Apparatuses and methods for determining if user equipment is located in registration area

Abstract

To provide a method and apparatus for facilitating efficient paging for NTN (non-terrestrial network) communication systems with earth moving cells.SOLUTION: A communication system includes a gNB which is a transceiver for receiving a registration request and transmitting a registration accept message including a list of one or more tracking areas forming a registration area, the registration request including an indication of a first location of user equipment (UE), the list of one or more tracking areas including the indication of the first location of the UE. The gNB comprises a circuit for generating the registration accept message including the list of one or more tracking areas. The tracking areas correspond to cell IDs of a plurality of earth moving cells associated with time intervals forming the registration area.SELECTED DRAWING: Figure 26

Description

[Technical Field]

[0001] This disclosure relates to transmitting and receiving signals in communication systems, and more particularly to methods and apparatus for such transmitting and receiving. [Background technology]

[0002] The 3rd Generation Partnership Project (3GPP®) is working on technical specifications for next-generation cellular technology, also known as fifth generation (5G), including "New Radio" (NR) radio access technology (RAT) operating in the frequency range up to 100 GHz. NR is the successor to technologies represented by Long Term Evolution (LTE) and LTE Advanced (LTE-A).

[0003] In systems such as LTE, LTE-A, and NR, further improvements and options may facilitate efficient operation of the communication systems and certain devices associated with the systems. [Prior art documents] [Non-patent literature]

[0004] [Non-Patent Document 1] 3GPP TS38.300 v15.6.0 [Non-patent document 2] 3GPP TS38.211 v15.6.0 [Non-patent document 3] ITU-R M.2083 [Non-patent document 4] TR38.913 [Non-patent document 5] 3GPP TS38.211 V15.3.0 [Non-patent document 6] TS23.501v16.1.0 [Non-Patent Document 7] E. Dahlman,et al.,5GNR: The Next Generation Wireless Access Technology,1st Edition [Non-patent document 8] TS38.304 v15.4.0 [Non-Patent Document 9] TS38.331 v15.6.0 [Non-Patent Document 10] 3GPP TS38.304 v15.3.0 [Non-Patent Document 11] 3GPP TR38.811,Study on New Radio(NR) to support non-terrestrial networks,version 15.2.0 [Non-Patent Document 12] 3GPP TR38.821,Solutions for NR to support non-terrestrial networks,version 16.0.0 Summary of the Invention

[0005] One non-limiting exemplary embodiment facilitates efficient paging for an NTN communication system having earth moving cells.

[0006] A main aspect of the present invention is a base station, a transceiver configured to receive a registration request and to transmit a registration accept message including a list of one or more tracking areas forming a registration area, the registration request including an indication of a first location of a user equipment (UE), the list of one or more tracking areas including the indication of the first location of the UE; a circuit for generating the registration accept message including a list of the one or more tracking areas, the tracking areas corresponding to cell IDs of a plurality of terrestrial mobile cells associated with a time interval forming the registration area; and The base station is provided with:

[0007] In one embodiment, the technology disclosed herein is a user equipment (UE) comprising: When operating, sending a registration request, the registration request comprising: an indication of a first location of the UE, or a cell ID of the last cell visited by the UE and a timestamp indicating the first time instant the UE was located in the last cell; and receiving a registration accept message including a notification of a registration area, the registration area including the first location of the UE; A transmitter / receiver, When operating, a list of cell IDs of a plurality of terrestrial mobile cells or cell sections of the terrestrial mobile cells, and a notification of a second time when the plurality of terrestrial mobile cells form the registration area, and for each of the plurality of terrestrial mobile cells, coverage area information indicating a coverage area of ​​the cell or cell section relative to a satellite position of a satellite generating the cell and ephemeris data of the satellite, and a second position measurement of the UE, wherein the list of the plurality of terrestrial mobile cells and the notification of the second time are included in the notification of the registration area, or based on the list of cell IDs, a notification of a time interval during which the plurality of terrestrial mobile cells or cell sections form the registration area, and a cell ID of a newly visited cell or cell section that includes the second location of the UE and is different from the last cell, wherein the list of cell IDs and the notification of the time interval are included in the notification of the registration area, or based on the measurement of the second location, a mapping between a geographic area and a tracking area, and a list of one or more tracking areas forming the registration area, wherein the mapping is read from a storage, and the list of one or more tracking areas is included in the notification of the registration area; a circuit for determining whether the UE is located within the registration area at the second location; The present invention relates to a user equipment comprising:

[0008] It should be noted that the general or specific embodiments may be implemented as a system, a method, an integrated circuit, a computer program, a storage medium, or any selective combination thereof.

[0009] Further benefits and advantages of the disclosed embodiments will become apparent from the specification and drawings. Benefits and / or advantages may be obtained individually by various embodiments and features of the specification and drawings, and it is not necessary for all of them to be provided to obtain one or more of such benefits and / or advantages.

[0010] Exemplary embodiments will now be described in more detail with reference to the accompanying figures and drawings. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 illustrates an example architecture of a 3GPP NR system. [Figure 2] 1 is a schematic diagram showing the division of functions between NG-RAN and 5GC. [Figure 3] FIG. 1 is a sequence diagram of an RRC connection setup / reconfiguration procedure. [Figure 4]FIG. 1 is a schematic diagram illustrating usage scenarios for Enhanced Mobile Broadband (eMBB), Massive Machine Type Communications (mMTC), and Ultra Reliable and Low Latency Communications (URLLC). [Figure 5] FIG. 1 is a block diagram illustrating an example 5G system architecture for a non-roaming scenario. [Figure 6] FIG. 10 is a diagram illustrating a registration procedure. [Figure 7] FIG. 1 illustrates a UE configuration update procedure. [Figure 8] FIG. 10 is a diagram showing an NG setup procedure. [Figure 9] FIG. 1 illustrates a RAN configuration update procedure. [Figure 10] FIG. 1 is a schematic diagram showing the relationship between registration areas, tracking areas and cells. [Figure 11] FIG. 1 illustrates a non-terrestrial network (NTN) scenario in which transmission to and from terminals is performed via satellites and remote radio units including NTN gateways. [Figure 12] This figure shows a scenario of a non-terrestrial network in which transmission between terminals is performed via a satellite including a gNB as a scheduling device. [Figure 13] FIG. 1 illustrates the mapping of one cell (PCI) onto multiple satellite beams. [Figure 14] FIG. 1 illustrates the mapping of one cell (PCI) to a single satellite beam. [Figure 15] FIG. 1 illustrates a terrestrial mobile cell scenario in NTN. [Figure 16] FIG. 2 is a diagram illustrating ephemeris parameters. [Figure 17] FIG. 1 is a block diagram illustrating an AMF system, a base station, and user equipment (UE). [Figure 18]FIG. 2 is a block diagram illustrating RA location determination circuitry of a user equipment. [Figure 19] 1 is a flowchart of a communication method for user equipment. [Figure 20] 1 is a flowchart of a communication method for a base station. [Figure 21] 1 is a flowchart of a communication method for AMF. [Figure 22] FIG. 1 illustrates the notification of cell coverage area by satellite beam direction and diameter. [Figure 23] FIG. 1 illustrates the reporting of cell coverage areas with non-overlapping shapes. [Figure 24] FIG. 1 illustrates reporting of cell coverage area by cell center and in-coverage distance. [Figure 25] FIG. 1 illustrates the definition of a tracking area as a union of cell areas at a given time. [Figure 26] FIG. 1 illustrates a registration and paging call flow. [Figure 27] FIG. 10 illustrates notification of a tracking area by a list of cells with associated time intervals. [Figure 28] FIG. 1 illustrates a registration and paging call flow. [Figure 29] FIG. 10 illustrates the definition of a registration area with a restricted cell area. [Figure 30] FIG. 1 illustrates a registration and paging call flow. DETAILED DESCRIPTION OF THE INVENTION

[0012] 5G NR System Architecture and Protocol Stack

[0013] 3GPP is working on the next release of fifth-generation cellular technology, simply known as 5G, which includes the development of a new radio access technology (NR) that will operate in frequencies up to 100 GHz. The first version of the 5G standard was completed at the end of 2017, allowing for the development of 5G NR-compliant smartphones for testing and commercial deployment.

[0014] In particular, the overall system architecture assumes an NG-RAN (Next Generation-Radio Access Network) that includes gNodeBs (gNBs) that provide NG radio access user plane (SDAP / PDCP / RLC / MAC / PHY) and control plane (RRC, Radio Resource Control) protocol terminations to UEs. The gNBs are interconnected by an Xn interface. The gNBs are also connected to the Next Generation Core (NGC) by a Next Generation (NG) interface, more specifically to the Access and Mobility Management Function (AMF) (e.g., a specific core entity that runs the AMF) by an NG-C interface, and to the User Plane Function (UPF) (e.g., a specific core entity that runs the UPF) by an NG-U interface. The NG-RAN architecture is shown in Figure 1 (see, for example, Section 4 of Non-Patent Document 1).

[0015] The NR user plane protocol stack (see, for example, Section 4.4.1 of 3GPP) includes the PDCP (Packet Data Convergence Protocol, see Section 6.4 of 3GPP), the RLC (Radio Link Control, see Section 6.3 of 3GPP), and the MAC (Medium Access Control, see Section 6.2 of 3GPP) sublayers, which are terminated at the gNB on the network side. In addition, a new access stratum (AS) sublayer (SDAP, Service Data Adaptation Protocol) has been introduced on top of PDCP (see, for example, Subclause 6.5 of 3GPP). A control plane protocol stack has also been defined for NR (see, for example, Section 4.4.2 of 3GPP). An overview of Layer 2 functions is given in Subclause 6 of 3GPP. The functions of the PDCP, RLC, and MAC sublayers are listed in sections 6.4, 6.3, and 6.2, respectively, of 3GPP TS 26.10. The functions of the RRC layer are listed in subclause 7 of 3GPP TS 26.10.

[0016] For example, the medium access control layer handles logical channel multiplexing, as well as scheduling and scheduling-related functions, including handling of various numerologies.

[0017] The physical layer (PHY) is responsible for, for example, coding, PHY HARQ processing, modulation, multi-antenna processing, and mapping of signals to appropriate physical time-frequency resources. It also handles the mapping of transport channels to physical channels. The physical layer provides services to the MAC layer in the form of transport channels. A physical channel corresponds to a set of time-frequency resources used for the transmission of a specific transport channel, and each transport channel is mapped to a corresponding physical channel. For example, physical channels are the PRACH (Physical Random Access Channel), PUSCH (Physical Uplink Shared Channel), and PUCCH (Physical Uplink Control Channel) for the uplink, and the PDSCH (Physical Downlink Shared Channel), PDCCH (Physical Downlink Control Channel), and PBCH (Physical Broadcast Channel) for the downlink.

[0018] NR use cases / deployment scenarios may include enhanced mobile broadband (eMBB), ultra-reliable and low-latency communications (URLLC), and massive machine-type communications (mMTC), which have diverse requirements in terms of data rate, latency, and coverage. For example, eMBB is expected to support peak data rates (20 Gbps for downlink and 10 Gbps for uplink) and user-experienced data rates on the order of three times the data rates offered by IMT-Advanced. On the other hand, URLLC requires ultra-low latency (user-plane latency of 0.5 ms for UL and DL, respectively) and high reliability (1-10 ms latency within 1 ms). -5Finally, mMTC preferably requires high connection density (1,000,000 devices / km in urban environments). 2 ), wide coverage in harsh environments, and extremely long battery life (15 years) for low-cost devices.

[0019] Therefore, OFDM numerology (e.g., subcarrier spacing, OFDM symbol duration, cyclic prefix (CP) duration, number of symbols per scheduling interval) suitable for one use case may not work well for another use case. For example, low-latency services may preferably require a shorter symbol duration (and thus a larger subcarrier spacing) and / or fewer symbols per scheduling interval (a.k.a., TTI) than mMTC services. Furthermore, deployment scenarios with large channel delay spreads may preferably require a longer CP duration than scenarios with small delay spreads. The subcarrier spacing needs to be optimized accordingly to maintain similar CP overhead. NR may support more than one value of subcarrier spacing. Correspondingly, subcarrier spacings of 15 kHz, 30 kHz, 60 kHz, ... are currently being considered. The symbol duration T u and the subcarrier spacing Δf is given by the formula Δf=1 / T u As in LTE systems, the term "resource element" may be used to denote the smallest resource unit consisting of one subcarrier over the length of one OFDM / SC-FDMA symbol.

[0020] In the new radio system 5G-NR, a resource grid of subcarriers and OFDM symbols is defined for each numerology and carrier for uplink and downlink, respectively. Each element in the resource grid is called a resource element and is identified based on a frequency index in the frequency domain and a symbol position in the time domain (see Non-Patent Document 2).

[0021] 5G NR function split between NG-RAN and 5GC

[0022] Figure 2 shows the functional division between NG-RAN and 5GC. The logical node of NG-RAN is gNB or ng-eNB (next generation eNB). 5GC has logical nodes AMF, UPF, and SMF.

[0023] Specifically, the gNB and ng-eNB host the following main functions: - Functions for radio resource management, e.g. radio bearer control, radio admission control, connection mobility control, dynamic allocation of resources to UEs in both uplink and downlink (scheduling) - IP header compression, encryption, and data integrity protection - AMF selection at UE attachment time if routing to an AMF cannot be determined from information provided by the UE - Routing of user plane data to UPF(s) - Routing control plane information to AMF - Connection setup and release - Scheduling and sending paging messages - Scheduling and transmission of system broadcast information (originating from AMF or OAM) - Configuring measurements and measurement reporting for mobility and scheduling - Transport-level packet marking in the uplink - Session Management - Network slicing support - QoS flow management and mapping to data radio bearers - Support for UEs in RRC_INACTIVE state - NAS (Non-access stratum) message delivery function - Wireless access network sharing - Dual Connectivity - Close cooperation between NR and E-UTRA

[0024] The Access and Mobility Management Function (AMF) hosts the following main functions: - Non-Access Stratum NAS Signaling Termination - NAS signaling security - Access Layer AS Security Management - Core network CN inter-node signaling for mobility between 3GPP access networks - Reachability of UEs in idle mode (including control and execution of paging retransmissions) - Registration area management - Support for intra- and inter-system mobility - Access authentication - Access authorization, including roaming rights checks - Mobility management controls (subscriptions and policies) - Network slicing support - Selection of Session Management Function (SMF)

[0025] In addition, the user plane function UPF hosts the following main functions: - Anchor points for intra-RAT / inter-RAT mobility (if applicable) - External PDU session points for interconnection to data networks - Packet Routing & Forwarding - User plane part of packet inspection and policy rule enforcement - Traffic usage reporting - An uplink classifier that supports routing of traffic flows to the data network. - Branching points to support multi-homed PDU sessions - User plane QoS handling, e.g., packet filtering, gating, UL / DL rate enforcement - Uplink traffic validation (SDF to QoS flow mapping) - Buffering downlink packets and triggering downlink data notifications

[0026] Finally, the Session Management Function SMF hosts the following main functions: - Session Management - UE IP address allocation and management - UP function selection and control - Configuring traffic steering in the user plane function UPF to route traffic to the appropriate destination - Policy enforcement and QoS control parts - Downlink data notification

[0027] RRC connection setup and reconfiguration procedures

[0028] Figure 3 shows some interactions between the UE, gNB and AMF (5GC entities) in the context of the UE transitioning from RRC_IDLE to RRC_CONNECTED for the NAS part (see non-patent document 1).

[0029] RRC is a higher layer signaling protocol used to configure the UE and the gNB. Specifically, this transition involves the AMF preparing UE context data (e.g., including PDU session context, security keys, UE radio capabilities, and UE security capabilities) and sending it to the gNB using an Initial Context Setup Request. The gNB then activates AS security with the UE, which is performed by the gNB sending a SecurityModeCommand message to the UE and the UE responding with a SecurityModeComplete message to the gNB. The gNB then performs reconfiguration and sets up signaling radio bearer 2 (SRB2) and data radio bearer(s) (DRB(s)) by sending an RRCReconfiguration message to the UE and receiving an RRCReconfigurationComplete message from the UE in response. In the case of a signaling-only connection, steps related to RRCReconfiguration are skipped because SRB2 and DRBs are not set up. Finally, the gNB informs the AMF that the setup procedure is complete using an initial context setup response.

[0030] To this end, the present disclosure provides a 5th Generation Core (5GC) entity (e.g., AMF, SMF, etc.) that includes, in operation, a control circuit that establishes a Next Generation (NG) connection with a gNodeB, and a transmitter that, in operation, sends an initial context setup message to the gNodeB over the NG connection to cause a signaling radio bearer to be set up between the gNodeB and a user equipment (UE). Specifically, the gNodeB sends radio resource control (RRC) signaling, including a resource allocation configuration information element, to the UE over the signaling radio bearer. The UE then performs uplink transmission or downlink reception based on the resource allocation configuration.

[0031] IMT usage scenarios for 2020 and beyond

[0032] Figure 4 shows some of the use cases for 5G NR. The 3rd generation partnership project new radio (3GPP NR) is considering three use cases that are expected to support a wide variety of services and applications with IMT-2020. The enhanced mobile broadband (eMBB) phase 1 specifications have been finalized. In addition to further extending eMBB support, current and future work will include standardization of ultra-reliable and low-latency communications (URLLC) and massive machine-type communications. Figure 4 shows some examples of usage scenarios expected for IMT beyond 2020 (see, for example, Figure 2 in Non-Patent Document 3).

[0033] URLLC use cases have stringent requirements for capabilities such as throughput, latency, and availability, and are envisioned as one of the enablers for future vertical applications such as wireless control of industrial manufacturing or production processes, remote medical surgery, power distribution automation in smart grids, and transportation safety. URLLC's ultra-high reliability is supported by identifying technologies that meet the requirements set out in [4]. For Release 15 NR URLLC, key requirements include a target user plane latency of 0.5 ms for the uplink (UL) and 0.5 ms for the downlink (DL). A typical URLLC requirement for a single transmission of a packet is a BLER (block error rate) of 1E-5 for a 32-byte packet size with a user plane latency of 1 ms.

[0034] From the physical layer perspective, reliability can be improved in several possible ways. The current scope for improving reliability includes defining a separate CQI table for URLLC, a more compact DCI (Downlink Control Information) format, PDCCH repetition, etc. However, as NR becomes more stable and evolves (regarding the key requirements of NR URLLC), this scope can be broadened to achieve ultra-high reliability. Specific use cases for NR URLLC in Release 15 include Augmented Reality / Virtual Reality (AR / VR), e-health, e-safety, and mission-critical applications.

[0035] Additionally, targeted technology enhancements for NR URLLC aim to improve latency and reliability. Technology enhancements for latency improvement include configurable numerology, non-slot-based scheduling with flexible mapping, grant-free (configured grant) uplink, slot-level repetition for data channels, and downlink preemption. Preemption means that a transmission for which resources have already been allocated is stopped, and the allocated resources are used for another transmission requested later but with lower latency / higher priority requirements. Thus, a transmission that has already been granted is preempted by a later transmission. Preemption is applicable regardless of the specific service type. For example, a transmission of service type A (URLLC) can be preempted by a transmission of service type B (eMBB, etc.). Technology enhancements for reliability improvement include dedicated CQI / MCS tables for a target BLER of 1E-5.

[0036] The mMTC (Massive Machine Type Communication) use case is characterized by a very large number of connected devices that typically transmit relatively small amounts of latency-insensitive data. The devices need to be inexpensive and have very long battery life. From an NR perspective, utilizing very narrow bandwidth parts is one possible solution to save power and achieve long battery life from the UE perspective.

[0037] As mentioned above, the scope of reliability in NR is expected to be broader. One major requirement for all cases, especially for URLLC and mMTC, is high or ultra-high reliability. Several mechanisms can be considered to improve reliability from a radio perspective and a network perspective. In general, there are several main potential areas that can help improve reliability. Among these areas are compact control channel information, repetition of data / control channels, and diversity with respect to frequency, time, and / or spatial domains. These areas are generally applicable to reliability and do not depend on a specific communication scenario.

[0038] For NR URLLC, further use cases with more stringent requirements have been identified, including factory automation, the transportation industry, and power distribution. The more stringent requirements translate into higher reliability (up to 10 times lower) depending on the use case. -6 level), higher availability, packet sizes up to 256 bytes, time synchronization down to the order of a few μs, whose value can be 1 μs or a few μs depending on the frequency range, and short latency on the order of 0.5-1 ms, with a target user plane latency of 0.5 ms in particular.

[0039] For NR URLLC, several technology enhancements from a physical layer perspective have also been identified. Among these are PDCCH (Physical Downlink Control Channel) enhancements related to compact DCI, PDCCH repetition, and increased PDCCH monitoring. Also, UCI (Uplink Control Information) enhancements related to enhanced HARQ (Hybrid Automatic Repeat Request) and CSI feedback enhancements. Also, PUSCH enhancements related to minislot-level hopping and retransmission / repetition enhancements have been identified. The term "minislot" refers to a transmission time interval (TTI) containing fewer symbols than a slot (a slot containing 14 symbols).

[0040] In slot-based scheduling or allocation, a slot corresponds to the timing granularity (TTI) of the scheduling assignment. Generally, the TTI determines the timing granularity of the scheduling assignment. One TTI is the time interval over which a given signal is mapped to the physical layer. For example, traditionally, the TTI length can vary from 14 symbols (slot-based scheduling) to 2 symbols (non-slot-based scheduling). Downlink (DL) and uplink (UL) transmissions are specified to be organized into frames (10 ms duration) consisting of 10 subframes (1 ms duration). In slot-based transmission, subframes are further divided into slots, the number of slots being defined by the numerology / subcarrier spacing. Specified values ​​range from 10 slots per frame (1 slot per subframe) for a 15 kHz subcarrier spacing to 80 slots per frame (8 slots per subframe) for a 120 kHz subcarrier spacing. The number of OFDM symbols per slot is 14 for the normal cyclic prefix and 12 for the extended cyclic prefix (see sections 4.1 (general frame structure), 4.2 (Numerologies), 4.3.1 (frames and subframes), and 4.3.2 (slots) in Non-Patent Document 5, "Physical Channels and Modulation," 2018-09). However, time resource allocation for transmission may be non-slot-based. Specifically, the TTI for non-slot-based allocation may correspond to a minislot rather than a slot. That is, one or more minislots may be allocated for the transmission of requested data / control signaling. In non-slot-based allocation, the minimum TTI length may be, for example, one or two OFDM symbols.

[0041] QoS Control

[0042] The 5G Quality of Service (QoS) model is based on QoS flows and supports both QoS flows that require a guaranteed flow bit rate (GBR QoS flows) and QoS flows that do not require a guaranteed flow bit rate (non-GBR QoS flows). Therefore, at the NAS level, QoS flows are the finest granularity of QoS differentiation in a PDU session. QoS flows are identified within a PDU session by a QoS flow ID (QFI), which is carried in the encapsulation header over the NG-U interface.

[0043] For each UE, the 5GC establishes one or more PDU sessions. For each UE, the NG-RAN establishes at least one Data Radio Bearer (DRB) with the PDU session, and additional DRB(s) for the QoS flow(s) of that PDU session may be configured later (when this is up to the NG-RAN), e.g., as shown above with reference to Figure 3. The NG-RAN maps packets belonging to different PDU sessions to different DRBs. NAS-level packet filters in the UE and the 5GC associate UL and DL packets with QoS flows, and AS-level mapping rules in the UE and the NG-RAN associate UL and DL QoS flows with DRBs.

[0044] Figure 5 shows the 5G NR non-roaming reference architecture (see section 4.23 of 3GPP TS 36544-10001). Application Functions (AFs), e.g., external application servers hosting the 5G services exemplarily shown in Figure 4, interact with the 3GPP core network to provide services and support, e.g., application influence on traffic routing, access to Network Exposure Functions (NEFs), or interaction with a policy framework (see Policy Control Function (PCF)) for policy control such as QoS control. Based on the operator's deployment, application functions deemed trusted by the operator can be allowed to interact directly with the relevant network functions. Application functions not allowed by the operator to directly access network functions interact with the relevant network functions using the external exposure framework via the NEF.

[0045] Figure 5 shows further functional units of the 5G architecture, namely the Network Slice Selection Function (NSSF), the Network Repository Function (NRF), the Unified Data Management (UDM), the Authentication Server Function (AUSF), the Access and Mobility Management Function (AMF), the Session Management Function (SMF), and the Data Network (DN), e.g., operator services, internet access, or third-party services. All or part of the core network functions and application services may be deployed and run in a cloud computing environment.

[0046] For this reason, the present disclosure provides an application server (e.g., an AF in a 5G architecture) that includes: a transmitter that, in operation, sends a request including QoS requirements for at least one of URLLC, eMMB, and mMTC services to at least one of 5GC functions (e.g., NEF, AMF, SMF, PCF, UPF, etc.) to establish a PDU session including a radio bearer between a gNodeB and a UE in accordance with the QoS requirements; and a control circuit that, in operation, performs a service using the established PDU session.

[0047] In LTE and NR, a terminal is called user equipment (UE). This may be a mobile device or communication device having user equipment functionality, such as a wireless phone, smartphone, tablet computer, or USB (Universal Serial Bus) stick. However, the term mobile device is not limited thereto, and in general, a repeater may also have such mobile device functionality, or a mobile device may function as a repeater.

[0048] A base station is a network node or a scheduling node forming part of a network, for example for providing services to terminals. A base station is a network node that provides wireless access to terminals.

[0049] 6 to 9 show some additional examples of interactions between the AMF and the UE and NG-RAN node (e.g., gNB) for the example of FIG. 3.

[0050] Specifically, Figure 6 illustrates a registration procedure in which a UE sends a registration request to the AMF, and the AMF responds by sending a registration accept message. For example, the UE initiates the registration procedure for initial registration, mobility registration update, or periodic registration update.

[0051] On the other hand, if the AMF wants to update the UE configuration regarding, for example, access and mobility related parameters, the AMF may initiate a UE configuration update procedure, as shown in Figure 7. As shown in Figure 7, the AMF sends a configuration update command, to which the UE responds with a configuration update complete message.

[0052] The NG setup procedure between an NG-RAN node and an AMF is shown in Figure 8. Specifically, an NG-RAN node (e.g., gNB) sends an NG setup request to the AMF and receives an NG setup response from the AMF. The NG setup procedure may be used to exchange application-level data (e.g., configuration data) required for the NG-RAN node and the AMF to interoperate correctly over the NG interface.

[0053] Furthermore, a RAN configuration update procedure may be used to update application-level configuration data required for the NG-RAN node and the AMF to interoperate correctly over the NG interface. As shown in Figure 9, the RAN configuration update procedure may include the NG-RAN node sending a RAN configuration update and receiving a RAN configuration update acknowledgement in response.

[0054] RRC Status

[0055] In wireless communication systems including NR, a device or communication apparatus (e.g., a UE) can be in different states depending on traffic activity. In NR, a device can be in one of three RRC states: RRC_IDLE, RRC_CONNECTED, and RRC_INACTIVE. The first two RRC states, RRC_IDLE and RRC_CONNECTED, are similar to their LTE counterparts, while RRC_INACTIVE is new to NR and does not exist in the original LTE design. There are also core network states, CN_IDLE and CN_CONNECTED, which depend on whether the device has established a connection with the core network.

[0056] In RRC_IDLE, the RRC context, i.e., the parameters necessary for communication between the device and the network, does not exist in the radio access network, and the device does not belong to a specific cell. From the core network's perspective, the device is in the CN_IDLE state. Data transfer may not occur, as the device sleeps most of the time to reduce battery consumption. In the downlink, a device in the idle state periodically wakes up to receive paging messages, if any, from the network. Mobility is handled by the device through cell reselection. Uplink synchronization is not maintained; therefore, the only uplink transmission activity that can take place is random access, e.g., transitioning to the connected state. As part of the transition to the connected state, an RRC context is established in both the device and the network.

[0057] In RRC_CONNECTED, the RRC context is established and all parameters required for communication between the device and the radio access network are known to both entities. From the core network's perspective, the device is in the CN_CONNECTED state. The cell to which the device belongs is known, and the Cell Radio-Network Temporary Identifier (C-RNTI), the device's identity used for signaling between the device and the network, is configured. The connected state is intended for data transfer to and from the device, but discontinuous reception (DRX) can be configured to reduce device power consumption. Since the gNB has an RRC context established in the connected state, leaving DRX to start transmitting or receiving data is relatively fast because no connection setup with associated signaling is required. Mobility is managed by the radio access network; the device provides measurements of neighboring cells to the network, and the network commands the device to perform handovers if relevant. Uplink time alignment, which may or may not exist, must be established and maintained using random access for data transmission to occur.

[0058] In LTE, only the idle and connected states are supported. A common case in practice is to use the idle state as the primary sleep state to reduce device power consumption. However, frequent transmission of small packets is common in many smartphone applications, resulting in a significant amount of idle-to-active transitions in the core network. These transitions come at a cost in terms of signaling load and associated delay. Therefore, to reduce the signaling load and generally reduce delay, NR defines a third state, the RRC_INACTIVE state.

[0059] In RRC_INACTIVE, the RRC context is maintained at both the device and the gNB. The core network connection is also maintained, i.e., the device is in CN_CONNECTED from the core network's perspective. Therefore, the transition to the connected state for data transfer is fast. No core network signaling is required. The RRC context is already in place in the network, and the transition from idle to active can be handled within the radio access network. At the same time, the device can sleep in a similar way to the idle state, and mobility is handled through cell reselection, i.e., without network involvement. Therefore, communication device or device mobility is device-controlled rather than network-controlled, and the communication device can contact the network via random access. Therefore, RRC_INACTIVE can be considered a mixture of the idle and connected states (see 3GPP TS 36549-1000, sections 6.5.1 to 6.5.3 for details).

[0060] Paging procedure in 5G NR

[0061] An exemplary implementation of paging functionality in 5G NR, including PDCCH monitoring, according to the currently standardized version is described below in a simplified abbreviated form.

[0062] There are two different paging procedures in 5G NR: a RAN-based paging procedure (e.g., based on RAN-based notification areas) and a core network-based paging procedure (see, for example, Non-Patent Document 1, Non-Patent Document 8, and Non-Patent Document 9, which refer to RAN paging and CN paging in some sections, e.g., Section 9.2.5 "Paging" of Non-Patent Document 1).

[0063] Paging allows the network to reach UEs in RRC_IDLE and RRC_INACTIVE states via paging messages and to notify UEs in RRC_IDLE, RRC_INACTIVE, and RRC_CONNECTED states of system information changes and public warning information (e.g., ETWS / CMAS, Earthquake and Tsunami Warning System / Commercial Mobile Alert System) notifications via short messages. Both paging messages and short messages are addressed with the P-RNTI on the PDCCH monitored by the UE. However, the actual paging message (e.g., containing the paging record) is subsequently sent on the PCCH (as indicated by the PDCCH), while the short message can be sent directly over the PDCCH.

[0064] In RRC_IDLE, the UE monitors the paging channel for paging initiated by the CN, whereas in RRC_INACTIVE, the UE also monitors the paging channel for paging initiated by the RAN. However, the UE does not need to continuously monitor the paging channel; paging DRX is defined, and a UE in RRC_IDLE or RRC_INACTIVE only needs to monitor the paging channel during one paging occasion (PO) per DRX cycle (see 3GPP TS 23.2006.02.01, e.g., sections 6.1 and 7.1). The paging DRX cycle is configured by the network.

[0065] The POs of a UE in CN-initiated paging and RAN-initiated paging are based on the same UE ID, so both POs overlap. The number of different POs in a DRX cycle is configurable via system information, and the network may distribute UEs to those POs based on their IDs. A PO is a set of PDCCH monitoring occasions and may consist of multiple time slots (e.g., subframes or OFDM symbols) in which paging DCI can be transmitted. A paging frame (PF) is a radio frame and may contain one or more PO(s) or the starting point of a PO.

[0066] In RRC_CONNECTED, the UE monitors the paging channel for System Information (SI) change notifications and / or Public Warning System (PWS) notifications in POs signaled in the system information. In case of Bandwidth Adaptation (BA) (see 3GPP TS 36.10), an RRC_CONNECTED UE only monitors the paging channel on active BWPs with a common search space configured.

[0067] If the UE receives a paging message, PDCCH monitoring can be stopped by the UE. Depending on the cause of the paging, the UE may continue, for example, to acquire system information or establish an RRC connection with the base station to receive traffic / instructions from the network.

[0068] Tracking Area and Tracking Area Code

[0069] Since the location of the UE is typically known at cell level, paging messages are typically sent across multiple cells within a so-called tracking area (TA) which may be controlled by an AMF / MME (Mobility Management Entity).

[0070] A group of nearby gNBs may be defined as a TA. This definition may be performed, for example, during the initial deployment of the network, and each gNB may be configured with its TA. A tracking area code (TAC) is a unique code assigned to each TA.

[0071] Since the network needs to have updated location information for UEs in RRC_IDLE to find out which TA a particular UE is located in, the UE may inform the network of its current location by sending a tracking area update (TAU) message every time it moves between TAs.

[0072] For this purpose, when a UE connects to the network, a list is obtained indicating the TA in which the network considers the UE to be located. If the UE moves within a TA indicated in the list, there is no need to perform a TAU procedure. However, if the UE moves to a TA not indicated by the list, a TAU procedure is initiated.

[0073] Furthermore, a UE in RRC_IDLE may send TAU messages in a regular periodic manner even if the UE remains in the same TA. By providing TAU messages regularly, the network may be informed that the UE is still available and can receive data.

[0074] The tracking area code associated with a cell may be broadcast in the system information by each gNB.

[0075] Registration Area

[0076] As mentioned above, in order to efficiently page a UE when it is idle, tracking areas (TAs) are used to track UE mobility at the core network level (e.g., by AMF). Each UE includes a list of TAIs (tracking area identifiers) (e.g., as the TA list mentioned above). Registration Area (RA) is assigned by the core network. In general, registration areas are UE specific and may vary for different UEs even in similar locations (e.g., due to load balancing).

[0077] When the core network needs to page a UE (e.g., when there is downlink data to send to the UE), it sends a paging message to one or more gNBs, which then page the UE in all cells belonging to the registration area.

[0078] The relationship between registration areas, tracking areas, and cells is shown in Figure 10, where tracking areas TAI1 and TAI2 both include multiple cells. For example, the registration area assigned to a UE may be Registration Area = {TAI1, TAI2}. In this example, a gNB serves a single cell. However, this disclosure is not limited to a particular relationship between a gNB (or base station) and a cell, and a gNB may also serve multiple cells.

[0079] When the UE moves to a cell outside the area defined by the RA, it needs to access the network to perform a mobility registration update procedure. In the mobility update procedure, if the registration procedure shown in Figure 6 can be used, the UE reports the TAI to the network via a registration request message. The core network then provides the UE with a new TAI list including the new TAI in a registration accept message. In this way, a new registration area is assigned to the UE.

[0080] Therefore, when moving to a new cell, the UE needs to determine whether it is in the same RA. To know whether it is still in the same RA, the UE considers the TAC associated with the cell. Each cell broadcasts its associated TAC (the tracking area code of the TA to which the cell belongs) and PLMN ID (public land mobile network identity) in system information (e.g., SIB1, i.e., system information block 1). When the UE visits or camps on a new cell, the UE reads the system information and derives the TAI by cascading the TAC with the PLMN ID or appending the TAC to the PLMN ID (TAI = PLMN ID + TAC). The UE then compares the derived TAI with the list of TAIs in the RA. Here, "camping" on a cell includes at least one of starting paging monitoring, reading the SIB from the cell, and performing measurements using the RS from the cell.

[0081] Non-terrestrial network (NTN)

[0082] In 3GPP, NR-based operation in non-terrestrial networks (NTN) has been studied and described (see, for example, Non-Patent Document 11 and Non-Patent Document 12).

[0083] Thanks to their wide service coverage capabilities and reduced vulnerability of spacecraft / aircraft to physical attacks and natural disasters, NTNs may facilitate the introduction of NR services to unserved areas that cannot be covered by terrestrial NR networks (e.g., isolated or remote areas, on aircraft or ships) and are not served (e.g., suburban and rural areas). Furthermore, NTNs may enhance the reliability of NR services by providing service continuity for passengers on moving platforms and by making services available everywhere, especially for critical communications.

[0084] The benefits relate to either non-terrestrial based networks operating alone or integrated terrestrial and non-terrestrial based networks, which may impact coverage, user bandwidth, system capacity, service reliability or availability.

[0085] A non-terrestrial network refers to a network or segment of a network that uses RF resources onboard a satellite, for example. An NTN is typically characterized by the following system elements: an NTN terminal, which may refer to a 3GPP UE or a terminal specific to a satellite system if the satellite does not directly serve 3GPP UEs; a service link, which refers to the radio link between the user equipment and the space / airborne platform; an airborne platform carrying the payload; a gateway, which connects the space / airborne platform to the core network; and a feeder link, which refers to the radio link between the gateway and the space / airborne platform.

[0086] Figure 11 shows a non-terrestrial network scenario in which transmissions to and from terminals (UEs) are performed via a remote radio unit (RRU) including a satellite and an NTN gateway. A gNB is located in the gateway as a scheduling device. The satellite payload implements frequency conversion and radio frequency amplification in both the uplink and downlink directions. Thus, the satellite repeats the NR radio interface from the feeder link (between the NTN gateway and the satellite) to the service link (between the satellite and the UE) and vice versa. A satellite with this configuration is called a transparent satellite.

[0087] Figure 12 shows a non-terrestrial network scenario in which transmissions to and from terminals (UEs) are performed via satellites that include gNBs as scheduling devices. Satellites in this configuration are called regenerative satellites.

[0088] NTNs can have various types of platforms, including satellites and UAS (Unmanned Aerial System) platforms, examples of which are listed in Table 1 (corresponding Table 4.1-1 in Non-Patent Document 12, see also Non-Terrestrial Networks overview in Section 4.1 of Non-Patent Document 12).

[0089] [Table 1]

[0090] For LEO, MEO, and HEO satellites that do not maintain a fixed position relative to a given point on Earth, the satellite beams corresponding to the cells or PCI (Physical Cell ID) or SSB (Synchronization Signal Block) beams of NR wireless systems may move around the Earth.

[0091] Regarding the mapping between satellite beams, NR cells, and NR SSB beams, different deployment options can be considered, for example, options a and b shown in Figures 13 and 14. According to deployment option a shown in Figure 13, one cell (corresponding to a PCI) has multiple satellite beams (e.g., the same PCI for multiple satellite beams), and according to deployment option b shown in Figure 14, one cell corresponds to one satellite beam (there is one PCI per satellite beam).

[0092] A satellite beam can consist of one or more SSB beams. For example, one satellite beam can be mapped to one SSB beam, e.g., there is a one-to-one correspondence between satellite beams and SSB beams. Here, the beam used to transmit the NR synchronization signal block is referred to as the SSB beam. One NR cell (PCI) can have up to L SSB beams, where L can be 4, 8, or 64 depending on the band. An SSB beam can be used as a reference beam for beam management in NR.

[0093] An NTN scenario that provides cells that move continuously on Earth (e.g., a LEO-, MEO-, or HEO-based NTN) is called an Earth-moving cell scenario. The Earth-moving cell scenario is illustrated in Figure 15. The continuous movement of cells on Earth is due to operations in which the satellite beams are fixed relative to the NTN platform. Therefore, the cell footprint, which may correspond to several satellite beams or one satellite beam according to deployment options a and b above, slides across the Earth's surface as the NTN platform (e.g., the LEO satellite illustrated in Figure 15) moves.

[0094] Information about a satellite's orbital trajectories is contained in ephemeris data (or "satellite ephemeris data"). Various possible representations of ephemeris data exist; one possibility is to use orbital parameters such as semimajor axis, eccentricity, inclination, right ascension of the ascending node, argument of periapsis, mean anomaly at the reference epoch, and epoch. The first five parameters can determine the orbital plane (orbital plane parameters), while the other two parameters are used to determine the exact satellite position at a given time (satellite-level parameters). The orbital plane parameters and satellite-level parameters are listed in Table 2 and illustrated in Figure 16 (see also Section 7.3.6.1 of "Representation of Complete Ephemeris Data" in Non-Patent Document 12). Another possible option is to provide the satellite position coordinates (x, y, z), the velocity vector (vx, vy, vz), and the reference epoch.

[0095] [Table 2]

[0096] Therefore, the representation of the ephemeris data may require seven parameters (e.g., double-precision floating-point numbers) and possibly some overhead. In an NTN system, several satellites may share a common orbital plane. In such cases, to reduce the amount of data, some ephemeris data may be provided for an orbital plane rather than for a single satellite. The ephemeris data for each orbital plane may be stored in the UE or in the UE's Subscriber Identity Module (SIM).

[0097] However, for networks with many satellites, the size of the ephemeris data can be significant. Therefore, rather than storing the ephemeris data, the ephemeris data may be at least partially transmitted from the gNB.

[0098] For example, satellite-level orbital parameters for all satellites that can serve the UE may be stored in the UE or SIM, and the ephemeris data for each satellite may be linked to a satellite ID or index. The satellite ID or index of the serving satellite may then be broadcast in the system information so that the UE can find the corresponding ephemeris data in the UE's SIM or storage.

[0099] Alternatively, satellite-level orbital parameters of the serving satellite may be broadcast in the system information, and the UE derives the position coordinates of the serving satellite. Ephemeris data of nearby satellites may also be provided to the UE via system information or dedicated RRC signaling. If baseline orbital plane parameters are provisioned in the UE or SIM, it may be sufficient to broadcast the mean anomaly at the reference time instant, reducing overhead from the need to broadcast the epoch to the UE.

[0100] As discussed above with reference to Figure 15, the Earth moving cell scenario is an NTN scenario that provides a cell that is continuously moving on Earth. This is due to the operation of the satellite beam being fixed relative to the NTN platform. Therefore, the footprint of the satellite beam slides across the Earth's surface as the NTN platform (e.g., a LEO satellite) moves.

[0101] As mentioned above, there is an association between a cell and a tracking area. However, in a terrestrial mobile cell scenario, if the TAC broadcast by the cell does not change, this means that the TA sweeps the earth as the cell moves. For such moving tracking areas, even stationary UEs need to keep performing frequent registration updates, which incurs additional overhead and power consumption.

[0102] For these reasons, instead of moving tracking areas, fixed tracking areas can be considered for NTNs. Tracking areas therefore correspond to fixed geographical locations on the Earth. For moving cells, a fixed TA can be achieved in two ways: According to one approach, the TAC broadcasted by the (moving) cell changes as the cell covers different geographical areas; According to another approach, the TAC is not broadcasted and the UE derives the registration area in other ways, for example from its location information.

[0103] Regarding the mapping between cells and tracking areas, "hard switch" and "soft switch" options can be considered. Hard switch means that a cell broadcasts only one TAC per PLMN. Some fluctuations may occur in the border areas between TAs when a cell's new TAC replaces the old one. On the other hand, the "soft switch" option allows a cell to broadcast more than one TAC per PLMN. The cell adds the new TAC to the system information in addition to the old one and deletes the old one a little later. However, signaling more TACs may increase overhead (see also section 7.3.1.3.1 of 3GPP TS 36.2544-12012 for hard switch and soft switch information).

[0104] The following will provide some details about location-based TA determination. Specifically, it can be considered that the Earth is divided into multiple geographical areas corresponding to TAs. Mapping rules between geographical areas and their associated TAC values ​​can further be maintained in both the UE and the network.

[0105] For example, during initial registration, the UE derives a TAC based on its location information and mapping rules, and then forms a TAI from the derived TAC and the broadcasted PLMN ID. The UE then reports the TAI to the AMF via a registration request message. The AMF then provides the UE with a TAI list including the reported TAI via a registration accept message.

[0106] When a UE moves to a new geographical area, the UE derives a TAC based on its location information and mapping rules, and then forms a TAI from the TAC and the broadcasted PLMN ID. If the formed TAI is not in the TAI list, a mobility registration update procedure is triggered. At this time, the UE reports the TAI to the AMF via a registration request message. The AMF provides the UE with a TAI list including the reported TAI via a registration accept message. The UE then replaces the old TAI list with a new one including the reported TAI (see also section 7.3.1.3.2 of 3GPP TS 36.1101).

[0107] Regarding the TA determination mechanism described above, it is generally unclear how the mapping rules between geographical areas and TACs are made available to the UE. Furthermore, as a specific example, when cell selection or reselection is based on radio signal strength and the TAC is not broadcast, e.g., when positioning functionality is unavailable, it is unclear how to determine that the UE is still within the RA.

[0108] Furthermore, due to cell movement, there is no fixed relationship between cells and registration areas. When the core network needs to page a UE, it is unclear what information is needed and how such information is obtained for the AMF to select the gNB(s) to deliver the paging message and for the gNB to select the cell(s) to page the UE.

[0109] The present disclosure is directed to tracking area determination and paging handling for non-terrestrial based networks.

[0110] This disclosure describes scheduling nodes, such as UEs and base stations, and corresponding methods for new radio access technologies intended for 5G mobile communication systems, such as 3GPP NR, but which may also be used in LTE mobile communication systems.

[0111] Therefore, the communication device (or user terminal or communication terminal) is referred to as UE (User Equipment), and the scheduling node, such as a base station, may correspond to a gNodeB (gNB).

[0112] Furthermore, although some of the terms used below, such as procedures, entities, and layers, are closely related to those used in the LTE / LTE-A system or current 3GPP 5G standardization, specific terms used in the context of the new radio (NR) access technology of the upcoming 3GPP 5G communication system have not yet been fully determined or may eventually change. Therefore, terms may change in the future without affecting the functionality of the embodiments. Therefore, those skilled in the art will recognize that the embodiments and their scope of protection should not be limited to the specific terms used illustratively herein due to the absence of newer or ultimately agreed-upon terms.

[0113] A communication apparatus or device, such as a UE, and a scheduling node or base station may include circuits such as a transceiver and a processing circuit. In turn, a transceiver may include and / or function as a receiver and a transmitter. The processing circuit may be one or more hardware components, such as one or more processors or any LSI (Large Scale Integration). Between the transceiver and the processing circuit, there are input / output points (or nodes) through which the processing circuit can control the transceiver in operation, i.e., control the receiver and / or transmitter, and exchange receive / transmit data. As a transmitter and receiver, the transceiver may include an RF (radio frequency) front, including one or more antennas, amplifiers, RF modulators / demodulators, etc. The processing circuit may perform control tasks, such as, for example, transmitting user data and control data provided by the processing circuit and / or controlling the transceiver to receive user data and control data that are further processed by the processing circuit. The processing circuit may also be responsible for performing other processing, such as, for example, determining, deciding, calculating, measuring, etc. The transmitter may be responsible for performing the transmission process and other processes related thereto, and the receiver may be responsible for performing the reception process and other processes related thereto, such as monitoring the channel.

[0114] Communication devices such as UEs and base stations, as well as core network entities such as AMF systems, may include circuits, which may include processing circuits and control circuits.

[0115] 17, the UE includes a transceiver 1780, which, in operation, transmits a registration request. The registration request (or "registration request message") may include: notification of the first location of the UE, or The cell ID of the last cell visited by the UE and a timestamp indicating the first time the UE was located in the last cell; It includes at least one of the following:

[0116] The transceiver 1780 of the UE 1770 (or "UE transceiver") receives the registration accept message including notification of a registration area (RA), where the registration area includes a first location of the UE.

[0117] The UE 1770 further comprises a circuit 1790 (or “UE circuitry”) that, in operation, determines whether the UE is located within a registration area at the second location. The determination as to whether the UE is within a registration area is made based on at least one of the following: a list of cell IDs of a plurality of Earth mobile cells or cell sections of Earth mobile cells, a notification of a second time at which the plurality of Earth mobile cells form a registration area, and, for each of the plurality of Earth mobile cells, coverage area information and satellite ephemeris data indicating the coverage area of ​​the cell or cell section relative to the satellite position of the satellite generating the cell, and a second position measurement of the UE. The list of the plurality of Earth mobile cells and the notification of the second time are included in the notification of the registration area; or a list of cell IDs, a notification of a time interval in which a plurality of terrestrial mobile cells or cell sections form a registration area, and a cell ID of a newly visited cell or cell section that includes a second location of the UE and is different from the last cell; the list of cell IDs and the notification of the time interval are included in the notification of the registration area; or The second location measurement, a mapping between the geographic area and the tracking area, and a list of one or more tracking areas forming the registration area, the mapping being read from storage, and the list of one or more tracking areas being included in the notification of the registration area.

[0118] User equipment 1770 is a mobile device, communication device, or mobile terminal of a wireless communication system.

[0119] For example, the UE circuitry 1790 may include an RA position determination circuitry 1795. An exemplary RA position determination circuitry 1795 is shown in FIG.

[0120] A base station 1740 is further provided and is also shown in FIG. 17. The base station 1740 comprises an interface 1755 (also referred to as a "base station interface") that, in operation, receives a paging request for paging a UE. The paging request includes an indication of a registration area. The base station further comprises circuitry 1760 ("base station circuitry") that, in operation, based on a list of cell IDs of the first plurality of Earth mobile cells or cell sections of Earth mobile cells, a notification of a second time when the first plurality of Earth mobile cells form a registration area, and, for each of the first plurality of Earth mobile cells, coverage area information and satellite ephemeris data indicating the coverage area of ​​the cell or cell section relative to the satellite position of the satellite generating the cell (the list of the first plurality of Earth mobile cells and the notification of the time are included in the notification of the registration area), or based on a list of cell IDs and a notification of a time interval during which a first plurality of terrestrial mobile cells or cell sections form a registration area (the list of cell IDs and the notification of the time interval are included in the notification of the registration area), or based on a mapping between the geographic area and the tracking area and a list of one or more tracking areas forming the registration area (the mapping is read from a storage and the list of one or more tracking areas is included in the notification of the registration area), and determining a second plurality of terrestrial mobile cells, the second plurality of terrestrial mobile cells being a plurality of cells currently mapped to the registration area. The base station 1740 further comprises a transceiver 1750 that, in operation, transmits a paging message to page the UE in the second plurality of cells.

[0121] For example, the base station circuitry 1760 includes an RA determination circuitry 1765 .

[0122] The base station 1740 is a scheduling node or scheduling device of a wireless communication system, such as a gNB of 3GPP NR, in which a non-terrestrial network is implemented. Thus, terrestrial mobile cells are served by satellites (e.g., LEOs) or other non-terrestrial platforms, such as airships or balloons. For example, the communication system is an NR-NTN communication system. The communication system may include terrestrial mobile cells, either alone or in combination with or supplemented by fixed cells, for example, generated by terrestrial base stations. The UE 1770 and the base station 1740 communicate via wireless channels. This disclosure is not limited to the particular relationship between base stations and satellites; communication systems implementing both regenerative and transparent satellites, or both regenerative and transparent satellites, are possible, as shown in FIGS. 11 and 12 .

[0123] Furthermore, the base station communicates with core network entities or systems such as the AMF via interface 1755.

[0124] In the above description of the base station, the "first plurality of cells" refers to terrestrial mobile cells that define a registration area in association with information about the time (time of day or time interval) during which the first plurality of cells constitute the registration area, while the "second plurality of cells" refers to cells to which the UE is paged. As will be further described, the second plurality of cells are determined based on the first plurality of cells.

[0125] A base station may serve one cell or two or more cells, and a registration area may be larger than the number of cells served by the base station 1740. Thus, the "second plurality of cells" determined by the base station to page the UE may cover the entire registration area or a sub-area of ​​the registration area.

[0126] 17, an AMF (Access Mobility and Management Function) system 1710 is disclosed. The AMF system 1710 comprises an interface 1720 ("AMF interface") and a circuit 1730 (AMF circuit). In operation, the AMF interface 1720 receives a registration request from a UE, the registration request being notification of the first location of the UE, or The cell ID of the last cell visited by the UE and a timestamp indicating the first time the UE was located in the last cell; Includes.

[0127] The AMF circuit 1730 generates a notification of a registration area that includes the first location of the UE. The notification of the registration area includes: a list of cell IDs of a plurality of Earth mobile cells or cell sections of Earth mobile cells and notification of a second time at which the plurality of Earth mobile cells form a registration area (the registration area is determined for each of the plurality of Earth mobile cells or cell sections based on coverage area information indicating a coverage area of ​​the cell or cell section relative to a satellite position of a satellite generating the cell and ephemeris data of the satellite); or a list of cell IDs and notification of time intervals in which a plurality of terrestrial mobile cells or cell sections form a registration area, or · Includes a list of one or more tracking areas that form the registration area (the list of one or more tracking areas is determined based on a mapping between geographical areas and tracking areas, the mapping being read from storage).

[0128] In operation, the AMF interface 1720 sends a registration acceptance message that includes notification of the registration area.

[0129] The AMF system 1710 is an AMF entity of a core network, such as a fifth-generation core. For example, the AMF system may be implemented as a server or within a server that hosts additional core network entities, or may be distributed among multiple nodes.

[0130] The AMF system 1710 and the base station 1740 communicate via interfaces 1720 and 1755. For example, interfaces 1720 and 1755 form an NG interface. The AMF system 1710 and the base station 1740 may communicate via interfaces 1720 and 1755 by a wired connection (which may include fiber optic cable) or a wireless connection (such as in a regenerative satellite scenario). The base station interface 1755 may be included in the base station transceiver 1750 or may be separate from the base station transceiver 1750.

[0131] For example, as shown in FIG. 17, the AMF circuit 1730 includes an RA determination circuit 1735.

[0132] As described above, the UE 1770 and the AMF 1710 exchange registration request messages and registration accept messages. This exchange may be performed via the base station 1740, which may forward these control messages for the registration procedure. In operation, the base station transceiver 1750 may then receive registration request messages from the UE and send registration accept messages to the UE. Similarly, the base station interface 1755 may send registration request messages to the AMF and receive registration accept messages from the AMF.

[0133] Corresponding to the above-mentioned user equipment, a communication method for a user equipment (UE) is provided. As shown in Figure 19, the method includes a step S1910 of sending a registration request, the registration request including: notification of the first location of the UE, or The cell ID of the last cell visited by the UE and a timestamp indicating the first time the UE was located in the last cell; It includes at least one of the following:

[0134] The method includes receiving a registration accept message including notification of a registration area (S1920), the registration area including a first location of the UE. The method also includes determining (S1930), the determining (S1930) including: based on a list of cell IDs of a plurality of Earth mobile cells or cell sections of Earth mobile cells, a notification of a second time at which the plurality of Earth mobile cells form a registration area, and, for each of the plurality of Earth mobile cells, coverage area information and satellite ephemeris data indicating the coverage area of ​​the cell or cell section relative to the satellite position of the satellite generating the cell, and a second position measurement of the UE (wherein the list of the plurality of Earth mobile cells and the notification of the second time are included in the notification of the registration area), or based on a list of cell IDs and a notification of a time interval in which a plurality of terrestrial mobile cells or cell sections form a registration area and a cell ID of a newly visited cell or cell section that includes a second location of the UE and is different from the last cell (the list of cell IDs and the notification of the time interval are included in the notification of the registration area), or based on the second location measurement, a mapping between the geographic area and the tracking area, and a list of one or more tracking areas forming the registration area (the mapping is read from storage, and the list of one or more tracking areas is included in the notification of the registration area), At the second location, it is determined whether the UE is located within the registration area.

[0135] Corresponding to the above-mentioned base station, a communication method for the base station is further disclosed. As shown in FIG. 20, the method includes a step S2010 of receiving a paging request for paging a user equipment (UE), the paging request including notification of a registration area. The method further includes a step S2020 of determining: based on a list of cell IDs of the first plurality of Earth mobile cells or cell sections of Earth mobile cells, a notification of a second time when the first plurality of Earth mobile cells form a registration area, and, for each of the first plurality of Earth mobile cells, coverage area information and satellite ephemeris data indicating the coverage area of ​​the cell or cell section relative to the satellite position of the satellite generating the cell (the list of the first plurality of Earth mobile cells and the notification of the time are included in the notification of the registration area), or based on a list of cell IDs and a notification of a time interval during which a first plurality of terrestrial mobile cells or cell sections form a registration area (the list of cell IDs and the notification of the time interval are included in the notification of the registration area), or based on a mapping between the geographic area and the tracking area and a list of one or more tracking areas forming the registration area (the mapping is read from a storage and the list of one or more tracking areas is included in the notification of the registration area), A second plurality of terrestrial mobile cells currently mapped to the registration area are determined. The method further includes a step S2030 of transmitting a paging message for paging the UE in the second plurality of cells.

[0136] Also, corresponding to the AMF system disclosed above, a communication method for the AMF system is provided. As shown in Figure 21, the method for the AMF system includes step S2110 of receiving a registration request of a user equipment (UE), the registration request including: notification of the first location of the UE, or The cell ID of the last cell visited by the UE and a timestamp indicating the first time the UE was located in the last cell; Includes.

[0137] The method for an AMF system includes generating a notification of a registration area that includes a first location of the UE. The notification of the registration area includes: a list of cell IDs of a plurality of Earth mobile cells or cell sections of Earth mobile cells and notification of a second time at which the plurality of Earth mobile cells form a registration area (the registration area is determined for each of the plurality of Earth mobile cells or cell sections based on coverage area information indicating a coverage area of ​​the cell or cell section relative to a satellite position of a satellite generating the cell and ephemeris data of the satellite); or a list of cell IDs and notification of time intervals in which a plurality of terrestrial mobile cells or cell sections form a registration area, or - Including a list of one or more tracking areas forming the registration area (the list of one or more tracking areas is determined based on a mapping between geographical areas and tracking areas, the mapping being read from storage).

[0138] Further, the method for AMF includes sending a registration acceptance message including notification of the registration area.

[0139] In this disclosure, unless the context dictates otherwise, any descriptions and examples shall be construed as applicable to each of the UE, base station, and AMF system, and shall apply to both the apparatus and the method.

[0140] Stored mapping of TACs to geographic areas

[0141] In some embodiments, a mapping between a TAC and a geographical area is predefined as a fixed relationship and installed in the memory of the UE. The memory may be a memory device, a SIM (Subscriber Identity Module), an internal memory, or another memory device. The UE determines its location, for example, using a GNSS (Global Navigation Satellite System), derives a TAI based on its location information, and transmits the derived TAI to the AMF as a notification of its location. The UE then receives a list of one or more tracking areas (which may be indicated by the TAC) as a notification of the registration area in a registration accept message from the AMF. When the UE needs to determine whether it is still within the registration area at a certain location (the “second location”) (e.g., for a periodic update or when camping or visiting a new cell), the UE circuit 1790 reads the mapping between the tracking areas or TACs and the geographical areas from the storage. Therefore, the UE may further include a storage interface that reads the mapping from the storage. The UE determines whether the UE is within a registration area consisting of the TAC(s) in the list based on the second location (specifically, the TAC formed based on the second location and thereby indicating the second location), the received list of TAC(s), and the stored mapping.

[0142] For example, in a mapping between TACs and geographic areas, one TAC may be assigned to one country (e.g., TAC1=Germany, TAC2=Austria, TAC3=Switzerland, etc.). For countries with larger areas, multiple TACs may be defined, which may be assigned to states, federal states, etc. The boundaries of the geographic areas may be stored in the UE or a storage device such as a SIM, or may be derivable from map information, such as a digital map stored in the UE or a storage device. Thus, the UE can know in which area it is located based on location measurements.

[0143] Embodiments that use a stored mapping between TACs and geographic areas provide backward compatibility in that one or more TACs can be used to conventionally signal a registration area to a UE. However, if the mapping is stored in the UE or a storage device such as a SIM, the TA definition (the mapping from one TAC to a specific region) can be difficult to update.

[0144] Cell coverage area at time

[0145] In some embodiments, a registration area (or tracking area) is defined by the union of (earth moving) cell coverage areas at a particular time.

[0146] At this time, the cell coverage area may be defined by one of the following information, which may be included in the coverage area information for each of the multiple terrestrial mobile cells and therefore be available to the UE, as shown in Figures 22 to 24:

[0147] In a first example, as shown in Figure 22, the cell area is defined by the satellite beam direction of each beam forming the cell (a cell may consist of one beam or may include multiple beams, as described with reference to Figures 13 and 14), and the beam radius or diameter on Earth, such as the radius or diameter of the cell or beam footprint on Earth. In this case, the cells may overlap.

[0148] In a second example, the cell area of ​​an Earth mobile cell is defined by polygons that define non-overlapping coverage areas, as shown in Figure 23. For example, the cell area is defined by the vertices of non-overlapping shapes such as rectangles or hexagons.

[0149] For example, the polygon may be represented using a reference point (e.g., a corner or center) that may be relative to the current satellite position available from the ephemeris data, and a side length of the polygon or another indication of the size of the polygon. As another example, the polygon may be represented using the coordinates of all corners of the polygon relative to the satellite position.

[0150] In a third example shown in Figure 24, a cell may be defined by a cell center and an in-coverage distance from the center (e.g., an in-coverage radius). In this example, the signaling may be similar to the first example.

[0151] The above definitions of coverage area information according to the first to third options can be provided relative to the satellite position, e.g., relative to the satellite position of the satellite (or satellites) generating the satellite beam(s), which changes over time and can be derived for a given point in time from ephemeris data. As the satellite moves over time, the coverage area, e.g., its size, can also change over time. For example, the size of the satellite beam area can be adjusted to the UE density or population density in the area covered by the satellite beam. Thus, if a satellite is moving over a more densely populated area of ​​the Earth, the coverage area, e.g., beam footprint or terrestrial cell / beam area, can shrink to provide smaller cells to address the increased demand caused by more UEs that need to be served.

[0152] A tracking area or registration area is defined by the union of cell areas associated with a timestamp (e.g., TA1={cell 1, cell 2, cell 3, cell 4, t=13:01} and TA2={cell 5, cell 6, cell 7, cell 8, t=13:01}), as shown in Figure 25.

[0153] For the definition of cell coverage areas for moving cells according to the above examples of Figures 22-24 associated with a given timestamp, the user equipment may use the cell coverage area information, the timestamp, and the satellite ephemeris data to calculate the area on Earth covered by these cells at the indicated time. A registration area and / or a tracking area may then be determined as the area covered by multiple cells at a particular time. Thus, the tracking area and / or registration area may be considered to be defined by the "frozen cells" that covered or will cover the registration area at the indicated time.

[0154] For example, the UE receives coverage area information in the system information. For example, the cell coverage area is signaled to the UE from the gNB via broadcasted RRC signaling such as an SIB. In addition to the cell coverage area, the UE may further receive satellite ephemeris data or a portion of the ephemeris data in the system information, which the UE may then use to calculate the movement of the satellite relative to the Earth's surface (possibly using a further portion of the ephemeris data that may be pre-stored in a storage device).

[0155] The registration area is signaled from the AMF to the UE via NAS signaling, such as the registration accept message or configuration update command message shown in Figures 6 and 7. At this time, it is sufficient to signal only the TAs in which the UE is registered to the UE. These TAs can be signaled by signaling a list of "frozen cells," i.e., cell IDs, and the timestamps of the times at which the cells in the list form the registration area. For example, registration area = {cell 1, cell 2, cell 3, cell 4, cell 5, cell 6, cell 7, cell 8, t = 13:01}, which corresponds to TAC1 and TAC2 in Figure 25. These cell IDs can be signaled instead of TA codes, which are not required for the UE to determine the registration area. Nevertheless, the concept of tracking area can still be used on the AMF or base station side. For example, the AMF can include multiple cells to form a registration area assigned to the UE.

[0156] Thus, the UE knows the mapping between registration areas and geographic locations, and based on this, the UE can determine from its location information, such as GNSS position measurements, whether it has left its registration area.

[0157] For example, to determine whether the UE is still within a registration area, the UE may test, for each of the cell coverage areas of the "frozen cells" that make up the registration area at a given time, whether the UE is within each cell coverage area by, for example, comparing the distance from the UE to the cell center with the cell radius. If the UE identifies a coverage area of ​​a frozen cell whose distance to the center is less than the radius, the UE may know that it is within the registration area and may stop calculating. Alternatively, based on multiple cell coverage areas, the UE may calculate the range or boundaries of the registration area and determine, for the entire registration area, whether the UE is located within these boundaries.

[0158] The cell coverage area information may further be pre-configured in both the AMF system and the gNB during the cell planning phase, or alternatively may be signaled from the gNB to the AMF via NGAP signaling, for example, an NG Setup Request message, or a RAN Configuration Update message (see Figures 8 and 9). Furthermore, the mapping between cells and gNBs may be pre-configured in the AMF. The UE reports the cell ID of the last visited cell with a timestamp to the AMF via a Registration Request message, or alternatively reports an indication of the UE location.

[0159] Thus, the AMF knows which gNB(s) cover the registration area at any given time and can decide which gNB or gNB(s) should deliver the paging message.

[0160] Furthermore, the definition of the tracking and registration areas in the form of cell IDs and timestamps corresponding to the "frozen cells" is signaled to the gNB from the AMF, for example in a paging message. Thus, the gNB knows which cell(s) cover the registration area and can decide in which cells the paging should be broadcast.

[0161] One possible example of a registration and paging call flow is shown in Figure 26. As shown, the gNB sends a SIB to the UE containing cell coverage information, including indication of the cell coverage area relative to the satellite positions. The SIB may further include indication of satellite ephemeris data, except in cases where the ephemeris data is fully stored on the UE side. Furthermore, the gNB may send the cell coverage area information included in the NG Setup Request message to the AMF (e.g., if the cell coverage information is not also pre-configured in the AMF).

[0162] At time t of initial registration, the UE sends a registration request message to the AMF, which includes UE location information or the cell ID of the last visited cell along with a timestamp. In response, the AMF sends a registration accept message to the UE as a notification of the registration area, which includes a list of cell IDs and a timestamp of the time when the cells indicated by the list form the registration area. As shown in Figure 26, the registration request and registration accept can be forwarded by the gNB.

[0163] At time t+1, while the UE is in an idle state, the AMF receives downlink data for the UE. The AMF system then determines the gNB(s) that are currently mapped to the registration area and that serve the cells currently mapped to the registration area. To these gNBs, the AMF system sends a paging message (or paging request message) that includes a list of cells and timestamps that indicate which cells form the registration area. Using the list, timestamps, and ephemeris data held at the gNB, the gNB determines which of the cells it serves are currently included in the registration area and performs paging of the UE over these cells included in the registration area.

[0164] Paging is initiated by the AMF when the UE is in RRC idle mode. Thus, the AMF sends a paging message to base station(s), which then broadcasts the paging message to cells in its registration area to page the UE. In this disclosure, the terms "paging request" or "paging request message" are used for a message from the AMF to the base station, which includes notification of the registration area and may include a paging message for paging the UE.

[0165] At time t+2, the UE may detect that its location is outside its registration area based on location measurements. The UE then sends a new registration request including its current location and receives a registration accept message with a list of new cell IDs and timestamps that indicate that these cells form the UE's new registration area. The UE then replaces its previous registration area with the new one.

[0166] If the cell coverage area information is in the SIB together with the ephemeris data, this data may further facilitate the UE to perform cell selection without measuring radio signal strength, which may otherwise be frequent due to cell movement. Thus, the cell coverage area information can be used by the UE for cell selection and reselection, and for determining whether the UE is within a registration area.

[0167] Furthermore, if the cell coverage area is already available via the SIB, only a limited amount of signaling overhead (cell ID + timestamp) is required to indicate the registration area based on the cell coverage area information.

[0168] Cells with their own timing

[0169] In some embodiments, a registration area or tracking area is defined by listing all cells with associated timings (or time intervals) that the cells cover in a given geographic location or area on Earth. As a notification of a registration area, a list of cell IDs of the terrestrial mobile cells and notification of the time intervals in which the terrestrial mobile cells form the registration area are provided to the UE.

[0170] In addition, the notification of the registration area included in the registration acceptance message from the AMF may include a list of multiple cell IDs of terrestrial mobile cells (or cell sections) and, for each list of multiple cell IDs, notification of multiple time intervals each indicating when the terrestrial mobile cells (or cell sections) respectively indicated by that list of cell IDs form the registration area.

[0171] Therefore, by informing the UE of the cells that are in the registration area for multiple time intervals, it is not necessary to signal the registration area every time the cells that make up the registration area change.

[0172] An example is shown in FIG. 27 where two tracking areas TA1 and TA2 change as follows within two time intervals, 13:01-13:10 and 13:11-13:20 (as with the example in FIG. 25, this example is merely illustrative and the present disclosure is not limited to any particular length of time interval or number of cell IDs within a registration area or tracking area): ·TA1={13:01~13:10 Cell 1, Cell 2, Cell 3; 13:11~13:20 Cell 2, Cell 3, Cell 4; ...} ·TA2={13:01~13:10 Cell 4, Cell 5, Cell 6; 13:11~13:20 Cell 5, Cell 6, Cell 7; ...}

[0173] As can be seen from Figure 27, the set of cells included in a TA remains the same for a period or time interval (10 minutes in the example above). Therefore, and moreover, since cells are constantly moving, the resulting TA (and therefore the registration area) also changes.

[0174] In an embodiment in which one or more lists of such cell IDs and corresponding time intervals are signaled to the UE as a registration area notification, a tracking area code is not required on the UE side. Nevertheless, the tracking area may be used to determine the registration area to be assigned to the UE on the AMF side. This disclosure is not limited to a particular method for how the tracking area is determined on the AMF side.

[0175] For example, considering the example of Figure 27, the UE may be assigned registration areas {TA1;TA2}.

[0176] Thus, the UE may be indicated the registration area for two subsequent time intervals as follows: RA={13:01~13:10 Cell 1, Cell 2, Cell 3, Cell 4, Cell 5, Cell 6; 13:11~13:20 Cell 2, Cell 3, Cell 4, Cell 5, Cell 6, Cell 7

[0177] The registration area is signaled from the AMF to the UE via NAS signaling, e.g., a registration accept message or a configuration update command message, in the form of a set of cells (corresponding to a list of cell IDs) associated with timing (e.g., respective time intervals during which one of the set of cells forms the registration area).

[0178] There is no need to notify the UE of the coverage area of ​​each cell. Legacy cell (re)selection based on radio signal strength can be reused. As a result, when the UE performs legacy cell (re)selection based on radio signal strength, the UE can determine whether it has left its registration area from the cell ID of the newly visited or camped cell and the timing of visiting the cell, without determining its own location.

[0179] Also, cell coverage area information may be pre-configured in the AMF (and possibly gNBs) during the cell planning phase, for example based on cell coverage estimates for terrestrial mobile cells. Also, mapping between cells and gNBs may be pre-configured in the AMF. Thus, the AMF knows which gNB(s) cover the registration area at any time or times and can therefore determine to which gNB(s) a paging message should be delivered.

[0180] Additionally, in the registration request message, the UE signals to the AMF the cell ID of the last visited cell and the timestamp that the UE was located in that cell (e.g., the timestamp of the signal strength measurement).

[0181] Also, the registration area (and / or tracking area) is signaled to the gNB in ​​the form of a set of cells (corresponding to a list of cell IDs) associated with a timing (e.g., respective time intervals during which one of the set of cells forms the registration area), e.g., in a paging message (or in a paging request that includes the paging message), so that the gNB knows which cell(s) cover the registration area and can decide to which cells to broadcast the paging.

[0182] An exemplary registration and paging call flow is shown in Figure 28. At time t, for example, when an initial registration of a UE is performed, the UE sends a registration request to the AMF indicating the last visited cell with a timestamp. The UE then receives a registration accept message from the AMF, which includes a registration area notification including a set of cells (e.g., a list of cell IDs) and an associated timing when a set of cells forms a registration area.

[0183] At time t+1, when the UE is paged by the core network, the AMF that received the DL data for the UE determines the gNB(s) currently mapped to the registration area and sends a paging message (or a paging request message containing a paging message) to these gNBs, containing a set of multiple cells with associated timing as the registration area. In principle, it is sufficient for the gNBs to receive the IDs of the cells served by each gNB. The gNBs determine the cells currently mapped to the registration area and perform paging for the UE.

[0184] At time t+2, if the UE camps on a new cell outside its registration area, a registration request containing the cell ID of the newly visited cell and a registration accept message containing a new set of cells indicating the new registration area are exchanged between the UE and the AMF in the same manner as during the initial registration at time t.

[0185] If the registration area is presented to the UE as a list of cell IDs of the set of cells and the associated timings that form the registration area, the UE does not need to be able to determine its own location and legacy cell selection based on radio strength can be reused. Nevertheless, rather than the cell ID and timestamp of the last visited cell, the UE may instead send location information in the registration request.

[0186] Furthermore, the TAC does not need to be broadcast by the moving cell, and therefore the problems associated with broadcasting the TAC do not necessarily arise, which may include TAC fluctuations due to "hard switches" or overhead due to soft switches.

[0187] Geographic Zones and Wireless Signal Coverage

[0188] In some embodiments, the TA and / or registration area RA are defined by a timing associated cell area or "restricted cell area" (corresponding to a cell section), where the "restricted cell area" is defined by the intersection of a geographical zone and radio signal coverage.

[0189] Geographical zones may be pre-installed in the UE (e.g., stored on a SIM or other memory device) and pre-defined in the network (gNB and core network). These geographical zones can be used, for example, to define borders of authorization areas.

[0190] For example, a satellite beam may broadcast multiple cell IDs (cell IDs may correspond not only to cells but also to cell sections or "restricted cell areas") associated with different cells, possibly belonging to different countries or licensed areas. In this case, when performing cell (re)selection using signal strength, the UE may receive the same signal strength from multiple cells or cell sections because they are generated by the same satellite beam. However, the sections corresponding to multiple cells or "restricted cell areas" may be associated with different licensed areas. For example, a satellite beam may travel on the Earth along the border of two countries and broadcast two cell IDs, one for each country. In this disclosure, "restricted cell IDs," each of which may have its own cell ID, refer to cell sections of cells within one of the predefined geographic areas. The UE then selects the cell with the strongest radio strength permitted (or authorized) in a given location.

[0191] For example, if the UE determines that it is not located within a registration area (e.g., by location measurements or by comparing the cell ID (or signal strength from multiple cell IDs) of a newly camped or visiting cell with a list of cell IDs defining a previous registration area over a given time interval), the UE may perform signal strength measurements for cell (re)selection and receive identical or similar signal strengths from multiple cells, which are therefore candidates for the new visiting cell.

[0192] The UE may then determine the geographical area in which it is located from stored or pre-installed geographical areas based on the location measurements and a definition of the geographical area that may be read from storage or memory.

[0193] The UE then selects one candidate included in the geographical area in which the UE is located as a new cell or cell section to visit, based on an association between a cell ID of each of the candidates and one of the stored geographical areas.

[0194] This association between cell IDs and geographic areas (e.g., mapping between cell IDs and geographic zone information) may be signaled to the UE for each cell from the gNB within the system information (e.g., SIBs) received by the UE.

[0195] Also, for example, if the list of cell IDs indicated by the AMF exceeds a restricted geographic area, the installed or stored geographic area may be used by the UE to determine which of the cells included in the list of cell IDs or lists of multiple cell IDs are present within the geographic area. The UE circuit 1790 may then determine a registration area formed by a cell or section of cells from the list(s) of cell IDs associated with the geographic area in which the UE is located.

[0196] An example of multiple cell sections or “restricted cell areas” divided into different geographic areas or zones is shown in FIG. 29. It may be assumed that one satellite beam transmits multiple (e.g., two or more) cell IDs. For example, beam 1 covers both cell 1 and cell 2. Because both cells or restricted cell areas are within the same radio coverage, the UE detects similar (e.g., substantially the same) radio signal strength from both cells associated with the same radio satellite beam. The UE may select restricted cell area (RCA) 1 or RCA2 based on location information regarding whether the UE is located in Zone A or Zone B, where RCA1 = intersection {cell 1, zone A} and RCA2 = intersection {cell 2, zone B}. Different tracking or registration areas may be indicated by signaling a list of multiple cell IDs (or RCA IDs or cell section IDs) and associated timing or time intervals. TA1 (or RA1) = {13:01~13:10 RCA1, RCA3, RCA5; 13:11~13:20 RCA3, RCA5, RCA7}; TA2 (or RA2) = {13:01~13:10 RCA2, RCA4, RCA6; 13:11~13:20 RCA4, RCA6, RCA8}

[0197] As described above, the definition of the geographical zone or area may be stored or installed in the UE or a memory device. Furthermore, the association between the cell ID (or RCA ID) and the geographical zone may be broadcast by the gNB, for example, via a SIB. The registration area in the form of a set of multiple cells with associated timings is signaled to the UE from the AMF via NAS signaling (e.g., a registration accept message), similar to the above description of the embodiment entitled "Cells with Respective Timings."

[0198] As a result, the UE can perform cell (re)selection based on both location information and radio wave strength, and determine whether the UE has left its registration area based on the camping cell ID and timing.

[0199] The aspects of the AMF system and signaling to the gNB may be similar to those described above in the section "Cells with Respective Timings." Cell coverage area information (including mapping to the gNB) may be configured or pre-configured in the AMF (and gNB) during the cell planning phase. The UE signals the last visited cell with a timestamp or signals location information to the AMF in a registration request message. The definition of the TA and / or registration area is also signaled to the gNB in ​​the form of a set of multiple cells with associated timings (a list of cell IDs / RCA IDs), for example, in a paging message or in a paging request message that also includes a paging message sent to the UE.

[0200] As a result, the AMF knows which gNBs cover the registration area at any given time and can decide to which gNBs a paging message (or paging request message) needs to be delivered, and since the gNB knows which cell(s) cover the registration area, it can decide in which cell(s) the paging should be broadcast.

[0201] The registration and paging call flow between the UE, gNB, and AMF is shown in Figure 30. As described above, the UE receives the SIB sent from the gNB, which includes a mapping between cell IDs (RCA IDs) and zone information. Furthermore, although the UE is shown sending location information in the registration request (steps 1 and 6), the UE may also send the cell ID and associated timing. Also, at timing t+2, the UE camps on a new cell outside the registration area, which is selected or determined based on radio strength and the UE location (e.g., to determine which zone or geographic area the UE is located in). The further flow shown in Figure 30 is similar to the above description of the flow shown in Figure 28.

[0202] As described in this section, cell accessibility is controlled using additional location information in addition to received signal strength. When multiple cells or cell sections are transmitted by the same satellite, this additional use of location information to control cell accessibility can help reduce the number of cells in a registration area and reduce paging overhead.

[0203] As mentioned above, a UE may perform cell (re)selection, e.g., selection of a newly visited cell within or outside a registration area, based on either location information (e.g., location measurements such as GNSS) or signal strength measurements. For example, if location information is used to determine whether the UE is still within the registration area, cell selection may also be location-based, which may facilitate reducing signal strength measurements. On the other hand, using signal strength to determine whether the UE is within the registration area may be practical for UEs for which positioning is not possible or for which positioning capabilities are turned off.

[0204] Further, as seen in Figures 26, 28, and 30, if the circuitry determines that the UE is not located within a registration area, the circuitry transmits a registration request that includes at least one of a notification of the UE location or a cell ID of the newly visiting cell and a timestamp indicating the time the UE was located (e.g., measured signal strength) within the newly visiting cell.

[0205] On the other hand, if the UE is within the registration area and DL data is available for the UE, the UE receives paging (e.g., one or both of a paging DCI and a paging message) transmitted by a gNB (or multiple gNBs) within the registration area.

[0206] The one or more base stations (e.g., gNBs) that will perform paging of the UE are determined by the AMF system. Specifically, in some embodiments, the AMF determines the base stations currently mapped to the registration area (which has already been indicated to the UE via the registration acceptance) and sends a paging request message to the one or more base stations. The paging request message includes: a list of cell IDs of a plurality of earth mobile cells or cell sections and a second time notification; or a list of cell IDs and notification of the time intervals during which several Earth mobile cells or cell sections form a registration area, or A list of tracking areas that form the registration area; Includes.

[0207] For example, the paging request message may further include a paging message.

[0208] As noted above, embodiments of the present disclosure show that there is no need to broadcast a TA code (TAC) in the cell system information to enable UEs to indicate their registration area. Thus, problems with moving tracking areas, e.g., associated with "hard switches" and "soft switches," may be reduced or avoided. Specifically, in the embodiments described with reference to Figures 22-30, a TA code may not be required at all.

[0209] Additionally, each of the above embodiments shown in Figures 22-30 includes timing information for defining tracking and registration areas (e.g., the time of day defining "frozen" cells or the time interval during which each cell covers the registration area). Such timing information allows cell movement to be known to the gNB and core network in a predictable manner. Furthermore, in the embodiments described in the section entitled "Cell Coverage Area at Time," ephemeris data is also available to the UE, which the UE may use to determine the registration area and potentially for cell (re)selection.

[0210] As described above, examples and embodiments of the present disclosure have been presented using registration area management for RRC idle UEs as an example. However, the present disclosure can also be applied to RAN Notification Area (RNA) management for inactive UEs. The RAN Notification Area is the basis for device tracking at the RAN level. RAN Notification Area updates are managed by RRC RAN Notification Area Updates sent from the UE to the gNB. Because a change in tracking area implies a change in RNA, an RRC RAN Notification Area Update is implicitly performed every time the UE performs a registration update as described above.

[0211] The present disclosure can be realized by software, hardware, or software cooperating with hardware. Each functional block used in the description of each embodiment above can be partially or completely realized by an LSI (large-scale integration) such as an integrated circuit (IC), and each process described in each embodiment can be partially or completely controlled by the same LSI or a combination of LSIs. The LSI can be formed as an individual chip, or a single chip can be formed to include some or all of the functional blocks. The LSI can include data inputs and outputs coupled thereto. The LSI referred to herein can be referred to as an IC, system LSI, super LSI, or ultra LSI depending on the degree of integration. However, the technology for implementing an integrated circuit is not limited to LSI, and can be realized using dedicated circuits, general-purpose processors, or dedicated processors. Also, a field programmable gate array (FPGA), which can be programmed after LSI fabrication, or a reconfigurable processor, which can reconfigure the connections and settings of circuit cells arranged in the LSI, can be used. The present disclosure can be realized as digital processing or analog processing. If future integrated circuit technologies replace LSI as a result of advances in semiconductor technology or other derivative technologies, functional blocks can be integrated using future integrated circuit technologies. Biotechnology can also be applied.

[0212] The present disclosure may be implemented by any type of apparatus, device or system having communication capabilities, referred to as a communications apparatus.

[0213] A communication device may include a transceiver and processing / control circuitry. The transceiver may include and / or function as a receiver and a transmitter. The transceiver as a transmitter and receiver may include an RF (radio frequency) module including an amplifier, an RF modulator / demodulator, etc., and one or more antennas.

[0214] Some non-limiting examples of such communication devices include telephones (e.g., cellular phones, smartphones), tablets, personal computers (PCs) (e.g., laptops, desktops, netbooks), cameras (e.g., digital still / video cameras), digital players (digital audio / video players), wearable devices (e.g., wearable cameras, smart watches, tracking devices), game consoles, digital book readers, telehealth / telemedicine (remote health and medicine) devices, and vehicles (e.g., automobiles, airplanes, ships) that provide communication capabilities, and various combinations thereof.

[0215] Communication devices are not limited to portable or mobile, but may include any type of non-portable or fixed apparatus, device, or system, such as smart home devices (e.g., appliances, lights, smart meters, control panels), vending machines, and any other "things" in the network of the "Internet of Things" (IoT).

[0216] Communications may include, for example, data exchange via cellular systems, wireless LAN systems, satellite systems, and the like, as well as various combinations thereof.

[0217] A communications apparatus may include devices such as a controller or a sensor coupled to a communications device that performs the communications functions described in this disclosure. For example, a communications apparatus may include a controller or a sensor that generates control or data signals used by the communications device to perform the communications functions of the communications apparatus.

[0218] Communications equipment may also include infrastructure facilities such as base stations, access points, and any other equipment, devices, or systems that communicate with or control equipment such as those in the non-limiting examples above.

[0219] In summary, a first embodiment provides a user equipment (UE) that, in operation, transmits a registration request, the registration request comprising: notification of a first location of the UE, or a cell ID of the last cell visited by the UE and a timestamp indicating the first time that the UE was located in the last cell; and receiving a registration accept message including notification of a registration area, the registration area including the first location of the UE; and a list of cell IDs of a plurality of terrestrial mobile cells or cell sections of the terrestrial mobile cells, and a notification of a second time when the plurality of terrestrial mobile cells form the registration area, and for each of the plurality of terrestrial mobile cells, coverage area information indicating a coverage area of ​​the cell or cell section relative to a satellite position of a satellite generating the cell and ephemeris data of the satellite, and a second position measurement of the UE, wherein the list of the plurality of terrestrial mobile cells and the notification of the second time are included in the notification of the registration area, or based on the list of cell IDs, a notification of a time interval during which the plurality of terrestrial mobile cells or cell sections form the registration area, and a cell ID of a newly visited cell or cell section that includes the second location of the UE and is different from the last cell, wherein the list of cell IDs and the notification of the time interval are included in the notification of the registration area, or based on the measurement of the second location, a mapping between a geographic area and a tracking area, and a list of one or more tracking areas forming the registration area, wherein the mapping is read from a storage, and the list of one or more tracking areas is included in the notification of the registration area; and a circuit for determining whether the UE is located within the registration area at the second location.

[0220] In a second embodiment, in addition to the first embodiment, the transceiver, in operation, receives the coverage area information in system information.

[0221] In a third embodiment, in addition to the first or second embodiment, the coverage area information further comprises, for each of the plurality of terrestrial mobile cells: the satellite beam direction of each beam forming said cell and the radius or diameter of said coverage area, or - polygons defining said coverage areas in a non-overlapping manner, or the center and radius of said coverage area; Includes.

[0222] In a fourth embodiment, in addition to the first embodiment, the notification of the registration area includes a list of multiple cell IDs of earth mobile cells or cell sections of earth mobile cells including the list of cell IDs, and for each of the list of multiple cell IDs, multiple notifications of time intervals including the time intervals, each indicating the time interval during which the earth mobile cells or cell sections respectively indicated by the list of cell IDs form the registration area.

[0223] In a fifth embodiment, in addition to the first or fourth embodiment, if the circuit determines that the UE is not located within the registration area at the second location and the received signal strengths of multiple candidates for the newly visited cell or cell section are substantially the same, the circuit, in operation, determines a geographical area in which the UE is located from among the geographical areas based on the measurement values ​​at the second location and the definition of the geographical area read from storage, and selects a candidate included in the geographical area in which the UE is located as the newly visited cell or cell section based on an association between each cell ID of the multiple candidates included in system information and one of the geographical areas.

[0224] In a sixth embodiment, in addition to any one of the first to fifth embodiments, the circuit, in operation, selects the new cell to visit based on the second position.

[0225] In a seventh embodiment, further to the first, fourth or fifth embodiment, the circuitry, in operation, selects the new cell to visit based on a signal strength measurement.

[0226] In the eighth embodiment, in addition to any one of the first to seventh embodiments, the transceiver receives a paging message within the registration area during operation.

[0227] In a ninth embodiment, in addition to any of the first to eighth embodiments, if the circuit determines that the UE is not located within the registration area at the second location, the transceiver, in operation, transmits a second registration request, and the second registration request includes: notification of the second location of the UE, or a cell ID of the new visiting cell and a timestamp indicating a third time that the UE was located within the new visiting cell; It includes at least one of the following:

[0228] In a tenth embodiment, a base station includes an interface that, in operation, receives a paging request message for paging a user equipment (UE), the paging request message including a notification of a registration area; and, in operation, - based on a list of cell IDs of a first plurality of Earth mobile cells or cell sections of said Earth mobile cells, a notification of a second time when said first plurality of Earth mobile cells form said registration area, and, for each of said first plurality of Earth mobile cells, coverage area information indicating the coverage area of ​​said cell or cell section relative to a satellite position of a satellite generating said cell and ephemeris data of said satellite, wherein said list of said first plurality of Earth mobile cells and said notification of said time are included in said notification of said registration area, or based on the list of cell IDs and a notification of a time interval during which the first plurality of terrestrial mobile cells or cell sections form the registration area, wherein the list of cell IDs and the notification of the time interval are included in the notification of the registration area, or based on a mapping between a geographical area and a tracking area and a list of one or more tracking areas forming the registration area, wherein the mapping is read from a storage and the list of one or more tracking areas is included in the notification of the registration area; A base station is provided, comprising: circuitry for determining a second plurality of terrestrial mobile cells currently mapped to the registration area; and a transceiver for transmitting, in operation, paging messages for paging the UE within the second plurality of cells.

[0229] In an eleventh embodiment, an Access and Mobility Management Function (AMF) system, comprising an interface for receiving a registration request of a user equipment (UE), wherein the registration request comprises: notification of a first location of the UE, or a cell ID of the last cell visited by the UE and a timestamp indicating the first time that the UE was located in the last cell; and a circuit that, upon operation, generates a notification of a registration area that includes the first location of the UE, the notification of the registration area comprising: a list of cell IDs of a plurality of Earth mobile cells or cell sections of said Earth mobile cells and notification of a second time when said plurality of Earth mobile cells form said registration area, wherein said registration area is determined for each of said plurality of Earth mobile cells or cell sections based on coverage area information indicating a coverage area of ​​said cell or cell section relative to a satellite position of a satellite generating said cell and ephemeris data of said satellite; or a list of said cell IDs and notification of the time intervals during which said plurality of terrestrial mobile cells or cell sections form said registration area, or a list of one or more tracking areas forming the registration area, wherein the list of one or more tracking areas is determined based on a mapping between geographical areas and tracking areas, and the mapping is read from a storage; and the circuit, wherein the interface, in operation, transmits a registration acceptance message including the notification of the registration area.

[0230] In a twelfth embodiment, in addition to the eleventh embodiment, the circuit, in operation, determines one or more base stations currently mapped to the registration area, and the interface, in operation, sends a paging request message to the one or more base stations, the paging request message including: the notification of the list of cell IDs of the plurality of terrestrial mobile cells or cell sections and the second time; or the list of cell IDs and the notification of the time interval during which the plurality of terrestrial mobile cells or cell sections form the registration area, or a list of the tracking areas that form the registration area; Includes.

[0231] In a thirteenth embodiment, a communication method for a user equipment (UE) includes sending a registration request, the registration request comprising: notification of a first location of the UE, or a cell ID of the last cell visited by the UE and a timestamp indicating the first time that the UE was located in the last cell; receiving a registration accept message including notification of a registration area, the registration area including the first location of the UE; and determining: a list of cell IDs of a plurality of terrestrial mobile cells or cell sections of the terrestrial mobile cells, and a notification of a second time when the plurality of terrestrial mobile cells form the registration area, and for each of the plurality of terrestrial mobile cells, coverage area information indicating a coverage area of ​​the cell or cell section relative to a satellite position of a satellite generating the cell and ephemeris data of the satellite, and a second position measurement of the UE, wherein the list of the plurality of terrestrial mobile cells and the notification of the second time are included in the notification of the registration area, or based on the list of cell IDs, a notification of a time interval during which the plurality of terrestrial mobile cells or cell sections form the registration area, and a cell ID of a newly visited cell or cell section that includes the second location of the UE and is different from the last cell, wherein the list of cell IDs and the notification of the time interval are included in the notification of the registration area, or based on the measurement of the second location, a mapping between a geographic area and a tracking area, and a list of one or more tracking areas forming the registration area, wherein the mapping is read from a storage, and the list of one or more tracking areas is included in the notification of the registration area; and determining at the second location whether the UE is located within the registration area.

[0232] In a fourteenth embodiment, a communication method for a base station includes steps of receiving a paging request message for paging a user equipment (UE), the paging request message including a registration area notification; and determining: - based on a list of cell IDs of a first plurality of Earth mobile cells or cell sections of said Earth mobile cells, a notification of a second time when said first plurality of Earth mobile cells form said registration area, and, for each of said first plurality of Earth mobile cells, coverage area information indicating the coverage area of ​​said cell or cell section relative to a satellite position of a satellite generating said cell and ephemeris data of said satellite, wherein said list of said first plurality of Earth mobile cells and said notification of said time are included in said notification of said registration area, or based on the list of cell IDs and a notification of a time interval during which the first plurality of terrestrial mobile cells or cell sections form the registration area, wherein the list of cell IDs and the notification of the time interval are included in the notification of the registration area, or based on a mapping between a geographical area and a tracking area and a list of one or more tracking areas forming the registration area, wherein the mapping is read from a storage and the list of one or more tracking areas is included in the notification of the registration area; A communication method is provided, comprising: determining a second plurality of terrestrial mobile cells currently mapped to the registration area; and transmitting a paging message to page the UE in the second plurality of cells.

[0233] In a fifteenth embodiment, a communication method for an Access Mobility Function (AMF) system, comprising steps of receiving a registration request for a user equipment (UE), the registration request comprising: notification of a first location of the UE, or a cell ID of the last cell visited by the UE and a timestamp indicating the first time that the UE was located in the last cell; generating a notification of a registration area including the first location of the UE, wherein the notification of the registration area comprises: a list of cell IDs of a plurality of Earth mobile cells or cell sections of said Earth mobile cells and notification of a second time when said plurality of Earth mobile cells form said registration area, wherein said registration area is determined for each of said plurality of Earth mobile cells or cell sections based on coverage area information indicating a coverage area of ​​said cell or cell section relative to a satellite position of a satellite generating said cell and ephemeris data of said satellite; or a list of said cell IDs and notification of the time intervals during which said plurality of terrestrial mobile cells or cell sections form said registration area, or a list of one or more tracking areas forming the registration area, wherein the list of one or more tracking areas is determined based on a mapping between geographical areas and tracking areas, and the mapping is read from a storage; and sending a registration acceptance message including said notification of said registration area.

[0234] It should be noted that the second to ninth embodiments are applicable in a manner corresponding to the base station of the tenth embodiment and the AMF system of the eleventh embodiment, and the twelfth embodiment is applicable in a manner corresponding to the base station of the tenth embodiment. Also, the steps performed in operation by the circuit, the steps performed in operation by the transceiver, and the steps performed in operation by the interface mentioned in the above embodiments of the UE, base station, and AMF correspond to the respective methods.

[0235] Also provided is a non-transitory medium storing program instructions that, when executed on a processing circuit, such as a general-purpose processor, cause the processing circuit to perform all of the steps of the above-described method embodiments.

[0236] Furthermore, there is provided an integrated circuit for a communication device, such as a UE, a base station, or an AMF system, for controlling the communication device to perform all the steps of the above method embodiments.

[0237] In summary, a user equipment (UE), a base station, an AMF (Access and Mobility Management Function) system, and a corresponding method are provided, in which the UE determines whether it is located in a registration area indicated to the UE by the AMF and in which the UE is paged by the base station based on a combination of signal strength measurements or location and either a list of cell IDs of terrestrial mobile cells and timing or a stored mapping between geographical areas and tracking areas.

Claims

1. A base station, a transceiver configured to receive a registration request and to transmit a registration accept message including a list of one or more tracking areas forming a registration area, the registration request including an indication of a first location of a user equipment (UE), the list of one or more tracking areas including the indication of the first location of the UE; a circuit for generating the registration accept message including a list of the one or more tracking areas, the tracking areas corresponding to cell IDs of a plurality of terrestrial mobile cells associated with a time interval forming the registration area; and A base station comprising:

2. 2. The base station of claim 1, wherein the registration request includes a cell ID of a last cell visited by the UE and a timestamp indicating a first time the UE was located in the last cell.

3. The base station of claim 2 , wherein the transceiver transmits coverage area information within system information.

4. The coverage area information includes, for each of the plurality of terrestrial mobile cells: the satellite beam direction of each beam forming the cell and the radius or diameter of the coverage area, or - polygons defining the coverage areas in a non-overlapping manner, or - the center and radius of said coverage area; The base station of claim 3 , comprising:

5. The notification of the registration area includes: a list of cell IDs of a terrestrial mobile cell or a cell section of a terrestrial mobile cell including said list of cell IDs; a plurality of notifications of time intervals including said time intervals, each indicating for each of said plurality of lists of cell IDs, said time intervals during which said earth moving cells or cell sections respectively indicated by said list of cell IDs form said registration area; The base station of claim 2 , comprising:

6. The base station of claim 2 , wherein the transceiver transmits paging messages within the registration area.

7. 1. A communication method for a base station, comprising: receiving a registration request, the registration request including an indication of a first location of a user equipment (UE); sending a registration accept message including a list of one or more tracking areas forming a registration area, the one or more tracking areas including an indication of the first location of the UE; generating the registration accept message including a list of the one or more tracking areas, the tracking areas corresponding to cell IDs of a plurality of terrestrial mobile cells associated with a time interval forming the registration area; A communication method, including:

8. An integrated circuit for controlling processing of a base station, the processing comprising: receiving a registration request, the registration request including an indication of a first location of a user equipment (UE); sending a registration accept message including a list of one or more tracking areas forming a registration area, the one or more tracking areas including an indication of the first location of the UE; generating the registration accept message including a list of the one or more tracking areas, the tracking areas corresponding to cell IDs of a plurality of terrestrial mobile cells associated with a time interval forming the registration area; , an integrated circuit.

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