User equipment mobility management

Abstract

In the field of wireless communications, efficient management of the movement of a mobile device can ensure a continuous communication connection. A user equipment (UE) may have improved mobility management. UE mobility may be managed by transmitting mobility assistance information. The mobility assistance information may include a target cell indication, a delivery interrogation indication, or a serving beam measurement configuration.

Description

Technical Field

[0001] This application relates to wireless communication. More specifically, an improved user equipment mobility management method in a mobile device communication system is provided. Background Art

[0002] Wireless communication technologies are driving the world towards an increasingly connected and networked society. Wireless communication relies on efficient network resource management and allocation between user mobile stations and radio access network nodes (including but not limited to radio base stations). The new generation of networks is expected to provide high-speed, low-latency, and ultra-reliable communication capabilities and meet the needs of different industries and users. User mobile stations or user equipment (UE) are becoming increasingly complex, and the amount of data transmitted is continuously increasing. To improve communication and meet the reliability requirements of vertical industries while supporting new generation network services, communication improvements should be made. Summary of the Invention

[0003] This application relates to methods, systems, and apparatuses for wireless communication, where user equipment UE can have improved mobility management. Mobility assistance information can be transmitted for managing UE mobility. The mobility assistance information can include target cell indication, delivery inquiry indication, or serving beam measurement configuration.

[0004] In one embodiment, a wireless communication method includes: a base station distributed unit DU receives a target cell indication; the base station DU activates one or more beams indicated by the target cell indication. The target cell indication includes a list of synchronization signal block (SSB) indices to be activated. The target cell indication is provided by a base station centralized unit CU. The base station CU receives one or more successfully activated beams from the base station DU. The list of SSB indices to be activated is included in a handover request message from another base station. The handover confirmation message response from the base station centralized unit CU includes the successfully activated beams. The receiving action and the activation action are part of context setup communication or context modification communication.

[0005] In another embodiment, a wireless communication method includes: a base station distributed unit (DU) receives delivery inquiry indication information sent by a base station centralized unit (CU), where the delivery inquiry indication information indicates whether to report that a user equipment (UE) can receive broadcast information in a target cell; and the base station DU determines whether the UE can receive broadcast information in the target cell based on the delivery inquiry indication information. The delivery inquiry indication information includes a system information block (SIB) delivery inquiry indication. The method includes: the base station DU sends a broadcast reception indication to the base station CU, where the broadcast reception indication is used to indicate whether the UE can receive broadcast information in the target cell or whether dedicated signaling for SIB delivery is required. The base station CU determines the type of SIB to be delivered to the UE based on the broadcast reception indication. After a successful handover, the base station CU delivers at least one piece of SIB block information in the SIB block information to the UE through dedicated RRC signaling. The receiving action and the sending action are partial actions in context setup communication or context modification communication.

[0006] In another embodiment, a wireless communication method includes: a base station distributed unit (DU) receives a serving beam measurement configuration; and records serving synchronization signal block (SSB) information based on the serving beam measurement configuration. The method includes at least one of the following: an indication for requesting a report of the last serving SSB; an indication for requesting a report of one or more SSBs serving the UE within a defined time period; an indication for requesting a report of the residence time of the UE on each serving SSB. The base station DU reports the recorded serving SSB information to the base station centralized unit (CU). When the serving beam measurement configuration is not received, the base station DU reports the index of the last serving SSB to the base station CU. The base station DU includes the report in the UE context release complete message during the UE context release procedure. The receiving action is performed during user equipment (UE) context setup or UE modification.

[0007] In one implementation, a wireless communication device includes a processor and a memory, and the processor is configured to read code from the memory to implement any of the implementations discussed above.

[0008] In one implementation, a computer program product includes computer-readable program medium code stored thereon, and the code, when executed by a processor, causes the processor to implement any of the implementations discussed above.

[0009] In some embodiments, there is a wireless communication device that includes a processor and a memory. The processor is configured to read code from the memory and implement any method described in any of the embodiments. In some embodiments, a computer program product includes computer-readable program medium code stored thereon, which, when executed by a processor, causes the processor to implement any method described in any of the embodiments. The above aspects and other aspects and their implementations are described in more detail in the drawings, the specification, and the claims. Description of the Drawings

[0010] Figure 1 An exemplary base station is shown.

[0011] Figure 2 An exemplary random access (RA) messaging environment is shown.

[0012] Figure 3 The network architecture of a base station central unit (CU) and a base station distributed unit (DU) is shown.

[0013] Figure 4 Embodiments of user equipment (UE) mobility within a DU are shown.

[0014] Figure 5 Embodiments of user equipment (UE) mobility within a CU and between DUs are shown.

[0015] Figure 6 Embodiments of user equipment (UE) mobility between CUs are shown.

[0016] Figure 7 An exemplary mobility assistance information is shown.

[0017] Figure 8 An exemplary serving beam measurement configuration is shown.

[0018] Figure 9 Embodiments of UE mobility between different base stations using target cell indication information are shown.

[0019] Figure 10 Embodiments of UE mobility between different base stations using delivery inquiry indication information are shown.

[0020] Figure 11 Embodiments of UE mobility between different base stations using serving beam measurement configuration information are shown.

[0021] Figure 12 Embodiments of UE mobility within a base station within a DU using target cell indication information are shown.

[0022] Figure 13 Illustrates an embodiment of UE mobility within a base station in a DU by delivering interrogation indication information.

[0023] Figure 14 Illustrates an embodiment of UE mobility within a base station in a DU by using serving beam measurement configuration information.

[0024] Figure 15 Illustrates an embodiment of paging a UE with restricted mobility within a base station in a DU. Detailed Embodiments

[0025] This application will be described in detail based on the following drawings, which form a part of the content of this application and show specific implementation manners by way of examples. However, please note that this application can be embodied in various different forms, and therefore, the subject matter covered or claimed is intended to be construed as not limited to any of the implementation manners to be described below.

[0026] Throughout the specification and claims, in addition to the explicitly stated meanings, terms may also have nuanced meanings implied or suggested in the context. Similarly, as used herein, the phrase "in one embodiment" or "in some embodiments" does not necessarily refer to the same embodiment, and the phrase "in another embodiment" or "in other embodiments" does not necessarily refer to different embodiments. As used herein, the phrase "in one implementation" or "in some implementations" does not necessarily refer to the same implementation, and the phrase "in another implementation" or "in other implementations" does not necessarily refer to different implementations. For example, the claimed subject matter is intended to include, in whole or in part, combinations of exemplary embodiments or implementations.

[0027] Generally, terms can be understood, at least in part, from their usage in context. For example, terms such as "and," "or," and "and / or" as used herein can include a variety of meanings that can depend, at least in part, on the context in which such terms are used. Generally, if "or" is used to associate a list such as A, B, or C, then "or" is intended to mean A, B, and C (used herein in an inclusive sense) as well as A, B, or C (used herein in an exclusive sense). Additionally, the term "one or more" or "at least one" as used herein can be used to describe any feature, structure, or characteristic in a singular sense or can be used to describe a combination of features, structures, or characteristics in a plural sense, at least in part depending on the context. Similarly, terms such as "a" or "the" can also be understood to convey a singular usage or to convey a plural usage, at least in part depending on the context. Additionally, the term "based on" or "determined by" can be understood to not necessarily be intended to convey a set of exclusive factors, but can allow for the existence of additional factors that are not necessarily explicitly described, again at least in part depending on the context.

[0028] Radio Resource Control (RRC) is a protocol layer between the UE and the base station at the IP level (network layer). There may be multiple Radio Resource Control (RRC) states, such as the RRC_CONNECTED state, the RRC_INACTIVE state, and the RRC_IDLE state. RRC messages are transported via the Packet Data Convergence Protocol (PDCP). As described above, the UE can send data via the Random Access Channel (RACH) protocol scheme or the Configured Grant (CG) scheme. The CG can reduce the waste of periodically allocated resources by enabling multiple devices to share periodic resources. The base station or node can allocate CG resources to eliminate packet transmission delays and improve the utilization rate of the allocated periodic radio resources. The CG scheme is just one example of a communication protocol scheme, and other possible examples include, but are not limited to, RACH. The wireless communication described herein can be achieved via radio access.

[0029] A user equipment (UE) device can move between different nodes or cells. In this case, a handover operation, or a change / addition operation, can occur to enhance the network reliability of the UE during movement. Based on several potential target cells (which are referred to as candidate cells), the movement can be from a source cell to a target cell. The movement between cells can also include several target cells as potential candidate cells. Conditional handover ("CHO") and conditional PSCell addition / change ("CPAC") will be described below. CPAC can include conditional PSCell change ("CPC") and / or conditional PSCell addition ("CPA"). Conditional handover ("CHO") can reduce the handover interruption time and improve the mobility reliability. CHO is a handover performed by the UE and is triggered when one or more execution conditions are met. The UE can evaluate the execution conditions when receiving the CHO configuration, and once the handover is triggered, it can stop evaluating the execution conditions. The CHO configuration can include the candidate PCell configuration generated by the candidate target node and the corresponding execution conditions for the candidate cell.

[0030] Conditional PSCell addition / change ("CPAC") can include the network configuration that the UE has for initiating access to the candidate PSCell to consider whether the PSCell is suitable for SN addition or SN change, and the SN change includes in-SN change. This consideration can be based on the configured conditions. The UE in the radio access network can operate in dual connectivity ("DC"), and dual connectivity ("DC") includes DC within E-UTRA or multi-radio DC ("MR-DC"). In an example of DC within E-UTRA, both the MN and the SN provide E-UTRA access. In an example of MR-DC, one node can provide new radio ("NR") access, while the other node provides E-UTRA or NR access. As described below Figures 1 to 6 The network provider can include several network nodes (i.e., base stations) for providing network access to the user equipment (UE) device. In some embodiments, the network nodes are referred to as base stations. Figures 4 to 6 Cell mobility is shown, where the UE device moves between cells. Control signaling can be used to facilitate this mobility. The mobility can be referred to as handover (HO) or handover process.

[0031] Figure 1 An example base station 102 is shown. A base station may also be referred to as a radio network node and may be a network node as shown in Figure 3 Network nodes shown in FIGS. A to 7B (e.g., a master node (“MN”), a secondary node (“SN”), and a source / destination node). In the context of mobile telecommunications, the base station 102 may also be identified as a Node B (NB, e.g., an eNB or a gNB). Exemplarily, the base station may include radio transceiver circuitry 113 for receiving and transmitting with a user equipment UE 104. The base station may also include network interface circuitry 116 for connecting the base station to a core network 110 (e.g., connected via optical fiber or wired interconnection, Ethernet, and / or other data transmission media / protocols).

[0032] The base station may also include system circuitry 122. The system circuitry 122 may include a processor 124 and / or a memory 126. The memory 126 may include operation instructions 128 and control parameters 130. The operation instructions 128 may include instructions for execution on one or more processors 124 to support the operation of the base station. For example, these operation instructions may process random access transmission requests from multiple UEs. The control parameters 130 may include parameters or support the execution of the operation instructions 128. For example, the control parameters may include network protocol settings, random access message format rules, bandwidth parameters, radio frequency mapping assignments, and / or other parameters.

[0033] Figure 2An exemplary random access messaging environment 200 is shown. In the random access messaging environment, the UE 104 can communicate with the base station 102 via the random access channel 252. In this example, the UE 104 supports one or more subscriber identity modules (SIMs) (such as SIM 1202). The electrical and physical interface 206 connects the SIM 1202 to the rest of the user equipment hardware, for example via the system bus 210. The mobile device 200 includes a communication interface 212, system logic 214, and a user interface 218. The system logic 214 can include any combination of hardware, software, firmware, or other logic. The system logic 214 can be implemented, for example, using one or more systems on a chip (SoCs), application specific integrated circuits (ASICs), discrete analog and digital circuits, and other circuits. The system logic 214 is a component that implements any desired functionality in the UE 104. In this regard, the system logic 214 can include logic that facilitates, as examples, the following: decoding and playing music and video (e.g., decoding and playing audio in MP3, MP4, MPEG, AVI, FLAC, AC3, or WAV formats); running applications; accepting user input; saving and retrieving application data; establishing, maintaining, and terminating a cellular phone call or data connection to achieve an Internet connection (as an example); establishing, maintaining, and terminating a wireless network connection, a Bluetooth connection, or other connections; and displaying relevant information on the user interface 218. The user interface 218 and input 228 can include a graphical user interface, a touch-sensitive display, haptic feedback or other haptic output, voice or face recognition input, buttons, switches, speakers, and other user interface elements. Other examples of the input 228 include a microphone, video and still image cameras, temperature sensors, vibration sensors, rotation and orientation sensors, headphone and microphone input / output jacks, universal serial bus (USB) connectors, memory card slots, radiation sensors (e.g., infrared (IR) sensors), and other types of input.

[0034] System logic 214 may include one or more processors 216 and a memory 220. For example, the memory 220 stores control instructions 222, and the processor 216 executes these control instructions to implement various functions required by the UE 104. Control parameters 224 provide and specify configuration and operation options for the control instructions 222. The memory 220 may also store any BT, WiFi, 3G, 4G, 5G, or other data 226 that the UE 104 is to send or has received via the communication interface 212. In various implementations, system power may be provided by a power storage device (such as a battery 282).

[0035] In the communication interface 212, radio frequency (RF) transmit (Tx) and receive (Rx) circuits 230 transmit and receive signals via one or more antennas 232. The communication interface 212 may include one or more transceivers. A transceiver may be a wireless transceiver, and a wireless transceiver includes modulation / demodulation circuits, multiple digital-to-analog converters (DACs), multiple waveform tables, multiple analog-to-digital converters (ADCs), multiple filters, multiple waveform shapers, multiple filters, multiple preamplifiers, multiple power amplifiers, and / or other logic components for transmitting and receiving via one or more antennas, or for some devices, via a physical (e.g., wired) medium.

[0036] The signals transmitted and received may conform to any one of a variety of formats, protocols, modulations (e.g., QPSK, 16-QAM, 64-QAM, or 256-QAM), frequency channels, bit rates, and codings. As a specific example, the communication interface 212 may include a transceiver that supports transmission and reception according to 2G, 3G, BT, WiFi, Universal Mobile Telecommunications System (UMTS), High Speed Packet Access (HSPA)+, and 4G / Long Term Evolution (LTE) standards. However, the techniques described below are equally applicable to other wireless communication technologies, whether originating from the 3rd Generation Partnership Project (3GPP), GSM Association, 3GPP2, IEEE, or other partners or standards bodies.

[0037] Multiple RAN nodes (e.g., eNB, gNB) supporting the same or different Radio Access Technologies (RATs) can be deployed on the same or different frequency carriers within a specific geographical area, and they can cooperate with each other through dual connectivity operations to provide joint communication services to the same target UE. The multi-RAT dual connectivity (MR-DC) architecture can have a non-collocated Master Node (MN) and Secondary Node (SN). In New Radio (NR) or 5GC, the Access Mobility Function (AMF) and Session Management Function (SMF) can be control plane entities, and the User Plane Function (UPF) is a user plane entity. The signaling connection between the AMF / SMF and the Master Node (MN) can be the Next Generation-Control Plane (NG-C) / MN interface. The signaling connection between the MN and the SN can be the Xn-Control Plane (Xn-C) interface. The signaling connection between the MN and the UE is the Uu-Control Plane (Uu-C) RRC interface. All these connections manage the configuration and operation of the MR-DC. The user plane connection between the User Plane Function (UPF) and the MN can be an NG-U (MN) interface instance.

[0038] Figure 3 Shows the network architecture of the base station Centralized Unit CU and the base station Distributed Unit DU. Figure 3 Shows a base station (labeled "gNB") communicating with the entire network (labeled "5GC"). The base stations can communicate with each other through the control plane interface ("Xn-C"). One base station is shown to have one CU that is connected to two DUs via the F1 interface. This is just one example of the arrangement of the base stations. In some embodiments, there can be one or any number of DUs connected to a single CU.

[0039] The base station can be divided into two physical entities, which are referred to as the Centralized Unit (“CU”) and the Distributed Unit (“DU”). Generally, the CU can provide support for the higher layers of the protocol stack (such as SDAP, PDCP, and RRC), while the DU provides support for the lower layers of the protocol stack (such as RLC, MAC, and the physical layer). In addition to the functions specifically allocated to the DU, the CU can include operations for the transmission of user data, mobility control, radio access network sharing, session management, etc. The DU is a logical node with partial functions of the base station and can be controlled by the CU.

[0040] The CU can be a logical node that controls the operations of one or more DUs, and this logical node bears the RRC protocol, SDAP protocol, and PDCP protocol of the base station, or the RRC protocol and PDCP protocol of the base station. The DU can be a logical node that bears the RLC layer, MAC layer, and PHY layer of the base station, and at least some of its operations may be controlled by the CU. A single DU can support one or more cells. However, each cell is supported by only a single DU. Each base station can support many cells. As described in the embodiments herein, mobility between cells may occur between different CUs or DUs, or may occur within a single CU or DU.

[0041] The intra-cell mobility described herein can occur in a variety of different scenarios. There can be intra-DU mobility, i.e., the UE changes cells within a single DU. Examples of intra-DU mobility include: 1) PCell change within a DU (which may also include a PCell change within a DU along with an SCell change); 2) PSCell change within a DU (which may also include a PSCell change within a DU along with an SCell change); and 3) PCell change within a DU and PSCell change within a DU (which may also include an SCell change within a cell group). In another mobility implementation, there can be intra-CU and inter-DU mobility, i.e., the UE changes cells between different DUs but within a single CU. Examples of intra-CU and inter-DU mobility include: 1) PCell change across DUs but within a single CU (which may also include a PCell change within a CU along with an SCell change); and 2) PSCell change across DUs but within a single CU (which may also include a PSCell change within a CU along with an SCell change). In another mobility implementation, there can be inter-CU mobility, i.e., the UE changes cells between different CUs. Examples of inter-CU mobility include: 1) PCell change across CUs (which may also include a PCell change across CUs along with an SCell change); and 2) PSCell change across CUs (which may also include a PSCell change across CUs along with an SCell change). In another implementation, there can be SCell change / addition, and examples thereof can include SCell addition / change within a cell group. Figures 4 to 6 Embodiments of UE mobility between cells are shown.

[0042] Figure 4 Embodiments of user equipment (UE) intra-DU mobility are shown. The base station can include a CU and at least one DU. In this embodiment, a single DU with multiple cells is shown. Both Cell 1 and Cell 2 belong to the single DU. In this example, UE 402 can move from Cell 1 to Cell 2, and is depicted in Figure 4 using the UE trajectory from Cell 1 to Cell 2. Mobility from a cell can occur when UE 402 is at a position between the two cells and is moving towards a third position within Cell 2. This is intra-DU mobility because the UE is moving between multiple cells within a single DU.

[0043] Figure 5Illustrates an implementation of mobility within the user equipment (UE) CU and between DUs. In this implementation, the base station may include a CU and two DUs (DU_1 and DU_2). Although each DU may have multiple cells, for this example, each DU is shown as providing a single cell, such that DU_1 provides cell 1 and DU_2 provides cell 2. In this example, UE 502 may move from cell 1 to cell 2, and Figure 5 depicts this process using the UE trajectory from cell 1 to cell 2 (which also results in a transition from DU_1 to DU_2). Mobility from a cell may occur when UE 402 is at a position between two cells and is moving towards a third position within cell 2. This is mobility within the CU because the UE is moving between multiple cells within a single CU. However, this is also mobility between DUs because the UE is moving between different DUs.

[0044] Figure 6 Illustrates an implementation of mobility between user equipment (UE) CUs. In this implementation, the base station may include multiple CUs (CU_1 and CU_2). Each CU may include multiple DUs, but in this example, each CU is shown as having one corresponding DU (CU_1 has DU_1 and CU_2 has DU_2). Each of the DUs is shown as having multiple cells. In this example, the UE trajectory of UE 602 is from cell_2 to cell_3, then to an inter-CU position 604 between CU_1 and CU_2, and then to cell_5 and cell_6. As the UE moves, as shown, the mobility may change cells and may transition between several cells. Since UE 602 (at the inter-CU position 604) switches from a cell of CU_1 to a cell of CU_2, this transition is referred to as inter-CU mobility.

[0045] The following regarding Figures 7 to 15The described embodiments demonstrate implementation methods for improving the quality of user services. When a UE accesses a dedicated downlink bandwidth part (DLBWP) in a target cell during a handover process, the first activated BWP may include a cell defining synchronization signal block (CD-SSB). Alternatively, it may be an initial BWP associated with the CD-SSB. After a successful handover, the UE may receive broadcast information in the target cell. However, for a non-cell defining synchronization signal block (NCD-SSB), the common search space (CSS) may not be configured as a resource for receiving cell broadcast system information. During UE mobility, if the first activated BWP of the UE in the target cell is associated with an NCD-SSB for which the CSS is not configured, the UE may not be able to receive broadcast information in that target cell after a successful handover. In some of the embodiments described below, the base station may decide whether to deliver broadcast information to the UE via a dedicated RRC message. Specifically, for a base station with CU / DU separation, the base station DU may know whether a specific NCD-SSB is configured with a CSS, while the base station CU may not know the UE's first active DLBWP, or may not know whether the first active DL BWP is associated with an NCD-SSB for which the CSS is not configured. This makes it impossible for the base station CU to decide whether to deliver broadcast information to the UE via a dedicated RRC message. This embodiment is addressed by transmitting certain mobility assistance information (such as the delivery inquiry indication described below).

[0046] In another embodiment, during UE mobility, if the UE moves into the coverage area of a deactivated beam within the target cell during handover, the Random Access Node (RAN) may not be able to successfully hand over the UE to the target cell. The base station can turn off some beams of the cell based on the cell load or user distribution in the area. The base station can use the Next Generation Radio Access Network (NG-RAN) node configuration update message to notify its neighboring base stations, and this message contains the list of cells and beams with activation / deactivation status and modified coverage (represented by the Synchronization Signal Block SSB index). During UE mobility, if the UE moves into the coverage area of some deactivated beams in the target cell during handover, the RAN may not be able to complete the handover of the UE to the target cell. This embodiment is solved by transmitting certain mobility assistance information (such as the target cell indication described below).

[0047] In another embodiment, for UE mobility restricted to a restricted area, if the base station knows the latest location of the UE (e.g., beam information) when the UE is released, it may not be necessary to page the UE on all SSBs in the paging cell. However, for a base station with CU / DU separation, when the UE is released, the base station CU may not know the serving beam information. In this case, the UE may not be paged promptly, and it may cause waste of energy on the RAN. This embodiment is solved by transmitting certain mobility assistance information (such as the serving beam measurement configuration described below).

[0048] Figures 7 to 8 Shows an exemplary mobility assistance information that can be transmitted in the Figures 9 to 15 embodiment shown above. Figure 7 Shows an exemplary mobility assistance information. The mobility assistance information can include a target cell indication, a delivery inquiry indication, and / or a serving beam measurement configuration. The target cell indication can also be referred to as a list of SSB indices to be activated. This can indicate to the target cell which beam(s) need to be turned on. The delivery inquiry indication can include a System Information Block (SIB) delivery inquiry indication, which requests to report whether the UE can receive broadcast information in the target cell. The serving beam measurement configuration can include information about the beam.

[0049] Figure 8shows an exemplary serving beam measurement configuration. The serving beam measurement configuration may include an indication for requesting a report of the last serving SSB. In another example, the serving beam measurement configuration may include an indication for requesting a report of one or more SSBs that have served the UE during a time period. In another example, the serving beam measurement configuration may include an indication for requesting a report of the time the UE has stayed in each reported serving SSB. Further, the communication embodiments described below describe Figure 7 mobility assistance information and Figure 8 the serving beam measurement configuration.

[0050] Figure 9 shows an embodiment of UE mobility between different base stations using target cell indication information. At stage 902, the UE establishes a Packet Data Unit (PDU) session between the UE, the source base station, and the target CU base station. During UE mobility, the source base station identifies the target base station for handover, and the source base station knows which beam(s) in the target cell of the target base station have been deactivated. If the source base station assumes that the UE may move to an area covered by some deactivated beams in the target cell, at stage 904, the base station sends a handover request message to the target base station via the Xn interface. The handover request may include the target cell indication as a list of SSB indices to be activated in the message.

[0051] After receiving the handover request message, at stage 906, the base station CU of the target base station sends a UE CONTEXT SETUP REQUEST message to the target base station DU. The target cell locates the target base station DU. This is a request to allocate resources and set up the UE context for the UE handover, and the message may contain mobility assistance information. An example of the mobility assistance information is described by Figures 7 to 8 and is separately shown in Figures 9 to 11 At stage 906, the request includes the target cell indication.

[0052] After receiving the UE context setup request message, the base station DU allocates resources for the UE in the target cell and establishes the UE context in the base station DU. In the case of receiving the target cell indication information (the list of SSB indices to be activated), at stage 908, the base station DU will turn on the beams indicated by the information and include the list of successfully activated SSB indices (to indicate which beam(s) have been successfully activated) in the UE CONTEXT SETUP RESPONSE message. Using this information, the successful handover rate can be improved.

[0053] After receiving the UE context setup response message, if a target cell indication (a list of successfully activated SSB indexes) is received, the base station-CU will decide in phase 910 whether to include this target cell indication (i.e., the list of successfully activated SSB indexes) in its processing. When making the decision, this information will be incorporated into the "HANDOVER REQUEST ACKNOWLEDGE" message in phase 912. Subsequently, in phase 914, the target base station sends an RRC RECONFIGURATION message to the UE. The HO command can include broadcast information of the target cell (e.g., at least one piece of SIB information in the SIB information) in the HO command information within this message. In this way, even if the UE cannot receive the broadcast information broadcast by the target cell, the UE can receive this information through an RRC message (e.g., the RRC reconfiguration message). In phase 916, a handover (HO) of the UE from the source base station to the target base station is performed.

[0054] Figure 10 Embodiments of UE mobility between different base stations using delivery inquiry indication information are shown. In phase 1002, the UE establishes a packet data unit (PDU) session among the UE, the source base station, and the target CU base station. During UE mobility, the source base station identifies the target base station for handover, and the source base station knows which beam(s) in the target cell of the target base station have been deactivated. If the source base station assumes that the UE may move into the coverage area of some deactivated beams within the target cell, in phase 1004, the base station sends a handover request message to the target base station via the Xn interface. The handover request may include a delivery inquiry indication (SIB delivery inquiry indication) in this message.

[0055] After receiving the handover request message, in phase 1006, the base station CU of the target base station sends a UE context setup request message to the target base station DU. The target cell locates the target base station DU. This is a request to allocate resources for the UE handover and set up the UE context, and mobility assistance information may be included in this message. Examples of mobility assistance information are described by Figures 7 to 8 and separately shown in Figures 9 to 11 . In phase 1006, the request includes a delivery inquiry indication (SIB delivery inquiry indication).

[0056] After receiving the UE context setup request message, the base station DU allocates resources for the UE in the target cell and establishes a UE context in the base station DU. At the stage of block 1008, the context setup response may include a broadcast reception indication. In the case of receiving the delivery inquiry indication (SIB delivery inquiry indication) information, at the stage of block 1008, the base station DU will include a SIB delivery requirement indication in the UE context setup response message (to indicate whether the UE can receive broadcast information in the target cell or to indicate whether dedicated signaling for SIB delivery is required).

[0057] After receiving the UE context setup response message, if the delivery inquiry indication (system information block (SIB) delivery requirement indication) is received, then at the stage of block 1010, the base station CU decides whether to transmit or include broadcast information in the RRC message. For example, if the indication has indicated that the UE cannot receive broadcast information in the target cell or dedicated signaling for SIB delivery is required, then as shown at the stage of block 1012, the broadcast information is included in the handover command information in the handover request confirmation message. In some embodiments, the base station CU may also decide to deliver the broadcast information to the UE via dedicated RRC signaling after the handover is successful. At the stage of block 1014, the target base station sends an RRC reconfiguration message to the UE. The HO command may include the broadcast information of the target cell (e.g., at least one of the SIB information in the SIB information) in the HO command information within the message. In this way, even if the UE cannot receive the broadcast information broadcast by the target cell, the UE can receive this information via the RRC message (e.g., the RRC reconfiguration message). At the stage of block 1016, a handover (HO) from the source base station to the target base station is performed on the UE.

[0058] Figure 11 Embodiments of UE mobility between different base stations using service beam measurement configuration information are shown. At the stage of block 1102, the UE establishes a packet data unit (PDU) session among the UE, the source base station, and the target CU base station. During UE mobility, the source base station identifies the target base station for handover, and the source base station knows which (which) beam(s) in the target cell of the target base station have been turned off. If the source base station assumes that the UE may move into the coverage area of some deactivated beams in the target cell, then at the stage of block 1104, the base station sends a handover request message to the target base station via the Xn interface. The handover request may include the service beam measurement configuration information in the message.

[0059] After receiving the handover request message, at the stage of block 1106, the base station CU of the target base station sends a UE context setup request message to the target base station DU. The target cell locates the target base station DU. This is a request to allocate resources for UE handover and set up the UE context, and mobility assistance information may be included in this message. Examples of mobility assistance information are described by Figures 7 to 8 and are separately shown in Figures 9 to 11 . At the stage of block 1106, this request includes serving beam measurement configuration information.

[0060] After receiving the UE context setup request message, the base station DU allocates resources for the UE in the target cell and establishes the UE context in this base station DU. In the case of receiving the serving beam measurement configuration, at the stage of block 1108, the base station DU will record the serving SSB information according to this information. In one example, if there is an indication that only the last serving SSB needs to be reported, the base station - DU only records the index of this last serving SSB. In another example, if there is an indication that one or more SSBs serving the UE within a specific time period need to be reported, the base station DU will periodically record the serving SSBs. In another example, if there is an indication that requires reporting the dwell time of the UE on each serving SSB, the base station DU will record the dwell time of the UE on each SSB. At the stage of block 1110, the base station DU sends a UE context setup response message to the base station CU. After receiving the UE context setup response message, as at the stage of block 1112, a handover request confirmation message is sent.

[0061] At the stage of block 1114, the target base station sends an RRC reconfiguration message to the UE. The HO command may include the broadcast information of the target cell (for example, at least one item of SIB information in the SIB information) in the HO command information within this message. In this way, even if the UE cannot receive the broadcast information broadcast by the target cell, the UE can receive this information through an RRC message (for example, an RRC reconfiguration message). At the stage of block 1116, a handover (HO) of the UE from the source base station to the target base station is performed.

[0062] Figures 9 - 11 Shows an embodiment of UE (User Equipment) context setup communication under different mobility assistance information communications. Figures 12 to 14 Illustrates an implementation manner using UE context modification communication. When there is a UE context in the base station DU (that is, the target cell and the source cell are in the same base station DU), UE context modification communication can be used. On the contrary, when there is no UE context in the new target base station DU, the implementation manner in Figures 9 to 11 needs to be used for communication.

[0063] Figure 12 Illustrates an implementation of UE mobility within a base station in the DU using target cell indication information. At stage 1202, the UE establishes a Packet Data Unit (PDU) session among the UE, the base station, and the network. During UE mobility, the base station CU determines the target cell for handover, which is within the same base station DU as the source cell. Since the UE context already exists in the base station DU, at stage 1204, the base station CU sends a UE CONTEXT MODIFICATION REQUEST message to the base station DU. This request is for allocating resources for the UE handover in the target cell and modifying the UE context. The request 1204 may include the target cell indication in the message. The target cell indication may be a list of SSB indexes to be activated, to indicate which beam(s) need to be turned on for the target cell. The base station CU knows which beam(s) are turned off in the target cell of the base station DU. If the base station CU assumes that the UE may move to an area covered by some unactivated beams, the base station CU may include this information in the message.

[0064] After receiving the UE context modification request message, the base station DU modifies the UE context and allocates resources for the UE in the target cell. When receiving the target cell indication (list of SSB indexes to be activated) information, at stage 1206, the base station DU turns on the beams indicated by this information and includes the list of successfully activated SSB indexes (to indicate which beam(s) are successfully activated) in the UE CONTEXT MODIFICATION RESPONSE message. This can improve the handover success rate.

[0065] After receiving the UE context modification response message containing the list of successfully activated SSB indexes, at stage 1208, the base station CU decides which target cell indication information to include in the Handover (HO) command. Before this decision, at stage 1210, the list of successfully activated SSB indexes is included in the RRC reconfiguration message. At stage 1212, the UE performs a handover (HO) from the source cell to the target cell within the same base station DU.

[0066] Figure 13An embodiment of UE mobility within a base station in a DU using delivery inquiry indication information is shown. At stage 1302, the UE establishes a Packet Data Unit (PDU) session among the UE, the base station, and the network. During UE mobility, the base station CU determines a target cell for handover, and the target cell is within the same DU as the source cell. Since the UE context already exists in the base station DU, at stage 1304, the base station CU sends a UE context modification request message to the base station DU. The request is for allocating resources for the UE handover in the target cell and modifying the UE context. The request 1304 may include the delivery inquiry indication information in the message. The delivery inquiry indication may be an SIB delivery inquiry indication to request reporting whether the UE can receive broadcast information in the target cell.

[0067] After receiving the UE context modification request message, the base station DU modifies the UE context and allocates resources for the UE in the target cell. When receiving the delivery inquiry indication (SIB delivery inquiry indication) information, the base station DU determines whether the UE can receive broadcast information in the target cell. The context modification response at stage 1306 may include a broadcast reception indication. Specifically, at stage 1306, the base station DU will include an SIB delivery requirement indication (to indicate whether the UE can receive broadcast information in the target cell; or to indicate whether dedicated signaling for SIB delivery is required) in the UE context modification response message.

[0068] After receiving the UE context modification response message with a broadcast reception indication or an SIB delivery requirement indication, at stage 1308, the base station CU decides whether to deliver broadcast information in an RRC message. For example, when the indication has indicated that the UE cannot receive broadcast information in the target cell or dedicated signaling for SIB delivery is required, then at stage 1310, the broadcast information or SIB information is included in the RRC reconfiguration message together with the handover command information. In some embodiments, the base station CU may also decide to deliver broadcast information to the UE via dedicated RRC signaling after a successful handover. The HO command may include the broadcast information of the target cell (e.g., at least one SIB information in the SIB information) in the HO command information within the message. In this way, even if the UE cannot receive the broadcast information broadcast by the target cell, the UE can receive this information via an RRC message (e.g., the RRC reconfiguration message). At stage 1312, the UE performs a handover (HO) from the source cell to the target cell within the same base station DU.

[0069] Figure 14An embodiment of UE mobility within a base station in a DU using service beam measurement configuration information is shown. At stage 1402, the UE establishes a Packet Data Unit (PDU) session between the UE, the base station, and the network. During UE mobility, the base station CU determines a target cell for handover, and the target cell is within the same DU as the source cell. Since the UE context already exists in the base station DU, at stage 1404, the base station CU sends a UE context modification request (UE CONTEXT MODIFICATION REQUEST) message to the base station DU. This request is used to allocate resources for the UE handover in the target cell and modify the UE context. The request 1404 may include the service beam measurement configuration information in this message. The service beam measurement configuration may include at least one of the following: an indication to request reporting of the last served SSB; an indication to report one or more SSBs that served the UE within a time period; or an indication to report the time the UE stayed in each reported served SSB.

[0070] After receiving the UE context modification request message, the base station DU modifies the UE context and allocates resources for the UE in the target cell. When receiving the service beam measurement configuration information, at stage 1406, the base station DU records the served SSB information according to this information. For example, if there is an indication that only the last served SSB needs to be reported, the base station DU only records the index of this last served SSB. In another example, if there is an indication that one or more SSBs that served the UE within a specific time period need to be reported, the base station DU records the served SSBs periodically. In another example, if there is an indication that requires reporting the dwell time of the UE on each served SSB, the base station DU records the dwell time of the UE on each SSB. At stage 1408, the base station DU sends a UE context modification response message to the base station CU.

[0071] At stage 1410, the base station CU sends an RRC reconfiguration message to the UE. The HO command may include the broadcast information of the target cell (e.g., at least one item of SIB information in the SIB information) in the HO command information in this message. In this way, even if the UE cannot receive the broadcast information broadcast by the target cell, the UE can receive this information through an RRC message (e.g., the RRC reconfiguration message). At stage 1412, a handover (HO) of the UE from the source cell to the target cell is performed within the same base station DU.

[0072] Figure 15Illustrates an implementation of paging a UE with limited mobility within a base station in the DU. At stage 1502, a PDU session has been established between the UE, the base station, and the Core Network (CN). At stage 1504, if the base station DU has received a serving beam measurement configuration (e.g., as shown in Figure 11 and Figure 14 ) when establishing / modifying the UE context in the base station DU, the base station DU will record the serving SSB information according to the serving beam measurement configuration. In one example, if there is an indication that only the last serving SSB needs to be reported, the base station DU only records the index of this last serving SSB. In another example, if there is an indication that one or more SSBs serving the UE within a specific time period need to be reported, the base station DU will periodically record the serving SSBs. In another example, if there is an indication that requires reporting the dwell time of the UE on each serving SSB, the base station DU will record the dwell time of the UE on each SSB. At stage 1506, the base station CU decides whether to release the UE context in the base station DU. This may include whether to release the UE to the RRC idle or inactive state. At stage 1508, the base station CU sends a UE CONTEXT RELEASE REQUEST message to the base station DU. After the base station DU receives the UE context release request message, at stage 1510, the base station DU releases the UE context.

[0073] If a serving beam measurement configuration was received previously (such as when establishing / modifying the UE context in the base station DU), at stage 1510, the base station DU will include a serving beam report in the UE CONTEXT RELEASE COMPLETE message. The serving beam report may include: the index of the last serving SSB; a list of serving SSB indices indicating that one or more SSBs have served the UE during a time period; and / or the time the UE stayed on each reported serving SSB. In other implementations, at stage 1510, the base station DU may include the index of the last serving SSB in the UE context release complete message.

[0074] In the stage of block 1512, the UE is released to an inactive or idle state (e.g., RRC inactive state or RRC idle state). If the base station CU decides to page the UE (e.g., for data transmission), then in the stage of block 1514, the base station CU sends an F1 paging message to the base station DU via the F1 interface. The paging may include at least one of the following: the last served SSB index in the last visited cell; a list of the last served SSB indices in the last visited cell (indicating one or more served SSBs within a time period); the last served SSB index in each paging cell; and / or a list of the last served SSB indices in each paging cell (indicating one or more served SSBs within a time period). In the stage of block 1516, the base station DU sends an RRC paging message to page the UE. It may take into account the received served SSB information (e.g., page the UE only via the last served SSB indicated in the last visited cell or paging cell). The UE can be paged quickly, and the energy consumption on the RAN can be reduced.

[0075] The systems and processes described above can be encoded in a signal-bearing medium, a computer-readable medium (such as a memory), programmed within a device (such as one or more integrated circuits, one or more processors), or processed by a controller or computer. The data can be analyzed in a computer system and used to generate a spectrum. If these methods are executed by software, the software can reside in a memory that resides in or interfaces with the following: a storage device that communicates with a transmitter, a synchronizer, a communication interface, or a non-volatile or volatile memory. The circuit or electronic device is designed to send data to another location. The memory may include an ordered list of executable instructions for implementing logical functions. The described logical functions or any system elements can be implemented by optical circuits, digital circuits, source code, analog circuits, analog sources (such as analog electrical signals, audio signals, or video signals, or combinations). The software can be embodied in any computer-readable or signal-bearing medium for use by or in combination with an instruction-executable system, apparatus, or device. Such a system can include a computer-based system, a system including a processor, or another system that can selectively obtain instructions from an instruction-executable system, apparatus, or device (which can also execute the instructions).

[0076] "Computer-readable medium", "machine-readable medium", "propagated signal" medium, and / or "signal-bearing medium" can include any apparatus that includes storing, transmitting, propagating, or conveying software for use in or in connection with an instruction-executable system, apparatus, or device. A machine-readable medium can optionally be, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, device, or propagation medium. A non-exhaustive list of examples of machine-readable media will include: an electrical connection "electronic device" having one or more wires, a portable magnetic disk or optical disc, a volatile memory such as random access memory "RAM", read-only memory "ROM", erasable programmable read-only memory (EPROM or flash memory), or an optical fiber. A machine-readable medium can also include a tangible medium on which software is printed, as the software can be stored as an image or in another format (e.g., by optical scanning), then compiled, and / or interpreted, or otherwise processed. The processed medium can then be stored in a computer and / or machine memory.

[0077] The description of the embodiments described herein is intended to provide a general understanding of the structure of the various embodiments. These descriptions are not intended to be a complete description of all elements and features of the devices and systems that utilize the structures or methods described herein. After reviewing this application, many other embodiments may be apparent to those skilled in the art. Other embodiments can be utilized and derived from this application such that structural and logical substitutions and changes can be made without departing from the scope of this application. Additionally, the illustrations are only representative and may not be drawn to scale. Some of the ratios within the illustrations may be exaggerated while others may be minimized. Accordingly, the present disclosure and the drawings are to be regarded as illustrative and not restrictive.

[0078] One or more embodiments of the present disclosure may be referred to herein individually and / or collectively by the term "invention" merely for convenience and not intended to voluntarily limit the scope of this application to any particular invention or inventive concept. Furthermore, although specific embodiments have been shown and described herein, it should be understood that any subsequent arrangement designed to achieve the same or similar purpose may replace the specific embodiments shown. The present disclosure is intended to cover any and all subsequent adaptations or variations of the various embodiments. After reviewing the specification, combinations of the above embodiments as well as other embodiments not specifically described herein will be apparent to those skilled in the art.

[0079] The phrase "coupled to" is defined to mean directly connected or indirectly connected through one or more intermediate components. Such intermediate components can include components based on both hardware and software. Variations in the arrangement and type of components may be made without departing from the spirit or scope of the claims as set forth herein. Additionally, different or fewer components may be provided.

[0080] The subject matter disclosed above will be regarded as illustrative and not restrictive, and the appended claims are intended to cover all such modifications, enhancements, and other embodiments falling within the true spirit and scope of the invention. Accordingly, to the maximum extent permitted by law, the scope of the invention will be determined by the broadest permissible interpretation of the claims and their equivalents, and shall not be restricted or limited by the foregoing detailed description. Although various embodiments of the invention have been described, it will be apparent to those of ordinary skill in the art that more embodiments and implementations are possible within the scope of the invention. Accordingly, the invention is not limited except as by the appended claims and their equivalents.

Claims

1. A wireless communication method, comprising: The base station distributed unit DU receives a target cell indication; The base station DU activates one or more beams indicated by the target cell indication.

2. The method according to claim 1, wherein The target cell indication includes a list of synchronization signal block SSB indices to be activated.

3. The method according to claim 1, wherein, The target cell indication is provided by the base station centralized unit CU.

4. The method according to any one of claims 1 to 3, wherein The base station CU receives the successfully activated one or more beams from the base station DU.

5. The method according to any one of claims 1 to 4, wherein, The list of SSB indices to be activated is included in a handover request message from another base station.

6. The method according to any one of claims 1 to 5, wherein The handover confirmation message response of the base station centralized unit CU includes the successfully activated beams.

7. The method according to any one of claims 1 to 6, wherein The receiving action and the activating action are partial actions in context setup communication or context modification communication.

8. A wireless communication method, comprising: The base station distributed unit DU receives delivery inquiry indication information sent by the base station centralized unit CU, where the delivery inquiry indication information indicates whether to report whether a user equipment UE can receive broadcast information in a target cell; The base station DU determines whether the user equipment UE can receive broadcast information in the target cell based on the delivery inquiry indication information.

9. The method according to claim 8, wherein, The delivery inquiry indication information includes a system information block SIB delivery inquiry indication.

10. The method according to claims 8 to 9, comprising: The base station DU sends a broadcast reception indication to the base station CU, where the broadcast reception indication is used to indicate whether the UE can receive the broadcast information in the target cell or whether dedicated signaling for SIB delivery is required.

11. The method according to claims 8 to 9, wherein, The base station CU determines the type of SIB to be delivered to the UE based on the broadcast reception indication.

12. The method according to any one of claims 8 to 11, wherein, After a successful handover, the base station CU delivers at least one item of SIB block information in the SIB block information to the UE through dedicated RRC signaling.

13. The method according to claims 8 to 12, wherein, The receiving action and the sending action are partial actions in context setup communication or context modification communication.

14. A wireless communication method, comprising: The base station distributed unit DU receives a serving beam measurement configuration; Records serving synchronization signal block SSB information based on the serving beam measurement configuration.

15. The method according to claim 14, wherein, The serving beam measurement configuration includes at least one of the following: An indication for requesting a report of the last serving SSB; An indication for requesting a report of one or more SSBs serving the UE within a defined time period; An indication for requesting a report of the residence time of the UE on each serving SSB.

16. The method according to claim 14, wherein, The base station DU reports the recorded serving SSB information to the base station centralized unit CU.

17. The method according to any one of claims 14 to 16, wherein, When the serving beam measurement configuration is not received, the base station DU reports the last serving SSB index to the base station CU.

18. The method according to claims 16 to 17, wherein, The base station DU includes the report in a UE context release completion message during the UE context release process.

19. The method according to claim 14, wherein, The receiving action is performed during user equipment UE context setup or UE modification.

20. A wireless communication device includes a processor and a memory, wherein, The processor is configured to read code from the memory to implement the method recited in any one of claims 1 to 19.

21. A computer program product, comprising stored computer-readable program medium code which, when executed by a processor, causes the processor to implement the method recited in any one of claims 1 to 19.

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