional) handover.

[0146] When beam management is to be extended for ICBM operation, the CSI (channel state information) measurement configuration and TCI (transmission configuration indication) state for PDCCH and PDSCH will have to be modified to include (multiple) target cells that are close to or adjacent to the UE's current serving cell. It is worth noting that, unless otherwise stated, in the context of the present disclosure, the CSI measurement (related) configuration can generally be divided / classified into two (sub) configuration sets, namely: a configuration set related to CSI resource configuration (e.g., specifying which type of reference signal is to be sent thereon) and another configuration set related to CSI reporting / reporting configuration (e.g., related to the configuration of CSI reporting behavior, such as periodic, semi-persistent or non-periodic reporting, etc.). However, as can be understood and appreciated by those skilled in the art, the CSI measurement (related) configuration may also include any other suitable configuration, depending on various implementations and / or requirements.

[0147] Specifically, the following problems may arise when the above configuration is to be extended to include resources of multiple cells (depending on various implementations, this may include a source cell currently serving the UE, and one or more target cells adjacent to the UE's serving cell, which are configured to support ICBM operations).

[0148] First, if the CSI reporting related configuration is kept common between cells associated with ICBM, the (multiple) target cells may need to reserve resources for reporting at the same location (e.g., control channels (such as PUCCH) and / or data channels (such as PUSCH)), which may affect the current scheduling of the (multiple) target cells.

[0149] Second, extending the configuration to include all possible configurations of target cell(s) would appear redundant from a signaling perspective and would thus create overhead from a UE perspective.

[0150] Third, the modification of beam management related configurations to achieve efficient beam switching operation without affecting the cell-specific beam refinement operation within the same cell also seems to need to be considered.

[0151] In view of this, the present disclosure generally proposes an apparatus (such as a UE, DU, CU, etc.) and a corresponding method to address some or all of the above comments in a particularly efficient and flexible manner. In particular, in a broad sense, it can be seen that the present disclosure generally attempts to propose a solution to identify, for example, CSI resources and / or CSI reporting configurations applicable to one or more specific cells in a CSI measurement configuration, so as to selectively use a "resource / report subset" particularly depending on the current serving cell.

[0152] Before describing in detail the exemplary embodiments of the present disclosure, it is also worthwhile to provide a brief description from a high / abstract level perspective, which can serve as a basis for understanding the possible underlying technologies (and the terms used therein) described in the present disclosure. However, as described above, the techniques described in the present disclosure can be applicable to some other possible technologies, such as making appropriate / proper adjustments when necessary, as can be understood and appreciated by those skilled in the art.

[0153] In particular, as exemplarily described above, within the technical context of a radio network architecture for New Radio (NR), a gNB, which is a radio network controller component of an NR / 5G system, may be implemented in two (separate) units, generally referred to as a central unit (CU) and a distributed unit (DU). More specifically, the CU generally handles higher layer functions of the radio interface, such as radio resource signaling and radio resource management (RRM). In addition, for the user plane (UP), higher layers such as PDCP may also be hosted in the unit. On the other hand, the DU generally handles lower layer functions, including, for example, radio link control (RLC) and media access control (MAC) as well as physical layer functions. Specifically, the DU may support lower layer processing for multiple (i.e., more than one) NR cells according to various implementations and / or requirements, and the UE is generally unaware of the differences between cells of the same DU or different DUs.

[0154] (Conventional) techniques related to serving cell change (SCC) may include, but are not limited to, (conventional) handover procedures and SCC using lower layer mobility. In particular, the procedure of SCC using lower layer mobility is generally considered to be similar to handover or conditional handover, except that the handover execution is generally performed based on L1 measurements. In contrast, in the case of SCC using lower layer mobility, the "handover" (from the serving cell to the target cell) is performed based on a MAC CE from the serving DU, which contains TCI state change information / indication corresponding to the target cell, the configuration of which has been provided by the higher layers for execution. In addition, similar to the conventional (involving higher layers) handover procedure, the MAC and RLC layers need to be reset to restart operation at the corresponding layers. In addition, in this case, the UE may need to apply the target cell configuration on the current cell configuration, and after applying the new configuration, if this reconfiguration requires the synchronous use of the new configuration, a random access procedure is further triggered.

[0155] In contrast, target cell configuration and handover preparation are typically not involved in ICBM. Instead, the target cell provides (multiple) "secondary cell" operation and typically acts as an extended ("borrowed") beam for the serving cell. Therefore, when the UE switches to a new cell beam, the UE typically only switches the TCI state, so the UE does not need to modify its RRC configuration during the beam switch. In addition, higher layer data transmission is also not affected, i.e., there is no need to reset the MAC and RLC layers. However, it should be noted that since the L1 measurement results are typically based on instantaneous measurements, the ICBM process will also allow returning to the source cell in a seamless manner similar to the (traditional) intra-cell beam management process. Therefore, in some cases, ICBM can also be referred to as dynamic switching ICBM or simply dynamic switching.

[0156] Furthermore, with respect to ICBM, and more specifically with respect to its relevance for inter-DU communications, it should be noted that, as described above, ICBM generally extends the (conventional) beam management mechanism present within the same cell (i.e., intra-cell beam management) so that neighboring cell beams can also be used for beam management operations. Hereinafter, unless otherwise specified, these (neighboring) cells are generally referred to as target cells in the present disclosure. Specifically, as described above, ICBM may be limited to cells of the same DU, or, depending on various implementations and / or requirements, may also be extended to cells of (multiple) other DUs, which may be correspondingly classified as intra-DU (i.e., within the same DU) ICBM and inter-DU (i.e., involving multiple DUs) ICBM.

[0157] Reference is now made to the drawings. In particular, it should be noted that unless otherwise specified, the same or similar reference numerals used in the drawings of the present disclosure may indicate the same or similar elements, so that repeated descriptions thereof may be omitted for the sake of brevity.

[0158] Figure 1 An example of a high-level block diagram of a (modified) CSI (channel state information) measurement (related) configuration according to an example embodiment of the present disclosure is schematically shown. For example, in some possible implementations, the block diagram may represent a configuration that may be used (e.g., as part of an information element / IE) to be transmitted between various network elements (e.g., CU, DU, UE, etc.) in certain high-level messaging (e.g., as part of an RRC (radio point resource control) reconfiguration message, etc.).

[0159] In a broad sense, Figure 1 The illustrated example embodiments may generally be viewed as implementing a CSI measurement configuration (modified compared to the prior art) that includes a common CSI resource related configuration and a cell-specific CSI report related configuration.

[0160] Specifically, Figure 1 As shown, an exemplary (overall) CSI measurement configuration 100 includes a CSI resource-related configuration 110, which is typically used for measurements at cells (all or a subset thereof) involved in the ICBM process. In addition, the CSI measurement configuration 100 also includes a cell-specific CSI report / report-related configuration for a subset of cells. In some possible implementations, the cells in the subset may be determined (e.g., by a CU) based on the (current) source cell, for example, based on the overall topology of the cell, the configuration of the cell (e.g., operation), neighboring cells of the current source cell, etc. In other words, when the UE is served by a new cell (e.g., due to mobility or beam switching), the subset of cells for preparing / generating CSI report-related configurations may be determined based on the new source / serving cell (rather than the previous one). Depending on various implementations, the subset may include at least a source cell 120 and at least one (potential) target cell 130, as well as other possible / potential cells that also participate in the ICBM process. It is worth noting that by providing different reporting configurations for the source cell and the target cell(s), in general, the target cell(s) may be configured with a different (cell-specific) reporting configuration (e.g., different uplink resources) than the source cell. In other words, the target cell(s) do not necessarily need to maintain a common CSI reporting related configuration between cells associated with ICBM, thereby avoiding possible impact on the current scheduling of the target cell(s).

[0161] As can be understood and appreciated by those skilled in the art, in general, the term CSI resource-related configuration can be regarded as specifying which type of reference signal the UE should measure and include it in the CSI report to be sent. Therefore, in some possible implementations, the CSI resource-related configuration can also be referred to as CSI-RS (reference signal) resource (related) configuration. It can also configure the type of transmission (e.g., periodic, aperiodic or semi-persistent). On the other hand, the term CSI report configuration can be regarded as specifying which CSI RS resources are measured and reported from the configured resource set. The CSI report configuration can also include uplink resource configurations on how the CSI report is transmitted to the base station. Typically, a mapping table between the measurement type and the corresponding CSI resource configuration identifier (ID) is also defined. In addition, the CSI report configuration can also provide other suitable configurations / (multiple) parameters for, for example, codebook configuration, time domain behavior, frequency granularity for CQI and PMI, measurement restriction configuration, and CSI-related quantities to be reported by the UE, such as layer indicator (LI), L1-RSRP, etc.

[0162] It is worth noting that in Figure 1 In the example embodiments shown, it is generally assumed that only two cells (i.e., represented as a source cell and a target cell) are present in the operation of the ICBM. However, as can be understood and appreciated by those skilled in the art, in some other possible implementations, more cells may also be present in the ICBM, which may include (but of course not limited to) a source cell and one or more (potential) target cells. In such a case, the cells do not necessarily need to be named "source" or "target", but can be referred to by simply using numbers, such as cell 1, cell 2, cell 3, etc. Therefore, depending on various implementations and / or requirements, there may be instances for such a cell-specific CSI reporting configuration for the target cell 130. Of course, in some other possible implementations, for example, Figure 1 The single instance of the cell-specific CSI reporting configuration for the target cell 130 shown may itself include all necessary information for all target cells, as may be understood and appreciated by those skilled in the art.

[0163] Now, the message sequence for the signaling procedure for activating the cell specific reporting configuration together with the TCI status management within the network will be referred to below. Figure 2 In particular, it should be noted that in Figure 2In the example embodiments shown, it is generally assumed that the source cell is located at the source DU (or in other words, under the control of the source DU), while the (adjacent) target cell resides at the target DU (or in other words, under the control of the target DU). In some cases, the source cell / DU may also be referred to as a serving cell / DU, as can be understood and appreciated by those skilled in the art. However, as described above, the deployment of the source / target cell and / or source / target DU may not always be the case. For example, in some possible implementations, both the source cell and the target cell may be under the control of the source DU only. Of course, as can be understood and appreciated by those skilled in the art, depending on various implementations and / or requirements, any other suitable configuration is also possible (of course with appropriate adjustments to the signaling / messages).

[0164] Broadly speaking, in steps S201-S205, the UE connects (exemplarily indicated as "RRC connection activated" in step S201) to a source cell (or simply referred to as cell 1, not explicitly shown in the figure), which is under the control of the source DU, and reports (among other things) the target cell (or simply referred to as cell 2) to the CU in its measurements (step S202). In response, the CU obtains the CSI resource configuration from the source DU (e.g., by sending a UE context setup request message, as shown in step S203, or by using any other suitable method), and once a corresponding response message (e.g., a UE context setup response message as shown in step S204, etc.) is received, it is forwarded to the target DU (where the target cell resides) with a flag indicating "dynamic switching" or "ICBM" (step S205). As can be understood and appreciated by those skilled in the art, the flag can be implemented using any suitable means, for example, as a (new or existing) field, as an entry in a lookup table (LUT), as a predefined / predetermined parameter, etc. Thus, any suitable flag may be used, for example, in addition to those in the examples above (i.e., "dynamic switching" or "ICBM"). In addition, it is worth mentioning that, in some possible implementations, the term "dynamic switching" (or sometimes also referred to as the term "ICBM") may generally mean the possibility for the UE to switch its (beam's) operation from the source cell (current serving cell) back and forth to the neighboring target cell, depending on various circumstances and / or criteria (e.g., received signal power before and after beam switching, etc.).

[0165] Subsequently, in steps S205-S206, the target DU (e.g., after receiving another UE context setup request message as shown in step S205 or any other suitable message) merges the CSI resource configuration corresponding to the target cell (prepared by the target DU for ICBM) into the received CSI resource configuration provided by the source DU. The target DU also generates (e.g., by appending or using any other suitable means) a report configuration mapped to the CSI of the target cell and sends it to the CU (e.g., in a corresponding context setup response message as shown in step S206 or any other suitable message).

[0166] Furthermore, in steps S207-S208, the CU updates the source DU with the modified CSI measurement configuration updated by the target DU, as described above. This can be achieved, for example, by exchanging a pair of UE context modification request and response messages between the CU and the source DU, such as Figure 2 or in any other suitable manner.

[0167] In step S209, the CU prepares an RRC reconfiguration message (or any other suitable message depending on various implementations), in which the cell-specific bitmap points to the cell-specific configuration for each of the source cell and the target cell. Of course, as can be understood and appreciated by those skilled in the art, any other suitable implementation (e.g., other data formats / structures other than bitmaps, such as pointers, LUTs, etc.) may be used to provide such an association for the cell-specific reporting configurations for the source cell and the target cell. In addition, it should be noted that, as Figure 2 As exemplarily shown in FIG, the RRC reconfiguration message may also include the CSI resource configuration that has been modified by the source DU in step S208, etc. As can be understood and appreciated by those skilled in the art, depending on various implementations, the modification may include but is not limited to encoding and / or encapsulating the CSI resource configuration (prepared by the target DU or CU) into a different format, form or data structure (e.g., "CellGroupConfig" shown in step S208).

[0168] Furthermore, steps S210 and S213 generally describe two options / possibilities (which may be used together or as alternatives, depending on various implementations and / or requirements) to support sending a merged TCI state configuration for ICBM operation, as the entire set of cells (step S210) or a subset thereof (step S213), which is generally determined by the (present or even potentially future) source / serving DU, depending on various implementations and / or requirements (e.g., distance between the two cells, received signal power, etc.). For example, in some possible implementations, the decision to send an indication on a subset of cells in the TCI state configuration may be determined based on measurements (e.g., layer 1 / L1 measurements, such as reference signal received power (RSRP), etc.), as shown in step S212, where the UE sends a corresponding report using the serving cell reporting configuration (step S211). As an illustrative example (but not as any kind of limitation), assuming that there are a total of 5 cells (indicated by using numbers 1 to 5) involved in or participating in ICBM, and cell 1 is currently being used as a source cell (so cells 2 to 5 are target cells at the time), the source DU (of cell 1) may decide to switch to cell 2 (the current target cell) (for example, based on a measurement report from a UE, such as L1-RSRP). At this time, the source DU may further determine (for example, based on the measurement report or by using any other suitable method) that cells 3 and 4 appear to be close to the vicinity of cell 2 (so that once cell 2 becomes a "source cell" after the current beam switching operation, cells 3 and 4 can be considered as potential "target cells"). Therefore, the current source DU (of cell 1) can select and prepare to select from a total of 5 cells in the TCI state configuration (in this illustrative example, cells 2, 3 and 4) and prepare to send an indication of a subset of cells to the target DU (of the current target cell, that is, cell 2 in this illustrative example). Of course, as can be understood and appreciated by those skilled in the art, any other suitable implementation may also be adopted, depending on various circumstances. In some possible implementations, normal F1 procedures (e.g., UE context modification request from serving DU to CU-CP (central unit control plane) and UE context modification request from CU-CP to target DU) may be used here. Alternatively, in some other possible implementations, a control PDU indicating an index of a previously shared TCI state configuration may also be used. Of course, any other suitable (existing or new) (multiple) procedures / (multiple) processes may also be used, as may be understood and appreciated by those skilled in the art.

[0169] Subsequently, in steps S214-S215, in particular when a TCI state switch to a target cell is indicated (e.g., in the MAC CE illustrated in step S214), the UE updates the report configuration switch using the bitmap, but continues to use the previous "merged" CSI resource configuration as described above (step S215). It is worth noting that, as can be understood and appreciated by those skilled in the art, in some possible implementations, the UE may, for example, be configured with a measurement configuration related to one or more beams in the target cell, so that according to the measurement report (e.g., performed for one or more beams in step S212), the TCI state change information / message in step S214 may indicate a specific beam in the target cell to which the UE switches.

[0170] In steps S216-S218, in the event that the UE is to handover back to the source cell (this is supported by the "dynamic handover" functionality previously enabled in step S205), then the UE may perform such a handover by updating the reporting configuration using the bitmap, but continuing to use the previous "merged" CSI resource configuration which is now based on the source cell rather than the target cell. More specifically, if Figure 2 As shown in the example of , the UE switches its monitoring of the control channel (e.g., PDCCH (Physical Downlink Control Channel), etc.) from the source cell to the target cell (step S216), and in step S217 (similar to the above) reports the L1-RSRP (or any other suitable form) measurement to the target DU (of the target cell) by using the uplink resources of the target cell (e.g., PUSCH (Physical Uplink Shared Channel), PUCCH (Physical Uplink Control Channel), etc.), but this time indicates the earlier source cell as a potential target cell (e.g., with a better signal). In response to the measurement report, the target DU may send a corresponding message indicating a TCI state change corresponding to the earlier source cell in step S218, or in some possible implementations, send to a specific beam of the earlier source cell (e.g., by using MAC CE, etc.). As a result, the UE switches back to the CSI reporting configuration of the previous source cell as before.

[0171] In summary, reference Figure 1 and 2The example embodiments described can generally be viewed as proposing the use of cell-specific reporting configurations in CSI measurement configurations (but resource configurations are maintained as common across all cells) and short TCI subset maintenance for ICBM operation. More specifically, there may be the following new aspects (for optimizing signaling for supporting ICBM) that are worth mentioning compared to conventional techniques. First, the CU (e.g., gNB-CU-CP) can merge the CSI configurations of all ICBM / dynamic handover participating cells into a single configuration that contains a portion applicable to a specific serving cell and a common portion applicable to all cells (or subsets thereof) participating in ICBM. Second, the UE can select a subset of CSI reporting configurations for L1-RSRP reporting based on the UE's current serving cell. Third, inter-node (inter-DU) coordination is proposed to enable different CSI reporting configurations in the target cell as part of preparation for ICBM operation. Specifically, this is about coordination and communication between the serving DU and the target DU via the CU-CP to configure ICBM / dynamic handover on the UE and network side. Last but not least, further inter-node (inter-DU) coordination is proposed to provide a subset of TCI states for switching to the target cell's (multiple) potential TCI states before beam switching to the new cell. In other words, it is about relaying the necessary information (from the target DU via CU-CP) to the serving DU in order to enable inter-DU ICBM / dynamic switching at the serving DU.

[0172] Reference now Figures 3 to 5 , which schematically describes some further example embodiments, which may (depending on various implementations) be similar to those of reference Figure 1 to Figure 2 The described example embodiments may be used (at least in part) in combination with or as an alternative to them.

[0173] In particular, Figure 3 Another example implementation of a high level block diagram of a CSI (Channel State Information) measurement (correlation) configuration is schematically shown.

[0174] In a broad sense, Figure 3 The illustrated example embodiments may generally be viewed as implementing CSI resource configuration and reporting configuration (as modified compared to the prior art) within a CSI measurement configuration, but categorizing the configuration of beam operation modes (e.g., beam refinement, beam switching, etc.).

[0175] More specifically, if Figure 3 As shown, the CSI resource configuration set is now divided into three (sub) sets, namely a set 310 for beam switching between all cells participating in ICBM operation (similar to Figure 1and two sets 340 and 350 for (source) cell-specific beam refinement-related resource configuration. Figure 1 , the CSI measurement configuration 300 may also include (at least) (source) cell-specific CSI report-related configurations for the source cell 320 and for the (potential) target cell 330. That is, the reporting configuration is (source) cell-specific and points to any resource set (e.g., by using Figure 2 or in any other suitable manner).

[0176] In addition, Figure 1 and 2 In contrast to the example embodiment of (where the TCI state configuration is typically sent / selected by the source DU), Figure 4 Further schematically illustrated is an example of a high level block diagram of a modified TCI state configuration that may be used.

[0177] More specifically, if Figure 4 As shown, the (overall) TCI state configuration 400 can be modified to also include cell-specific and common parts. Here, "cell-specific" and "common" TCI state configurations should be understood in a similar or similar manner as described above with respect to, for example, CSI reporting related configurations. More specifically, a TCI state configuration 410 of a control channel resource (such as PDCCH, or specifically PDCCH CORESET (control resource set)) is provided, which is commonly referenced in all cells (or a part thereof) of ICBM (including but not limited to TCI states for source and target cells). In addition, a (source) cell-specific TCI state configuration 420 of a data channel resource (such as PDSCH, or specifically PDSCH CORESET) dedicated to the source cell and a cell-specific TCI state configuration 430 of a data channel resource (such as PDSCH, or specifically PDSCH CORESET) dedicated to the target cell are also provided. As shown above, depending on various implementations, in the case where multiple target cells are configured for ICBM operation, there may be more than one instance of such a cell-specific TCI state configuration for the target cell.

[0178] Now, the message sequence of the signaling procedure for configuring the UE with modified CSI measurement configuration and TCI state configuration will be referred to below. Figure 5 is described in more detail. Similar to what is shown above, Figure 5In the example embodiments of , it is generally assumed that the source cell resides at the source DU (or in other words, is under the control of the source DU), while the (neighboring) target cell resides at the target DU (or in other words, is under the control of the target DU). However, as can be understood and appreciated by those skilled in the art, the deployment of source / target cells and / or source / target DUs may not always be the case. For example, in some possible implementations, both the source cell and the target cell may be under the control of the source DU only. Of course, depending on various implementations and / or requirements, any other suitable configuration is also possible (of course, with appropriate adjustments to the signaling / messages). It should also be noted that with Figure 2 Compared with the example embodiment of , it can be seen that in the present example embodiment, higher layer configuration (e.g., RRC signaling) is generally not affected / modified during beam switching.

[0179] More specifically, as described above, the CSI resource configuration includes a common configuration and a cell-specific part (e.g., for the source cell and the target cell). Each cell-specific part includes beam refinement related measurement information. However, for beam switching across cells, there is still only one CSI resource configuration pool. Figure 1 Similar to the example shown, the reporting configuration is also cell-specific and points to the cell-specific CSI resource configuration.

[0180] Specifically, similar to the above, in steps S501 and S502, the UE connects to the source cell (or simply referred to as cell 1, not explicitly shown in the figure) under the control of the source DU, and reports (among other things) the target cell (or simply referred to as cell 2) to the CU in its measurements.

[0181] In addition, Figure 2 Similar to step S209, in step S503, the CU prepares an RRC reconfiguration message (or any other suitable message, depending on various implementations), but this time with a modified CSI measurement configuration and a modified TCI state configuration.

[0182] Then, similar to Figure 2 In step S212, in step S504, the UE uses the serving cell reporting configuration to send an L1 RSRP report (or in any other suitable form) to the source DU, indicating that the target cell (cell 2) is a potential "strong" cell.

[0183] In response to the measurement report, the source DU performs step S505 (similar to Figure 2 In step S214 of the UE, the UE sends an appropriate MAC CE to the target cell, indicating a TCI state change for a control channel (e.g., PDCCH, etc.). As a result, the UE switches its monitoring of the control channel (e.g., PDCCH, etc.) from the source cell to the target cell, similar to Figure 2From then on, as shown in step S507, the UE may start to use the common CSI configuration and TCI state configuration of the target cell and the cell-specific CSI configuration and TCI state configuration.

[0184] It may be worth noting that, although not explicitly shown in the figure, Figure 5 The example embodiments may also implement “dynamic switching” as described above (eg, switching from cell 2 back to cell 1).

[0185] It may also be worth noting that in some possible implementations, the concept / idea of ​​determining / selecting a subset of TCI state configurations (such as reference Figure 2 Step S213) can also be Figure 5 is adopted in the example embodiments (i.e., on top of the proposed TCI state configuration classification), possibly with appropriate adjustments and / or modifications where appropriate, thereby further reducing the TCI state configurations that need to be transmitted between network nodes to support ICBM operations.

[0186] In summary, reference Figures 3 to 5 The example embodiments described can generally be viewed as proposing a classification of beam refinement and beam switching configurations for CSI measurement configurations and TCI state switching. More specifically, compared to conventional techniques, there may be the following new aspects worth mentioning (for optimizing signaling to support ICBM). First, a modification of the CSI-RS resource configuration within the CSI measurement configuration is proposed to include additional information to identify the CSI-RS resources for beam refinement and the CSI-RS resources for beam switching within the configuration. In other words, the ICBM / dynamic switching CSI measurement configuration can be viewed as including both the serving DU and the target DU cells selected for ICBM / dynamic switching. Second, new fields can be introduced in the CSI resource configuration, such as using a cell ID to support beam refinement resources. In some other possible implementations, a cell-specific bitmap can be implemented to identify cell-specific beam refinement resources. Third, the beam switching resource is applicable to all serving cells that are part of ICBM. On the other hand, a beam refinement configuration applicable to a serving cell is used. Fourth, for a PDSCH TCI state configuration as an example for a beam refinement configuration, a cell-specific identifier can be included from the DU to the UE. Last but not least, the UE may switch its CSI measurement operation from a “superset” of CSI measurement configurations, which is considered as a container for all serving cell CSI measurement configurations, to a subset of the configurations applicable to the current ICBM cell.

[0187] It should be noted that although in the above-mentioned example embodiments (refer to the accompanying drawings), the messages transmitted / exchanged between network components / elements may appear to have specific / clear names, depending on various implementations (e.g., underscore technology), these messages may have different names and / or be transmitted / exchanged in different forms / formats, as can be understood and appreciated by those skilled in the art.

[0188] According to some example embodiments, corresponding methods suitable for execution by the above-mentioned apparatus (network element / component), such as UE, CU, DU, etc., are also provided.

[0189] However, it should be noted that the above-mentioned device (equipment) features correspond to corresponding method features, but for the sake of brevity, may not be explicitly described. The disclosure of this document is considered to also extend to such method features. Specifically, the disclosure is understood to relate to methods of operating the above-mentioned devices, and / or providing and / or arranging the corresponding elements of these devices.

[0190] In addition, according to some other example embodiments, a corresponding device (for example, implementing the UE, CU, DU, etc. as described above) is also provided, which includes at least one processing circuit system and at least one memory for storing instructions to be executed by the processing circuit system, wherein the at least one memory and the instructions are configured to enable the corresponding device to perform at least the corresponding steps as described above together with the at least one processing circuit system.

[0191] However, in some other example embodiments, a corresponding apparatus (eg, implementing the UE, CU, DU, etc. as described above) is provided, which includes corresponding components configured to at least perform the corresponding steps as described above.

[0192] It should be noted that the examples of the embodiments of the present disclosure are applicable to various network configurations. In other words, the examples shown in the above-mentioned figures (which are used as the basis for the examples discussed above) are only illustrative and do not limit the present disclosure in any way. That is, based on the defined principles, additional existing and proposed new functions available in the corresponding operating environment can be used in conjunction with the examples of the embodiments of the present disclosure.

[0193] It should also be noted that the disclosed example embodiments can be implemented in a variety of ways using hardware and / or software configurations. For example, the disclosed embodiments can be implemented using dedicated hardware and / or hardware associated with software executable thereon. The components and / or elements in the figures are only examples and do not limit the scope of use or functionality of any hardware, software combined with hardware, firmware, embedded logic components, or combinations of two or more such components that implement a particular embodiment of the present disclosure.

[0194] It should also be noted that the description and drawings illustrate only the principles of the present disclosure. Those skilled in the art will be able to implement various arrangements that, although not explicitly described or shown herein, embody the principles of the present disclosure and are included in its spirit and scope. In addition, all examples and embodiments summarized in this disclosure are primarily and explicitly used only for explanatory purposes to help the reader understand the principles of the proposed method. In addition, all statements of the principles, aspects and embodiments of the present disclosure and their specific examples provided herein are intended to cover their equivalents.

Claims

1. A user equipment (UE), configured to support inter-cell beam management (ICBM) involving multiple cells, wherein the multiple cells include a source cell serving the UE and at least one neighboring target cell, wherein the UE comprises: at least one processor; as well as at least one memory storing instructions, which, when executed by at least one processor, cause the UE to at least: sending a measurement report including information of a target cell indicating the at least one neighbor target cell to a first network node supporting at least one of: a central unit control plane, CU-CP functionality, or a layer 3 protocol of a radio access network; and A configuration message is received from the first network node, the configuration message including information indicating a channel state information (CSI) measurement related configuration, wherein the CSI measurement related configuration includes: a CSI resource related configuration generally used for measurement at the cell involved in the ICBM, and a cell-specific CSI report related configuration for a subset of the cells, wherein the subset is determined based on the source cell, and wherein the subset includes the source cell and at least one of the target cells.

2. The UE according to claim 1, wherein the UE is further caused to: Based on the CSI measurement related configuration, performing measurement; and Based on the CSI report related configuration corresponding to the source cell, the result of the measurement is reported to a second network node of the source cell supporting at least one of the following: a distributed unit DU function, or a layer 2 protocol of a radio access network.

3. The UE according to claim 1 or 2, wherein the UE is further caused to: receiving a message indicating a transmission configuration indication (TCI) state corresponding to the target cell from the second network node of the source cell, for switching the UE to a beam of the target cell indicated by the TCI state.

4. The UE according to any one of the preceding claims, wherein the UE is further caused to: Control channel monitoring is switched from the source cell to the target cell.

5. The UE according to any one of the preceding claims, wherein the UE is further caused to: Perform measurements based on the CSI measurement related configuration, and report the results thereof to a second network node of the target cell supporting at least one of the following items: a distributed unit DU function, or the layer 2 protocol of the radio access network based on the CSI reporting related configuration corresponding to the target cell.

6. A UE according to any one of the preceding claims, wherein the UE is further caused to: receiving a message indicating a TCI state corresponding to the source cell from the second network node of the target cell, for switching the UE back to the beam of the source cell indicated by the TCI state. 7 . The UE according to claim 5 , wherein the second network node of the source cell and the second network node of the target cell are different network nodes.

8. The UE according to any one of the preceding claims, wherein the CSI resource related configuration normally used for measurement at a cell is used for beam switching; and wherein the CSI measurement related configuration further comprises: A cell-specific CSI resource-related configuration for beam refinement for the subset of cells.

9. The UE according to claim 8, wherein the configuration message further comprises: A control channel related TCI state configuration commonly referenced in the cells involved in the ICBM, and a cell specific data channel related TCI state configuration for the subset of cells.

10. The UE according to any one of the preceding claims, wherein the configuration message further comprises: a cell-specific bitmap associated with the cell-specific CSI reporting related configuration for the subset of cells.

11. The UE according to any of the preceding claims, wherein the configuration message is a Radio Resource Control (RRC) reconfiguration message.

12. A first network node, the first network node supporting at least one of a central unit control plane (CU-CP) function or a layer 3 protocol of a radio access network, the first network node being configured to support inter-cell beam management (ICBM) involving a plurality of cells, the plurality of cells comprising a source cell serving a user equipment (UE), and at least one neighboring target cell, wherein the first network node comprises: at least one processor; as well as at least one memory storing instructions that, when executed by the at least one processor, cause the first network node to at least: receiving a measurement report from the UE, the measurement report comprising: information indicating a target cell of the at least one neighboring target cell; generating a configuration message, the configuration message comprising information indicating a channel state information (CSI) measurement related configuration, wherein the CSI measurement related configuration comprises: a CSI resource related configuration commonly used for measurement at the cell involved in the ICBM, and a cell-specific CSI report related configuration for a subset of the cells, wherein the subset is determined according to the source cell, and wherein the subset comprises the source cell and at least one target cell; and Sending the configuration message to the UE.

13. The first network node according to claim 12, wherein the first network node is further caused to: sending a first request message including information indicating ICBM to a second network node of the source cell, the source cell supporting at least one of: a distributed unit DU function, or the layer 2 protocol of the radio access network; and A first response message including information indicating the CSI resource related configuration is received from the second network node of the source cell.

14. The first network node according to claim 12 or 13, wherein the first network node is further caused to: sending a second request message including information indicating the ICBM and information indicating the CSI resource related configuration to a second network node of the target cell, the target cell supporting at least one of the following: a distributed unit DU function, or the layer 2 protocol of the radio access network; and A second response message is received from the second network node of the target cell, the second response message comprising: Information indicating CSI measurement related configuration for the target cell.

15. The first network node according to any one of claims 12 to 14, wherein the first network node is further caused to: Sending a third request message to the second network node of the source cell, where the third request message includes: Information indicating the CSI measurement related configuration for the target cell; as well as A third response message is received from the second network node of the source cell, the third response message comprising information indicating the CSI measurement related configuration modified based on the information indicating the CSI measurement related configuration for the target cell.

16. The first network node according to any one of claims 12 to 15, wherein each of the first request message and the second request message is a corresponding UE context setup request message; and each of the first response message and the second response message is a corresponding UE context setup response message.

17. The first network node according to any one of claims 12 to 16, wherein the third request message is a UE context modification request message; and the third response message is a UE context modification response message.

18. The first network node according to claim 12, wherein the CSI resource related configuration normally used for measurement at a cell is used for beam switching; and wherein the CSI measurement related configuration further comprises: A cell-specific CSI resource-related configuration for beam refinement of the subset of cells.

19. The first network node according to claim 18, wherein the configuration message further comprises: A control channel related transmission configuration indication TCI state configuration commonly referenced in the cells involved in the ICBM, and a cell specific data channel related TCI state configuration for the subset of cells.

20. The first network node according to any one of claims 12 to 19, wherein the configuration message further comprises: a cell-specific bitmap associated with the cell-specific CSI reporting related configuration for the subset of cells.

21. The first network node according to any one of claims 12 to 20, wherein the configuration message is a Radio Resource Control (RRC) reconfiguration message.

22. A second network node supporting at least one of a distributed unit (DU) function or a layer 2 protocol of a radio access network, the second network node being configured to support inter-cell beam management (ICBM) involving a plurality of cells including a source cell of the second network node serving a user equipment (UE), and at least one neighboring target cell, wherein the second network node comprises: at least one processor; as well as at least one memory storing instructions that, when executed by the at least one processor, cause the second network node to at least: receiving a first request message from a first network node supporting at least one of a Central Unit Control Plane (CU-CP) functionality or a layer 3 protocol of the radio access network, the first request message comprising: information indicating a channel state information (CSI) measurement related configuration of a target cell for the at least one neighboring target cell; generating a first response message, the first response message comprising: information indicating a CSI measurement related configuration modified based on the received information indicating the CSI measurement related configuration for the target cell, wherein the CSI measurement related configuration comprises: a CSI resource related configuration commonly used for measurement at the cell involved in the ICBM, and a cell-specific CSI report related configuration for a subset of the cells, wherein the subset is determined according to the source cell, and wherein the subset comprises the source cell and at least one target cell; and The first response message is sent to the first network node.

23. The second network node according to claim 22, wherein the second network node is further caused to: receiving, from the first network node, a second request message including information indicating an ICBM; and and sending a second response message including information indicating the CSI resource related configuration to the first network node.

24. The second network node according to claim 22 or 23, wherein the second network node is further caused to: Send a configuration message, the configuration message including: Information indicating transmission configuration indication TCI status information of the cell involved in the ICBM.

25. The second network node according to any one of claims 22 to 24, wherein the second network node is further caused to: receiving, from the UE, a report of measurements performed based on the CSI reporting related configuration corresponding to the source cell; and Send a configuration message, the configuration message including: Information indicating TCI status information for another subset of the cells involved in the ICBM, wherein the another subset of the cells is determined based on the target cell.

26. The second network node according to any one of claims 22 to 25, wherein the second network node is further caused to: A message indicating a transmission configuration indication TCI state corresponding to the target cell is sent to the UE, so as to switch the UE to the beam of the target cell indicated by the TCI state.

27. The second network node according to any one of claims 22 to 26, the first request message is a UE Context Modification Request message; and the first response message is a UE Context Modification Response message.

28. The second network node according to any one of claims 22 to 27, wherein the second request message is a UE context setup request message; and the first response message is a UE context setup response message.

29. A method for a user equipment (UE), the UE being configured to support inter-cell beam management (ICBM) involving a plurality of cells, the plurality of cells including a source cell serving the UE and at least one neighboring target cell, the method comprising: sending a measurement report including information of a target cell indicating the at least one neighbor target cell to a first network node supporting at least one of: a central unit control plane, CU-CP functionality, or a layer 3 protocol of a radio access network; and A configuration message is received from the first network node, the configuration message including information indicating a channel state information (CSI) measurement related configuration, wherein the CSI measurement related configuration includes: a CSI resource related configuration generally used for measurement at the cell involved in the ICBM, and a cell-specific CSI report related configuration for a subset of the cells, wherein the subset is determined based on the source cell, and wherein the subset includes the source cell and at least one of the target cells.

30. A method of a first network node, the first network node supporting at least one of a central unit control plane (CU-CP) functionality or a layer 3 protocol of a radio access network, the first network node being configured to support inter-cell beam management (ICBM) involving a plurality of cells, the plurality of cells comprising a source cell serving a user equipment (UE), and at least one neighboring target cell, the method comprising: receiving a measurement report from the UE, the measurement report comprising: information indicating a target cell of the at least one neighboring target cell; generating a configuration message, the configuration message comprising information indicating a channel state information (CSI) measurement related configuration, wherein the CSI measurement related configuration comprises: a CSI resource related configuration commonly used for measurement at the cell involved in the ICBM, and a cell-specific CSI report related configuration for a subset of the cells, wherein the subset is determined according to the source cell, and wherein the subset comprises the source cell and at least one target cell; and Sending the configuration message to the UE.

31. A method of a second network node, the second network node supporting at least one of a distributed unit (DU) functionality or a layer 2 protocol of a radio access network, the second network node being configured to support inter-cell beam management (ICBM) involving a plurality of cells, the plurality of cells comprising: A source cell of the second network node serving a user equipment UE, and at least one neighboring target cell, the method comprising: receiving a first request message from a first network node supporting at least one of a Central Unit Control Plane (CU-CP) functionality or a layer 3 protocol of the radio access network, the first request message comprising: information indicating a channel state information (CSI) measurement related configuration of a target cell for the at least one neighboring target cell; generating a first response message, the first response message comprising: information indicating a CSI measurement related configuration modified based on the received information indicating the CSI measurement related configuration for the target cell, wherein the CSI measurement related configuration comprises: a CSI resource related configuration commonly used for measurement at the cell involved in the ICBM, and a cell-specific CSI report related configuration for a subset of the cells, wherein the subset is determined according to the source cell, and wherein the subset comprises the source cell and at least one target cell; and The first response message is sent to the first network node.

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