COMMUNICATION CONTROL METHOD, USER EQUIPMENT, AND RADIO ACCESS NETWORK NODE

Abstract

The aspect of the present invention provides a communication control method in a mobile communication system. This communication control method comprises a step of transmitting, by a base station, to a user device, a first paging message associated with a network slice.

Description

[Technical Field]

[0001] The present disclosure relates to a communication control method in a mobile communication system. [Background technology]

[0002] Network slicing is defined in the specifications of the Third Generation Partnership Project (3GPP) (registered trademark; the same applies hereinafter), a standardization project for mobile communication systems. Network slicing is a technology that creates network slices, which are virtual networks, by logically dividing the physical networks built by telecommunications carriers.

[0003] A user equipment in a radio resource control (RRC) idle state or an RRC inactive state can perform a cell reselection procedure. 3GPP is considering slice-specific cell reselection (slice-aware cell reselection, or slice-based cell reselection), which is a cell reselection procedure that depends on a network slice (see, for example, Non-Patent Document 1). By performing the slice-specific cell reselection procedure, the user equipment can, for example, camp on a neighboring cell that supports a desired network slice. [Prior art documents] [Non-patent literature]

[0004] [Non-Patent Document 1] 3GPP TS 38.300 V17.8.0 (2022-3) Summary of the Invention

[0005] A communication control method according to one aspect is a communication control method in a mobile communication system, the communication control method including a step of transmitting, by a base station, a first paging message associated with a network slice to a user equipment. [Brief explanation of the drawings]

[0006] [Figure 1] FIG. 1 is a diagram illustrating an example of the configuration of a mobile communication system according to the first embodiment. [Figure 2] FIG. 2 is a diagram illustrating an example of the configuration of a UE (user equipment) according to the first embodiment. [Figure 3] FIG. 3 is a diagram illustrating an example configuration of a gNB (base station) according to the first embodiment. [Figure 4] FIG. 4 is a diagram illustrating an example of the configuration of a protocol stack related to a user plane according to the first embodiment. [Figure 5] FIG. 5 is a diagram illustrating an example of the configuration of a protocol stack related to the control plane according to the first embodiment. [Figure 6] FIG. 6 is a diagram for explaining an outline of the cell reselection procedure. [Figure 7] FIG. 7 is a diagram illustrating a general flow of a general cell reselection procedure. [Figure 8] FIG. 8 is a diagram illustrating an example of network slicing. [Figure 9] FIG. 9 is a diagram outlining a slice-specific cell reselection procedure. [Figure 10] FIG. 10 is a diagram illustrating an example of slice frequency information. [Figure 11] FIG. 11 is a diagram illustrating the basic flow of a slice-specific cell reselection procedure. [Figure 12] FIG. 12 is a diagram illustrating an example of operation according to the first embodiment. [Figure 13] FIG. 13 is a diagram illustrating an example of operation according to the second embodiment. [Figure 14] FIG. 14 is a diagram illustrating an example of operation according to the third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0007] The present disclosure aims to provide a communication control method that enables a user equipment to connect to an appropriate cell.

[0008] A mobile communication system according to an embodiment will be described with reference to the drawings. In the description of the drawings, the same or similar parts are denoted by the same or similar reference numerals.

[0009] [First embodiment]

[0010] (Configuration of a mobile communication system) FIG. 1 is a diagram illustrating the configuration of a mobile communication system according to a first embodiment. The mobile communication system 1 conforms to the 3GPP standard 5th Generation System (5GS). In the following description, 5GS is used as an example, but the mobile communication system may also be at least partially applied to an LTE (Long Term Evolution) system. The mobile communication system may also be at least partially applied to a 6th Generation (6G) system.

[0011] The mobile communication system 1 includes a user equipment (UE) 100, a 5G radio access network (NG-RAN) 10, and a 5G core network (5GC) 20. Hereinafter, the NG-RAN 10 may be simply referred to as the RAN 10. The 5GC 20 may be simply referred to as the core network (CN) 20.

[0012] The UE 100 is a mobile wireless communication device. The UE 100 may be any device that is used by a user. For example, the UE 100 is a mobile phone terminal (including a smartphone), a tablet terminal, a notebook PC, a communication module (including a communication card or a chipset), a sensor or a device provided in a sensor, a vehicle or a device provided in a vehicle (Vehicle UE), or an aircraft or a device provided in an aircraft (Aerial UE).

[0013] The NG-RAN 10 includes a base station (called "gNB" in the 5G system) 200. The gNBs 200 are connected to each other via an Xn interface, which is an interface between base stations. The gNB 200 manages one or more cells. The gNB 200 performs wireless communication with a UE 100 that has established a connection with its own cell. The gNB 200 has a radio resource management (RRM) function, a routing function for user data (hereinafter simply referred to as "data"), a measurement control function for mobility control and scheduling, etc. The term "cell" is used to indicate the smallest unit of a wireless communication area. The term "cell" is also used to indicate a function or resource that performs wireless communication with a UE 100. One cell belongs to one carrier frequency (hereinafter simply referred to as "frequency").

[0014] In addition, gNBs can also connect to the Evolved Packet Core (EPC), which is the LTE core network. LTE base stations can also connect to 5GC. LTE base stations and gNBs can also be connected via a base station-to-base station interface.

[0015] The 5GC20 includes an Access and Mobility Management Function (AMF) and a User Plane Function (UPF) 300. The AMF performs various mobility controls for the UE 100. The AMF manages the mobility of the UE 100 by communicating with the UE 100 using NAS (Non-Access Stratum) signaling. The UPF controls data forwarding. The AMF and UPF are connected to the gNB 200 via an NG interface, which is an interface between a base station and a core network.

[0016] 2 is a diagram showing the configuration of a UE 100 (user equipment) according to the first embodiment. The UE 100 includes a receiving unit 110, a transmitting unit 120, and a control unit 130. The receiving unit 110 and the transmitting unit 120 constitute a wireless communication unit that performs wireless communication with the gNB 200.

[0017] The receiving unit 110 performs various types of reception under the control of the control unit 130. The receiving unit 110 includes an antenna and a receiver. The receiver converts a radio signal received by the antenna into a baseband signal (received signal) and outputs the baseband signal to the control unit 130.

[0018] The transmitting unit 120 performs various transmissions under the control of the control unit 130. The transmitting unit 120 includes an antenna and a transmitter. The transmitter converts a baseband signal (transmission signal) output by the control unit 130 into a radio signal and transmits it from the antenna.

[0019] The control unit 130 performs various controls and processes in the UE 100. Such processes include processes in each layer, which will be described later. The control unit 130 includes at least one processor and at least one memory. The memory stores programs executed by the processor and information used in the processes by the processor. The processor may include a baseband processor and a CPU (Central Processing Unit). The baseband processor performs modulation / demodulation and encoding / decoding of baseband signals. The CPU executes programs stored in the memory to perform various processes. Note that the control unit 130 may perform each process or operation in the UE 100 in each of the embodiments described below.

[0020] 3 is a diagram showing the configuration of a gNB200 (base station) according to the first embodiment. The gNB200 includes a transmitter 210, a receiver 220, a controller 230, and a backhaul communication unit 240. The transmitter 210 and the receiver 220 constitute a wireless communication unit that performs wireless communication with the UE 100. The backhaul communication unit 240 constitutes a network communication unit that performs communication with the CN20.

[0021] The transmission unit 210 performs various transmissions under the control of the control unit 230. The transmission unit 210 includes an antenna and a transmitter. The transmitter converts a baseband signal (transmission signal) output by the control unit 230 into a radio signal and transmits it from the antenna.

[0022] The receiving unit 220 performs various types of reception under the control of the control unit 230. The receiving unit 220 includes an antenna and a receiver. The receiver converts a radio signal received by the antenna into a baseband signal (received signal) and outputs the baseband signal to the control unit 230.

[0023] The control unit 230 performs various controls and processes in the gNB 200. Such processes include processes in each layer, which will be described later. The control unit 230 includes at least one processor and at least one memory. The memory stores programs executed by the processor and information used in the processes by the processor. The processor may include a baseband processor and a CPU. The baseband processor performs modulation / demodulation and encoding / decoding of baseband signals, etc. The CPU executes programs stored in the memory to perform various processes. Note that the control unit 230 may perform each process or operation in the gNB 200 in each of the embodiments described below.

[0024] The backhaul communication unit 240 is connected to neighboring base stations via an Xn interface, which is an interface between base stations. The backhaul communication unit 240 is connected to the AMF / UPF 300 via an NG interface, which is an interface between a base station and a core network. Note that the gNB 200 may be configured (i.e., functionally divided) with a CU (Central Unit) and a DU (Distributed Unit), and both units may be connected via an F1 interface, which is a fronthaul interface.

[0025] FIG. 4 is a diagram showing the configuration of a protocol stack of a radio interface of a user plane that handles data.

[0026] The user plane radio interface protocol includes a physical (PHY) layer, a medium access control (MAC) layer, a radio link control (RLC) layer, a packet data convergence protocol (PDCP) layer, and a service data adaptation protocol (SDAP) layer.

[0027] The PHY layer performs encoding / decoding, modulation / demodulation, antenna mapping / demapping, and resource mapping / demapping. Data and control information are transmitted between the PHY layer of UE100 and the PHY layer of gNB200 via a physical channel. The PHY layer of UE100 receives downlink control information (DCI) transmitted from gNB200 on a physical downlink control channel (PDCCH). Specifically, UE100 performs blind decoding of the PDCCH using a radio network temporary identifier (RNTI) and acquires successfully decoded DCI as DCI addressed to the UE. The DCI transmitted from gNB200 has CRC parity bits scrambled by the RNTI added.

[0028] The MAC layer performs data priority control, retransmission processing using Hybrid Automatic Repeat reQuest (HARQ), random access procedures, etc. Data and control information are transmitted between the MAC layer of UE100 and the MAC layer of gNB200 via transport channels. The MAC layer of gNB200 includes a scheduler, which determines the uplink and downlink transport format (transport block size, modulation and coding scheme (MCS)) and the resource blocks to be allocated to UE100.

[0029] The RLC layer transmits data to the RLC layer on the receiving side using the functions of the MAC layer and PHY layer. Data and control information are transmitted between the RLC layer of the UE 100 and the RLC layer of the gNB 200 via logical channels.

[0030] The PDCP layer performs header compression / decompression, encryption / decryption, etc.

[0031] The SDAP layer maps IP flows, which are the units for Quality of Service (QoS) control by the core network, to radio bearers, which are the units for QoS control by the Access Stratum (AS). Note that if the RAN is connected to the EPC, SDAP is not necessary.

[0032] FIG. 5 is a diagram showing the configuration of a protocol stack of a radio interface of a control plane that handles signaling (control signals).

[0033] The protocol stack of the radio interface of the control plane has a Radio Resource Control (RRC) layer and a Non-Access Stratum (NAS) instead of the SDAP layer shown in FIG.

[0034] RRC signaling for various settings is transmitted between the RRC layer of UE100 and the RRC layer of gNB200. The RRC layer controls logical channels, transport channels, and physical channels according to the establishment, re-establishment, and release of radio bearers. When there is a connection (RRC connection) between the RRC of UE100 and the RRC of gNB200, UE100 is in an RRC connected state. When there is no connection (RRC connection) between the RRC of UE100 and the RRC of gNB200, UE100 is in an RRC idle state. When the connection between the RRC of UE100 and the RRC of gNB200 is suspended, UE100 is in an RRC inactive state.

[0035] The NAS, which is located above the RRC layer, performs session management, mobility management, etc. NAS signaling is transmitted between the NAS of the UE 100 and the NAS of the AMF 300. Note that the UE 100 has an application layer and the like in addition to the radio interface protocol. The layer below the NAS is called an AS (Access Stratum).

[0036] (Overview of cell reselection procedure) FIG. 6 is a diagram for explaining an overview of a cell reselection procedure.

[0037] When the UE 100 is in an RRC idle state or an RRC inactive state, it performs a cell reselection procedure to transition from a current serving cell (cell #1) to a neighboring cell (any of cells #2 to #4) as it moves. Specifically, the UE 100 identifies a neighboring cell on which it should camp by the cell reselection procedure, and reselects the identified neighboring cell. When the current serving cell and the neighboring cell have the same frequency (carrier frequency), this is called intra-frequency, and when the current serving cell and the neighboring cell have different frequencies (carrier frequencies), this is called inter-frequency. The current serving cell and the neighboring cell may be managed by the same gNB 200. The current serving cell and the neighboring cell may be managed by different gNBs 200.

[0038] FIG. 7 is a diagram illustrating a general flow of a typical (or legacy) cell reselection procedure.

[0039] In step S11, the UE 100 performs a frequency prioritization process based on the priority (also referred to as "absolute priority") for each frequency specified by the gNB 200, for example, by a system information block or an RRC release message. Specifically, the UE 100 manages the frequency priority specified by the gNB 200 for each frequency.

[0040] In step S12, UE 100 performs a measurement process to measure radio quality for each of the serving cell and the neighboring cell. UE 100 measures the received power and received quality of reference signals transmitted by each of the serving cell and the neighboring cell, specifically, CD-SSB (Cell Defining-Synchronization Signal and PBCH block). For example, UE 100 always measures radio quality for frequencies having a higher priority than the frequency priority of the current serving cell, and for frequencies having a priority equal to or lower than the frequency priority of the current serving cell, UE 100 measures the radio quality of the frequency having the same priority or lower priority when the radio quality of the current serving cell falls below a predetermined quality.

[0041] In step S13, UE 100 performs a cell reselection process to reselect a cell on which UE 100 will camp based on the measurement result in step S12. For example, if the frequency priority of a neighboring cell is higher than the priority of a current serving cell and the neighboring cell satisfies a predetermined quality standard (i.e., a minimum required quality standard) for a predetermined period, UE 100 may perform cell reselection to the neighboring cell. If the frequency priority of the neighboring cell is the same as the priority of the current serving cell, UE 100 may rank the radio qualities of the neighboring cells and perform cell reselection to the neighboring cell having a higher rank than the rank of the current serving cell for a predetermined period. If the frequency priority of the neighboring cell is lower than the priority of the current serving cell and the radio quality of the current serving cell is lower than a certain threshold and the radio quality of the neighboring cell is higher than another threshold, UE 100 may perform cell reselection to the neighboring cell.

[0042] (Network Slicing Overview) Network slicing is a technology that creates multiple virtual networks by virtually dividing a physical network constructed by a carrier (for example, a network consisting of NG-RAN10 and 5GC20). Each virtual network is called a network slice. In the following, a network slice may be simply referred to as a "slice."

[0043] Network slicing allows telecommunications operators to create slices that meet the service requirements of different service types, such as eMBB (enhanced Mobile Broadband), URLLC (Ultra-Reliable and Low Latency Communications), and mMTC (massive Machine Type Communications), thereby optimizing network resources.

[0044] FIG. 8 is a diagram illustrating an example of network slicing.

[0045] Three slices (slice #1 to slice #3) are configured on a network 50 configured with an NG-RAN 10 and a 5GC 20. Slice #1 is associated with a service type called eMBB, slice #2 is associated with a service type called URLLC, and slice #3 is associated with a service type called mMTC. Note that three or more slices may be configured on the network 50. One service type may be associated with multiple slices.

[0046] Each slice is provided with a slice identifier that identifies the slice. An example of a slice identifier is S-NSSAI (Single Network Slicing Selection Assistance Information). S-NSSAI includes an 8-bit SST (slice / service type). S-NSSAI may further include a 24-bit SD (slice differentiator). SST is information indicating the service type to which the slice is associated. SD is information for differentiating multiple slices associated with the same service type. Information including multiple S-NSSAIs is called NSSAI (Network Slice Selection Assistance Information).

[0047] Furthermore, one or more slices may be grouped to form a slice group. A slice group is a group including one or more slices, and a slice group identifier is assigned to the slice group. The slice group may be configured by a core network (e.g., AMF 300) or a radio access network (e.g., gNB 200). The configured slice group may be notified to UE 100.

[0048] Hereinafter, the term "network slice (slice)" may refer to an S-NSSAI, which is an identifier of a single slice, or an NSSAI, which is a collection of S-NSSAIs. The term "network slice (slice)" may also refer to a slice group, which is a group of one or more S-NSSAIs or NSSAIs.

[0049] Furthermore, UE100 determines a desired slice that it wishes to use. A desired slice is sometimes called an "intended slice." In the first embodiment, UE100 determines a slice priority for each network slice (desired slice). For example, the NAS of UE100 determines the slice priority based on the operation status of an application in UE100 and / or user operation / settings, and notifies the AS of slice priority information indicating the determined slice priority. Note that the NAS of UE100 may receive the slice priority information from AMF300. In this case, the NAS of UE100 may determine the slice priority based on the slice priority information received from AMF300.

[0050] (Overview of slice-specific cell reselection procedure) FIG. 9 is a diagram illustrating an overview of a slice-specific cell reselection (also referred to as slice-aware cell reselection or slice-based cell reselection) procedure.

[0051] In the slice-specific cell reselection procedure, the UE 100 performs a cell reselection process based on slice frequency information provided by the network 50. The slice frequency information may be provided to the UE 100 from the gNB 200 by broadcast signaling (e.g., a system information block) or dedicated signaling (e.g., an RRC release message).

[0052] The slice frequency information indicates the correspondence between network slices, frequencies, and frequency priorities. For example, for each slice (or slice group), the slice frequency information indicates the frequency (one or more frequencies) that supports the slice and the frequency priority assigned to each frequency. An example of the slice frequency information is shown in FIG. 10.

[0053] In the example shown in Fig. 10, three frequencies F1, F2, and F4 are associated with slice #1 as frequencies supporting slice #1. Of these three frequencies, F1 has a frequency priority of "6," F2 has a frequency priority of "4," and F4 has a frequency priority of "2." In the example of Fig. 10, the larger the frequency priority number, the higher the priority; however, it may also be the case that the smaller the number, the higher the priority.

[0054] Furthermore, three frequencies F1, F2, and F3 are associated with slice #2 as frequencies supporting slice #2. Of these three frequencies, F1 has a frequency priority of "0," F2 has a frequency priority of "5," and F3 has a frequency priority of "7."

[0055] Furthermore, three frequencies F1, F3, and F4 are associated with slice #3 as frequencies supporting slice #3. Of these three frequencies, F1 has a frequency priority of "3," F3 has a frequency priority of "7," and F4 has a frequency priority of "2."

[0056] Hereinafter, the frequency priority indicated in the slice frequency information may be referred to as a "slice-specific frequency priority" to distinguish it from the absolute priority in the conventional cell reselection procedure.

[0057] As shown in FIG. 9, UE 100 may perform a cell reselection process based on slice support information provided by network 50. The slice support information may be information indicating a correspondence between a cell (e.g., a serving cell and each neighboring cell) and a network slice that the cell does not provide or provides. For example, a cell may temporarily not provide some or all network slices due to congestion or other reasons. That is, even if a slice support frequency has the capability to provide a certain network slice, some cells within the frequency may not provide the network slice. UE 100 can identify the network slices that each cell does not provide based on the slice support information. Such slice support information may be provided to UE 100 by broadcast signaling (e.g., a system information block) or dedicated signaling (e.g., an RRC release message) from gNB 200.

[0058] 11 is a diagram showing a basic flow of a slice-specific cell reselection procedure. Before starting the slice-specific cell reselection procedure, the UE 100 is in an RRC idle state or an RRC inactive state, and has received and stored the above-mentioned slice frequency information. Note that the procedure of "slice-specific cell reselection" is represented by a "slice-specific cell reselection procedure." However, hereinafter, "slice-specific cell reselection" and "slice-specific cell reselection procedure" may be used interchangeably.

[0059] In step S0, the NAS of UE 100 determines slice identifiers of desired slices of UE 100 and slice priorities of each desired slice, and notifies the AS of UE 100 of slice priority information including the determined slice priorities. A "desired slice" is an "intended slice" and includes a slice that is likely to be used, a candidate slice, a desired slice, a slice to be communicated, a requested slice, an allowed slice, or an intended slice. For example, the slice priority of slice #1 is determined to be "3," the slice priority of slice #2 is determined to be "2," and the slice priority of slice #3 is determined to be "1." A larger number for the slice priority indicates a higher priority, but a smaller number may also indicate a higher priority.

[0060] In step S1, the AS of the UE 100 sorts the slices (slice identifiers) notified from the NAS in step S0 in descending order of slice priority. The list of slices sorted in this way is called a "slice list."

[0061] In step S2, the AS of the UE 100 selects one network slice in descending order of slice priority. The network slice selected in this manner is called a "selected network slice."

[0062] In step S3, the AS of UE100 assigns frequency priorities to each frequency associated with the selected network slice. Specifically, the AS of UE100 identifies a frequency associated with the slice based on slice frequency information, and assigns frequency priorities to the identified frequencies. For example, if the selected network slice selected in step S2 is slice #1, the AS of UE100 assigns frequency priority "6" to frequency F1, frequency priority "4" to frequency F2, and frequency priority "2" to frequency F4 based on slice frequency information (e.g., information in FIG. 10). The AS of UE100 calls the list of frequencies arranged in descending order of frequency priority a "frequency list."

[0063] In step S4, the AS of UE 100 selects one frequency in descending order of frequency priority for the selected network slice selected in step S2, and performs measurement processing on the selected frequency. The frequency selected in this manner is called a "selected frequency." The AS of UE 100 may rank the cells measured within the selected frequency in descending order of wireless quality. Among the cells measured within the selected frequency, a cell that satisfies a predetermined quality standard (i.e., a required minimum quality standard) is called a "candidate cell."

[0064] In step S5, the AS of UE100 identifies the highest-ranked cell based on the result of the measurement process in step S4, and determines whether the cell provides the selected network slice based on the slice support information. If it is determined that the highest-ranked cell provides the selected network slice (step S5: YES), in step S5a, the AS of UE100 reselects the highest-ranked cell and camps on the cell.

[0065] On the other hand, if it is determined that the highest-ranked cell does not provide the selected network slice (step S5: NO), in step S6, the AS of UE 100 determines whether or not there is an unmeasured frequency in the frequency list created in step S3. In other words, the AS of UE 100 determines whether or not there is a frequency assigned in step S3 other than the selected frequency in the selected network slice. If it is determined that there is an unmeasured frequency (step S6: YES), the AS of UE 100 resumes processing on the frequency with the next highest frequency priority and performs measurement processing with that frequency as the selected frequency (returning to step S4).

[0066] If it is determined that there are no unmeasured frequencies in the frequency list created in step S3 (step S6: NO), in step S7, the AS of UE100 may determine whether or not there are any unselected slices in the slice list created in step S1. In other words, the AS of UE100 may determine whether or not there are any network slices other than the selected network slice in the slice list. If it is determined that there are any unselected slices (step S7: YES), the AS of UE100 resumes processing on the network slice with the next highest slice priority and selects that network slice as the selected network slice (returns processing to step S2). Note that in the basic flow shown in FIG. 11, the processing of step S7 may be omitted.

[0067] If it is determined that there is no unselected slice (step S7: NO), in step S8, the AS of UE 100 performs a conventional cell reselection process. The conventional cell reselection process may mean the entire general (or legacy) cell reselection procedure shown in Fig. 7. The conventional cell reselection process may mean only the cell reselection process (step S13) shown in Fig. 7. In the latter case, UE 100 may use the measurement result in step S4 without measuring the radio quality of the cell again.

[0068] (Paging) Next, paging according to the first embodiment will be described.

[0069] Paging is a technique for calling the UE 100 in an RRC idle state or an RRC inactive state from the network. Paging is used, for example, to notify the user of incoming data (such as voice) or emergency information.

[0070] Paging can be categorized into CN-initiated paging and RAN-initiated paging. CN-initiated paging is sometimes referred to as "CN paging." RAN-initiated paging is sometimes referred to as "RAN paging."

[0071] CN paging is performed on a UE 100 in an RRC idle state. For example, upon receiving notification of downlink data addressed to the UE 100, a core network device (e.g., AMF 300) of the CN 20 generates a PAGING message including a Tracking Area Identity (TAI) list. The core network device transmits the PAGING message to each gNB 200 included in the tracking area (TA). In response to receiving the PAGING message, each gNB 200 (or each cell) transmits a PAGING message including the identifier of the UE 100. As a result, paging messages are transmitted simultaneously from each gNB 200 (or each cell) included in the TA.

[0072] On the other hand, RAN paging is performed on UE 100 in the RRC inactive state. For example, a gNB 200 that receives downlink data addressed to UE 100 transmits a RAN paging message to other gNBs (or other cells) within a RAN-based Notification Area (RNA). Each gNB 200 (or each cell) transmits a paging message including an identifier of the UE 100. As a result, paging messages are transmitted simultaneously from each gNB 200 (or each cell) included in the RNA.

[0073] A UE 100 in an RRC idle state or an RRC inactive state can use discontinuous reception (DRX) to reduce power consumption, and monitors a paging channel at one paging occasion (PO) per DRX cycle.

[0074] The UE 100 in the RRC idle state monitors the paging channel by CN paging. In the CN paging, the UE 100 monitors the paging channel using a shorter cycle (DRX cycle) between a default cycle notified in the system information (SIB: System Information Block) and a cycle specific to the UE 100 set in the NAS message.

[0075] On the other hand, the UE 100 in the RRC inactive state monitors the paging channel by the RAN paging. In the RAN paging, the UE 100 uses the shortest cycle (DRX cycle) among the default cycle transmitted in the SIB, the UE 100-specific cycle set in the NAS message, and the UE 100-specific cycle set in the RRC message.

[0076] However, there is an overlap between the paging occasions (PO) in CN paging and the paging occasions (PO) in RAN paging, as both are based on the same UEID.

[0077] When UE 100 in the RRC idle state or the RRC inactive state receives a paging message using the paging channel, it understands that there is an incoming call addressed to itself. Then, UE 100 in the RRC idle state executes an RRC connection establishment procedure with the serving cell. Also, UE 100 in the RRC inactive state executes an RRC resume procedure with the serving cell (or a neighboring cell in the RRC). This allows UE 100 to connect to the network, transition to the RRC connected state, and exchange messages (such as RRC messages) with the network.

[0078] (Communication control method according to the first embodiment) Assume that a slice is associated with a paging message. In the current 3GPP specifications, UE 100 cannot grasp the slice associated with the paging message. Assume that UE 100 executes an RRC connection establishment procedure with a serving cell upon receiving the paging message. In this case, although UE 100 can establish an RRC connection with the serving cell, if the serving cell does not support the slice, UE 100 cannot receive the service corresponding to the slice from the serving cell. In this case, UE 100 will perform handover to a neighboring cell to receive another service. In this way, the serving cell may not necessarily be an appropriate cell for UE 100.

[0079] Therefore, the first embodiment aims to enable the UE 100 to connect to an appropriate cell.

[0080] Therefore, in the first embodiment, a base station (e.g., gNB200) transmits a first paging message associated with a network slice to a user equipment (e.g., UE100).

[0081] In this way, since a slice is associated with the paging message, the UE 100 that receives the paging message can know the slice for paging. For example, if the UE 100 can know whether the serving cell supports the slice, it can perform an RRC connection establishment procedure with the serving cell or a slice-specific cell reselection procedure to connect to a neighboring cell. Therefore, the UE 100 can connect to an appropriate cell.

[0082] (Operation example according to the first embodiment) Fig. 12 is a diagram illustrating an example of operation according to the first embodiment. Fig. 12 illustrates an example of operation in CN paging.

[0083] As shown in FIG. 12, in step S110, the UE 100 is in an RRC idle state.

[0084] In step S111, CN20 transmits a PAGING message (e.g., a second paging message) associated with a slice to gNB200. For example, a core network device (e.g., AMF300) transmits a PAGING message including slice information to gNB200. The slice information indicates the slice associated with the PAGING message. By transmitting the PAGING message including the slice information, CN20 transmits the PAGING message associated with the slice indicated by the slice information. Note that the PAGING message is an example of an NG message.

[0085] Here, the slice information may include information about one slice. The slice information may also include information about multiple slices. When the slice information includes information about multiple slices, the information about the multiple slices may be expressed in a list format. Alternatively, the slice information itself may include information about one slice, and multiple slice information may be included in the PAGING message.

[0086] The slice information may be represented by Single Slice Assist Information (S-NSSAI) (or slice number). Alternatively, the slice information may be represented by Slice Assist Information (NSSAI). Alternatively, the slice information may be represented by a Slice Group Number (NSAG: Network Slice AS Group). The NSAG includes one or more S-NSSAIs. The NSAG is configured by the RAN (i.e., the gNB 200) and provided to the UE 100 via the AMF 300.

[0087] Alternatively, the slice information may be represented by an Allowed NSSAI. The Allowed NSSAI is assigned by the CN 20 and may include up to eight S-NSSAIs. Alternatively, the slice information may be represented by a Configured NSSAI. The Configured NSSAI is an NSSAI that is valid in one or more Public Land Mobile Networks (PLMNs) and may include up to 16 S-NSSAIs. The NSAG may be set from the Configured NSSAI.

[0088] In step S112, in response to receiving the PAGING message from CN20 (step S111), gNB200 transmits a Paging message (e.g., a first paging message) associated with a slice to UE100. For example, gNB200 transmits a Paging message including slice information. The slice information indicates a slice associated with the Paging message. The slice information may be the same as the slice information received by gNB200 from CN20. By transmitting a Paging message including slice information, gNB200 transmits a Paging message associated with a slice.

[0089] The paging message includes a UE identifier (ue-Identity) of the UE 100. The gNB 200 may associate slice information included in the paging message with the UE identifier included in the paging message. When the paging message includes multiple slice information pieces, the multiple slice information pieces may be represented in a list format. Furthermore, the paging message may also include multiple UE identifiers. When the paging message includes multiple pieces of slice information and multiple UE identifiers, each entry of the multiple slice information pieces (i.e., each slice information piece) may correspond to each entry of the multiple UE identifiers (i.e., each UE identifier). Alternatively, a corresponding UE identifier may be listed for each slice information piece.

[0090] In step S113, when the UE 100 receives the paging message, the UE 100 checks whether slice information is included in the paging message.

[0091] First, when slice information is included in the paging message, the AS of UE 100 may notify the NAS of UE 100 of the slice information. The NAS of UE 100 manages slice priority. Therefore, the AS of UE 100 may notify the NAS of UE 100 of the slice information included in the paging message, and the NAS of UE 100 may update the slice priority of the slice represented by the slice information in response to receiving the paging message. Updating the slice priority is an example of a predetermined process. The NAS of UE 100 may update the slice priority by increasing the slice priority of the slice to a threshold or more. The NAS may update the slice priority of the slice to the highest priority (i.e., a desired slice). The NAS of UE 100 may notify the AS of UE 100 of the updated slice priority. For example, the NAS of UE 100 may transmit, to AMF 300, a NAS message including information indicating that the slice priority has been updated. Before paging, the CN 20 may transmit a NAS message including information indicating that the priority of the slice to be paged is to be changed (or the priority of the slice to be paged is to be changed) to the NAS of the UE 100. The NAS of the UE 100 may update the slice priority (or change the priority of the slice) according to the information.

[0092] Second, when slice information is included in the paging message, the UE 100 may perform a slice-specific cell reselection procedure in response to receiving the paging message. The UE 100 may perform the slice-specific cell reselection procedure with the slice included in the slice information as the highest slice priority (i.e., the intended slice). The slice-specific cell reselection procedure is an example of a predetermined process.

[0093] Third, when slice information is included in the paging message, UE100 may execute a slice-specific random access (slice-specific Random Access Channel (RACH)) procedure in response to receiving the paging message. The slice-specific random access procedure is a random access procedure performed using a PRACH (Physical Random Access Channel) resource that differs for each slice. The slice-specific random access procedure is an example of a predetermined process. UE100 may select a PRACH resource linked to the slice information and execute the slice-specific random access procedure. Note that, when UE100 is unable to select a PRACH resource linked to the slice information, UE100 may determine that the PRACH resource linked to the slice information is not provided by the network, that is, that the serving cell that transmitted the paging message is a cell that does not support the slice included in the slice information. In this case, UE100 may execute a slice-specific cell reselection procedure.

[0094] In step S114, the UE 100 performs an RRC connection establishment procedure.

[0095] In step S115, UE 100 connects to gNB 200 and transitions to an RRC connected state. Note that if the cell to which UE 100 is connected does not correspond to the slice included in the slice information, UE 100 may perform handover processing to a neighboring cell after RRC connection.

[0096] In step S116, the UE 100 executes a PDU session establishment procedure for the cell included in the slice information included in the paging message.

[0097] (Another example according to the first embodiment) In the first embodiment, an example of CN paging has been described, but the present invention is not limited to this. For example, the first embodiment can also be applied to RAN paging. In this case, UE100 enters an RRC inactive state instead of an RRC idle state (step S110). Also, in this case, CN20 does not transmit a PAGING message (step S111). The gNB200 transmits a PAGING message linked to slice information when triggered to transmit a PAGING message (when the gNB200 receives downlink data addressed to UE100 or when the gNB200 receives control information addressed to UE100) (step S112). Then, UE100 checks the slice information (step S113) and executes an RRC recovery process for the gNB200.

[0098] During RAN paging, UE100 may perform an RRC recovery procedure not to the serving cell (gNB200) but to a cell (or a neighboring cell) controlled by another gNB in ​​the RNA. In this case, a RAN paging message, which is an Xn message, is transmitted from the gNB200 to which UE100 last connected to the other gNB. The gNB200 to which UE100 last connected transmits slice information linked to (the bearer of) DL data addressed to UE100 in the Xn message to the other gNB200. Then, the other gNB that has received the RAN paging message transmits a paging message linked to the slice information to UE100 (step S112).

[0099] In addition, in a paging message used in RAN paging, for example, an I-RNTI (Inactive-RNTI) is used as a UE identifier.

[0100] Furthermore, in the first embodiment, an example in which the gNB200 transmits a paging message including slice information has been described, but this is not limiting. For example, instead of transmitting a paging message including slice information, the gNB200 may transmit to the UE100 a paging message including a frequency that supports the slice represented by the slice information. By including the frequency in the paging message, the slice information may be linked to the paging message. In this case, the UE100 may increase the frequency priority (e.g., FIG. 10) of the frequency included in the paging message by a threshold or more (or set it to the highest priority), and perform a slice-specific cell reselection procedure.

[0101] Furthermore, in the first embodiment, an example in which slice information is included in a paging message has been described, but the present invention is not limited to this. For example, slice information does not have to be included in a paging message. In this case, information indicating an association between a paging occasion (PO) and a slice may be transmitted in system information (SIB) or the like. Then, when UE 100 receives a paging message at a certain paging occasion (PO), it may check the slice associated with the paging occasion (PO) based on the information indicating the association. The slice associated with the paging occasion (PO) is checked based on the paging occasion (PO) at which the paging message is transmitted (or the paging message is received). Therefore, in this case as well, it is possible to consider that slice information is associated with the paging message.

[0102] [Second embodiment] Next, a second embodiment will be described, focusing on the differences from the first embodiment.

[0103] The second embodiment is an example in which the UE 100 includes, in the Paging message, information specifying a process to be performed after receiving the Paging message associated with the slice. Specifically, after the base station (e.g., the gNB 200) receives the first paging message (e.g., the Paging message associated with the slice information) in the user equipment (e.g., the UE 100), the base station transmits, to the user equipment, a first paging message including specified process information specifying a process to be performed first.

[0104] As a result, UE 100 that has received the paging message can execute processing in accordance with the information included in the designated processing information. Therefore, the network side can set in advance the processing to be performed after receiving the paging message for UE 100. UE 100 can connect to an appropriate cell by executing processing in accordance with the designated processing information.

[0105] As described above, information that specifies the process that UE 100 performs first after UE 100 receives a paging message associated with a slice may be referred to as "specified process information."

[0106] (Example of operation according to the second embodiment) Next, an example of operation according to the second embodiment will be described.

[0107] Fig. 13 is a diagram illustrating an example of operation according to the second embodiment. Fig. 13 illustrates an example of CN paging.

[0108] As shown in FIG. 13, in step S120, the UE 100 is in an RRC idle state.

[0109] 13, in step S121, the CN 20 transmits a PAGING message including designated processing information to the gNB 200. For example, a core network device (e.g., the AMF 300) included in the CN 20 transmits the PAGING message including designated processing information to the gNB 200. As in the first embodiment, the PAGING message includes slice information.

[0110] The process specified by the designated process information may be either a slice-specific cell reselection procedure or an RRC connection establishment procedure. When the process specified by the designated process information is a slice-specific cell reselection procedure, the process indicates that the slice-specific cell reselection procedure is first executed in the UE 100 after receiving a paging message. Also, when the process specified by the designated process information is an RRC connection establishment procedure, the process indicates that the RRC connection establishment procedure is first executed in the UE 100 after receiving a paging message.

[0111] In step S122, in response to receiving the PAGING message (step S121), the gNB 200 transmits a Paging message including designation processing information to the UE 100. As in the first embodiment, the Paging message includes slice information.

[0112] In step S123, the UE 100 checks the slice information and the designated process information.

[0113] In step S124, the UE 100 executes the process designated by the designated process information.

[0114] First, when the process specified by the designated process information is a slice-specific cell reselection procedure, the UE 100 may perform a slice-specific cell reselection procedure with the slice included in the slice information as the highest priority cell (i.e., the intended slice). Then, the UE 100 performs an RRC connection establishment procedure for the reselected cell.

[0115] Secondly, if the process specified by the designated process information is an RRC connection establishment procedure, the RRC connection establishment procedure is executed with respect to the serving cell, as in the first embodiment (step S114).

[0116] (Another example of the second embodiment) In the second embodiment, an example has been described in which processing is designated by designated processing information. For example, instead of the designated processing information, processing after receiving a paging message in the UE 100 may be defined in the specifications (or hard-coded in the UE 100). That is, as processing after receiving a paging message, whether the UE 100 first performs a slice-specific cell reselection procedure or first performs an RRC connection establishment procedure may be defined in the specifications.

[0117] Furthermore, in the second embodiment, an example has been described in which the process specified by the designated process information is specified by the gNB200, but this is not limiting. For example, the UE100 may be able to select from the designated processes. In this case, the CN20 transmits a PAGING message including both a slice-specific cell reselection procedure and an RRC connection establishment procedure as designated process information to the gNB200 (step S121). The gNB200 also transmits a Paging message including both a slice-specific cell reselection procedure and an RRC connection establishment procedure as designated process information to the UE100 (step S122). The UE100 selects and executes either the slice-specific cell reselection procedure or the RRC connection establishment procedure as the first process after receiving the Paging message (step S124).

[0118] Furthermore, as another example of the second embodiment, the initial process after receiving a paging message may be set in advance in the UE 100. For example, when the UE 100 is connected to the network before entering the RRC idle state, the process may be specified by a NAS message from the AMF 300 to the UE 100. The NAS message includes specified process information. After receiving the paging message including slice information (step S122), the UE 100 executes the process specified by the specified process information included in the NAS message.

[0119] Furthermore, although the second embodiment has been described with reference to an example of CN paging, RAN paging can also be implemented as in the first embodiment. In this case, UE100 enters an RRC inactive state instead of an RRC idle state (step S110). Furthermore, when triggered to transmit a paging message, gNB200 transmits a paging message including designated processing information to UE100 (step S122). In this case, the designated processing information may be either a slice-specific cell reselection procedure or an RRC recovery procedure. In this way, the other examples described in the first embodiment can also be applied to the second embodiment.

[0120] [Third embodiment] Next, a third embodiment will be described, focusing on the differences from the first embodiment.

[0121] In the third embodiment, an example will be described in which information indicating up to which cells a paging message associated with a slice is supported or up to which area a paging message associated with a slice is applied is transmitted. Specifically, a base station (e.g., gNB200) transmits a first paging message (e.g., paging message associated with a slice) including slice support information to a user apparatus (e.g., UE100). Here, the slice support information includes information indicating an area supporting the slice.

[0122] SIB16 broadcast from a cell includes a list of slices supported by neighboring cells (list of allow-listed neighboring cells for slicing). Therefore, UE 100 can know what slices are supported in neighboring cells only after receiving SIB16.

[0123] However, the UE 100 cannot know what slices are supported in the neighboring cells until it receives the SIB16.

[0124] Therefore, in the third embodiment, an example will be described in which slice support information is included in the paging message and transmitted.

[0125] As a result, for example, when the UE 100 receives a paging message, the UE 100 can ascertain up to which area (for example, neighboring cells) the slice associated with the paging message is supported without receiving the SIB 16. Depending on the result, the UE 100 can connect to an appropriate cell, such as by performing a slice-specific cell reselection procedure or an RRC connection establishment procedure with respect to the serving cell.

[0126] Here, the slice support information includes information indicating an area that supports a slice. Specifically, the slice support information may include a cell ID (or PCI) of a cell that supports the slice. The cell ID may be in a list format. An example of the list format is a PCI list. Alternatively, the slice support information may include identification information (TAI: Tracking Area Identity) of a tracking area (TA) that uniformly supports the slice. Alternatively, the slice support information may include identification information (e.g., a TAI list) of a registration area (RA) that uniformly supports the slice. Alternatively, the slice support information may include identification information (PLMN ID) of a PLMN that uniformly supports the slice.

[0127] (Operation example according to the third embodiment) Next, an operation example according to the third embodiment will be described.

[0128] Fig. 14 is a diagram illustrating an example of operation according to the third embodiment. Fig. 14 also illustrates an example of CN paging.

[0129] As shown in FIG. 14, in step S130, the UE 100 is in an RRC idle state.

[0130] In step S131, the gNB 200 transmits slice support information for its own cell to the CN 20. For example, the gNB 200 transmits slice support information including slice #1 supported by cell #1 and slice #2 supported by cell #2 in an NG message to a core network device (e.g., the AMF 300).

[0131] The core network device also receives slice support information from other gNBs about slices supported in the cells of the other gNBs. Therefore, the core network device can determine which cells (e.g., cell #1 of gNB200 and cell #3 of another gNB) support slice #1 and which cells (e.g., cell #2 of gNB200 and cell #4 of another gNB) support slice #2. Furthermore, the core network device can determine whether slice #1 is uniformly supported in TA or whether slice #1 is uniformly supported in RA. In this way, the core network device can determine in which region each slice is uniformly supported.

[0132] In step S132, the CN20 transmits a PAGING message (e.g., a second paging message) including slice information and slice support information to the gNB200. For example, the core network device transmits the slice associated with the PAGING message and the region in which the slice is supported as slice information and slice support information, respectively, to the gNB200.

[0133] In step S133, in response to receiving the PAGING message (step S132), gNB200 transmits a Paging message (e.g., a first paging message) including slice information and slice support information to UE100.

[0134] In step S134, the UE 100 checks the slice information included in the paging message.

[0135] In step S135, UE 100 checks the slice support information included in the paging message.

[0136] UE100 may confirm, using the slice support information, that the slice represented by the slice information is supported in the serving cell, and perform an RRC connection establishment procedure (step S114) with the serving cell, as in the first embodiment. Alternatively, UE100 may confirm, using the slice support information, that the slice represented by the slice information is not supported in the serving cell, and perform a slice-specific cell reselection procedure.

[0137] (Another example of the third embodiment) In the third embodiment, an example of CN paging has been described, but RAN paging can also be implemented, as in the first embodiment. In this case, the UE 100 enters an RRC inactive state instead of an RRC idle state (step S130). Also, in this case, an RRC recovery procedure is executed instead of the RRC connection establishment procedure (step S114). Furthermore, when an opportunity to transmit a paging message occurs, the gNB 200 transmits a paging message including slice support information to the UE 100 (step S133). In this way, the other examples described in the first embodiment can also be applied to the third embodiment.

[0138] [Other embodiments] A program may be provided that causes a computer to execute each process performed by UE100 or gNB200. The program may be recorded on a computer-readable medium. The computer-readable medium can be used to install the program on a computer. Here, the computer-readable medium on which the program is recorded may be a non-transitory recording medium. The non-transitory recording medium is not particularly limited, and may be, for example, a recording medium such as a CD-ROM or a DVD-ROM. Furthermore, circuits that execute each process performed by UE100 or gNB200 may be integrated, and at least a part of UE100 or gNB200 may be configured as a semiconductor integrated circuit (chip set, SoC: System on a chip).

[0139] As used in this disclosure, the terms "based on" and "depending on" do not mean "based only on" or "depending only on," unless expressly stated otherwise. The term "based on" means both "based only on" and "based at least in part on." Similarly, the term "depending on" means both "depending only on" and "depending at least in part on." Furthermore, the terms "include" and "comprise" do not mean including only the listed items, but may mean including only the listed items or may include additional items in addition to the listed items. Furthermore, the term "or" as used in this disclosure is not intended to mean an exclusive or. Furthermore, any reference to elements using designations such as "first," "second," etc., as used in this disclosure does not generally limit the quantity or order of those elements. These designations may be used herein as a convenient method of distinguishing between two or more elements. Thus, a reference to a first and a second element does not imply that only two elements may be employed therein or that the first element must precede the second element in some way. In this disclosure, where articles are added by translation, such as a, an, and the in English, these articles shall include the plural unless the context clearly indicates otherwise.

[0140] Although one embodiment has been described in detail above with reference to the drawings, the specific configuration is not limited to the above, and various design changes can be made within the scope of the gist. Furthermore, it is also possible to combine all or part of each embodiment, each operation, each process, and each step within the scope of consistent combinations.

[0141] This application claims priority from Japanese Patent Application No. 2022-119404 (filed July 27, 2022), the entire contents of which are incorporated herein by reference.

[0142] (Addendum) (Appendix 1) A communication control method in a mobile communication system, comprising: a base station transmitting a first paging message to the user equipment, the first paging message being associated with the network slice; Communication control method.

[0143] (Appendix 2) The core network device transmits a second paging message to which the network slice is bound. Radio Access Network Node and transmitting the The step of transmitting to the user device includes: Radio Access Network Node In response to receiving the second paging message, the first paging message is transmitted to the user device. to transmitting 10. The communication control method according to claim 1.

[0144] (Appendix 3) The method further includes a step of performing a predetermined process by the user device in response to receiving the first paging message; The predetermined process is any one of updating the slice priority of the network slice, a slice-specific cell reselection procedure, and a slice-specific random access procedure. 10. The communication control method according to claim 1 or 2.

[0145] (Appendix 4) The step of transmitting to the user equipment includes a step of the base station transmitting the first paging message including slice information representing the network slice to the user equipment. A communication control method according to any one of Supplementary Note 1 to Supplementary Note 3.

[0146] (Appendix 5) The step of transmitting to the base station includes a step of the core network device transmitting the second paging message including slice information representing the network slice to the base station; The step of transmitting to the user device includes a step of the base station transmitting the first paging message including the slice information to the user device in response to receiving the second paging message. A communication control method according to any one of Supplementary Note 1 to Supplementary Note 4.

[0147] (Appendix 6) The step of transmitting to the user device includes a step of the base station transmitting to the user device the first paging message including designated processing information that designates a processing to be executed first after the user device receives the first paging message. A communication control method according to any one of Supplementary Note 1 to Supplementary Note 5.

[0148] (Appendix 7) the step of transmitting to the base station includes a step of transmitting, by the core network device, the second paging message to the base station, the second paging message including designated processing information that designates processing to be performed in response to receiving the first paging message in the user equipment; the step of transmitting to the user equipment includes a step of the base station transmitting the first paging message including the designated processing information to the user equipment in response to receiving the second paging message. A communication control method according to any one of Supplementary Note 1 to Supplementary Note 6.

[0149] (Appendix 8) The process included in the designated process information is Either a slice-specific cell reselection procedure and an RRC connection establishment procedure, or The slice-specific cell reselection procedure is one of an RRC recovery procedure and a slice-specific cell reselection procedure. A communication control method according to any one of Supplementary Note 1 to Supplementary Note 7.

[0150] (Appendix 9) The step of transmitting to the user equipment includes a step of the base station transmitting the first paging message including slice support information to the user equipment; The slice support information includes information indicating an area that supports the network slice. A communication control method according to any one of Supplementary Note 1 to Supplementary Note 8.

[0151] (Appendix 10) The step of transmitting to the base station includes a step of the core network device transmitting the second paging message including the slice support information to the base station; The step of transmitting to the user device includes a step of the base station transmitting the first paging message including the slice support information to the user device in response to receiving the second paging message. A communication control method according to any one of Supplementary Note 1 to Supplementary Note 9. [Explanation of symbols]

[0152] 1: Mobile communication system 20 :CN 100:UE 110: Receiving unit 120: Transmitter 130: Control unit 200 :gNB 210: Transmission unit 220: Receiving unit 230: Control unit 300:AMF

Claims

1. A communication control method in a mobile communication system, comprising: a radio access network node transmitting a first paging message to a user equipment, the first paging message having a network slice associated therewith; The transmitting to the user equipment includes transmitting, by the radio access network node, the first paging message to the user equipment, the first paging message including designated processing information that designates a processing to be executed first after the user equipment receives the first paging message. Communication control method.

2. The core network node further comprises transmitting a second paging message to the radio access network node, the second paging message being associated with the network slice; transmitting to the user equipment includes the radio access network node transmitting the first paging message to the user equipment in response to receiving the second paging message. The communication control method according to claim 1.

3. The method further includes the user equipment performing a predetermined process in response to receiving the first paging message; The predetermined process is any one of updating the slice priority of the network slice, a slice-specific cell reselection procedure, and a slice-specific random access procedure. The communication control method according to claim 1.

4. The transmitting to the user equipment includes the radio access network node transmitting the first paging message to the user equipment, the first paging message including slice information representing the network slice. The communication control method according to claim 1.

5. The transmitting to the radio access network node includes the core network node transmitting the second paging message to the radio access network node, the second paging message including slice information representing the network slice; and transmitting to the user equipment, the radio access network node transmitting the first paging message including the slice information to the user equipment in response to receiving the second paging message. The communication control method according to claim 2.

6. and transmitting the second paging message to the radio access network node includes transmitting, by the core network node, the second paging message to the radio access network node, the second paging message including designation processing information that designates processing to be performed in response to receiving the first paging message at the user equipment. and transmitting to the user equipment, by the radio access network node, the first paging message including the designated processing information in response to receiving the second paging message. The communication control method according to claim 2.

7. The process included in the designated process information is Either a slice-specific cell reselection procedure and an RRC connection establishment procedure, or Any of the slice-specific cell reselection procedure and the RRC recovery procedure The communication control method according to claim 1 or 6.

8. transmitting to the user equipment includes the radio access network node transmitting the first paging message including slice support information to the user equipment; The slice support information includes information indicating an area that supports the network slice. The communication control method according to claim 1.

9. The transmitting to the radio access network node comprises: sending a second paging message to the radio access network node, the second paging message including the slice support information; The transmitting to the user equipment includes the radio access network node transmitting the first paging message including the slice support information to the user equipment in response to receiving the second paging message. The communication control method according to claim 8.

10. A user device, a receiving unit configured to receive a first paging message associated with the network slice from a radio access network node; After receiving the first paging message at the user equipment, the radio access network node transmits the first paging message to the user equipment, the first paging message including designated processing information that designates a processing to be executed first. User equipment.

11. 1. A radio access network node, comprising: a transmitter that transmits a first paging message associated with a network slice to a user device, wherein the transmitter transmits the first paging message to the user device after the user device receives the first paging message, the first paging message including designated processing information that designates a processing to be executed first; Radio access network node.

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