Communication control method, mobile communication system, user device, program, and chipset

Abstract

A communication control method according to a first embodiment is for a mobile communication system that has user equipment and a base station and that enables wireless communication between the user equipment and the base station. The communication control method includes the user equipment executing a slice-specific random access channel procedure which is a random access procedure that uses resources separated per slice or per slice group. The communication control method also includes recording first log information to memory, the first log information acquired when the user equipment executed a slice-specific random access channel procedure. The communication control method further includes the user equipment transmitting the first log information to the base station.

Description

[Technical Field]

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

[0002] Network slicing (or network slice) has been specified in the 3GPP (Third Generation Partnership Project), a standardization project for mobile communication systems.

[0003] Network slicing is a concept that allows differentiated processing according to the requirements of each customer. Alternatively, network slicing is a technology that virtually slices a network to efficiently provide a network that meets the requirements of the services used by customers. [Prior art documents] [Non-patent literature]

[0004] [Non-Patent Document 1] 3GPP TS 38.300 V16.6.0 (2021-06) Summary of the Invention

[0005] A communication control method according to a first aspect is a communication control method in a mobile communication system including a user device and a base station, and capable of wireless communication between the user device and the base station. The communication control method includes the user device executing a random access procedure using resources associated with a slice group. The communication control method also includes the user device recording first log information acquired when the random access procedure is executed in a memory. The communication control method also includes the user device transmitting the first log information to the base station.

[0006] A communication control method according to a second aspect is a communication control method in a mobile communication system including a user device and a base station, and capable of wireless communication between the user device and the base station. The communication control method includes the user device performing slice-specific cell reselection using prioritized frequencies mapped to each slice group. The communication control method also includes the user device recording second log information acquired when the user device performs slice-specific cell reselection in a memory. The communication control method also includes the user device transmitting the second log information to the base station. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a diagram illustrating an example of the configuration of a mobile communication system according to an embodiment. [Figure 2] FIG. 2 is a diagram illustrating an example of the configuration of a UE (user equipment) according to an embodiment. [Figure 3] FIG. 3 is a diagram illustrating an example configuration of a gNB (base station) according to one 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 an embodiment. [Figure 5] FIG. 5 is a diagram illustrating an example of the configuration of a protocol stack related to a control plane according to an embodiment. [Figure 6] FIG. 6 is a diagram illustrating an example of the configuration of a mobile communication system 1 according to the first embodiment. [Figure 7] FIG. 7 is a diagram illustrating an example of operation according to the first embodiment. [Figure 8] FIG. 8 is a diagram illustrating an example of operation according to the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] An object of the present disclosure is to provide a communication control method that can appropriately record a log for a predetermined process and transmit the log to a base station.

[0009] 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.

[0010] (Mobile communication system) First, a configuration of a mobile communication system according to an embodiment will be described. The mobile communication system according to an embodiment is a 3GPP 5G system, but LTE may be applied at least partially to the mobile communication system. Furthermore, future mobile communication systems such as 6G may also be applied to the mobile communication system.

[0011] FIG. 1 is a diagram illustrating an example of the configuration of a mobile communication system 1 according to an embodiment.

[0012] As shown in FIG. 1, the mobile communication system 1 includes a user equipment (UE) 100, a 5G radio access network (NG-RAN: Next Generation Radio Access Network) 10, and a 5G core network (5GC: 5G Core Network) 20.

[0013] The UE 100 is a mobile device. The UE 100 may be any device that is used by a user, and may be, for example, 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).

[0014] The NG-RAN 10 includes a base station (called a "gNB" in a 5G system) 200. The gNB 200 is sometimes called an NG-RAN node. 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.

[0015] Note that the gNB 200 may be connected to an EPC (Evolved Packet Core), which is an LTE core network, or an LTE base station may be connected to the 5GC 20. In addition, the LTE base station and the gNB 200 may be connected via an inter-base station interface.

[0016] The 5GC 20 includes an AMF (Access and Mobility Management Function) 301 (301-1, 301-2) and a UPF (User Plane Function) 302 (302-1, 302-2). The AMF 301 performs various mobility controls for the UE 100. The AMF 301 manages information about the area in which the UE 100 is located by communicating with the UE 100 using NAS (Non-Access Stratum) signaling. The UPF 302 controls data forwarding. The AMF 301 and the UPF 302 are connected to the gNB 200 via an NG interface, which is an interface between a base station and a core network. The AMF 301 and the UPF 302 are examples of core network devices connected to the 5GC (core network) 20.

[0017] FIG. 2 is a diagram illustrating an example of the configuration of a UE 100 (user equipment) according to an embodiment.

[0018] As shown in FIG. 2, the UE 100 includes a receiving unit 110, a transmitting unit 120, and a control unit .

[0019] 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 (down-converts) a radio signal received by the antenna into a baseband signal (received signal) and outputs the baseband signal to the control unit 130.

[0020] 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 (up-converts) a baseband signal (transmission signal) output by the control unit 130 into a radio signal and transmits it from the antenna.

[0021] The control unit 130 performs various controls in the UE 100. The control unit 130 includes at least one processor and at least one memory electrically connected to the processor. The memory stores programs executed by the processor and information used in processing 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. The control unit 130 may perform various operations and processes executed by the UE 100 in each of the embodiments described below.

[0022] FIG. 3 is a diagram illustrating an example configuration of a gNB200 (base station) according to one embodiment.

[0023] As shown in FIG. 3, the gNB 200 has a transmitter 210, a receiver 220, a controller 230, and a backhaul communication unit 240.

[0024] 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 (up-converts) a baseband signal (transmission signal) output by the control unit 230 into a radio signal and transmits it from the antenna.

[0025] 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 (down-converts) a radio signal received by the antenna into a baseband signal (received signal) and outputs the baseband signal to the control unit 230.

[0026] The control unit 230 performs various controls in the gNB 200. The control unit 230 includes at least one processor and at least one memory electrically connected to the processor. The memory stores programs executed by the processor and information used in processing by the processor. The processor may include a baseband processor and a CPU. The baseband processor performs modulation / demodulation, encoding / decoding, etc. of baseband signals. The CPU executes programs stored in the memory to perform various processes. The control unit 230 may perform various operations and processes executed by the gNB 200 in each of the embodiments described below.

[0027] The backhaul communication unit 240 is connected to neighboring base stations via an inter-base station interface. The backhaul communication unit 240 is connected to the AMF 301 and / or the UPF 302 via a base station-core network interface. Note that the gNB 200 may be configured with a CU (Central Unit) and a DU (Distributed Unit), and both units may be connected via an F1 interface.

[0028] FIG. 4 is a diagram illustrating an example of the configuration of a protocol stack of a radio interface of a user plane according to an embodiment.

[0029] As shown in Figure 4, the radio interface protocol of the user plane that handles data has 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.

[0030] 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 the UE 100 and the PHY layer of the gNB 200 via a physical channel.

[0031] The MAC layer performs data priority control, retransmission processing using Hybrid ARQ (HARQ), random access procedures, etc. Data and control information are transmitted between the MAC layer of UE 100 and the MAC layer of gNB 200 via a transport channel. The MAC layer of gNB 200 includes a scheduler. The scheduler determines the uplink and downlink transport format (transport block size, modulation and coding scheme (MCS)) and the resource blocks to be allocated to UE 100.

[0032] 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.

[0033] The PDCP layer performs header compression / decompression, encryption / decryption. Data and control information are transmitted between the PDCP layer of the UE 100 and the PDCP layer of the gNB 200 via a radio bearer.

[0034] The SDAP layer maps QoS flows, which are the units for QoS control by the core network, to radio bearers, which are the units for QoS control by the AS (Access Stratum). Note that if the RAN is connected to the EPC, SDAP is not necessary.

[0035] FIG. 5 is a diagram illustrating an example of the configuration of a protocol stack of a radio interface of a control plane according to an embodiment.

[0036] As shown in FIG. 5, the protocol stack of the radio interface of the control plane that handles signaling (control signals) has an RRC (Radio Resource Control) layer and an NAS layer instead of the SDAP layer shown in FIG.

[0037] 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 in accordance with 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 RRC connection is suspended, UE100 is in an RRC inactive state.

[0038] A Non-Access Stratum (NAS) layer positioned above the RRC layer performs session management, mobility management, etc. NAS signaling is transmitted between the NAS layer of the UE 100 and the NAS layer of the AMF 301.

[0039] The UE 100 has an application layer and the like in addition to the radio interface protocol.

[0040] [First embodiment] Next, a first embodiment will be described.

[0041] As described above, network slicing makes it possible to provide a variety of services that meet user requirements. Hereinafter, network slicing may be referred to as a "slice." In network slicing, the portion supported by NG-RAN 10 may be referred to as RAN slicing. Hereinafter, even when there is no distinction between network slicing and RAN slicing, they may simply be referred to as a "slice."

[0042] A slice refers to a logically divided core network and / or radio access network. An identifier for identifying a slice is Network Slice Selection Assistance Information (NSSAI) or Single-NSSAI (S-NSSAI), etc.

[0043] A slice group is a group including one or more slices, and an identifier (ID) is assigned to the group. The slice group may be created in a core network (e.g., AMF 301) or a radio access network (e.g., gNB 200). The created slice group may be notified to the UE 100.

[0044] Slice-specific cell reselection is being studied in 3GPP. In slice-specific cell reselection, frequencies are mapped (or linked) to each slice, and a priority (absolute priority) is set for each frequency. Cell reselection using this setting is called slice-specific cell reselection. Slice-specific cell reselection makes it possible to provide frequency resources for each slice (or slice group), thereby preventing overlap of the frequency resources between slices. Furthermore, by controlling the frequency priority of the cell on which UE 100 camps (the cell to be reselected) for each slice (or slice group), UE 100 can be camped (distributed / distributed) on an appropriate frequency for each slice that UE 100 wishes to access. Furthermore, UE 100 can be camped (distributed) on a different frequency (or cell) from UEs (e.g., legacy UEs) that do not wish to access the slice.

[0045] Regarding slice-specific cell reselection, 3GPP has 1) Prioritized frequencies mapped to each slice are provided to the UE 100; 2) "slice" may mean "slice group"; 3) It was agreed that the prioritized frequencies mapped to each slice are part of the "Slice info".

[0046] Also, in 3GPP, slice-specific random access channels (Slice-specific RACH (Random Access Channel(s))) are being studied. The slice-specific random access channel (hereinafter sometimes referred to as "slice-specific RACH") uses a separated random access opportunity (separated RO (RACH Occasion)) and / or a separated preamble for each slice or slice group. In this way, a random access procedure performed using a RACH resource separated for each slice or slice group is called a slice-specific RACH. The slice-specific RACH can prevent overlapping of the resource between slices, slice groups, or between access using a slice and access not using a slice. Furthermore, by avoiding the resource overlapping, it is possible to suppress interference between RACHs transmitted by multiple UEs 100. Furthermore, it is possible to prioritize access to a certain slice or slice group (by allocating resources that are less likely to cause interference).

[0047] Furthermore, 3GPP is also considering an "intended slice." However, 3GPP has not yet reached an agreement on specifics, such as the definition of the "intended slice." In the first embodiment, a slice that is likely to be used, a candidate slice, a desired slice, a slice desired for communication, a requested slice, an allowed slice, or an intended slice is referred to as an "intended slice." For example, by accessing a cell that supports the "intended slice," UE 100 can receive a desired service from the cell.

[0048] Meanwhile, in the field of wireless communications, there are conventionally SON (Self Organizing / Optimizing Network) and MDT (Minimization of Drive Tests).

[0049] SON is a technology that autonomously organizes and optimizes networks. Specifically, SON is a technology that aims to continuously optimize networks in response to dynamic changes, optimize parameters associated with troubleshooting, and optimize coverage and capacity. By utilizing these SON functions, processes such as network planning, configuration, and optimization can be automated, reducing the workload of operators (telecommunications carriers) and reducing operational costs.

[0050] Furthermore, MDT is a technology that supports the collection of measurement values ​​specific to the UE 100. With MDT, measurement data that was previously collected through drive tests using an electrical measurement vehicle can be collected using the UE 100, thereby automating measurement and collection and reducing man-hours and costs.

[0051] In the first embodiment, an example will be described in which the UE 100 records information acquired by executing (attempting) a slice-specific RACH as a log in a memory as a function of the SON and MDT.

[0052] Specifically, first, the user equipment (e.g., UE100) executes a slice-specific random access channel, which is a random access procedure using resources separated for each slice or each slice group. Second, the user equipment records first log information acquired when executing the slice-specific random access channel in a memory. Third, the user equipment transmits the first log information to the base station (e.g., gNB200).

[0053] This enables, for example, UE100 to properly record logs related to slice-specific RACH and transmit them to gNB200.

[0054] (Operation example according to the first embodiment) Next, an example of operation according to the first embodiment will be described.

[0055] Fig. 6 is a diagram illustrating a configuration example of a mobile communication system 1 according to the first embodiment. As illustrated in Fig. 6, an operation example of the first embodiment will be described using an example in which UE100 executes a slice-specific RACH to connect to a cell in gNB200. In this example, UE100 records first log information resulting from the execution of the slice-specific RACH and transmits the first log information to gNB200.

[0056] FIG. 7 is a diagram illustrating an example of operation according to the first embodiment.

[0057] As shown in FIG. 7, in step S10, the UE 100 starts the process.

[0058] In step S11, the UE 100 executes the slice-specific RACH. For example, the UE 100 acquires parameters of the slice-specific RACH from the gNB 200 by an SIB (System Information Block) or dedicated signaling, and executes a random access procedure using the parameters, thereby executing the slice-specific RACH.

[0059] In step S12, the UE 100 records first log information regarding the executed slice-specific RACH in a memory.

[0060] The first log information may include log information that can be acquired by executing a normal random access procedure, instead of the slice-specific RACH. Examples of such log information include the following.

[0061] First, at least one of the number of random access preambles transmitted from the UE 100, the total number of consecutive random access preambles transmitted from the UE 100, and contention detection may be included. These pieces of information are also information that is transmitted from the UE 100 to the gNB 200 as information included in a connection establishment failure report (ConnEstFailReport).

[0062] Second, at least one of the cell ID of the cell where the slice-specific RACH is performed, the purpose of the random access, and the number of RACH opportunities (RACH Occasions) may be included. These pieces of information are also transmitted from the UE 100 to the gNB 200 as information included in a random access report (RA-Report) or a radio link failure report (RLF-Report).

[0063] In the first embodiment, a log specific to the slice-specific RACH is recorded in a memory as the first log information. That is, when the UE 100 executes the slice-specific RACH (RACH attempt), the UE 100 records any of the following information as the first log information:

[0064] (A1) A slice identifier associated with the physical random access channel (PRACH (Physical RACH)) resource on which the RACH attempt was made.

[0065] (A2) Resource information or resource ID of the RO that made the RACH attempt.

[0066] (A3) Resource information or resource ID related to the preamble that performed the RACH attempt.

[0067] (A4) Information indicating that the priority RACH was for a certain slice. The UE 100 may further record the identifier of the slice or slice group for which the priority RACH (priority access) was performed.

[0068] The above (A1) and (A4) include, for example, information about slices, and can be said to be logs specific to slice-specific RACHs. Also, for example, since the slice-specific RACH uses RACH resources separated for each slice group, (A2) and (A3) make it possible to record which RACH resources are used.

[0069] In step S13, UE 100 transmits the first log information recorded in the memory to gNB 200. For example, UE 100 may transmit a UE Information Response message including the first log information to gNB 200. In this case, UE 100 transmits the UE Information Response message as a response message to the UE Information Request message received from gNB 200. Note that UE 100 may transmit the above (A4) by transmitting a UE Information Response message in which "Slice-specific RACH attempt" is set in the IE "raPurpose" indicating the purpose of random access.

[0070] Then, in step S14, the UE 100 ends the series of processes.

[0071] (Modification of the first embodiment) In the first embodiment, an example has been described in which information included in a connection establishment failure report, a random access report, or a radio link failure report is recorded as a log as log information that can be acquired by executing a normal RACH. As a modification of the first embodiment, at least one of a timestamp, location information (latitude, longitude, altitude, etc.), and radio conditions (RSRP (Reference Signal Received Power), RSRQ (Reference Signal Received Quality), SINR (Signal to Interference plus Noise Ratio), etc.) may be recorded as first log information as log information that can be acquired by executing a normal RACH, and transmitted to the gNB 200.

[0072] [Second embodiment] Next, a second embodiment will be described.

[0073] As a function of the SON and MDT, the UE 100 may report the cell IDs of the cells it has visited as a mobility history report (Mobility History Report) to the gNB 200. However, reporting the result of cell reselection in the UE 100 to the gNB 200 is not specified.

[0074] On the other hand, when the above-described slice-specific cell reselection is introduced, it is expected that whether or not UE 100 has been able to reselect a cell supporting a desired slice ("intended slice") will be one piece of information for network optimization. For example, an operator can newly deploy a cell supporting an Ultra-Reliable and Low Latency Communications (URLLC) slice in an area where there are many UEs 100 that desire the URLLC slice as their desired slice.

[0075] Therefore, in the second embodiment, an example will be described in which the execution result of slice-specific cell reselection is recorded as a log. Specifically, first, a user equipment (e.g., UE100) executes slice-specific cell reselection using prioritized frequencies mapped for each slice. Second, the user equipment records second log information acquired when executing slice-specific cell reselection in a memory. Third, the user equipment transmits the second log information to a base station (e.g., gNB200).

[0076] This allows, for example, proper logging of slice-specific cell reselection, and also allows, for example, network optimization.

[0077] (Example of operation according to the second embodiment) FIG. 8 is a diagram illustrating an example of operation according to the second embodiment.

[0078] As shown in FIG. 8, in step S20, the UE 100 starts the process.

[0079] In step S21, the UE 100 performs slice-specific cell reselection. For example, the UE 100 can perform slice-specific cell reselection by acquiring slice-specific cell reselection parameters from the gNB 200 by SIB or dedicated signaling, and performing cell reselection using the parameters.

[0080] In step S22, UE 100 completes slice-specific cell reselection. Whether slice-specific cell reselection is completed may be determined based on whether a predetermined completion condition is met. The predetermined completion condition is, for example, any one of 1) a prioritized frequency (or cell) associated with a slice is reselected, 2) a frequency (or cell) with the highest priority is reselected, and 3) the reselected cell (or frequency) transmits slice-specific RACH parameters corresponding to a slice identifier indicating "intended slice". UE 100 may determine a condition other than such a predetermined completion condition as the completion condition.

[0081] In step S23, if the slice-specific cell reselection is successful, UE100 records the first information in the memory as second log information. Also, in step S23, if the slice-specific cell reselection is unsuccessful, UE100 records the second information in the memory as second log information. Whether the slice-specific cell reselection is successful or unsuccessful may be determined, for example, based on whether a completion condition is satisfied. Note that, if the slice-specific cell reselection is unsuccessful, UE100 performs normal cell reselection.

[0082] The first information may be, for example, any of the following:

[0083] (B1) Identifier of the desired slice ("intended slice"), for example, S-NSSAI of the "intended slice".

[0084] (B2) Information indicating that slice-specific cell reselection has been completed.

[0085] (B3) Information indicating that the cell supports the slice ("intended slice") in question.

[0086] (B4) Information indicating that the UE 100 is located in a cell that supports prioritized access to the slice ("intended slice"). For example, when the UE 100 receives parameters of a slice-specific RACH in the serving cell, the UE 100 can determine that the UE 100 is located in a cell that supports prioritized access to the slice.

[0087] (B5) Information indicating which cell (or frequency) has been reselected based on the priority specified by the slice-specific cell reselection parameter.

[0088] (B6) Information on the reselected cell (or frequency). Such information may be expressed as a cell ID or an ARFCN (Absolute radio-frequency channel number).

[0089] On the other hand, the second information may be, for example, any of the following:

[0090] (C1) Identifier of a desired slice ("intended slice"), for example, an identifier of the desired slice when slice-specific cell reselection to a cell that supports the desired slice fails.

[0091] (C2) Information indicating that slice-specific cell reselection failed.

[0092] (C3) Information indicating that the cell is located in a cell that may not support the slice ("intended slice").

[0093] (C4) Information indicating that the UE 100 is located in a cell that does not support prioritized access to the slice ("intended slice"). For example, when the UE 100 does not receive parameters of a slice-specific RACH in the serving cell, it can be determined that the UE 100 is located in a cell that does not support prioritized access to the slice.

[0094] (C5) Information on the reselected cell (or frequency).

[0095] The UE 100 may record at least one of a time stamp, location information (latitude, longitude, altitude, etc.), and radio conditions (RSRP, RSRQ, SINR, etc.) as the second log information.

[0096] In step S24, the UE 100 transitions to the RRC connected state. After transitioning to the RRC connected state, the UE 100 may notify the gNB 200 of information indicating that a log related to slice-specific cell reselection is being recorded. The notification is an RRC Setup Complete message or an RRC Release Complete message including "Slice-specific cell reselection log available". Release This may be performed by the UE 100 transmitting a "Repeat" (Repeat Complete) message.

[0097] In step S25, UE 100 transmits the log (second log information) recorded in the memory to gNB 200. For example, UE 100 may transmit the log together with a UE Information Response message, which is a response message to a UE Information Request message received from gNB 200.

[0098] Then, in step S26, the UE 100 ends the series of processes.

[0099] [Other embodiments] A program may be provided that causes a computer to execute each process performed by the UE 100 or the gNB 200. The program may be recorded on a computer-readable medium. Using the computer-readable medium, the program can be installed 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.

[0100] In addition, 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 (chipset, SoC).

[0101] 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 "based only on" and "at least in part on." Furthermore, "obtain" may mean obtaining information from stored information, obtaining information from information received from another node, or obtaining information by generating the information. The terms "include," "comprise," and variations thereof do not mean including only the listed items, but may also mean including only the listed items or including additional items in addition to the listed items. Furthermore, as used in this disclosure, the term "or" 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, reference to first and second elements does not imply that only two elements may be employed therein or that the first element must precede the second element in some manner. 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.

[0102] 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 without departing from the scope of the invention. Furthermore, it is also possible to combine all or part of each embodiment within a consistent range.

[0103] This application claims priority from Japanese Patent Application No. 2021-128845 (filed August 5, 2021), the entire contents of which are incorporated herein by reference. [Explanation of symbols]

[0104] 1: Mobile communication system 10:5GC 100:UE 110: Wireless communication unit 130: Control unit 200 :gNB 210: Radio Communication Department 220: Network Communication Department 230: Control unit 301:AMF 302:UPF

Claims

1. A communication control method in a mobile communication system having a user equipment and a network node, wherein wireless communication is possible between the user equipment and the network node, comprising: The user equipment performs a random access procedure using resources associated with a slice group; recording log information acquired when the user device executes the random access procedure in a memory; the user equipment transmitting the log information to the network node; The log information includes information indicating an identifier of a slice group associated with the resource, information indicating that the priority RACH was the purpose, and an identifier of a slice group that performed the priority RACH. Communication control method.

2. The log information further includes at least one of information about a random access opportunity, information about a preamble, and information indicating that the slice is for a priority random access. The communication control method according to claim 1.

3. The log information further includes the number of random access preambles transmitted from the user equipment, the total number of consecutive random access preambles transmitted from the user equipment, and contention detection; The communication control method according to claim 1 .

4. The log information further includes at least one of a cell ID of a cell in which the slice-specific random access procedure was performed, a purpose of random access, and a number of RACH opportunities. The communication control method according to claim 1 .

5. The log information includes at least one of a slice identifier associated with a physical random access channel resource on which the RACH attempt is made, resource information or a resource ID related to an RO on which the RACH attempt is made, and resource information or a resource ID related to a preamble on which the RACH attempt is made. The communication control method according to claim 1 .

6. a user device; a network node that wirelessly communicates with the user equipment; The user equipment includes a transceiver circuit and a processing circuit operatively associated with the transceiver circuit, the processing circuit comprising: performing a random access procedure using resources associated with the slice group; recording log information acquired when the random access procedure is executed in a memory; transmitting the log information to the network node; The log information includes information indicating an identifier of a slice group associated with the resource, information indicating that the priority RACH was the purpose, and an identifier of a slice group that performed the priority RACH. Mobile communication system.

7. a transmitting / receiving circuit; and a processing circuit operatively associated with the transmitting / receiving circuit, the processing circuit comprising: performing a random access procedure using resources associated with the slice group; recording log information acquired when the random access procedure is executed in a memory; transmitting the log information to a network node; The log information includes information indicating an identifier of a slice group associated with the resource, information indicating that the priority RACH was the purpose, and an identifier of a slice group that performed the priority RACH. User equipment.

8. a communication step of performing a random access procedure using resources associated with a slice group; a recording step of recording log information acquired when the random access procedure is executed in a memory; a log transmission step of transmitting the log information to a network node; on the computer, The log information includes information indicating an identifier of a slice group associated with the resource, information indicating that the priority RACH was the purpose, and an identifier of a slice group that performed the priority RACH. program.

9. a communication step of performing a random access procedure using resources associated with a slice group; a recording step of recording log information acquired when the random access procedure is executed in a memory; a log transmission step of transmitting the log information to a network node; a circuit for executing The log information includes information indicating an identifier of a slice group associated with the resource, information indicating that the priority RACH was the purpose, and an identifier of a slice group that performed the priority RACH. Chipset.

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