Inter-cell beam management

Abstract

A method and a radio access network node for inter-cell beam management, wherein a source distributed node and a target distributed node are controlled by a central node of a radio access network. A central node determines to initiate an inter-cell beam management procedure for user equipment served by a source distributed node and sends a setup request to a target distributed node to configure a beam of a cell of the target distributed node for the user equipment. The central node receives a setup response having user equipment-specific beam management configuration information relating to a requested beam of a cell of the target distributed node, and sends configuration information to the source distributed node, the configuration information being associated with the requested beam of the cell of the target distributed node. In this way, the source distributed unit can initiate an inter-cell beam management operation with the user equipment.

Description

Technical Field

[0001] The present disclosure relates generally to mobile communication networks, such as 5G communication networks, and more particularly to improving connectivity and quality of service for mobile terminals. Background Art

[0002] Wireless and mobile telecommunication systems are constantly evolving. Higher data rates and higher quality of service are required. Reliability and service requirements are constantly increasing, while reducing transmission delays and increasing throughput are further goals in the development of mobile communication standards.

[0003] One particular aspect is service continuity. User equipment (UE) traversing the network infrastructure of a mobile communication network using its radio access network is faced with a changing radio environment. In order to maintain continuous service and connectivity, the UE is handed over to another base station or radio cell when it moves away from the coverage of its current base station or cell. However, the number of handovers (commonly known as "ping-pong") should be reduced, since each execution of the handover procedure introduces signaling overhead. Summary of the invention

[0004] According to a first aspect, an inter-cell beam management method for a radio access network is provided. The radio access network includes a source distributed node and a target distributed node. The source distributed node and the target distributed node are controlled by a central node of the radio access network. The central node determines to initiate an inter-cell beam management process for a user equipment served by the source distributed node, and sends a setup request to the target distributed node in order to configure a beam of a cell of the target distributed node for the user equipment. The central node receives a setup response from the target distributed node, the setup response having beam management configuration information specific to the user equipment, the beam management configuration information specific to the user equipment being related to the requested beam of the cell of the target distributed node. The central node sends at least a portion of the configuration information to the source distributed node to enable the source distributed unit to initiate an inter-cell beam management operation with the user equipment.

[0005] In some embodiments, the inter-cell beam management operations include low-layer mobility procedures or dynamic cell switching procedures.

[0006] In some embodiments, the establishment request includes an inter-cell beam management indication and packet scheduling related information.

[0007] In some embodiments, the setup request comprises an indication of a bandwidth portion currently utilized by the user equipment, and the setup response comprises an indication that the beam of the cell of the target distributed node is to be configured on the first bandwidth portion.

[0008] In some embodiments, the central node sends a context modification request to a source distributed node requesting information related to inter-cell beam management of a user terminal, and receives a context modification response from the source distributed node, wherein the context modification response indicates information related to inter-cell beam management of the user terminal, and the information related to inter-cell beam management may indicate at least one of the following: timing advance information of the user equipment, bandwidth portion information of the user equipment, and measurement configuration of the user equipment.

[0009] In some embodiments, the central node configures the user equipment to perform measurement of at least a beam of a cell of the target distributed node, and receives at least one measurement report from the user equipment, the at least one measurement report indicating the result of the measurement of at least a beam of the cell of the target distributed node.

[0010] In some embodiments, the central node provides at least a portion of the results of the measurements in a setup request to a target distributed node.

[0011] In some embodiments, the central node receives from the source distributed node an indication of the number of beams or identities of beams aligned with the neighboring cell timing advance.

[0012] In some embodiments, the central node determines a bandwidth part switch for the user equipment to change the user equipment from the first bandwidth part to the second bandwidth part, and sends an indication of the bandwidth part switch for the user equipment to the target distributed node. The central node then receives a confirmation from the target distributed node that the beam of the cell of the target distributed node is reconfigured according to the bandwidth part switch for the user equipment, and the user equipment is reconfigured with the second bandwidth part.

[0013] In some embodiments, the central node receives an indication from a source distributed node to switch a first bandwidth portion of a user equipment to a second bandwidth portion. The central node may indicate to the source distributed node that a beam of a cell of a target distributed node is not to be used. The central node sends a modification request indicating the second bandwidth portion to the target distributed node, and receives a modification response from the target distributed node, the modification response confirming that the beam of the target distributed node is reconfigured to the second bandwidth portion. The central node then indicates to the source distributed node that the beam of the cell of the target distributed node will be reconfigured to the second bandwidth portion.

[0014] In some embodiments, the establishment request indicates a plurality of bandwidth portions suitable for the user equipment to communicate with the source distributed node, and the establishment response indicates at least a subset of the plurality of bandwidth portions suitable for the beam of the cell of the target distributed node, and the configuration information includes the subset of the plurality of bandwidth portions to enable the user equipment to operate any bandwidth portion of the subset of the plurality of bandwidth portions on the beam of the cell of the target distributed node.

[0015] In some embodiments, the central node receives a confirmation from the source distributed node indicating that the user equipment is successfully configured to operate on the beam of the target distributed node. The central node then causes a bearer configuration with the target distributed node to enable user data transmission through the beam of the target distributed node, and forwards user data for the user equipment to the target distributed node.

[0016] According to another aspect, an inter-cell beam management method for a radio access network is provided, the radio access network comprising a source distributed node and a target distributed node, the source distributed node and the target distributed node being controlled by a central node of the radio access network. The source distributed node receives configuration information related to a beam of a cell of the target distributed node from the central node, and initiates an inter-cell beam management operation with a user equipment to enable the user equipment to operate on the beam of the cell of the target distributed node.

[0017] In some embodiments, the inter-cell beam management operations include low-layer mobility procedures or dynamic cell switching procedures.

[0018] In some embodiments, the configuration information includes inter-cell beam management instructions or packet scheduling related information.

[0019] In some embodiments, the configuration information indicates a bandwidth portion of a beam currently used by the user equipment and the source distributed node to be used for the cell of the target distributed node.

[0020] In some embodiments, a source distributed node receives a context modification request from a central node requesting information related to inter-cell beam management of a user terminal, and sends a context modification response to the central node, wherein the context modification response indicates information related to inter-cell beam management of the user terminal, and the information related to inter-cell beam management may indicate at least one of the following: timing advance information of the user equipment, bandwidth portion information of the user equipment, and measurement configuration of the user equipment.

[0021] In some embodiments, the bandwidth part information of the user equipment indicates multiple bandwidth parts suitable for the user equipment to communicate with the source distributed node, and the configuration information includes at least a subset of the multiple bandwidth parts to enable the user equipment to operate any bandwidth part of the subset of the multiple bandwidth parts on the beam of the cell of the target distributed node.

[0022] In some embodiments, the source distributed node sends an indication to the central node indicating the number of beams or identities of beams aligned with neighboring cell timing advances.

[0023] In some embodiments, the source distributed node sends an indication to the central node to switch the first bandwidth portion of the user equipment to the second bandwidth portion. The source distributed node receives from the central node an indication that the beam of the target distributed node is not to be used and an indication that the beam of the target distributed node is to be reconfigured to the second bandwidth portion, and indicates the reconfiguration to the second bandwidth portion to the user equipment.

[0024] In some embodiments, the source distributed node sends an acknowledgement to the central node indicating successful configuration of the user equipment to operate on the beam of the target distributed node.

[0025] According to a further aspect, a central node for inter-cell beam management in a radio access network is provided, the radio access network comprising a source distributed node and a target distributed node. The source distributed node and the target distributed node are controlled by a central node of the radio access network. The central node comprises at least one processor and at least one memory comprising computer program code, which, when executed by at least one processor, causes the central node to: determine to initiate an inter-cell beam management procedure for a user equipment served by the source distributed node, and then send a setup request to the target distributed node to configure the beam of the cell of the target distributed node for the user equipment. The central node is also caused to receive a setup response from the target distributed node, the setup response having beam management configuration information specific to the user equipment, the beam management configuration information specific to the user equipment being related to the requested beam of the cell of the target distributed node, and send at least a portion of the configuration information to the source distributed node to enable the source distributed node to initiate an inter-cell beam management operation with the user equipment.

[0026] In some embodiments, the inter-cell beam management operations include low-layer mobility procedures or dynamic cell switching procedures.

[0027] In some embodiments, the establishment request includes inter-cell beam management instructions or packet scheduling related information.

[0028] In some embodiments, the setup request includes an indication of a bandwidth portion currently utilized by the user equipment, and the setup response includes an indication that the beam of the target distributed node is to be configured on the first bandwidth portion.

[0029] In some embodiments, the central node is also configured to send a context modification request to a source distributed node requesting information related to inter-cell beam management of a user terminal, and receive a context modification response from the source distributed node, wherein the context modification response indicates information related to inter-cell beam management of the user terminal, and the information related to inter-cell beam management may indicate at least one of the following: timing advance information of the user equipment, bandwidth portion information of the user equipment, and measurement configuration of the user equipment.

[0030] In some embodiments, the central node is also configured to configure the user equipment to perform measurements of at least a beam of a cell of the target distributed node, and to receive at least one measurement report from the user equipment, the at least one measurement report indicating the results of the measurements of at least a beam of the cell of the target distributed node.

[0031] In some embodiments, the central node is further caused to provide at least a portion of the results of the measurements in a setup request to the target distributed node.

[0032] In some embodiments, the central node is further caused to receive from the source distributed node an indication of the number of beams or identities of beams aligned with the neighboring cell timing advance.

[0033] In some embodiments, the central node is also caused to determine a bandwidth portion switch for the user equipment to change the user equipment from the first bandwidth portion to the second bandwidth portion; send an indication of the bandwidth portion switch for the user equipment to the target distributed node; receive a confirmation from the target distributed node that the beam of the cell of the target distributed node is reconfigured according to the bandwidth portion switch for the user equipment; and reconfigure the user equipment using the second bandwidth portion.

[0034] In some embodiments, the central node is also configured to receive an indication from a source distributed node to switch a first bandwidth portion of a user equipment to a second bandwidth portion; indicate to the source distributed node not to use a beam of a cell of a target distributed node; send a modification request indicating the second bandwidth portion to the target distributed node; receive a modification response from the target distributed node, the modification response confirming that the beam of the target distributed node is reconfigured to the second bandwidth portion; and indicate to the source distributed node that the beam of the cell of the target distributed node will be reconfigured to the second bandwidth portion.

[0035] In some embodiments, the establishment request indicates a plurality of bandwidth parts suitable for the user equipment to communicate with the source distributed node, and the establishment response indicates at least a subset of the plurality of bandwidth parts suitable for the beam of the cell of the target distributed node, and wherein the configuration information includes the subset of the plurality of bandwidth parts to enable the user equipment to operate any bandwidth part of the subset of the plurality of bandwidth parts on the beam of the cell of the target distributed node.

[0036] In some embodiments, the central node is also configured to receive a confirmation from the source distributed node indicating that the user equipment has been successfully configured to operate on the beam of the target distributed node; to perform bearer configuration with the target distributed node to enable user data transmission through the beam of the target distributed node; and to forward user data for the user equipment to the target distributed node.

[0037] According to a further aspect, a source distributed node for inter-cell beam management in a radio access network is provided. The radio access network comprises a source distributed node and a target distributed node. The source distributed node and the target distributed node are controlled by a central node of the radio access network. The source distributed node comprises at least one processor and at least one memory comprising computer program code, which, when executed by at least one processor, causes the central node to receive configuration information related to a beam of a cell of the target distributed node. The source distributed node is then caused to initiate an inter-cell beam management operation with a user equipment to enable the user equipment to operate on the beam of the cell of the target distributed node.

[0038] In some embodiments, the inter-cell beam management operations include low-layer mobility procedures or dynamic cell switching procedures.

[0039] In some embodiments, the configuration information includes inter-cell beam management instructions or packet scheduling related information.

[0040] In some embodiments, the configuration information indicates a bandwidth portion of a beam currently used by the user equipment and the source distributed node to be used for the cell of the target distributed node.

[0041] In some embodiments, the source distributed node is also configured to receive a context modification request from the central node requesting information related to inter-cell beam management of a user terminal, and send a context modification response to the central node, wherein the context modification response indicates information related to inter-cell beam management of the user terminal, and the information related to inter-cell beam management may indicate at least one of the following: timing advance information of the user equipment, bandwidth portion information of the user equipment, and measurement configuration of the user equipment.

[0042] In some embodiments, the bandwidth part information of the user equipment indicates multiple bandwidth parts suitable for the user equipment to communicate with the source distributed node, and the configuration information includes at least a subset of the multiple bandwidth parts to enable the user equipment to operate any bandwidth part of the subset of the multiple bandwidth parts on the beam of the cell of the target distributed node.

[0043] In some embodiments, the source distributed node is further caused to send an indication to the central node indicating the number of beams or identities of beams aligned with the neighboring cell timing advance.

[0044] In some embodiments, the source distributed node is further caused to send an indication to the central node to switch the first bandwidth portion of the user equipment to the second bandwidth portion. The source node may receive an indication from the central node not to use the beam of the cell of the target distributed node. The source distributed node receives an indication from the central node that the beam of the target distributed node is to be reconfigured to the second bandwidth portion, and indicates the reconfiguration to the second bandwidth portion to the user equipment.

[0045] In some embodiments, the source distributed node is further caused to send an acknowledgement to the central node indicating successful configuration of the user equipment to operate on the beam of the target distributed node.

[0046] According to a further aspect, a non-transitory computer-readable storage medium stores computer program instructions which, when executed by at least one processor, cause a central node of a radio access network to perform any of the central node-related methods described above.

[0047] According to a further aspect, a non-transitory computer-readable storage medium stores computer program instructions which, when executed by at least one processor, cause a source distributed node of a radio access network to perform any of the source distributed node-related methods described above.

[0048] According to a further aspect, a computer program comprises instructions which, when executed by at least one processor, cause a central node of a radio access network to perform any of the central node related methods described above.

[0049] According to a further aspect, a computer program comprises instructions which, when executed by at least one processor, cause a source distributed node of a radio access network to perform any of the source distributed node related methods described above. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Embodiments will be described in more detail below with reference to the accompanying drawings, in which:

[0051] Figure 1 A schematic diagram of an example communication system including a base station and a plurality of communication devices is shown.

[0052] Figure 2 A schematic diagram of an example mobile communication device is shown.

[0053] Figure 3 A schematic diagram of an example control device is shown.

[0054] Figure 4A and Figure 4B Depicted the NG-RAN architecture.

[0055] Figure 5Depicts an example of network coverage in a mobile communications network.

[0056] Figure 6 is a general representation of the inter-cell beam management (ICBM) process as described herein.

[0057] Figure 7 A more detailed inter-cell beam management (ICBM) process with base station components is shown.

[0058] Figure 8 The ICBM process with bandwidth portion processing is shown.

[0059] Fig. 9 An ICBM procedure with multiple possible bandwidth parts on the terminal side is shown.

[0060] Fig.10 The ICBM process with various components of a base station is depicted. DETAILED DESCRIPTION

[0061] 3GPP Technical Specification 38.300 V17.0.0 Subclause 9.2.3.1 distinguishes between cell-level mobility and beam-level mobility. Cell-level mobility requires explicit signaling through radio resource control (RRC) to enable the UE to switch to a new cell. On the other hand, beam-level mobility does not require explicit RRC signaling. Beam-level mobility can be within a cell or between cells, the latter of which is called inter-cell beam management (ICBM). For ICBM, the UE can receive or send UE-specific channels / signals via a TRP (transmit / receive point) associated with a physical cell identifier (PCI) different from the serving cell, while non-UE-specific channels / signals can only be received via a TRP associated with the PCI of the serving cell. The gNB (next generation NodeB, 5G base station) provides the UE with a measurement configuration via RRC signaling, which contains the configuration of SSB / CSI resources (SSB = synchronization signal block, CSI = channel state information) and resource sets, reports and trigger states for triggering channel and interference measurements and reports. In the case of ICBM, the measurement configuration includes SSB resources associated with a PCI that is different from the PCI of the serving cell. Beam-level mobility is then handled at low layers through physical layer and media access control (MAC) layer control signaling, and RRC is not required to know which beam is being used at a given point in time.

[0062] There is currently a lack of detailed concepts on how to use ICBM to improve mobility on the one hand and ensure connectivity and service continuity on the other.

[0063] The present disclosure provides a mechanism to extend the low-level mobility concept of Inter-Cell Beam Management (ICBM). In addition, the present disclosure solves the dynamic switching between different cells of a base station at the Layer 1 (L1) level by providing information for different communication messages between base station components and terminals to initiate the ICBM process.

[0064] Before explaining the examples in detail, refer to Figures 1 to 3 Certain general principles of wireless communication systems and mobile communication devices are briefly explained to aid the understanding of the technology on which the described examples are based.

[0065] In the wireless communication system 100 (e.g. Figure 1 As shown), mobile communication devices, user equipment, user devices (UE) 102, 104, 105 are provided with wireless access via at least one base station (e.g., next generation NB, gNB), similar wireless transmission and / or reception nodes or network nodes. The base station can be controlled or assisted by at least one appropriate controller device to enable operation of the base station and management of mobile communication devices communicating with the base station. The controller device can be located in a radio access network (RAN) (e.g., wireless communication system 100) or in a core network (CN) (not shown), and can be implemented as a central device, or its functionality can be distributed over multiple devices. The controller device can be part of the base station and / or provided by a separate entity (such as a radio network controller (RNC) or a central unit (CU)), typically implementing higher network layer (such as layer 3) protocols and / or radio resource control (RRC) protocols. In Figure 1 In the figure, control means 108 and 109 for controlling the respective macro-level base stations 106 and 107 are shown. The control means of the base stations may be interconnected with other control entities. The control means are typically provided with memory capacity and at least one data processor. The control means and functions may be distributed among a plurality of control units. In some systems, the control means may additionally or alternatively be provided in the RNC.

[0066] exist Figure 1 , base stations 106 and 107 are shown connected to a wider communications network 113 via a gateway 112. Further gateway functionality may be provided to connect to another network.

[0067] As used herein, the term "base station" has the full scope of its usual meaning and includes at least a wireless communication station installed in a fixed location and used to communicate as part of a wireless telephone system or a radio system. The communication area (or coverage area) of a base station may be referred to as a "cell". A base station and UE may be configured to communicate via a transmission medium using any of a variety of radio access technologies (RATs, also referred to as wireless communication technologies) or telecommunication standards described below. Figure 1As shown, although one of the base stations may act as a "serving cell" for the UE, the UE may also be able to receive signals from one or more other cells (which may be provided by the base station and / or any other base station and within the communication range of which the UE may be), which may be referred to as "neighboring cells". As described above, a base station may include multiple network nodes, such as an upper controller node that implements higher network layers (such as Layer 3 / RRC) and one or more lower nodes (such as distributed units (DUs) that typically implement lower network layers (such as the physical layer (Layer 1, L1) and Layer 2 (L2)). Note that these multiple units may be geographically co-located or may not be geographically co-located to some extent.

[0068] Small base stations 116, 118 and 120 may also be connected to network 113, for example, through a separate gateway function and / or via a controller of a macro-level station. Base stations 116, 118 and 120 may be micro-level or femto-level base stations, etc. In the example, stations 116 and 118 are connected via gateway 111, while station 120 is connected via controller device 108. In some embodiments, small base stations may not be provided. Small base stations 116, 118 and 120 may be part of a second network (e.g., a wireless local area network (WLAN)) and may be WLAN access points (APs). Communication devices 102, 104, 105 may access the communication system based on various access technologies, such as code division multiple access (CDMA) or wideband CDMA (WCDMA). Other non-limiting examples include time division multiple access (TDMA), frequency division multiple access (FDMA) and its various schemes such as interleaved frequency division multiple access (IFDMA), single carrier frequency division multiple access (SC-FDMA) and orthogonal frequency division multiple access (OFDMA), space division multiple access (SDMA), etc.

[0069] An example of a wireless communication system is an architecture standardized by the Third Generation Partnership Project (3GPP). The latest 3GPP-based development is generally referred to as the Long Term Evolution (LTE) of the Universal Mobile Telecommunications System (UMTS) radio access technology. The various stages of development of the 3GPP specification are referred to as releases. The newer development of LTE is generally referred to as Advanced LTE (LTE-A). LTE (or LTE-A) adopts a radio mobile architecture called Evolved Universal Terrestrial Radio Access Network (E-UTRAN) and a core network called Evolved Packet Core (EPC). The base station of such a system is called an evolved or enhanced Node B (eNB) and provides E-UTRAN functions such as user plane packet data convergence / radio link control / media access control / physical layer protocol (PDCP / RLC / MAC / PHY) and control plane radio resource control (RRC) protocol termination to the communication device. Other examples of radio access systems include systems provided by base stations based on technologies such as WLAN and / or Worldwide Interoperability for Microwave Access (WiMax). The base station can provide coverage for an entire cell or similar radio service area. The core network elements include the Mobility Management Entity (MME), the Serving Gateway (S-GW) and the Packet Gateway (P-GW).

[0070] An example of a suitable communication system is the 5G or NR concept. The network architecture in NR can be similar to that of LTE-A. The base station of the NR system can be referred to as the next generation Node B (gNB). Changes in the network architecture may depend on the need to support various radio technologies and more refined quality of service (QoS) support, as well as some on-demand requirements for QoS levels to support quality of experience (QoE) from the user's perspective. In addition, network-aware services and applications, as well as service- and application-aware networks may bring changes to the architecture. These are related to the information-centric network (ICN) and user-centric content delivery network (UC-CDN) approaches. NR may use multiple-input multiple-output (MIMO) antennas, have more base stations or nodes than LTE (the so-called small cell concept), including macro stations that operate in collaboration with small stations, and may also adopt various radio technologies for better coverage and enhanced data rates.

[0071] Future networks may utilize network function virtualization (NFV), a network architecture concept that proposes virtualizing network node functions into "building blocks" or entities that can be operably connected or linked together to provide services. A virtualized network function (VNF) may include one or more virtual machines that use standard or general-purpose types of servers rather than custom hardware to run computer program code. Cloud computing or data storage may also be utilized. In radio communications, this may mean that node operations are performed at least in part in a server, host, or node that is operably coupled to a remote radio head. Node operations may also be distributed among multiple servers, nodes, or hosts. It should also be understood that the division of labor between core network operations and base station operations may be different from LTE, or may even not exist.

[0072] An example 5G core network (CN) includes functional entities. The CN is connected to the UE via the radio access network (RAN). The role of the user plane function (UPF) is called the PDU session anchor (PSA), and the UPF can be responsible for forwarding frames back and forth between the data network (DN) and the tunnel established over 5G, which is towards the UE exchanging services with the DN.

[0073] The UPF is controlled by a Session Management Function (SMF), which receives policies from a Policy Control Function (PCF). The CN may also include an Access and Mobility Function (AMF).

[0074] Now refer to Figure 2 Describing a possible (mobile) communication device 200 in more detail, Figure 2 A schematic, partial cross-sectional view is shown. Such a mobile communication device 200 is generally referred to as a user device (UE), user equipment or terminal equipment. A suitable mobile communication device 200 can be provided by any device capable of sending and receiving radio signals. Non-limiting examples include a mobile station (MS) or a mobile device, such as a mobile phone or a so-called smart phone, a computer equipped with a wireless interface card or other wireless interface facilities (e.g., a USB dongle), a personal data assistant (PDA), or a tablet computer equipped with wireless communication capabilities, or any combination of these or the like. The communication device 200 can provide, for example, data communications for carrying communications such as voice, e-mail (e-mail), text messages, multimedia, etc. Therefore, a variety of services can be provided to the user via the communication device. Non-limiting examples of these services include two-way or multi-way calls, data communications or multimedia services or simply access to a data communication network system (such as the Internet). Broadcast or multicast data can also be provided to the user. Non-limiting examples of content include downloads, television and radio programs, videos, advertisements, various alarms and other information.

[0075] In industrial applications, the communications device may be a modem integrated into an industrial actuator (e.g., a robotic arm) and / or a modem acting as an Ethernet hub, which would act as a connection point for one or more connected Ethernet devices (the connection may be wired or wireless).

[0076] The communication device 200 is typically equipped with at least one data processing entity 201, at least one memory 202, and other possible components 203, which are used to assist in performing the tasks it is designed to perform with software and hardware, including controlling access and communication with access systems and other communication devices. Data processing, storage, and other related control devices can be provided on appropriate circuit boards and / or in chipsets 204. The user can control the operation of the communication device 200 through a suitable user interface (such as a keyboard 205, voice commands, a touch screen or touchpad, a combination thereof, etc.). A display 208, a speaker, and a microphone may also be provided. In addition, the communication device 200 may include appropriate connectors (wired or wireless) to connect to other devices and / or for connecting external accessories (such as hands-free devices) thereto.

[0077] The communication device 200 may receive signals via appropriate means for receiving, over the air or radio interface 207, and may transmit signals via appropriate means for transmitting radio signals. Figure 2 In the communication device 200, the transceiver arrangement is schematically indicated by the block 206. The transceiver arrangement 206 may be provided by, for example, a radio part and an associated antenna arrangement. The antenna arrangement may be arranged inside or outside the communication device 200.

[0078] If desired, the communication device 200 may also or alternatively be configured to communicate using one or more global navigation satellite systems (GNSS, such as GPS or GLONASS), one or more mobile television broadcast standards (e.g., ATSC-M / H or DVB-H), and / or any other wireless communication protocol. Other combinations of wireless communication standards (including more than two wireless communication standards) are also possible.

[0079] generally, Figure 2 The communication device 200 shown in includes a collection of components configured to perform core functions. For example, the collection of components can be implemented as a system on a chip (SoC), which can include parts for various purposes. Alternatively, the collection of components can be implemented as separate components or groups of components for various purposes. The collection of components can be (transitively) coupled (e.g., directly or indirectly) to various other circuits of the communication device 200.

[0080] The communication device 200 may include at least one antenna for communicating with a transmitter and a receiver (e.g., a transceiver device 206). Alternatively, the transmitting antenna and the receiving antenna may be separated. The communication device 200 may also include a processor (e.g., at least one data processing entity 201), which is configured to provide a signal to the transmitter and receive a signal from the receiver, respectively, and control the function of the communication device 200. The processor may be configured to control the function of the transmitter and the receiver by affecting the control signaling to the transmitter and the receiver via electrical conductors. Similarly, the processor may be configured to control other elements of the communication device 200 by affecting the control signaling that connects the processor to other elements (such as a display (e.g., display 208) or a memory (e.g., at least one memory 202)) via electrical conductors. The processor may be embodied, for example, in a variety of ways, including circuitry, at least one processing core, one or more microprocessors with (multiple) accompanying digital signal processors, one or more processors without accompanying digital signal processors, one or more co-processors, one or more multi-core processors, one or more controllers, processing circuitry, one or more computers, various other processing elements including integrated circuits (e.g., application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), etc.), or some combination thereof. Thus, in some examples, a processor may include multiple processors or processing cores.

[0081] The communication device 200 may be capable of operating with one or more air interface standards, communication protocols, modulation types, access types, etc. The signals sent and received by the processor may include signaling information in accordance with the air interface standard of the applicable cellular system, and / or any number of different wired or wireless network technologies, including but not limited to Wi-Fi, WLAN technologies such as Institute of Electrical and Electronics Engineers (IEEE) 802.11, 802.16, 802.3, ADSL, DOCSIS, etc. In addition, these signals may include voice data, user-generated data, user-requested data, etc.

[0082] For example, the communication device 200 and / or the cellular modem therein may be capable of operating according to various third generation (3G) communication protocols, fourth generation (4G) communication protocols, fifth generation (5G) communication protocols, Internet Protocol Multimedia Subsystem (IMS) communication protocols (e.g., Session Initiation Protocol (SIP), etc.), or 5G and above protocols. For example, the communication device 200 may be capable of operating according to 4G wireless communication protocols (such as LTE-A, 5G, etc.) and similar wireless communication protocols that may be subsequently developed.

[0083] It should be understood that the processor may include circuit systems for implementing the audio / video and logic functions of the communication device 200. For example, the processor may include a digital signal processor device, a microprocessor device, an analog-to-digital converter, a digital-to-analog converter, etc. The control and signal processing functions of the communication device 200 may be allocated between these devices according to their respective capabilities. Additionally, the processor may include an internal voice encoder, an internal data modem, etc. In addition, the processor may include the functionality of operating one or more software programs stored in the memory. Typically, the processor and the stored software instructions may be configured to cause the communication device 200 to perform an action. For example, the processor may be able to operate a connectivity program, such as a Web browser. The connectivity program may allow the communication device 200 to send and receive Web content (such as location-based content) according to a protocol (such as a wireless application protocol (WAP), a hypertext transfer protocol (HTTP), etc.).

[0084] The communication device 200 may also include a user interface, including, for example, a headset or speaker, a ringer, a microphone, a display, a user input interface, etc. that can be operably coupled to the processor. As described above, the display may include a touch-sensitive display, where the user can touch and / or gesture to make a selection, input a value, etc. The processor may also include a user interface circuit system configured to control at least some functions of one or more elements of the user interface (such as a speaker, a ringer, a microphone, a display, etc.). The processor and / or the user interface circuit system including the processor may be configured to control one or more functions of one or more elements of the user interface through computer program instructions, for example, software and / or firmware stored on a memory (e.g., volatile memory, non-volatile memory, etc.) accessible to the processor. The communication device 200 may include a battery for powering various circuits related to the mobile terminal (e.g., a circuit for providing mechanical vibration as a detectable output). The user input interface may include a device that allows the communication device 200 to receive data, such as a keyboard (e.g., keyboard 206) and / or other input devices. The keyboard may also be a virtual keyboard displayed on the display or an externally coupled keyboard.

[0085] The communication device 200 may also include one or more mechanisms for sharing and / or acquiring data. For example, the communication device 200 may include a short-range radio frequency (RF) transceiver and / or interrogator, so data can be shared with and / or acquired from electronic devices based on RF technology. The communication device 200 may include other short-range transceivers, such as infrared (IR) transceivers, Bluetooth TM Wireless technology operated by Bluetooth TM (BT) transceiver, wireless universal serial bus (USB) transceiver, Bluetooth TMLow energy transceiver, ZigBee transceiver, ANT transceiver, cellular device to device transceiver, wireless local area link transceiver and / or any other short-range radio technology. The communication device 200 and more specifically the short-range transceiver may be able to send data to electronic devices near the device (e.g., within 10 meters) and / or receive data from electronic devices near the device. The communication device 200 including a Wi-Fi or WLAN modem may also be able to send data and / or receive data from electronic devices according to various wireless network technologies (including 6LoWPAN, Wi-Fi, Wi-Fi low power, WLAN technology (such as IEEE 802.11 technology, IEEE 802.15 technology, IEEE802.16 technology), etc.).

[0086] The communication device 200 may include a memory, such as one or more subscriber identity modules (SIMs), one or more universal subscriber identity modules (USIMs), one or more removable user identity modules (R-UIMs), one or more embedded universal integrated circuit cards (eUICCs), one or more universal integrated circuit cards (UICCs), etc., which may store information elements related to mobile subscribers. In addition, the communication device 200 may include other removable and / or fixed memories. The communication device 200 may include volatile memory and / or non-volatile memory. For example, the volatile memory may include a random access memory (RAM), the random access memory including dynamic and / or static RAM, on-chip or off-chip cache memory, etc. The non-volatile memory may be embedded and / or removable, and may include, for example, read-only memory, flash memory, magnetic storage devices (such as hard disks, floppy disk drives, tapes, optical disk drives and / or media), non-volatile random access memory (NVRAM), etc. Like volatile memory, non-volatile memory may include a cache area for temporarily storing data. At least a portion of the volatile and / or non-volatile memory may be embedded in the processor. The memory may store one or more software programs, instructions, information segments, data, etc., which may be used by the apparatus to perform the operations disclosed herein.

[0087] The memory may include an identifier, such as an International Mobile Equipment Identity (IMEI), that can uniquely identify the communication device 200. In an example embodiment, the processor may be configured using computer code stored in the memory to cause the processor to perform the operations disclosed herein.

[0088] Some embodiments disclosed herein may be implemented in software, hardware, application logic, or a combination of software, hardware, and application logic. For example, the software, application logic, and / or hardware may reside in a memory, a processor, or an electronic component. In some example embodiments, the application logic, software, or an instruction set is stored on any of a variety of conventional computer-readable media. In the context of this document, a "computer-readable medium" may be any non-transitory medium that can contain, store, communicate, propagate, or transmit instructions for use by or in conjunction with an instruction execution system, apparatus, or device (such as a computer or data processor circuit system), Figure 2 An example of an instruction execution system, apparatus, or device is depicted in the figure. Computer-readable media may include non-transitory computer-readable storage media, which may be any medium containing or storing instructions for use by or in connection with an instruction execution system, apparatus, or device (such as a computer).

[0089] 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 at least one memory and the computer program code are configured to, together with at least one processor, cause the device to perform at least certain operations, such as an RRC connection to the RAN. The UE is, for example, configured to generate a message (e.g., including a cell ID) to be sent to the RAN via radio (e.g., arriving at a serving cell and communicating with it). The UE may generate, send, and receive an RRC message containing one or more RRC PDUs (packet data units).

[0090] 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). When an RRC connection has been established, the UE is in the RRC_CONNECTED state or in the RRC INACTIVE state.

[0091] In the RRC_CONNECTED state, the UE can store AS (access stratum) context, transmit unicast data to / from the UE, monitor the control channel associated with the shared data channel to determine whether data is scheduled for the data channel, provide channel quality and feedback information, perform neighbor cell measurements and measurement reporting.

[0092] In some embodiments, the communication device 200 (i.e., a UE or user equipment in a network) includes a processor (e.g., at least one data processing entity 201) and a memory (e.g., at least one memory 202). The memory includes a computer program code that causes the communication device 200 to perform operations according to the following reference Figure 6 Describes the method to perform the processing.

[0093] Figure 3 An example embodiment of a control device for a communication system is shown, for example, the control device is to be coupled to and / or used to control a station (such as a RAN node, such as a base station, eNB or gNB), a relay node or a core network node (such as an MME or S-GW or P-GW), or a core network function (such as an AMF / SMF), or a server or host of an access system. The method can be implanted in a single control device or across more than one control device. The control device can be integrated with a node or module of a core network or RAN, or located outside it. In some embodiments, the base station includes a separate control device unit or module. In other embodiments, the control device can be another network element, such as an RNC or a spectrum controller. In some embodiments, the base station can have such a control device, as well as a control device provided in the RNC. The control device 300 can be arranged to provide control of communications in a service area of ​​the system. The control device 300 includes at least one memory 301, at least one data processing unit 302, 303, and an input / output interface 304. Via the interface, the control device 300 can be coupled to a receiver and a transmitter of the base station. The receiver and / or the transmitter may be implemented as a radio front end or a remote radio head.

[0094] Typically, the control device 300 has an antenna that sends and receives radio signals. A radio frequency (RF) transceiver module coupled to the antenna receives an RF signal from the antenna, converts the RF signal into a baseband signal, and sends the baseband signal to a processor (e.g., at least one data processing unit 302, 303). The RF transceiver also converts the baseband signal received from the processor, converts it into an RF signal, and then sends it to the antenna. The processor processes the received baseband signal and calls different functional modules to perform functions in the control device 300. A memory (e.g., at least one memory 301) stores program instructions and data to control the operation of the control device 300. In Figure 3In the example of , the control device 300 also includes a set and circuit of a protocol stack and a control function module. The PDU session processing circuit processes the PDU session establishment and modification process. The policy control module configures policy rules for the UE. The configuration and control circuit provides different parameters to configure and control the UE of related functions (including mobility management and session management). Suitable processors include, for example, a dedicated processor, a digital signal processor (DSP), multiple microprocessors, one or more microprocessors associated with a DSP core, a controller, a microcontroller, an ASIC, an FPGA circuit, and other types of integrated circuits (ICs), and / or state machines.

[0095] In some embodiments, the control device 300 (i.e., a base station, a wireless transmission and / or reception point device, or a network node in a network) includes a processor (e.g., at least one data processing unit 302, 303) and a memory (e.g., at least one memory 301). The memory includes a computer program code, which enables the control device 300 to perform the following reference Figure 6 Describes the method to perform the processing.

[0096] Figure 4A and 4B A Next Generation Radio Access Network (NG-RAN) architecture 400 with a gNB 402 according to 3GPP TS 38.401 v16.9.0 is depicted. The gNB 402 employs NR user / control plane protocols to serve UEs and is connected to the 5GC 401 via a logical NG interface and to other gNBs 402 through an Xn interface to support the exchange of signaling information and forwarding PDUs. Figure 4A The gNB 402 in includes a central unit (i.e., CU) 403 and one or more distributed units (i.e., DU) 404. The CU is a logical node that hosts the RRC, SDAP, and PDCP protocols of the gNB or the RRC and PDCP protocols of the gNB, and controls the operation of one or more DUs 404. The CU 403 terminates at the F1 interface connected to the DU 404 under the CU 403. The DU 404 is a logical node that hosts the RLC, MAC, and PHY layers of the gNB 402, and its operation is partially controlled by the CU 403. One DU 404 supports one or more cells. One cell is supported by one DU 404. The DU 404 terminates at the F1 interface connected to the CU 403.

[0097] One DU 404 is connected to one CU 403 via an F1 interface. NG, Xn, and F1 are logical interfaces. The Xn-C interface interconnects CUs 403 of different gNBs 402. The gNB 402 may also include a CU control plane (CU-CP), multiple CU user planes (CU-UPs), and multiple DUs, which are Figure 4B Described in more detail in .

[0098] It should be noted that NG-RAN may also include a collection of ng-eNBs, which may include ng-eNB-CU and one or more (multiple) ng-eNB-DUs. During the initial transition and deployment phase of 5G NR (New Radio), 4G networks are available everywhere. Many places will not have 5G coverage, and the only available coverage will be using 4G LTE networks. In such locations, ng-eNB allows 5G subscribers to connect to 5G NG-core using the 4G air interface to utilize 5G services. ng-eNB-CU and ng-eNB-DU are connected via the W1 interface.

[0099] Figure 4B A split architecture of the control plane and the user plane for the gNB-CU (i.e., CU-CP and CU-UP) 403 is shown. The CU-CP 405 is a logical node that hosts the control plane portion of the RRC for the gNB 402 and the PDCP protocol for the CU 403. The CU-CP 405 terminates at an E1 interface connected to the CU-UP 406 and an F1-C interface connected to the DU 404. The CU-UP 406 is a logical node that hosts the user plane portion of the PDCP protocol for the CU 403 of the gNB, and the user plane portions of the PDCP protocol and the SDAP protocol for the CU 403 of the gNB 402. The CU-UP 406 terminates at an E1 interface connected to the CU-CP 405 and an F1-U interface connected to the DU 404, for example, in accordance with Section 3.1 of 3GPP TS 38.401 V16.6.0 (2021-07) incorporated by reference. The CU-UP 406 is connected to one CU-CP 405 , a plurality of CU-UPs 406 , and a plurality of DUs 404 under the control of the same CU-CP 405 .

[0100] In some embodiments, the CU-CP 405 includes or is associated with a processor and a memory. The memory includes computer program code that causes the CU-CP 405 to perform the following operations according to the reference Figure 6 Describes the method to perform the processing.

[0101] There can be different functional divisions between the central unit and the distributed units, known as options, for example:

[0102] Option 1 (Type 1A Partition): The functional division in this option is similar to the 1A architecture in DC (Dual Connectivity). RRC is located in the Central Unit (CU). PDCP, RLC, MAC, physical layer, and RF are located in the Distributed Unit (DU).

[0103] Option 2 (3C-like partitioning): The functional partitioning 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.

[0104] Option 3 (partitioning within RLC): Low RLC (part of the RLC functionality), MAC, physical layer and RF are located in a distributed unit. PDCP and High RLC (another part of the RLC functionality) are located in a central unit.

[0105] Option 4 (RLC-MAC split): MAC, physical layer and RF are located in a distributed unit. PDCP and RLC are located in a central unit.

[0106] Further functional divisions are also envisaged, for example according to 3GPP TR 38.801 V14.0.0 (2017-03) section 11, which is incorporated by reference.

[0107] As mentioned above, a base station (such as a gNB) supports different protocol layers, such as Layer 1 (L1) - physical layer. 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, the physical layer provides a transport channel for the MAC sublayer, the MAC sublayer provides a logical channel for the RLC sublayer, the RLC sublayer provides an RLC channel for the PDCP sublayer, the PDCP sublayer provides a radio bearer for the SDAP sublayer, the SDAP sublayer provides a QoS flow for the 5GC, and the control channels include BCCH (Broadcast Control Channel) and PCCH (Paging Control Channel).

[0108] Layer 3 (L3) includes Radio Resource Control (RRC) on the control plane, for example according to 3GPP TS 38.300 V16.6.0 (2021-06) section 6, incorporated by reference. The RRC protocol includes, for example, the following main functions: RRC connection control, measurement configuration and reporting, establishment / modification / release of measurement configurations (e.g., intra-frequency, inter-frequency and inter-RAT measurements), establishment and release of measurement intervals, and measurement reporting.

[0109] RAN (Radio Access Network) nodes or network nodes (e.g. gNB, base station, gNB CU or gNB DU or parts 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) and / or at least one protocol (sub) layer (e.g. layer 2 and / or layer 3) of the RAN (Radio Access Network), the at least one processor and / or at least one memory being configured to support and / or provide and / or process CU and / or DU related functionality and / or features. They may also be implemented using specific components configured to perform corresponding specific tasks, such as layer 3 components performing layer 3 operations, layer 2 components performing layer 2 operations, etc. The central node may, for example, implement CU-CP and / or CP-UP functionality.

[0110] The gNB CU and gNB DU parts may be, for example, co-located or physically separated. The gNB DU may be even further divided, for example into two parts, for example one part including processing equipment and the other part including antennas. 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.

[0111] The gNB-DU supports one or more cells and can therefore serve as a serving cell for a user equipment (UE).

[0112] Figure 5 An exemplary use case of the ICBM process is shown, where a mobile terminal (UE) moves through an exemplary network topology. The traditional cell topology of a radio access network (RAN) (e.g., 5G RAN) is implemented by a base station (gNB), and a gNB may be composed of multiple sub-elements (such as a CU and multiple DUs), as described above. Figure 5 The DU is represented by a hexagon containing three cells (labeled as micro BS 502 and small stars), and the macro BS 501 is represented by a larger star in the middle of the three hexagons.

[0113] When the UE traverses the RAN infrastructure, e.g. Figure 5 As shown by the trajectory of the arrows in the figure, the UE may pass through different cells, which may result in multiple handovers. The number of handovers should be kept low, for example, because each handover procedure introduces a signaling overhead consisting of signaling messages exchanged on the radio path between the UE and the RAN. Note that Figure 5The topology shown is often more complex in practice, the coverage may actually be more diverse due to "shadows, buildings, etc", there are "radio gaps" in a cell, and neighboring cells may provide better coverage. A more realistic "real world example" may result in more ping-pong effects, e.g. when there are islands of cell coverage and when the UE moves through or close to these islands. This may even become increasingly the case if more and more (narrow) beams are used (e.g. in mmWave radio connection scenarios).

[0114] The present disclosure seeks to provide tools for improving such mobility situations in 5G and beyond systems. Generally, the present disclosure includes switching to and / or temporarily adding beams of additional network elements in addition to the current serving network element for the UE to enhance radio coverage while keeping radio-level signaling and process complexity low. More specifically, the present disclosure includes switching to and / or temporarily adding beams of a distributed unit (DU) (hereinafter also referred to as a target distributed node) in addition to the currently serving distributed unit (hereinafter also referred to as a source distributed node), both distributed nodes being controlled by a central unit (CU). To this end, the present disclosure provides an extension of the inter-cell beam management (ICBM) process.

[0115] refer to Figure 6 , some general aspects of the ICBM process are shown. These general aspects can be described by reference to at least three elements, namely a central node (CU, 601), a source distributed node (also referred to as a serving DU, 600) and a target distributed node (target DU, 602). The distributed nodes 600, 602 support distributed unit functionality, layer 1 protocols of the radio access network or layer 2 protocol stacks. The central node 601 supports at least the central unit control plane functionality or layer 3 protocols of the radio access network. The central node 601 controls the source distributed node 600 and the target distributed node 602. The overall process can be represented from the perspective of any one of these network nodes. Optionally, the process can also be described from the perspective of a user equipment.

[0116] The UE is communicatively coupled to the source distributed node 600. For example, the UE is in the RRC_CONNECTED state and exchanges user plane data with the source distributed node (as well as the central node 601 and core network elements at higher layers) over a radio interface. At some point, at 603, the central node 601 determines to initiate an inter-cell beam management procedure for the UE currently served by the source distributed node 600. As further explained below, the determination 603 may be based on measurements of beams for neighboring cells, for which the UE has been previously configured, and based on which the UE periodically sends measurement reports indicating current radio channel conditions to the network (particularly to the central node 602). Then, at 604, the central node 601 sends a setup request to the target distributed node 602 to configure the beam of the cell of the target distributed node 602 for the UE. In an embodiment, the setup request 604 is a UE context setup request carrying multiple information elements (IEs), such as an IE indicating that the UE context setup request is part of an ICBM procedure, an IE with timing advance information, an IE indicating the beam of the target distributed node 602 to be configured for the UE and the UE's most recent measurements for the beam, an IE including packet scheduling information (e.g., physical channel information details, such as physical downlink shared channel, PDSCH, configuration), etc. Optionally, bandwidth part (BWP) information may be added to configure the beam of the target distributed node 602 on the bandwidth part currently used by the UE.

[0117] Accordingly, the target distributed node 602 receives the establishment request 604, checks whether the establishment request 604 can be answered in the affirmative, and if so, returns a establishment response 605 to the central node 601. Accordingly, the central node 601 receives the establishment response 605 from the target distributed node 602. The establishment response 605 carries user equipment-specific beam management configuration information, which is related to the requested beam of the cell of the target distributed node. Then, the configuration information 606 or at least part of the configuration information related to the beam of the cell to which the UE switches or adds the target distributed node is sent by the central node 601 to the source distributed node 600. Accordingly, the source distributed node 600 receives the configuration information 607 related to the beam of the cell of the target distributed node 602. Through the configuration information 606, the source distributed node 600 can dynamically, quickly and efficiently initiate inter-cell beam management operations with the UE at any given time with little overhead, for example depending on the current radio conditions reported by the UE at the low layer.

[0118] Inter-cell beam management operations are, for example, low-level mobility procedures. Low-level mobility (LLM) is a process that uses MAC layer indications to perform cell changes. Determine the use of L1 measurements sent by the UE to send MAC layer indications to the UE. For example, the TCI (Transmission Configuration Indicator) state change indication dynamically provides TCI to the UE in a DCI message. TCI may refer to a high-level (e.g., RRC) configuration or reconfiguration that provides a beam management configuration for the UE to switch to or add a beam of a cell of a target distributed node. Inter-cell beam management operations may also include a dynamic cell switching process. Dynamic cell switching is a process that continuously performs multiple LLM processes without any re-preparation. Preparation here refers to providing the target cell configuration to the UE. The target cell configuration is maintained at the UE and can be reused after the cell change.

[0119] Figure 6 The process enables the source distributed node 600 and the central node 601 to trigger ICBM accordingly by using a cell provided by a target distributed node 602 different from the source distributed node 600. This allows the UE to use ICBM operation to enjoy the additional radio resources of the cell provided by the target DU, which spans a cell different from the cell where the UE is currently located. This effectively extends the coverage of ICBM operation to a wider range of use cases. Since the ICBM process is adopted, the process contains little overhead and is therefore efficient.

[0120] Note that the ICBM process described herein may result in switching the data connection and control connection of the user equipment with the source distributed node (source DU) to the beam of the target distributed node (target DU), i.e., implementing a service cell change. Alternatively, the ICBM process may switch the data connection to the beam of the cell of the target distributed node (target DU), but may maintain the control connection with the service cell of the source distributed node (source DU). In this way, the UE may dynamically switch data connections back and forth between different DUs (more specifically, the current source DU may cause the UE to switch data connections back and forth) while maintaining a control connection with the service cell of the source distributed node.

[0121] like Figure 7Some embodiments depicted include additional messages and additional details of the ICBM process described herein. The ICBM configuration is established at the target DU 703 based on UE measurements. To this end, the UE 700 performs measurements of at least a beam of a cell of the target DU 703 in response to receiving a measurement configuration message from the source DU 701. The UE 700 then reports a set of best neighboring beams so that the CU 702 can determine potential targets for any subsequent ICBM operations. Therefore, the UE 700 sends at least one measurement report to the source DU 701, the at least one measurement report indicating the measurement results of at least one beam of a cell of the target DU 703.

[0122] More specifically, Figure 7 The preparation phase of the ICBM process includes activities 704 to 709 starting from the F1 setup request at 704, where the source DU 701 indicates the ICBM suitable beam list aligned with the timing advance (TA) of the neighboring cell to the CU 702. This information can be configured to the source DU 701, or the source DU 701 obtains this information for operation and maintenance.

[0123] Next, CU 702 sends an F1 Setup Response confirming the F1 Setup Request at 705. An alternative implementation uses a DU Configuration Update procedure that includes Configuration Update Request and Configuration Update Response messages.

[0124] Now, at 706, the UE 700 has established a connection to the cell of the source DU 701, which now acts as the serving DU 701. Subsequently, at 707, the CU 702 configures the UE 700 to perform measurements of the beams of the cell of the target DU 703 (and other beams generally provided by the target DU 703 or any other DU controlled by the CU 702), which measurement configuration may be indicated in the RRCReconfiguration message 707. Accordingly, the UE 700 confirms the configuration with an RRCReconfigurationComplete message at 708 and starts sending measurement reports at 709. The measurement reports may have been filtered and aggregated, so that the layer 3 (L3) data sets the measurement results for the beams of the neighboring cells (target DU 703) to the source DU 701 and further to the CU 702. Therefore, the CU 702 receives at least one measurement report from the UE 700 , the at least one measurement report indicating a measurement result of at least a beam of the cell of the target DU 703 .

[0125] At 710, CU 702 determines to initiate an ICBM process in order to switch UE 700 to the beam of the cell of target DU 703. The ICBM decision is based on a measurement report previously provided by UE 700, which may indicate that the radio conditions provided by the beam in the cell of target DU 703 are significantly better than the current beam utilized by source UE 700 in the cell of source DU 701. To this end, CU 702 sends and source DU 701 receives a context modification request, which is used to request inter-cell beam management related information about the UE to facilitate the ICBM process. In an embodiment, the requested ICBM related information may include timing advance information of UE 700 or possible bandwidth part or measurement configuration. UE 700 may also be configured with two timing advance loops to control the timing advance for different cells, or UE 700 may be configured to report DL synchronization differences between the source cell and the target cell that can be used to detect alignment on the UE side.

[0126] The source DU 701 returns a context modification response 711 to the CU, indicating the requested ICBM related information, such as the timing advance information of the UE, the bandwidth part information of the UE, and the measurement configuration of the UE. If the CU 702 intends to initiate an ICBM process for a beam (e.g., beam A of cell 2), the source DU 701 may also indicate the number of beams aligned with the timing advance (TA) of the neighboring cell and / or the identity of the beam, where the UE 700 has the same TA. Note that for micro cells with zero timing advance, this activity can be skipped and does not occur. The information of the micro cells with zero timing advance is configured to the CU 702.

[0127] At 712, CU 702 sends a setup request to target DU 703 (see Figure 6 ) (such as a UE context setup request), which includes an ICBM indication and packet scheduling related information (e.g., PDSCH configuration), and a beam management configuration related to the target cell 2 for UE 700, for example, beam A of cell 2 should be used for ICBM. In addition, the UE context setup request will also provide at least a portion of the measurement results in the setup request to the target distributed node.

[0128] The following UE context setup response 713 (see Figure 6) provides static beam information to the source DU 701 through the CU 702. In this way, the source DU 701 can use the information to add it to the UE beam management configuration and then notify the CU 702. The target DU 703 merges the beam configuration of the target cell into the beam management configuration of the UE 700, or alternatively, the beam configuration of the target cell is provided in a container to be included in the beam management configuration by the source DU 701.

[0129] At 714, CU 702 indicates the beam configuration obtained from target DU 703 to source DU 701 using another UE context modification request. If the alternative is used, source DU 701 may incorporate the beam configuration into the beam management configuration of UE 700. Otherwise, at 715, source DU 701 may note the beam configuration of the target cell so that UE 700 can be switched to the beam of target DU 703 using the following UE context modification response.

[0130] Next, at 716, CU 702 provides the ICBM configuration to UE 700, for example, via an RRCReconfiguration message, which includes, for example, beam information for beam A of cell 2. Thereby, at 717, UE 700 confirms the reconfiguration with an RRCReconfigurationComplete message. Thereafter, at 718, source DU 701 may initiate an inter-cell beam management operation by sending a signal such as a transmission configuration indication (TCI) to switch UE 700 to beam A of cell 2 of target DU 703. Alternatively, in an embodiment, beam A of cell 2 of target DU 703 is added, resulting in a dual connectivity type scenario that will last for a short time, which is cumbersome for network establishment and subsequent deconfiguration. Now at source DU 701, additional ICBM decisions made locally take advantage of the preparation that occurred in advance, in particular, providing beam-related configuration to UE 700 using RRCReconfiguration 716. The TCI state change is an efficient process with little overhead, since the reference to the RRC configuration of the beam switched to the target DU 703 may be included, for example, in the DCI (Downlink Control Information) sent to the UE. The ICBM decision of the source DU 701 may be based on the current L1 measurement report, such as CSI (Channel State Information).

[0131] Finally, at 719 , UE 700 and target DU 703 begin operating on the newly configured beam A of cell 2 provided by target DU 703 .

[0132] Reference now Figure 8In some embodiments, the ICBM process may also include processing of a bandwidth part (BWP). To further illustrate the various stages of ICBM initiation, assume that the UE is connected to cell 1 of the source DU 701 before performing the ICBM process.

[0133] In this embodiment, CU 702 indicates with UE Context Modification Request 804 that CU 702 intends to initiate an ICBM procedure and requests ICBM related information from source DU 701. With the ICBM related information, source DU 701 indicates the UE's serving BWP, such as X, with UE Context Modification Response at 805.

[0134] Next, at 806, the CU 702 indicates to the target DU 703 that the CU 702 intends to initiate an ICBM process and forwards the BWP information of the UE 700 with a UE context setup request, which includes an indication of the bandwidth portion currently utilized by the UE 700 (e.g., BWP X). The target DU 703 arranges the beam information on the BWP of the UE 700 by, for example, checking whether the UE 700 can be served in BWP X using beam A, because in some inter-cell interference cooperation schemes, the activation of some beams may be restricted to a specific portion of the bandwidth. The target DU 703 indicates this information to the CU 702 with a UE context setup response at 807, i.e., the beam of the target DU 703 will be configured on the first bandwidth portion, e.g., beam A of cell 2 operates in BWP X. Now, the CU 702 knows the BWP of beam A of cell 2, so the CU 702 can determine whether the BWP of the UE 700 needs to be changed.

[0135] In addition, at 808, CU 702 indicates the beam information provided by target DU 703 to source DU 701 using another UE context modification request. Source DU 701 can then merge the information into the UE context and provide the information back to CU 702 using another UE context modification request 809.

[0136] Next, at 810, CU 702 reconfigures the UE with new beam information of beam A (with BWP X of target DU 703) from cell 2 through RRCReconfiguration. At 811, UE 700 sends RRCReconfigurationComplete back to CU 702 to confirm the configuration.

[0137] At 812, the source DU 701 determines to switch the BWP X of the UE 700 to another BWP (e.g., Y), so the source DU 701 requests a UE context modification. Therefore, the CU 702 receives an indication from the source DU 701 to switch the first bandwidth portion (e.g., BWP X) currently utilized by the terminal to the second bandwidth portion (e.g., BWP Y). The reason for the BWP switching may be, for example, for energy saving purposes, so the UE 700 is switched to a narrower bandwidth so that when the UE 700 monitors in the narrower bandwidth, the UE consumes less energy. In addition, the BWP switching may be performed for load balancing reasons. In this case, the UE 700 may be moved to a bandwidth with less load, making it easier to keep the UE in a separate BWP for the cell. Additionally, considering the UE capabilities, which are generally classified by the UE category and the current BWP configuration situation, the BWP switching may be indicated to the CU 702. If the UE is a category 1 UE, the UE cannot generally be configured with more than one BWP. However, if the UE is a Category 2+ UE, and the UE has been configured with 4 BWPs, but the source DU 701 is preparing to switch the UE to another BWP in addition to the 4 BWPs that have been configured. In both cases, the BWP switch is indicated to the CU 702. The UE Context Modification Response 813 of the source DU 701 indicates to the CU 702 that the BWP is switched from X to Y. The CU 702 confirms the change and indicates that the beam A of cell 2 of the target DU 703 cannot be used with the current configuration in BWP X.

[0138] Next, at 814, the CU 702 determines that the information provided by the target DU 703 from the UE context setup response 807 (BWP X for beam A of cell 2) does not match the new BWP Y of the UE, and a BWP update is to be requested. Therefore, the CU 702 sends a modification request indicating the second bandwidth portion to the target DU 703, for example, the CU 702 indicates the new BWP Y to the target DU 703 using another UE context modification request 815, so that the target DU 703 can update the BWP X for beam A of cell 2. Then, the target DU 703 indicates to the CU 702 using another corresponding UE context modification response 816 that the update of the BWP for beam A is successful, that is, beam A is now configured on BWP Y. Therefore, the CU 702 receives a modification response from the target DU 703, which confirms that the beam of the target DU 703 is reconfigured to the second bandwidth portion, for example, BWP Y.

[0139] At 817, CU 702 indicates to source DU 701 that the beam of target DU 703 will be reconfigured to the second bandwidth portion, and source DU 701 incorporates the beam information of target DU 703 into the UE context, i.e., beam A of cell 2 on BWP Y can now be used. Thereafter, at 818, source DU 701 indicates this information to CU 702 using a UE context modification response. Source DU 701 uses the updated beam configuration as an indication that the UE has been configured with the second BWP.

[0140] In the following activities, at 819 , the UE 700 is again configured in the second BWP Y with the beam A of the cell 2 of the target DU 703 through the RRCReconfiguration message. Therefore, the UE 700 confirms the configuration to the CU 702 with the RRCReconfigurationComplete message 820 .

[0141] Thereafter, at 821, since connectivity issues or local impacts may have a negative impact on the radio channel between UE 700 and source DU 701, source DU 701 may determine to switch UE 700 to beam A of cell 2. If source DU 701 has determined to switch beams, source DU 701 may send a low-layer signal such as a TCI state change message 822 (using a MAC CE-based indication, or a DCI indicating TCI state activation using a MAC CE including additional information (such as PCI ID)) at 821. Finally, at 823, UE 700 switches to beam A of cell 2 or adds beam A of cell 2 to the active beam list and operates accordingly.

[0142] Figure 8 The embodiment enables CU 702 to update the beam configuration related to ICBM if the bandwidth portion at the UE changes. CU 702 knows the BWP configuration of the target cell for ICBM, which enables CU 702 to request an update of the configuration if the UE is moved to another BWP during the ICBM preparation phase. This provides higher reliability for ICBM operation across BWP switching.

[0143] In by Fig. 9 In some embodiments described, the ICBM process can consider multiple possible BWPs on the UE side from the beginning. Figure 8 During the ICBM process, the UE 700 is connected to the cell 1 of the source DU 701 before performing any ICBM process.

[0144] Fig. 9The process starts at 901, with the CU 702 indicating in a UE context setup request or alternatively in a UE context modification request that the CU 702 intends to initiate an ICBM process and requesting ICBM related information from the source DU 701, such as a plurality of BWPs suitable for the UE 700 to communicate with the source DU 701. Using the ICBM related information, the source DU 702 indicates the UE's serving BWP (e.g., X) using a UE context setup response at 902, and additionally, the source DU 701 indicates to the CU 702 a list of a plurality of BWPs (e.g., Y and Z) that are suitable for communication between the UE 700 and the target DU 703. If the UE 700 belongs to category 2+, then a configuration supporting more than one BWP may be applicable.

[0145] Now, at 903, CU 702 may determine to request the beam of target DU 703 on a possible BWP. This decision may be based on signaling optimization, which means not updating beam A of cell 2 every time a BWP is switched during the ICBM preparation phase, or the decision may be based on resource reservation cost at target DU 703.

[0146] At 904, CU 702 may indicate the requested BWP list (for X, Y, and Z) to target DU 703 in a UE context setup request. Thereafter, at 905, target DU 703 prepares the beam of cell 2 on multiple BWPs (X, Y, and Z) and indicates it back to CU 703 using a UE context setup response 905.

[0147] Finally, at 906, UE 700 and source DU 701 are configured with beam A of cell 2 on multiple BWPs, provided that target DU 703 supports the BWP of UE 700. The configuration information includes a subset of multiple bandwidth parts to enable UE 700 to operate any bandwidth part of the subset of multiple bandwidth parts on at least one beam of the cell of target DU 703. Then, if UE 700 is handed over to another BWP, no update is required. Now, when source DU 701 decides to initiate a low-level cell change procedure (such as signaling a TCI state change), UE 700 is ready to operate on beam A of cell 2 of target DU 703.

[0148] Additionally, Fig. 9An embodiment of the process is that the CU 702 is equipped with knowledge of possible BWPs so that the source DU 701 can configure the UE. This enables the CU 702 to request a specific BWP from the target DU 703 accordingly. This can reduce the signaling load at the F1 interface, because beam switching or beam addition prepared with a suitable BWP can reduce the reconfiguration in the time before the actual beam switching is performed through the low-level cell change process (such as the above reference 1). Figure 8 BWP reconfiguration discussed above).

[0149] In some embodiments, reference is now made to Fig.10 , the ICBM process is defined at another level of granularity (such as a central node 702 containing a CU control plane CU-CP 1000 and a CU user plane CU-UP 1001). In such an embodiment, the ICBM process is initiated usually with Figure 7 The process corresponds to that of , but additionally includes further process activities between the CU-UP 1001 of the target DU and the target DU 703.

[0150] Starting again at 706, UE 700 is connected to source DU 701 and operates normally with cell 1 before any ICBM procedures.

[0151] and Figure 7 Similarly, the CU-CP 1000 reconfigures the UE 700 using an RRCReconfiguration message 1003 to report measurements of the beams of the neighboring cells controlled by the target DU 703. The UE confirms the reconfiguration using an RRCReconfigurationComp message 1004, after which it starts sending measurements of the beams of the neighboring cells. As a result of the reconfiguration, an L3 measurement (i.e., beam measurements that are aligned by the TA, permanently available, or filtered with sufficient range) report 1005 including beam information of beam A of cell 2 is sent back to the CU-CP.

[0152] Now, the CU-CP 1000 sends a UE context setup request 1006 to the target DU 703 and instructs to start the ICBM process again including beam management and data packet scheduling (e.g., PDSCH configuration) related information. The target DU 703 combines the beam configuration of the target cell 2 and responds with a corresponding UE context setup response including the beam management configuration of the UE 700, or as described above, the target DU sends the beam management configuration in a container.

[0153] The following activities 1008 to 1013 and Figure 7Activities 714 to 719 correspond to those of the ICBM process, except that CU 702 is replaced by CU-CP 1000. Therefore, the use of CU-UP 1001 in the ICBM process is briefly discussed below.

[0154] After UE 700 is configured with beam A of cell 2 and can switch to the beam of target DU 703, or alternatively "borrow" (temporarily assign) the beam of target DU 703, the source DU receives a confirmation from UE 700 indicating that UE 700 is successfully configured to operate on at least one beam of target DU 703, i.e., UE 700 uses beam A of cell 2 of target DU 703. Then, source DU 701 indicates the new configuration by sending a response to CU-CP 1000 at 1014.

[0155] Next, the CU-CP 1000 causes a bearer establishment or modification by sending a bearer modification request 1015 to the target CU-UP 1001 to enable user data transmission through at least one beam of the target DU 703. Immediately thereafter, the CU-UP 1000 sends a bearer modification response 1016 to confirm the bearer. Finally, the CU-UP 1001 can use this information for the required bearer modification of the target DU 703, and can start forwarding the user data of the terminal to the target DU 703 through beam A of cell 2 at 1017. In this way, the UE 700 can now access a fully configured beam of another cell of the corresponding other DU for the ICBM process to avoid switching when it is completely unnecessary. The UE 700 is now able to send and / or receive user data through beam A of cell 2 of the target DU 703 at 1018.

[0156] It should be understood that the apparatus described herein may include or be coupled to other units or modules for or for transmission and / or reception, such as a radio part or a radio head. Although the apparatus has been described as one entity, different modules and memories may be implemented in one or more physical or logical entities.

[0157] It should be noted that although some embodiments have been described in relation to LTE and 5G NR, similar principles may be applied to other related networks and communication systems where fast connection reestablishment is required. Therefore, although certain embodiments are described above by way of example with reference to certain example architectures for wireless networks, technologies and standards, the embodiments may be applied to any other suitable form of communication system in addition to the communication system shown and described herein.

[0158] It should be noted herein that while exemplary embodiments are described above, various changes and modifications may be made to aspects of the present disclosure without departing from the scope of the present invention.

[0159] In general, various embodiments may be implemented in hardware or dedicated circuits, software, logic, or any combination thereof. Some aspects of the invention may be implemented in hardware, while other aspects may be implemented in firmware or software, which may be executed by a controller, microprocessor, or other computing device, although the disclosure is not limited thereto. Although various aspects of the disclosure are illustrated and described as block diagrams, flow charts, or using some other graphical representation, it should be understood that, as non-limiting examples, the boxes, devices, systems, techniques, or methods described herein may be implemented in hardware, software, firmware, dedicated circuits or logic, general hardware or controllers or other computing devices, or some combination thereof.

[0160] Embodiments of the present disclosure may be implemented by computer software executed by a data processor of a mobile device (such as in a processor entity), or by hardware, or by a combination of software and hardware. Computer software or programs (also referred to as program products) include software routines, applets and / or macros that can be stored in a data storage medium of any readable device, and they include program instructions for performing specific tasks. A computer program product may include one or more computer executable components that are configured to perform an embodiment when the program is running. One or more computer executable components may be at least one software code or a portion thereof.

[0161] It should also be noted in this regard that any box of the logic flow diagram in the accompanying drawings can represent program steps, or interconnected logic circuits, boxes and functions, or a combination of program steps and logic circuits, boxes and functions. The software can be stored on a physical medium (e.g., a memory chip, or a memory block implemented in a processor), on a magnetic medium (such as a hard disk or a floppy disk), and on an optical medium (e.g., a DVD and its data variant CD). The physical medium is a non-transient medium.

[0162] The memory may be of any type suitable for the local technical environment and may be implemented using any suitable data storage technology, such as semiconductor-based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory, and removable memory. The data processor may be of any type suitable for the local technical environment and may include, as non-limiting examples, one or more of the following: a general-purpose computer, a special-purpose computer, a microprocessor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), an FPGA, a gate-level circuit, and a processor based on a multi-core processor architecture.

[0163] Embodiments of the present disclosure may be practiced in various components, such as integrated circuit modules. The design of integrated circuits is generally a highly automated process. Complex and powerful software tools are available to convert a logic level design into a semiconductor circuit design ready to be etched and formed on a semiconductor substrate.

[0164] The foregoing description has provided a complete and informative description of exemplary embodiments of the present disclosure by way of non-limiting examples. However, when read in conjunction with the accompanying drawings and the appended claims, various modifications and adjustments may be apparent to those skilled in the relevant art in view of the foregoing description. However, all such and similar modifications taught by the present disclosure will still fall within the scope of the present invention as defined in the appended claims. In fact, there are additional embodiments that include a combination of one or more embodiments with any other embodiments previously discussed.

Claims

1. An inter-cell beam management method for a radio access network, the radio access network comprising a source distributed node and a target distributed node, the source distributed node and the target distributed node being controlled by a central node of the radio access network, the method comprising: At the central node, In response to determining to initiate an inter-cell beam management process for a user equipment served by the source distributed node, sending a setup request to the target distributed node to configure a beam of a cell of the target distributed node for the user equipment; receiving a setup response from the target distributed node, the setup response having user equipment-specific beam management configuration information relating to the requested beam of the cell of the target distributed node; At least a portion of the configuration information is sent to the source distributed node so that the source distributed unit can initiate an inter-cell beam management operation with the user equipment so that the user equipment can operate on the beam of the cell of the target distributed node.

2. The method according to claim 1, wherein the inter-cell beam management operation includes a low-layer mobility procedure or a dynamic cell switching procedure.

3. The method according to claim 1 or 2, wherein the establishment request includes inter-cell beam management instructions and / or packet scheduling related information.

4. A method according to any one of claims 1 to 3, wherein the establishment request includes an indication of a bandwidth portion currently utilized by the user equipment, and the establishment response includes an indication that the beam of the cell of the target distributed node is to be configured on the first bandwidth portion.

5. The method according to any one of claims 1 to 4, further comprising: At the central node, Sending a context modification request to the source distributed node requesting information related to inter-cell beam management of the user equipment; A context modification response is received from the source distributed node, the context modification response indicating inter-cell beam management related information about the user equipment.

6. The method according to any one of claims 1 to 5, wherein the inter-cell beam management related information indicates at least one of the following: timing advance information of the user equipment, bandwidth part information of the user equipment, and measurement configuration of the user equipment.

7. A method according to any one of claims 1 to 6, wherein the method further comprises: At the central node, configuring the user equipment to perform measurement of at least the beam of the cell of the target distributed node; as well as At least one measurement report is received from the user equipment, the at least one measurement report indicating a result of the measurement of at least the beam of the cell of the target distributed node.

8. The method according to claim 7, further comprising: At the central node, At least a portion of the results of the measurements are provided in the setup request to the target distributed node.

9. The method according to any one of claims 1 to 8, further comprising: At the central node, An indication of the number of beams and / or identities of beams aligned with a neighboring cell timing advance is received from the source distributed node.

10. The method according to any one of claims 1 to 9, further comprising: At the central node, determining a bandwidth portion switch for the user equipment to change the user equipment from a first bandwidth portion to a second bandwidth portion; Sending an indication of switching the bandwidth portion for the user equipment to the target distributed node; receiving a confirmation from the target distributed node that the beam of the cell of the target distributed node is reconfigured according to the bandwidth portion switching for the user equipment; as well as The user equipment is reconfigured using the second bandwidth portion.

11. The method according to claim 10, further comprising: At the central node, receiving, from the source distributed node, an indication to switch the first bandwidth portion of the user equipment to the second bandwidth portion; Instructing the source distributed node not to use the beam of the cell of the target distributed node; sending a modification request indicating the second bandwidth portion to the target distributed node; receiving a modification response from the target distributed node, the modification response confirming that the beam of the target distributed node is reconfigured to the second bandwidth portion; as well as The source distributed node is indicated that the beam of the cell of the target distributed node is to be reconfigured to the second bandwidth portion.

12. A method according to any one of claims 1 to 11, wherein the establishment request indicates a plurality of bandwidth parts suitable for the user equipment to communicate with the source distributed node, and the establishment response indicates at least a subset of the plurality of bandwidth parts, the subset of the plurality of bandwidth parts being suitable for the beam of the cell of the target distributed node, and wherein the configuration information includes the subset of the plurality of bandwidth parts so that the user equipment can operate on any bandwidth part of the subset of the plurality of bandwidth parts on the beam of the cell of the target distributed node.

13. The method according to any one of claims 1 to 12, further comprising: At the central node, receiving an acknowledgment from the source distributed node, the acknowledgment indicating successful configuration of the user equipment to operate on the beam of the target distributed node; Performing bearer configuration together with the target distributed node to implement user data transmission of the beam through the target distributed node; as well as The user data for the user equipment is forwarded to the target distributed node.

14. An inter-cell beam management method for a radio access network, the radio access network comprising a source distributed node and a target distributed node, the source distributed node and the target distributed node being controlled by a central node of the radio access network, the method comprising: At the source distributed node, receiving, from the central node, configuration information related to a beam of a cell of the target distributed node; An inter-cell beam management operation is initiated with a user equipment to enable the user equipment to operate on the beam of the cell of the target distributed node.

15. The method of claim 14, wherein the inter-cell beam management operation comprises a low-layer mobility procedure or a dynamic cell switching procedure.

16. The method according to claim 14 or 15, wherein the configuration information includes inter-cell beam management instructions and / or packet scheduling related information.

17. The method according to any one of claims 14 to 16, wherein the configuration information indicates: a bandwidth portion of the beam currently used by the user equipment and the source distributed node to be used for the cell of the target distributed node.

18. The method according to any one of claims 14 to 17, further comprising: At the source distributed node, receiving, from the central node, a context modification request for requesting inter-cell beam management related information about the user equipment; A context modification response is sent to the central node, where the context modification response indicates inter-cell beam management related information about the user equipment.

19. The method according to claim 18, wherein the inter-cell beam management related information indicates at least one of the following: timing advance information of the user equipment, bandwidth part information of the user equipment, and measurement configuration of the user equipment.

20. The method of claim 19, wherein the bandwidth part information of the user equipment indicates a plurality of bandwidth parts suitable for the user equipment to communicate with the source distributed node, and wherein the configuration information includes at least a subset of the plurality of bandwidth parts so that the user equipment can operate on any bandwidth part of the subset of the plurality of bandwidth parts on the beam of the cell of the target distributed node.

21. The method according to any one of claims 12 to 16, further comprising: At the source distributed node, An indication of the number of beams and / or identities of beams aligned with the neighboring cell timing advance is sent to the central node.

22. The method according to any one of claims 12 to 17, further comprising: At the source distributed node, sending an instruction to the central node to switch the first bandwidth part of the user equipment to the second bandwidth part; receiving, from the central node, an indication of not using the beam of the cell of the target distributed node; receiving, from the central node, an indication that the beam of the target distributed node is to be reconfigured to the second bandwidth portion; The reconfiguration to the second bandwidth portion is indicated to the user equipment.

23. The method according to any one of claims 12 to 18, further comprising: At the source distributed node, An acknowledgement is sent to the central node, the acknowledgement indicating successful configuration of the user equipment to operate on the beam of the target distributed node, so that the central node can forward user data for the user equipment to the target node.

24. A central node for inter-cell beam management in a radio access network, the radio access network comprising a source distributed node and a target distributed node, the source distributed node and the target distributed node being controlled by the central node of the radio access network, the central node comprising at least one processor and at least one memory comprising computer program code, the computer program code when executed by the at least one processor, causing the central node to: In response to determining to initiate an inter-cell beam management process for a user equipment served by the source distributed node, sending a setup request to the target distributed node to configure a beam of a cell of the target distributed node for the user equipment; receiving a setup response from the target distributed node, the setup response having user equipment-specific beam management configuration information relating to the requested beam of the cell of the target distributed node; At least a portion of the configuration information is sent to the source distributed node so that the source distributed unit can initiate an inter-cell beam management operation with the user equipment so that the user equipment can operate on the beam of the cell of the target distributed node.

25. The central node of claim 24, wherein the inter-cell beam management operation comprises a low-layer mobility procedure or a dynamic cell switching procedure.

26. The central node according to claim 24 or 25, wherein the establishment request includes inter-cell beam management instructions and / or packet scheduling related information.

27. A central node according to any one of claims 24 to 26, wherein the establishment request comprises an indication of a bandwidth portion currently utilized by the user equipment, and the establishment response comprises an indication that the beam of the cell of the target distributed node is to be configured on the first bandwidth portion.

28. The central node according to any one of claims 24 to 27, further being caused to: Sending a context modification request to the source distributed node requesting information related to inter-cell beam management of the user equipment; A context modification response is received from the source distributed node, the context modification response indicating inter-cell beam management related information about the user equipment.

29. The central node according to claim 28, wherein the inter-cell beam management related information indicates at least one of the following: timing advance information of the user equipment, bandwidth part information of the user equipment, and measurement configuration of the user equipment.

30. The central node according to any one of claims 24 to 29, further being caused to: configuring the user equipment to perform measurement of at least the beam of the cell of the target distributed node; and At least one measurement report is received from the user equipment, the at least one measurement report indicating a result of the measurement of at least the beam of the cell of the target distributed node.

31. The central node according to claim 30, further being caused to: At least a portion of the results of the measurements are provided in the setup request to the target distributed node.

32. The central node according to any one of claims 24 to 31, further configured to: An indication of the number of beams and / or identities of beams aligned with a neighboring cell timing advance is received from the source distributed node.

33. The central node according to any one of claims 20 to 26, further being caused to: determining a bandwidth portion switch for the user equipment to change the user equipment from a first bandwidth portion to a second bandwidth portion; Sending an indication of switching the bandwidth portion for the user equipment to the target distributed node; receiving a confirmation from the target distributed node that the beam of the cell of the target distributed node is reconfigured according to the bandwidth portion switching for the user equipment; as well as The user equipment is reconfigured using the second bandwidth portion.

34. The central node according to claim 33, further being caused to: receiving, from the source distributed node, an indication to switch the first bandwidth portion of the user equipment to the second bandwidth portion; Instructing the source distributed node not to use the beam of the cell of the target distributed node; sending a modification request indicating the second bandwidth portion to the target distributed node; receiving a modification response from the target distributed node, the modification response confirming that the beam of the target distributed node is reconfigured to the second bandwidth portion; as well as The source distributed node is indicated that the beam of the cell of the target distributed node is to be reconfigured to the second bandwidth portion.

35. A central node according to any one of claims 24 to 34, wherein the establishment request indicates a plurality of bandwidth parts suitable for the user equipment to communicate with the source distributed node, and the establishment response indicates at least a subset of the plurality of bandwidth parts, the subset of the plurality of bandwidth parts being suitable for the beam of the cell of the target distributed node, and wherein the configuration information includes the subset of the plurality of bandwidth parts to enable the user equipment to operate on any bandwidth part of the subset of the plurality of bandwidth parts on the beam of the cell of the target distributed node.

36. The central node according to any one of claims 24 to 35, further being caused to: receiving an acknowledgment from the source distributed node, the acknowledgment indicating successful configuration of the user equipment to operate on the beam of the target distributed node; Performing bearer configuration together with the target distributed node to implement user data transmission of the beam through the target distributed node; as well as The user data for the user equipment is forwarded to the target distributed node.

37. A source distributed node for inter-cell beam management in a radio access network, the radio access network comprising a source distributed node and a target distributed node, the source distributed node and the target distributed node being controlled by a central node of the radio access network, the source distributed node comprising at least one processor and at least one memory comprising computer program code, the computer program code when executed by the at least one processor, causing the source distributed node to: receiving, from the central node, configuration information related to a beam of a cell of the target distributed node; An inter-cell beam management operation is initiated with a user equipment to enable the user equipment to operate on the beam of the cell of the target distributed node.

38. The source distributed node of claim 37, wherein the inter-cell beam management operation comprises a low-layer mobility procedure or a dynamic cell switching procedure.

39. The source distributed node according to claim 37 or 38, wherein the configuration information includes inter-cell beam management instructions and / or packet scheduling related information.

40. The source distributed node according to any one of claims 37 to 39, wherein the configuration information indicates: a bandwidth portion of the beam currently used by the user equipment and the source distributed node to be used for the cell of the target distributed node.

41. A source distributed node according to any one of claims 37 to 40, further causing the source distributed node to: receiving, from the central node, a context modification request for requesting inter-cell beam management related information about the user equipment; A context modification response is sent to the central node, where the context modification response indicates inter-cell beam management related information about the user equipment.

42. The source distributed node according to claim 41, wherein the inter-cell beam management related information indicates at least one of the following: timing advance information of the user equipment, bandwidth part information of the user equipment, and measurement configuration of the user equipment.

43. A source distributed node according to claim 42, wherein the bandwidth part information of the user equipment indicates a plurality of bandwidth parts suitable for the user equipment to communicate with the source distributed node, and wherein the configuration information includes at least a subset of the plurality of bandwidth parts so that the user equipment can operate on any bandwidth part of the subset of the plurality of bandwidth parts on the beam of the cell of the target distributed node.

44. A source distributed node according to any one of claims 37 to 43, further causing the source distributed node to: An indication of the number of beams and / or identities of beams aligned with the neighboring cell timing advance is sent to the central node.

45. A source distributed node according to any one of claims 37 to 44, further causing the source distributed node to: sending an instruction to the central node to switch the first bandwidth part of the user equipment to the second bandwidth part; receiving, from the central node, an indication of not using the beam of the cell of the target distributed node; receiving, from the central node, an indication that the beam of the target distributed node is to be reconfigured to the second bandwidth portion; The reconfiguration to the second bandwidth portion is indicated to the user equipment.

46. ​​A source distributed node according to any one of claims 37 to 45, further causing the source distributed node to: An acknowledgement is sent to the central node, the acknowledgement indicating successful configuration of the user equipment to operate on the beam of the target distributed node, so that the central node can forward user data for the user equipment to the target node.

47. A non-transitory computer readable storage medium storing computer program instructions which, when executed by at least one processor, cause a central node of a radio access network to perform the method according to any one of claims 1 to 13.

48. A non-transitory computer readable storage medium storing computer program instructions which, when executed by at least one processor, cause a source distributed node of a radio access network to perform the method according to any one of claims 14 to 23.

49. A computer program comprising instructions which, when executed by at least one processor, cause a central node of a radio access network to perform a method according to any one of claims 1 to 13.

50. A computer program comprising instructions which, when executed by at least one processor, cause a source distributed node of a radio access network to perform a method according to any one of claims 14 to 23.

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