Communication device, base station, and communication method

Abstract

To provide user equipment, a base station, and a communication method that allow a network to know that a stationary criterion has been met.MEANS FOR SOLVING THE PROBLEM: User equipment (100) includes: a control unit (140) that determines whether a stationary criterion, which is a criterion used to select whether to make measurements according to a measurement relaxation method that relaxes measurements of radio quality for neighboring cells, and which is a determination criterion for whether the user equipment (100) is in a stationary state, has been met; and a communication unit (120) that transmits, to a network, a radio resource management (RRC) message indicating that the stationary criterion has been met, according to that the stationary criterion has been met.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a user equipment, a base station, and a communication control method used in a mobile communication system. [Background technology]

[0002] In recent years, the 3GPP (3rd Generation Partnership Project), a standardization project for mobile communication systems, has been considering providing specific user equipment with reduced communication capabilities compared to general user equipment in 5G systems (see Non-Patent Document 1). The specific user equipment is user equipment with mid-range performance and price for IoT (Internet of Things), and, for example, has a narrower maximum bandwidth used for wireless communication and a smaller number of receivers than general user equipment.

[0003] It has also been agreed to introduce a method of relaxing the measurement of radio quality for neighboring cells based on an RSRP (Reference Signal Received Power) / RSRQ (Reference Signal Received Quality) based stationarity criterion (so-called RRM relaxation; hereinafter, referred to as measurement relaxation method) for a specific user equipment in an RRC connected state (see Non-Patent Document 2).

[0004] A specific user equipment (UE) that is stationary does not need to frequently measure the radio quality of neighboring cells because the radio environment is less fluctuating. By regarding a specific UE as a stationary UE if it satisfies the stationary criterion, the measurement relaxation method can reduce the number of measurements, thereby saving power and improving battery life. [Prior art documents] [Non-patent literature]

[0005] [Non-Patent Document 1] 3GPP contribution “RP-201677” [Non-patent document 2] 3GPP contribution “R2-2106472” Summary of the Invention [Problem to be solved by the invention]

[0006] Currently, a network is being considered to enable measurements according to a measurement relaxation method for a specific user equipment in an RRC connected state. However, existing 3GPP technical specifications do not provide a specific mechanism for a network to know whether a specific user equipment satisfies the stationary criterion. Therefore, it is difficult for a network to enable measurements according to a measurement relaxation method based on the specific user equipment satisfying the stationary criterion. Note that similar concerns arise for general user equipment when a measurement relaxation method based on the stationary criterion is introduced.

[0007] Therefore, an object of the present invention is to provide a user equipment, a base station and a communication method that enable the network to know that the stationary criterion has been met. [Means for solving the problem]

[0008] The user equipment according to the first aspect includes a control unit (140) that determines whether a stationary criterion is satisfied, the stationary criterion being a criterion used to select whether to perform measurement according to a measurement relaxation method that relaxes measurement of radio quality for neighboring cells, and that is a criterion for determining whether the user equipment (100) is in a stationary state; and a radio resource indicating that the stationary criterion is satisfied when the stationary criterion is satisfied. control and a communication unit (120) for transmitting a (RRC) message to the network.

[0009] The base station according to the second aspect is a base station (200) that manages a serving cell of a user device (100), and is configured to receive a radio resource indicating that a stationary criterion, which is a criterion used to select whether or not to perform measurement according to a measurement relaxation method that relaxes measurement of radio quality for neighboring cells, and is a criterion for determining whether or not the user device (100) is in a stationary state, is satisfied. control The device includes a radio communication unit (220) that receives a RRC message from the user equipment (100), and a control unit (240) that controls the measurement of the user equipment (100) according to the measurement relaxation method.

[0010] A communication control method according to a third aspect is a communication control method executed by a user device (100), and includes a step of determining whether a stationary criterion is satisfied, the stationary criterion being a criterion used to select whether to perform measurement according to a measurement relaxation method that relaxes measurement of radio quality for neighboring cells, and determining whether the user device (100) is in a stationary state; and a step of determining whether the stationary criterion is satisfied, the step of determining whether the stationary criterion is satisfied, and determining whether the stationary criterion is satisfied. control and transmitting a RRC message to the network. [Effects of the Invention]

[0011] According to one aspect of the present invention, it is possible to provide a user equipment, a base station and a communication method that enable the network to know when stationary criteria have been met. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a diagram illustrating a 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 protocol stack according to the embodiment. [Figure 3] FIG. 2 is a diagram illustrating a configuration of a UE according to an embodiment. [Figure 4] FIG. 2 is a diagram illustrating a configuration of a base station according to an embodiment. [Figure 5]4 is a sequence diagram for explaining a first operation example and a third operation example of the mobile communication system according to the embodiment. FIG. [Figure 6] FIG. 10 is a diagram illustrating an example of information according to the embodiment. [Figure 7] FIG. 10 is a diagram illustrating an example of information according to the embodiment. [Figure 8] FIG. 2 is a diagram for explaining a first operation example of the mobile communication system according to the embodiment. [Figure 9] FIG. 2 is a diagram for explaining a first operation example of the mobile communication system according to the embodiment. [Figure 10] FIG. 2 is a diagram for explaining a first operation example of the mobile communication system according to the embodiment. [Figure 11] FIG. 2 is a diagram for explaining a first operation example of the mobile communication system according to the embodiment. [Figure 12] FIG. 10 is a sequence diagram for explaining a second operation example of the mobile communication system according to the embodiment. [Figure 13] FIG. 10 is a diagram illustrating an example of information according to the embodiment. [Figure 14] FIG. 2 is a diagram for explaining a first operation example of the mobile communication system according to the embodiment. [Figure 15] FIG. 10 is a diagram illustrating an example of information according to the embodiment. [Figure 16] FIG. 10 is a diagram for explaining a third operation example of the mobile communication system according to the embodiment. [Figure 17] FIG. 10 is a diagram illustrating an example of information according to the embodiment. [Figure 18] FIG. 10 is a diagram for explaining a fourth operation example of the mobile communication system according to the embodiment. [Figure 19] FIG. 10 is a diagram illustrating an example of information according to the embodiment. [Figure 20] FIG. 10 is a sequence diagram for explaining a fifth operation example of the mobile communication system according to the embodiment. [Figure 21] FIG. 10 is a diagram for explaining a fifth operation example of the mobile communication system according to the embodiment. [Figure 22] FIG. 10 is a diagram for explaining a fifth operation example of the mobile communication system according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0013] 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.

[0014] (System Configuration) First, the configuration of a mobile communication system 1 according to this embodiment will be described with reference to Fig. 1. The mobile communication system 1 is, for example, a system that complies with the 3GPP Technical Specification (TS). In the following, the mobile communication system 1 will be described as an example of a 5th Generation System (5GS) of the 3GPP standard, i.e., a mobile communication system based on NR (New Radio).

[0015] The mobile communication system 1 includes a network 10 and user equipment (UE) 100 that communicates with the network 10. The network 10 includes a next generation radio access network (NG-RAN) 20 that is a 5G radio access network, and a 5G core network (5GC) 30 that is a 5G core network.

[0016] The UE 100 is a device used by a user. The UE 100 is a mobile device, such as a mobile phone terminal such as a smartphone, a tablet terminal, a laptop PC, a communication module, or a communication card. The UE 100 may be a vehicle (e.g., a car, a train, etc.) or a device provided therein. The UE 100 may be a transport vehicle other than a vehicle (e.g., a ship, an airplane, etc.) or a device provided therein. The UE 100 may be a sensor or a device provided therein. Note that the UE 100 may be called by other names such as a mobile station, a mobile terminal, a mobile device, a mobile unit, a subscriber station, a subscriber terminal, a subscriber device, a subscriber unit, a wireless station, a wireless terminal, a wireless device, a wireless unit, a remote station, a remote terminal, a remote device, or a remote unit.

[0017] In this embodiment, two types of UEs are assumed as the NR UE 100: a general UE 100A and a specific UE 100B having reduced communication capabilities compared to the general UE 100A. The general UE 100A has advanced communication capabilities such as enhanced Mobile Broadband (eMBB) and Ultra-Reliable and Low Latency Communications (URLLC), which are features of NR. The specific UE 100B is a UE with reduced device cost and complexity compared to the general UE 100A. The specific UE 100B is a UE 100 with mid-range performance and price for IoT. For example, compared to the general UE 100A, the maximum bandwidth used for wireless communication is set narrower and the number of receivers is reduced. The receivers are sometimes referred to as receiving branches. The specific UE 100B is sometimes referred to as a Reduced capability NR device or RedCap UE.

[0018] Specifically, the specific UE 100B may be capable of communication at a communication speed equal to or higher than the communication speed specified in an LPWA (Low Power Wide Area) standard, for example, LTE Cat.1 / 1bis, LTE Cat.M1 (LTE-M), or LTE Cat.NB1 (NB-IoT). The specific UE 100B may be capable of communication at a bandwidth equal to or higher than the bandwidth specified in the LPWA standard. The specific UE 100B may have a limited bandwidth used for communication compared to a UE of Rel-15 or Rel-16. For example, for FR1 (Frequency Range 1), the maximum bandwidth of the specific UE 100B may be 20 MHz. Furthermore, for FR2 (Frequency Range 2), the maximum bandwidth of the specific UE 100B may be 100 MHz. The specific UE 100B may have only one receiver for receiving a wireless signal. The specific UE 100B may be, for example, a wearable device, a sensor device, or the like.

[0019] The NG-RAN 20 includes multiple base stations 200. Each base station 200 manages at least one cell. A cell constitutes the smallest unit of a communication area. One cell belongs to one frequency (carrier frequency). The term "cell" may refer to wireless communication resources or to a communication target of the UE 100. Each base station 200 can perform wireless communication with the UE 100 located in its own cell. The base station 200 communicates with the UE 100 using a RAN protocol stack. Details of the protocol stack will be described later. The base station 200 is connected to other base stations 200 (which may be referred to as neighbor base stations) via an Xn interface. The base station 200 communicates with the neighbor base stations via the Xn interface. The base station 200 provides NR user plane and control plane protocol termination for the UE 100 and is connected to the 5GC 30 via an NG interface. Such an NR base station 200 is sometimes referred to as a gNodeB (gNB).

[0020] The 5GC 30 includes a core network device 300. The core network device 300 includes, for example, an Access and Mobility Management Function (AMF) and / or a User Plane Function (UPF). The AMF performs mobility management for the UE 100. The UPF provides functions specialized for U-plane processing. The AMF and the UPF are connected to the base station 200 via an NG interface.

[0021] (Example of protocol stack configuration) Next, an example of the configuration of a protocol stack according to this embodiment will be described with reference to FIG.

[0022] The protocol for the wireless section between the UE 100 and the base station 200 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 an RRC layer.

[0023] 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 base station 200 via a physical channel.

[0024] 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 base station 200 via a transport channel. The MAC layer of base station 200 includes a scheduler. The scheduler determines the uplink and downlink transport format (transport block size, modulation and coding scheme (MCS)) and the resources to be allocated to UE 100.

[0025] 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 base station 200 via logical channels.

[0026] The PDCP layer performs header compression / decompression and encryption / decryption.

[0027] An SDAP (Service Data Adaptation Protocol) layer may be provided above the PDCP layer, which maps IP flows, which are units for QoS control by the core network, to radio bearers, which are units for QoS control by the AS (Access Stratum).

[0028] The RRC layer controls logical channels, transport channels, and physical channels according to the establishment, re-establishment, and release of radio bearers. RRC signaling for various settings is transmitted between the RRC layer of the UE 100 and the RRC layer of the base station 200. When there is an RRC connection between the RRC of the UE 100 and the RRC of the base station 200, the UE 100 is in an RRC connected state. When there is no RRC connection between the RRC of the UE 100 and the RRC of the base station 200, the UE 100 is in an RRC idle state. When the RRC connection between the RRC of the UE 100 and the RRC of the base station 200 is suspended, the UE 100 is in an RRC inactive state.

[0029] The NAS layer, which is located above the RRC layer in the UE 100, performs session management and mobility management for the UE 100. NAS signaling is transmitted between the NAS layer of the UE 100 and the NAS layer of the core network device 300.

[0030] The UE 100 has an application layer and the like in addition to the radio interface protocol.

[0031] (Configuration of user device) Next, the configuration of the UE 100 according to this embodiment will be described with reference to Fig. 3. The UE 100 includes a communication unit 120 and a control unit 140.

[0032] The communication unit 120 performs wireless communication with the base station 200 by transmitting and receiving radio signals to and from the base station 200. The communication unit 120 has at least one receiving unit 121 and at least one transmitting unit 122. The receiving unit 121 and the transmitting unit 122 may be configured to include an antenna and an RF circuit. The antenna converts a signal into radio waves and radiates the radio waves into space. The antenna also receives radio waves in space and converts the radio waves into a signal. The RF circuit performs analog processing of the signal transmitted and received via the antenna. The RF circuit may include a high-frequency filter, an amplifier, a modulator, a low-pass filter, etc.

[0033] The receiving unit 121 may be referred to as a receiver (RX). The transmitting unit 122 may be referred to as a transmitter (TX). When the UE 100 is a general UE 100A, the number of receivers included in the communication unit 120 may be two to four. When the UE 100 is a specific UE 100B, the number of receivers included in the communication unit 120 may be one or two.

[0034] The control unit 140 performs various controls in the UE 100. The control unit 140 controls communication with the base station 200 via the communication unit 120. The operation of the UE 100, described below, may be controlled by the control unit 140. The control unit 140 may include at least one processor capable of executing a program and a memory that stores the program. The processor may execute the program to perform the operation of the control unit 140. The control unit 140 may include a digital signal processor that performs digital processing of signals transmitted and received via the antenna and the RF circuit. The digital processing includes processing of a RAN protocol stack. The memory stores programs executed by the processor, parameters related to the programs, and data related to the programs. The memory may include at least one of a read-only memory (ROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), a random access memory (RAM), and a flash memory. All or a part of the memory may be included in the processor.

[0035] In the UE 100 configured as described above, the communication unit 120 receives from the serving cell a stationary threshold applied to a stationary criterion, which is a criterion used to select whether or not to perform measurement according to a measurement relaxation method that relaxes measurement of radio quality for neighboring cells and is a criterion for determining whether or not the UE 100 is in a stationary state. The control unit 140 measures at least one of received power and received quality as the radio quality of the serving cell. The control unit 140 determines whether or not the stationary criterion is satisfied based on the measurement result of the radio quality and the stationary threshold. As a result, the control unit 140 can appropriately perform measurement according to the measurement relaxation method by determining whether or not the stationary criterion is satisfied based on the measurement result of the radio quality and the stationary threshold.

[0036] When the stationary threshold includes a quality threshold that is compared with a value calculated based on reception quality, the control unit 140 may determine whether the stationary criterion is satisfied based on the quality threshold, regardless of whether the stationary threshold includes a power threshold that is compared with a value calculated based on reception power. This makes it possible to determine whether the stationary criterion is satisfied, taking into account the influence of interference, noise, and the like on communication quality, compared to determining whether the stationary threshold is satisfied based on reception power, for example.

[0037] When the stationary threshold includes a quality threshold that is compared with a value calculated based on reception quality and a power threshold that is compared with a value calculated based on reception power, the control unit 140 may determine whether the stationary criterion is satisfied based on the quality threshold and the power threshold. This allows the control unit 140 to determine whether the stationary criterion is satisfied based on both reception quality and reception power, so that the stationary criterion is not satisfied when the wireless quality is poor. Therefore, it is possible to appropriately perform measurements according to the measurement relaxation method.

[0038] When the stationary threshold does not include the quality threshold but includes the power threshold, the control unit 140 may determine whether the stationary criterion is satisfied based on the power threshold. As a result, in an environment where there is no interference from neighboring cells and traffic in the own cell is low, such as an isolated cell, the stationary state can be appropriately determined only based on the received power.

[0039] When the communication unit 120 determines that the stationary criterion is satisfied, the communication unit 120 may transmit a message indicating that the stationary criterion is satisfied to the serving cell, thereby allowing the network to know that the UE 100 satisfies the stationary criterion.

[0040] If the control unit 140 determines that the stationary criterion is satisfied, the control unit 140 may select to perform measurements on neighboring cells according to the measurement mitigation method, thereby allowing the UE 100 to perform measurements on neighboring cells according to the measurement mitigation method.

[0041] The communication unit 120 receives a radio resource including a stationary threshold. control(RRC) messages may be received from the serving cell, which allows the network to control measurements according to measurement mitigation methods.

[0042] The communication unit 120 may further receive a low mobility threshold from the serving cell that applies to a low mobility criterion indicating that the user equipment is in a low mobility state. The stationary threshold may be different from the low mobility threshold.

[0043] Furthermore, the control unit 140 determines whether a stationary criterion, which is a criterion used to select whether to perform measurement according to a measurement relaxation method that relaxes measurement of radio quality for neighboring cells and is a criterion for determining whether the UE 100 is in a stationary state, is satisfied. In response to the stationary criterion being satisfied, the communication unit 120 outputs a radio resource indicating that the stationary criterion is satisfied. control The UE 100 transmits a RRC message to the network, which allows the network to know that the stationary criterion is satisfied in the UE 100. This allows the network to enable measurements according to the measurement relaxation method based on the user equipment satisfying the stationary criterion.

[0044] The RRC message may be a measurement report message for transferring the measurement result of the radio quality to the network, which can not only know that the stationary criterion is met but also know the measurement result through the measurement report message.

[0045] When a condition for joining a stationary event indicating that a stationary criterion has been met is met, the control unit 140 may include a measurement identifier associated with the identifier of the stationary event in the measurement report message, so that the network can know that the condition for joining the stationary event has been met based on the measurement identifier.

[0046] The RRC message may be a UE assistance information message used to indicate information of the UE 100 to the network, so that the network can know that the stationary criterion is met through the UE assistance information message.

[0047] The control unit 140 may include, in the UE assistance information message, state information indicating that the UE 100 is in the stationary state, which allows the network to know that the UE 100 is in the stationary state.

[0048] The communication unit 120 may receive configuration information for providing state information to the network from the network. If the control unit 140 has not transmitted a UE assistance information message since receiving the configuration information, the control unit 140 may start transmitting a UE assistance information message. This allows the network to know the stationary state of the UE 100 by transmitting the configuration information to the UE 100.

[0049] When the UE assistance information message last transmitted to the network includes state information indicating that the UE 100 is not in a stationary state, the control unit 140 may start transmitting the UE assistance information message in response to the stationary criterion being satisfied, thereby enabling the network to know that the stationary criterion is satisfied in the UE 100 that is not in a stationary state.

[0050] The control unit 140 may start a prohibition timer in response to transmission of a UE assistance information message including the state information. If the prohibition timer is running, the communication unit 120 does not need to transmit the next UE assistance information message including the state information. This eliminates the need to transmit an RRC message every time the stationary state of the UE 100 switches frequently in a short period of time, thereby reducing an increase in signaling.

[0051] The control unit 140 determines whether a stationary criterion, which is used to select whether to perform measurement according to a measurement relaxation method that relaxes measurement of radio quality for neighboring cells and is a criterion for determining whether the UE 100 is in a stationary state, is satisfied. When the stationary criterion is no longer satisfied, the communication unit 120 transmits a radio resource control (RRC) message indicating that the stationary criterion is no longer satisfied to the network. This allows the network to know that the stationary criterion is no longer satisfied.

[0052] When a condition for leaving a stationary event indicating that a stationary criterion has been satisfied is satisfied, the control unit 140 may include a measurement identifier associated with the identifier of the stationary event in the measurement report message, thereby enabling the network to know that the condition for leaving a stationary event has been satisfied based on the measurement identifier.

[0053] The control unit 140 may include, in the UE assistance information message, state information indicating that the UE 100 is not in a stationary state, which allows the network to know that the UE 100 is not in a stationary state.

[0054] When the UE assistance information message last transmitted to the network includes state information indicating that the UE 100 is in a stationary state, the control unit 140 may start transmitting the UE assistance information message in response to the stationary criterion being no longer satisfied, thereby enabling the network to know that the stationary criterion is no longer satisfied for the UE 100 in the stationary state.

[0055] The control unit 140 determines whether a stationary criterion, which is a criterion used to select whether to perform measurement according to a measurement relaxation method that relaxes measurement of radio quality for neighboring cells and is a criterion for determining whether the UE 100 is in a stationary state, and a non-cell edge criterion, which is a criterion used to select whether to perform measurement according to the measurement relaxation method and is a criterion for determining whether the UE 100 is in a non-cell edge state that is not at the cell edge of the serving cell, are satisfied. In response to both the stationary criterion and the non-cell edge criterion being satisfied, the communication unit 120 outputs a radio resource indicating that both the stationary criterion and the non-cell edge criterion are satisfied. control (RRC) message to the network, which lets the network know that both the stationary and non-cell edge criteria are met.

[0056] When a condition for joining the stationary and non-cell edge events indicating that both the stationary criterion and the non-cell edge criterion are satisfied is met, the control unit 140 may include a measurement identifier associated with the identifier of the stationary and non-cell edge event in the measurement report message, thereby enabling the network to know that the condition for joining the stationary and non-cell edge events is satisfied based on the measurement identifier.

[0057] The control unit 140 may include, in the UE assistance information message, state information indicating that the UE 100 is in a stationary state and a non-cell edge state, thereby enabling the network to know that the UE 100 is in a stationary state and a non-cell edge state.

[0058] When the UE assistance information message last transmitted to the network includes state information indicating that the UE 100 is not in a stationary state or a non-cell edge state, the control unit 140 may start transmitting the UE assistance information message in response to both the stationary criterion and the non-cell edge criterion being satisfied. This allows the network to know that both the stationary criterion and the non-cell edge criterion are satisfied for the UE 100 that is not in a stationary state or a non-cell edge state.

[0059] The control unit 140 determines whether a stationary criterion, which is a criterion used to select whether to perform measurement according to a measurement relaxation method that relaxes measurement of radio quality for neighboring cells and is a criterion for determining whether the UE 100 is in a stationary state, and a non-cell edge criterion, which is a criterion used to select whether to perform measurement according to the measurement relaxation method and is a criterion for determining whether the UE 100 is in a non-cell edge state that is not at the cell edge of the serving cell, are satisfied. When at least one of the stationary criterion and the non-cell edge criterion is no longer satisfied, the communication unit 120 transmits a radio resource control (RRC) message to the network indicating that at least one of the stationary criterion and the non-cell edge criterion is no longer satisfied. This allows the network to know that at least one of the stationary criterion and the non-cell edge criterion is no longer satisfied.

[0060] When a condition for leaving a stationary and non-cell edge event indicating that both the stationary criterion and the non-cell edge criterion are satisfied is satisfied, the control unit 140 may include a measurement identifier associated with the identifier of the stationary and non-cell edge event in the measurement report message, thereby enabling the network to know that the condition for leaving a stationary and non-cell edge event is satisfied based on the measurement identifier.

[0061] The control unit 140 may include, in the UE assistance information message, state information indicating that the UE 100 is not in a stationary state or a non-cell edge state, so that the network can know that the UE 100 is not in a stationary state or a non-cell edge state.

[0062] When the UE assistance information message last transmitted to the network includes state information indicating that the UE 100 is in a stationary state and a non-cell edge state, the control unit 140 may start transmitting the UE assistance information message in response to at least one of the stationary criterion and the non-cell edge criterion no longer being satisfied. This allows the network to know that the UE 100, which is in a stationary state and a non-cell edge state, no longer satisfies at least one of the stationary criterion and the non-cell edge criterion.

[0063] Note that the operation of the functional units (specifically, at least one of communication unit 120 and control unit 140) included in UE 100 may be described as the operation of UE 100.

[0064] (Base station configuration) Next, the configuration of the base station 200 according to this embodiment will be described with reference to Fig. 4. The base station 200 has a wireless communication unit 220, a network communication unit 230, and a control unit 240.

[0065] The wireless communication unit 220, for example, receives a wireless signal from the UE 100 and transmits a wireless signal to the UE 100. The wireless communication unit 220 may include one or more receiving units that receive the wireless signal and one or more transmitting units that transmit the wireless signal.

[0066] The network communication unit 230 transmits and receives signals to and from the network. For example, the network communication unit 230 receives signals from adjacent base stations connected via an Xn interface, which is an interface between base stations, and transmits the signals to the adjacent base stations. The network communication unit 230 also receives signals from the core network device 300 connected via an NG interface, and transmits the signals to the core network device 300.

[0067] The control unit 240 performs various controls in the base station 200. The control unit 240 controls, for example, communication with the UE 100 via the radio communication unit 220. The control unit 240 also controls, for example, communication with a node (for example, an adjacent base station or the core network device 300) via the network communication unit 230. The operation of the base station 200 described below may be an operation controlled by the control unit 240.

[0068] The control unit 240 may include at least one processor capable of executing a program and a memory that stores the program. The processor may execute the program to perform the operations of the control unit 240. The control unit 240 may include a digital signal processor that performs digital processing of signals transmitted and received via the antenna and RF circuitry. The digital processing includes processing of a RAN protocol stack. The memory stores the program executed by the processor, parameters related to the program, and data related to the program. All or a part of the memory may be included in the processor.

[0069] In the base station 200 configured as described above, the control unit 240 adjusts a stationary threshold applied to a stationary criterion, which is a criterion used for selecting whether or not to perform measurement according to a measurement relaxation method that relaxes measurement of radio quality for neighboring cells and is a criterion for determining whether or not the UE 100 is in a stationary state, by using a radio resource control The radio communication unit 220 transmits the RRC message to the user equipment, which allows the network to control measurements according to the measurement relaxation method.

[0070] Further, the wireless communication unit 220 may select whether or not to perform measurement according to a measurement relaxation method that relaxes measurement of wireless quality for a neighboring cell, and may select whether or not to perform measurement. The selection may be made based on a radio resource indicating that a stationary criterion, which is a criterion for determining whether or not the UE 100 is in a stationary state, is satisfied. control The control unit 240 receives an RRC message from the UE 100. The control unit 240 controls the measurement of the UE 100 according to the measurement mitigation method. The RRC message allows the network to know that the stationary criterion is satisfied in the UE 100. This allows the network to control the measurement of the UE 100 according to the measurement mitigation method based on the stationary criterion.

[0071] The radio communication unit 220 may transmit a stationary threshold value that applies to the stationary criterion to the UE 100. This allows the network to control measurements according to a measurement relaxation method based on the stationary criterion.

[0072] The wireless communication unit 220 is configured to select whether to perform measurement according to a measurement relaxation method that relaxes measurement of wireless quality for neighboring cells, and is configured to select whether to perform measurement according to a measurement relaxation method that relaxes measurement of wireless quality for neighboring cells. ... control The control unit 240 receives an RRC message from the UE 100. The control unit 240 controls measurements by the UE 100 according to the measurement mitigation method. The RRC message allows the network to know that the stationary criterion is no longer satisfied in the UE 100. This allows the network to control measurements by the UE 100 according to the measurement mitigation method based on the stationary criterion.

[0073] The wireless communication unit 220 outputs a radio resource indicating that a stationary criterion, which is a criterion used to select whether to perform measurement according to a measurement relaxation method that relaxes measurement of wireless quality for neighboring cells and is a criterion for determining whether the UE 100 is in a stationary state, and a non-cell edge criterion, which is used to select whether to perform measurement according to the measurement relaxation method and is a criterion for determining whether the UE 100 is in a non-cell edge state that is not at a cell edge of the serving cell, are satisfied. control The network receives an RRC message from the UE 100. The control unit 240 controls the measurement of the UE 100 according to the measurement mitigation method. This allows the network to control the measurement of the UE 100 according to the measurement mitigation method.

[0074] The radio communication unit 220 may transmit a stationary threshold applied to the stationary criterion and a non-cell edge threshold applied to the non-cell edge criterion to the UE 100. This enables the network to control measurements in accordance with the measurement relaxation method based on the stationary criterion and the non-cell edge criterion.

[0075] The wireless communication unit 220 receives a radio resource notification indicating that at least one of a stationary criterion, which is a criterion used to select whether to perform measurement according to a measurement relaxation method that relaxes measurement of wireless quality for a neighboring cell and is a criterion for determining whether the UE 100 is in a stationary state, and a non-cell edge criterion, which is a criterion used to select whether to perform measurement according to the measurement relaxation method and is a criterion for determining whether the UE 100 is in a non-cell edge state that is not at a cell edge of the serving cell, is no longer satisfied. control The network receives an RRC message from the UE 100. The control unit 240 controls measurements by the UE 100 according to the measurement mitigation method, thereby enabling the network to control measurements by the UE 100 according to the measurement mitigation method based on the stationary criterion and the non-cell edge criterion.

[0076] The operation of the functional units (specifically, at least one of the wireless communication unit 220, the network communication unit 230, and the control unit 240) included in the base station 200 may be described as the operation of the base station 200.

[0077] (System Operation) (1) First operation example 5 to 11, a first operation example of the mobile communication system 1 will be described. In the first operation example, a case will be described in which the UE 100 transmits a measurement report message to the base station 200 depending on whether the stationary criterion is satisfied.

[0078] 5, the UE 100 is in an RRC connected state between the UE 100 and the base station 200. Therefore, the UE 100 has established an RRC connection with a cell (serving cell) C managed by the base station 200.

[0079] Hereinafter, communication between UE 100 and base station 200 may be communication between UE 100 and a serving cell for UE 100. Furthermore, communication (transmission and / or reception) between UE 100 and base station 200 may be referred to as communication (transmission and / or reception) between UE 100 and a network.

[0080] Step S101: The radio communication unit 220 of the base station 200 transmits the setting information to the UE 100. The communication unit 120 of the UE 100 receives the setting information from the base station 200 (serving cell).

[0081] The wireless communication unit 220 receives wireless resources including the setting information. control A RRC message can be transmitted to the UE 100. Therefore, the configuration information may be transmitted by broadcast using a system information block (e.g., SIB2, etc.). Alternatively, the configuration information may be transmitted individually to the UE 100 using an RRC reconfiguration message, etc.

[0082] In this operation example, the configuration information includes information for configuring measurement reporting in the UE 100. The configuration information may include NR reporting configuration information (ReportConfigNR) that specifies criteria for triggering a measurement reporting event. As shown in FIGS. 6 and 7, the NR reporting configuration information (ReportConfigNR) may include measurement type information (reportType) that indicates the type of measurement report to be configured. The measurement type information (reportType) may include relaxed trigger information (relaxedMeasEventTriggered) that is used by the UE 100 to report that a relaxed measurement condition has been met. The relaxed trigger information may include an event identifier (eventId) that indicates the trigger criteria for reporting. The event identifier (eventId) may indicate a stationary event (eventS1). The event identifier may indicate a stationary and non-cell edge event (eventS2), which will be described later.

[0083] The event identifier (eventId) may include a stationary threshold T1 applied to the stationary criterion. Therefore, the control unit 240 of the base station 200 can include the stationary threshold T1 in an RRC message. This allows the communication unit 120 of the UE 100 to receive the stationary threshold T1 from the serving cell. The stationary threshold T1 may include at least one of a power threshold (s-SearchDeltaP-Stationary) that is compared with a value calculated based on the received power measured as the radio quality for the serving cell, and a quality threshold (s-SearchDeltaQ-Stationary) that is compared with a value calculated based on the received quality measured as the radio quality for the serving cell. The power threshold (s-SearchDeltaP-Stationary) is calculated based on the S-SearchDeltaQ-Stationary described later. SearchDeltaP_stationary It may be. S SearchDeltaP_stationary specifies the threshold of fluctuation of the reception level value (Srxlev) for relaxation measurement. The reception level value (Srxlev) may be the reception level value for cell selection (Cell selection RX level value). The quality threshold (s-SearchDeltaQ-Stationary) is the threshold of fluctuation of the reception level value (Srxlev) for relaxation measurement. SearchDeltaQ_stationary It may be. S SearchDeltaQ_stationary specifies a threshold of a quality value (Squal) variation for mitigation measurement. The quality value (Squal) may be a quality value for cell selection.

[0084] The event identifier (eventId) may also include period information (t-SearchDeltaP-Stationary) that specifies a predetermined period during which fluctuations in the reception level value (Srxlev) are evaluated. The period information (t-SearchDeltaP-Stationary) is SearchDeltaP_stationary The event identifier (eventId) may also include leave report information (reportOnLeave) indicating whether the UE 100 should initiate a measurement report procedure when a leave condition is met for the serving cell.

[0085] The relaxation trigger information (relaxedMeasEventTriggered) may include report interval information (reportInterval) indicating an interval of measurement reports applied to the relaxation trigger information, and may also include report amount information (reportAmount) indicating the number of measurement reports applied to the relaxation trigger information.

[0086] The configuration information may include measurement configuration information (MeasConfig) that specifies measurements to be performed by the UE 100. The configuration information may include a measurement object list (MeasObjectToAddMod) related to a list for adding or modifying a measurement object. The measurement object list (MeasObjectToAddMod) may include an NR measurement object (MeasObjectNR) specifying information applicable to intra-frequency / inter-frequency measurements of SS (synchronization signal) / PBCH (physical broadcast channel) blocks and / or CSI-RS intra-frequency / inter-frequency measurements.

[0087] The configuration information may include a measurement identifier list (measIdList / MeasIdToAddModList) related to a list for adding or modifying a measurement identifier. The measurement identifier list may include a measurement identifier (measId), a measurement object identifier (measObjectId), and a report configuration identifier (ReportConfigId). The measurement identifier (measId), the measurement object identifier (measObjectId), and the report configuration identifier (ReportConfigId) are associated with each entry.

[0088] The configuration information may include a reporting configuration list (reportConfigList / ReportConfigToAddModList) for a list of reporting configurations to add or modify. The reporting configuration list may include a reporting configuration identifier (reportConfigId) and reporting configuration information (reportConfig). The reporting configuration information (reportConfig) may include NR reporting configuration information (ReportConfigNR).

[0089] The configuration information may include a low mobility threshold that applies to a low mobility criterion that indicates that the UE 100 is in a low mobility state. This allows the UE 100 to receive the low mobility threshold from the serving cell. The low mobility threshold may include Srxlev, which specifies a threshold for Srxlev for mitigation measurements. SearchThresholdP The low mobility threshold may be S, which specifies the threshold of S for relaxation measurement. SearchThresholdQ The stillness threshold T1 may be different from the low-mobility threshold, and the lowest setting value of the stillness threshold T1 may be lower than the lowest setting value of the low-mobility threshold.

[0090] Control unit 140 of UE 100 sets the information included in the setting information. UE 100 can perform the following operations based on the set information.

[0091] Step S102: The control unit 140 of the UE 100 performs measurement and determination. Specifically, the control unit 140 measures at least one of received power and received quality as the radio quality of the serving cell. The received power may be RSRP (Reference Signal Received Power). The received quality may be RSRQ (Reference Signal Received Quality). The control unit 140 measures the radio quality by measuring a reference signal (RS) from the serving cell.

[0092] The control unit 140 of the UE 100 determines whether a stationary criterion is satisfied based on the measurement result of the radio quality and the stationary threshold T1. The stationary criterion is a criterion used to select whether to perform measurement according to a measurement relaxation method that relaxes measurement of the radio quality of neighboring cells, and is a criterion for determining whether the UE 100 is in a stationary state. The control unit 140 may use either a first method or a second method as a method for determining whether the stationary criterion is satisfied.

[0093] In a first method, when the stationary threshold T1 includes a quality threshold, the control unit 140 may determine whether the stationary criterion is satisfied based on the quality threshold, regardless of whether the stationary threshold T1 includes a power threshold. As shown in E1 of FIG. 8, when the stationary threshold T1 includes a quality threshold, that is, when the stationary threshold T1 includes a power threshold, the control unit 140 may determine whether the stationary criterion is satisfied based on the quality threshold. SearchDeltaQ_stationary When S is set, the control unit 140 may determine whether the following equation is satisfied as a stationary criterion. SearchDeltaQ_stationary is applied to the following stationary criteria: (Squal Ref - Squal) < S SearchDeltaQ_stationary

[0094] Squal is the current Squal value of the serving cell. Ref is the reference Squal value of the serving cell. The reference Squal value is determined (i) after a new cell selection or reselection, and (ii) after (Squal - Squal Ref ) > 0, or (iii) the stationary criterion is satisfied for a predetermined period (T SearchDeltaP_stationary ) is not satisfied, the control unit 140 of the UE 100 Ref may be set to the serving cell's current Squal value.

[0095] The Squal value is calculated using the following formula: Squal = Q qualmeas - (Q qualmin + Q qualminoffset ) - Qoffset temp

[0096] Q qualmeas is the measured cell quality level (RSRQ). Q qualmin is the minimum required quality level. qualminoffset is a constant applied predetermined offset. temp is the offset that is applied temporarily.

[0097] Furthermore, when the rest threshold T1 does not include the quality threshold but does include the power threshold, the control unit 140 may determine whether the rest criterion is satisfied based on the power threshold. As shown in E2 of FIG. 8, when the rest threshold T1 does not include the quality threshold but does include the power threshold, the control unit 140 may determine whether the following formula is satisfied as the rest criterion. SearchDeltaP_stationary is applied to the following stationary criteria: (Srxlev Ref - Srxlev) < S SearchDeltaP_stationary

[0098] Srxlev is the current Srxlev value of the serving cell. Ref is the reference Srxlev value of the serving cell. The reference Srxlev value is (i) after a new cell selection or reselection, and (ii) after (Srxlev - Srxlev Ref ) > 0, or (iii) the stationary criterion is satisfied for a predetermined period (T SearchDeltaP_stationary ) is not satisfied, the control unit 140 of the UE 100 Ref may be set to the serving cell's current Srxlev value.

[0099] The Srxlev value is calculated using the following formula: Srxlev = Q rxlevmeas - (Q rxlevmin + Q rxlevminoffset )- P compensation - Qoffset temp

[0100] Q rxlevmeas is the measured cell received power (RSRP). Q rxlevmin is the minimum required received power. Q rxlevminoffset is a constant applied predetermined offset. compensation is a parameter related to uplink capacity. temp is the offset that is applied temporarily.

[0101] In a second method, when the stationary threshold T1 includes a quality threshold and a power threshold, the control unit 140 may determine whether the stationary criterion is satisfied based on the quality threshold and the power threshold. As shown in E3 of FIG. 9, when the stationary threshold T1 includes a quality threshold and a power threshold, that is, when the stationary threshold T1 includes a quality threshold and a power threshold, the control unit 140 may determine whether the stationary criterion is satisfied based on the quality threshold and the power threshold. SearchDeltaQ_stationary is set, and S is set as the power threshold in the UE 100. SearchDeltaP_stationary When S is set, the control unit 140 may determine whether the following equation is satisfied as a stationary criterion. SearchDeltaQ_stationary and S SearchDeltaP_stationary is applied to the following stationary criteria: (Srxlev Ref - Srxlev) < S SearchDeltaP_stationary and (Squal Ref - Squal) < S SearchDeltaQ_stationary

[0102] Furthermore, when the rest threshold T1 does not include the quality threshold but does include the power threshold, the control unit 140 may determine whether the rest criterion is satisfied based on the power threshold. As shown in E4 of FIG. 9, when the rest threshold T1 does not include the quality threshold but does include the power threshold, the control unit 140 may determine whether the following formula is satisfied as the rest criterion. SearchDeltaP_stationary is applied to the following stationary criteria: (Srxlev Ref - Srxlev) < S SearchDeltaP_stationary

[0103] As shown in A1 of Fig. 10, the control unit 140 may determine that the condition for joining the stationary event is met when a condition S1-1 is met. The condition S1-1 is: (i) the UE 100 is in a stationary state for at least a predetermined period (T SearchDeltaP_stationary ), a normal measurement of radio quality for an intra-frequency cell, a normal measurement of radio quality for an NR inter-frequency cell, or a normal measurement of radio quality for an inter-RAT cell has been performed, and (ii) a predetermined period (T SearchDeltaP_stationary ), the stationary criterion may be met.

[0104] As shown in A2 of FIG. 10, when the condition S1-2 is satisfied, the control unit 140 may determine that the condition for leaving the stationary event is satisfied. The condition S1-2 is a condition for leaving the stationary event for a predetermined period (T SearchDeltaP_stationary ), the stationary criterion may no longer be met.

[0105] As shown in A3 of FIG. 10, the control unit 140 may target the serving cell corresponding to the NR measurement object (MeasObjectNR) associated with the stationary event for this measurement.

[0106] Also, as shown in B1 of Figure 11, in UE100, for each measurement identifier (measId) included in the measurement identifier list (measIdList) included in the variable measurement configuration information (VarMeasConfig), if the corresponding reporting configuration information (reportConfig) includes measurement type information (reportType) set to relaxed trigger information (relaxedMeasEventTriggered) and the corresponding measurement object information (measObject) is related to NR, UE100 may consider it to apply only to the serving cell.

[0107] As shown in B2 of Fig. 11, when the variable measurement report list (VarMeasReportList) does not include a measurement report entry for this measurement identifier, but the measurement type information (reportType) is set to relaxed trigger information (relaxedMeasEventTriggered) and the subscription condition for the event indicated by the event identifier is satisfied, the control unit 140 of the UE 100 may perform the following operation: Note that the variable measurement report list (VarMeasReportList) for each measurement identifier may include a measurement identifier (measId), a cell trigger list (cellsTriggeredList), and report number information (numberOfReportsSent).

[0108] The control unit 140 may include a measurement report entry in the variable measurement report list (VarMeasReportList) for this measurement identifier. The control unit 140 may set the number of reports information (numberOfReportsSent) defined in the variable measurement report list (VarMeasReportList) for this measurement identifier to 0. The control unit 140 may include information of the serving cell in the cell triggered list (cellsTriggeredList) defined in the variable measurement report list (VarMeasReportList) for this measurement identifier. The control unit 140 may also initiate a measurement reporting procedure.

[0109] In the following description, it is assumed that the control unit 140 determines that the stationary criterion is met, specifically, that the condition for joining the stationary event is met.

[0110] Step S103: The communication unit 120 of the UE 100 transmits the measurement report message to the serving cell (base station 200, network). The radio communication unit 220 of the base station 200 receives the measurement report message.

[0111] The communication unit 120 may transmit a measurement report message to the serving cell (network) in response to the stationary criterion being met. The measurement report message may indicate that the stationary criterion has been met.

[0112] The measurement report message is control The measurement report message is a RRC (Reporting Control Message) message. The measurement report message may be a message for transferring measurement results of radio quality to the network. The measurement report message includes measurement result information (MeasResults). The measurement result information (MeasResults) may include a measurement identifier associated with an identifier (event identifier) ​​of a stationary event and the measurement results of the radio quality of the serving cell. When a subscription condition for a stationary event indicating that a stationary criterion has been met is met, the control unit 140 may include a measurement identifier associated with the identifier (event identifier) ​​of the stationary event in the measurement report message.

[0113] Based on the measurement report message, control unit 240 of base station 200 may select whether to cause UE 100 to perform measurement (hereinafter referred to as relaxed measurement) according to a measurement relaxation method that relaxes measurement of radio quality for neighboring cells. In this way, control unit 240 determines whether to cause UE 100 to perform relaxed measurement and controls the relaxed measurement.

[0114] When the control unit 240 selects to have the UE 100 perform mitigation measurement, the control unit 240 can execute the process of step S104. When the measurement report message includes a measurement identifier associated with the identifier (event identifier) ​​of the stationary event and the UE 100 is not performing mitigation measurement (for example, the control unit 240 has not caused the UE 100 to perform mitigation measurement), the control unit 240 can determine that the subscription condition for the stationary event is satisfied. Furthermore, the control unit 240 may determine whether or not the stationary criterion is satisfied based on the measurement result included in the measurement report message. The control unit 240 can determine whether or not the stationary criterion is satisfied, for example, from the stationary threshold value transmitted to the UE 100 and the measurement result.

[0115] When the condition for joining the stationary event is satisfied, the control unit 240 may determine that the mitigation measurement condition for causing the UE 100 to perform the mitigation measurement is satisfied, and may select to cause the UE 100 to perform the mitigation measurement. When the control unit 240 selects to cause the UE 100 to perform the mitigation measurement, the control unit 240 can perform the following processing.

[0116] Step S104: The radio communication unit 220 of the base station 200 transmits a mitigation measurement instruction to the UE 100 to cause the UE 100 to perform the mitigation measurement. The communication unit 120 of the UE 100 receives the mitigation measurement instruction from the serving cell.

[0117] The mitigation measurement instruction may be individually transmitted to the UE 100 by an RRC reconfiguration message or the like. The mitigation measurement instruction may include, for example, measurement configuration information (MeasConfig) for causing the UE 100 to perform the mitigation measurement. The mitigation measurement instruction may be an instruction for enabling the execution of the mitigation measurement. Note that the mitigation measurement instruction may include a parameter for multiplying the allowable time, which will be described later, by a predetermined factor.

[0118] Step S105: Control unit 140 of UE 100 performs relaxation measurement on neighboring cells in accordance with the relaxation measurement instruction. For example, when relaxation measurement is performed, an allowed time for detecting neighboring cells may be multiplied by a predetermined factor, an allowed time for measuring neighboring cells may be multiplied by a predetermined factor, or an allowed time for evaluating neighboring cells may be multiplied by a predetermined factor.

[0119] The neighboring cell is a cell different from the serving cell, and is at least one of an intra-frequency cell, an NR inter-frequency cell, and an inter-RAT frequency cell.

[0120] Step S106: The control unit 140 of the UE 100 performs measurement and determination in the same manner as in step S102. The control unit 140 may execute the process of step S107 when the condition for leaving the stationary event is satisfied. Therefore, the control unit 140 may execute the process of step S107 when the stationary criterion is no longer satisfied.

[0121] The control unit 140 may execute the process of step S107 based on the leave report information (reportOnLeave) included in the event identifier (eventId) indicating the stationary event. The control unit 140 may execute the process of step S107 when the leave report information (reportOnLeave) indicates that the UE 100 should start the measurement report procedure when the leave condition is satisfied for the serving cell.

[0122] As shown in B3 of Figure 11, when the measurement type information (reportType) is set to relaxed trigger information (relaxedMeasEventTriggered) and the condition for leaving the event indicated by the event identifier is met for a serving cell included in the cell trigger list (cellsTriggeredList) specified in the variable measurement report list (VarMeasReportList) for this measurement identifier, the control unit 140 of UE100 may perform the following operations.

[0123] The control unit 140 may delete the serving cell information specified in the variable measurement report list (VarMeasReportList) for this measurement identifier. The control unit 140 may also start a measurement reporting procedure if the leave report information (reportOnLeave) is set to "true" in the corresponding reporting configuration. The control unit 140 may also delete the measurement report entry in the variable measurement report list (VarMeasReportList) for this measurement identifier if the cell trigger list (cellsTriggeredList) specified in the variable measurement report list (VarMeasReportList) for this measurement identifier is empty. If a periodic reporting timer for this measurement identifier is running, the control unit 140 may stop the reporting timer.

[0124] Step S107: The communication unit 120 of the UE 100 transmits the measurement report message to the serving cell (base station 200, network) in the same manner as in step S103. The radio communication unit 220 of the base station 200 receives the measurement report message.

[0125] In response to the stationary criterion no longer being met, the communication unit 120 may transmit a measurement report message to the serving cell (network). The measurement report message may indicate that the stationary criterion is no longer being met.

[0126] When the condition for leaving the stationary event is met, the control unit 140 may include a measurement identifier associated with the identifier (event identifier) ​​of the stationary event in the measurement report message.

[0127] Similar to step S103, the control unit 240 of the base station 200 may select whether or not to cause the UE 100 to perform mitigation measurement based on the measurement report message.

[0128] When the control unit 240 selects not to cause the UE 100 to perform mitigation measurement, the control unit 240 can execute the process of step S108. When the measurement report message includes a measurement identifier associated with the identifier (event identifier) ​​of the stationary event and the UE 100 is performing mitigation measurement (for example, when the control unit 240 has caused the UE 100 to perform mitigation measurement), the control unit 240 can determine that the condition for leaving the stationary event is satisfied. Furthermore, the control unit 240 may determine whether the stationary criterion is satisfied based on the measurement result included in the measurement report message.

[0129] When the condition for leaving the stationary event is satisfied, the control unit 240 may determine that the mitigation measurement condition for causing the UE 100 to perform the mitigation measurement is no longer satisfied, and may select not to cause the UE 100 to perform the mitigation measurement. When the control unit 240 selects not to cause the UE 100 to perform the mitigation measurement, the control unit 240 can execute the following process.

[0130] Step S108: The radio communication unit 220 of the base station 200 transmits a normal measurement instruction to the UE 100 to prevent the UE 100 from performing the relaxed measurement. The communication unit 120 of the UE 100 receives the normal measurement instruction from the serving cell.

[0131] The normal measurement instruction may be individually transmitted to the UE 100 by an RRC reconfiguration message or the like. The normal measurement instruction may include, for example, measurement configuration information (MeasConfig) for preventing the UE 100 from performing mitigation measurements. The mitigation measurement instruction may be an instruction to disable the performance of mitigation measurements.

[0132] In accordance with the normal measurement instruction, control unit 140 of UE 100 ends the execution of mitigation measurement on the neighboring cell, and then starts normal measurement on the neighboring cell.

[0133] (2) Second operation example 12 to 15, the second operation example will be described, focusing on differences from the above-described operation example. In the second operation example, a case will be described in which the UE 100 transmits a UE assistance information message to the base station 200 depending on whether the stationary criterion is satisfied.

[0134] Step S201: 12, similarly to step S101, radio communication unit 220 of base station 200 transmits the setting information to UE 100. Communication unit 120 of UE 100 receives the setting information from base station 200 (serving cell).

[0135] In this operation example, as shown in Fig. 13, the configuration information may include status configuration information (stationaryStatusConfig) for configuring the UE 100 to report auxiliary information to notify the base station 200 of the stationary state detected by the UE 100. The status configuration information may include a setting value (stationaryStatusProhibitTimer) of a prohibit timer for reporting status information. The prohibit timer (Txxx) starts in response to transmission of a UE auxiliary information message including status information described below. The prohibit timer (Txxx) stops in response to release of the status configuration information (stationaryStatusConfig) or reception of information for releasing the status configuration information (stationaryStatusConfig).

[0136] The setting information may also include a stationary threshold T1. The status setting information (stationaryStatusConfig) may include a stationary threshold T1.

[0137] Control unit 140 of UE 100 sets the information included in the setting information. UE 100 can perform the following operations based on the set information.

[0138] Step S202: The control unit 140 of the UE 100 performs measurement and determination in the same manner as in step S102. The control unit 140 may determine that the UE 100 is in a stationary state when the stationary criterion is satisfied. On the other hand, the control unit 140 may determine that the UE 100 is not in a stationary state when the stationary criterion is not satisfied.

[0139] 14, when the control unit 140 of the UE 100 is configured to provide the stationary status information indicating whether or not the UE 100 is in the stationary state in the RRC connected state, and the control unit 140 is configured to provide the status information, the control unit 140 may perform the following operation when the UE 100 enters or leaves the stationary state. Note that the UE 100 may be configured to provide the status information based on the status setting information.

[0140] The control unit 140 may start transmitting a UE assistance information message if no UE assistance information message has been transmitted since receiving the state setting information. Furthermore, the control unit 140 may start transmitting a UE assistance information message in response to the stationary criterion being satisfied if the UE assistance information message last transmitted to the network included state information indicating that the UE 100 is not in a stationary state. Furthermore, the control unit 140 may start transmitting a UE assistance information message in response to the stationary criterion being no longer satisfied if the UE assistance information message last transmitted to the network included state information indicating that the UE 100 is in a stationary state.

[0141] Furthermore, the control unit 140 may start a prohibition timer in response to transmission of a UE assistance information message including the status information. If the prohibition timer is running, the communication unit 120 may not transmit the next UE assistance information message including the status information.

[0142] 14, the controller 140 may start a prohibit timer with a timer value set to a stationaryStatusProhibitTimer if (i) the controller 140 has not transmitted a UE assistance information message including status information since being configured to provide the status information, or (ii) the controller 140's current stationary status is different from the status indicated by the last transmitted UE assistance information message including status information and the prohibit timer is not running. The controller 140 may also start transmitting a UE assistance information message to provide the status information.

[0143] 14 and 15, when the control unit 140 starts transmitting a UE assistance information message to provide the status information, the control unit 140 includes the status information in the UE assistance information message. The status information indicates whether the UE 100 is in a stationary state. In this operation example, the status information indicates that the UE 100 is in a stationary state.

[0144] Step S203: The communication unit 120 of the UE 100 transmits the UE assistance information message to the serving cell (base station 200, network). The communication unit 120 can transmit the UE assistance information message to the serving cell (network) in response to the stationary criterion being satisfied. The wireless communication unit 220 of the base station 200 receives the UE assistance information message.

[0145] The UE assistance information message control The UE assistance information message may be a RRC message. The UE assistance information message may be a message used to indicate information about the UE 100 to the network. The UE assistance information message may indicate that the stationary criterion is met by state information indicating whether the UE 100 is in a stationary state.

[0146] Based on the UE assistance information message, control unit 240 of base station 200 may select whether to cause UE 100 to perform mitigation measurement. If control unit 240 selects to cause UE 100 to perform mitigation measurement, it can execute the process of step S204. If the UE assistance information message includes state information indicating that UE 100 is in a stationary state, control unit 240 may select to cause UE 100 to perform mitigation measurement.

[0147] Steps S204 and S205: This is the same as steps S104 and S105.

[0148] Step S206: Control unit 140 of UE 100 performs measurement and determination in the same manner as in step S202. Here, the description will proceed on the assumption that control unit 140 determines that the stationary criterion is no longer satisfied and that UE 100 is not in a stationary state.

[0149] The controller 140 may initiate transmission of the UE assistance information message if (ii) the inhibit timer is not running because the current stationary state is different from the state indicated by the last transmitted UE assistance information message containing the state information. The controller 140 includes state information in the UE assistance information message indicating that the UE 100 is not in the stationary state.

[0150] Step S207: The communication unit 120 of the UE 100 transmits a UE assistance information message to the serving cell (base station 200, network). The communication unit 120 can transmit the UE assistance information message to the serving cell (network) in response to the stationary criterion no longer being satisfied. The wireless communication unit 220 of the base station 200 receives the UE assistance information message.

[0151] Based on the UE assistance information message, control unit 240 of base station 200 may select whether to cause UE 100 to perform mitigation measurement. If control unit 240 selects not to cause UE 100 to perform mitigation measurement, it can execute the process of step S208. If the UE assistance information message includes state information indicating that UE 100 is not in a stationary state, control unit 240 may select not to cause UE 100 to perform mitigation measurement.

[0152] Steps S208 and S209: This is the same as steps S108 and S109.

[0153] (3) Third operation example 5 to 7 and 16, the third operation example will be described, focusing on the differences from the above operation examples. In the third operation example, the stationary and non-cell edge events (event S2) will be described. The sequence in this operation example is the same as that in the first operation example.

[0154] The event identifier may indicate a stationary or non-cell edge event (eventS2) described below. As shown in Figure 6, the event identifier (eventId) may include a stationary threshold T1 applied to the stationary criterion and a non-cell edge threshold T2 applied to the non-cell edge criterion.

[0155] The non-cell edge threshold T2 may include at least one of a power threshold (s-SearchThresholdP) that is compared with a value calculated based on the received power measured as the radio quality for the serving cell, and a quality threshold (s-SearchThresholdQ) that is compared with a value calculated based on the received quality measured as the radio quality for the serving cell.

[0156] The power threshold (s-SearchThresholdP) is SearchThresholdP The network may be configured such that the power threshold (s-SearchThresholdP) is IntraSearchP and S nonIntraSearchP It may be set to the following value: S IntraSearchPspecifies the Srxlev threshold for intra-frequency cell measurements. S nonIntraSearchP specifies the threshold of Srxlev for NR inter-frequency cell measurements and inter-RAT cell measurements. The quality threshold (s-SearchThresholdQ) is SearchThresholdQ The network may be configured such that the quality threshold (s-SearchThresholdQ) is IntraSearchQ and S nonIntraSearchQ It may be set to the following value: S IntraSearchQ specifies the Squal threshold for intra-frequency cell measurements. nonIntraSearchQ Specifies the Squal threshold for NR inter-frequency cell measurements and inter-RAT cell measurements.

[0157] Step S102: The control unit 140 of the UE 100 performs measurement and determination. The control unit 140 determines whether or not a stationary criterion is satisfied based on the measurement result of the radio quality and the stationary threshold T1. In addition, the control unit 140 determines whether or not a non-cell edge criterion is satisfied based on the measurement result of the radio quality and the non-cell edge threshold T2. The non-cell edge criterion is a criterion used to select whether or not to perform measurement according to a measurement relaxation method that relaxes measurement of the radio quality of neighboring cells, and is a criterion for determining whether or not the UE 100 is in a non-cell edge state, that is, not at the cell edge of the serving cell. As a method for determining whether or not the non-cell edge criterion is satisfied, the control unit 140 may determine whether or not the following formula is satisfied: Srxlev > S SearchThresholdP and Squal > S SearchThresholdQ

[0158] S SearchThresholdQ If not set, Squal > S SearchThresholdQ That is, the control unit 140 does not need to determine whether Srxlev > S SearchThresholdP is satisfied.

[0159] As shown in B1 of FIG. 16, the control unit 140 may determine that the stationary and non-cell edge event conditions are satisfied when a condition S2-1 is satisfied. The condition S2-1 is (i) whether the UE 100 has been stationary for at least a predetermined period (T SearchDeltaP_stationary ), a normal measurement of radio quality for an intra-frequency cell, a normal measurement of radio quality for an NR inter-frequency cell, or a normal measurement of radio quality for an inter-RAT frequency cell has been performed; (ii) a predetermined period (T SearchDeltaP_stationary ), the stationary criterion is met, and (iii) the non-cell edge criterion is met.

[0160] As shown in B2 of FIG. 16, when condition S2-2 is satisfied, the control unit 140 may determine that the stationary and non-cell edge event withdrawal conditions are satisfied. Condition S2-2 is a condition for determining whether the joining condition is satisfied after (i) a predetermined period (T SearchDeltaP_stationary ), the stationary criterion is no longer met, or (ii) the non-cell edge criterion is no longer met.

[0161] As shown in B3 of FIG. 16, for this measurement, the control unit 140 may target the serving cell corresponding to the NR measurement object (MeasObjectNR) associated with the stationary and non-cell edge events.

[0162] Step S103: The communication unit 120 may transmit a measurement report message to the serving cell (network) in response to both the stationary criterion and the non-cell edge criterion being met.

[0163] The measurement report message includes measurement result information (MeasResults). The measurement result information (MeasResults) may include a measurement identifier associated with an identifier (event identifier) ​​of the stationary and non-cell edge events, and a measurement result of the radio quality of the serving cell. When the subscription conditions for the stationary and non-cell edge events are met, the control unit 140 may include the measurement identifier associated with the identifier (event identifier) ​​of the stationary event in the measurement report message. The measurement report message may indicate that both the stationary criterion and the non-cell edge criterion are met by the measurement identifier.

[0164] When the measurement report message includes a measurement identifier associated with an identifier (event identifier) ​​of a stationary and non-cell edge event and UE 100 is not performing mitigation measurement (for example, UE 100 is not caused to perform mitigation measurement), control unit 240 of base station 200 can determine that the conditions for joining the stationary and non-cell edge events are satisfied. Furthermore, control unit 240 may determine whether or not both the stationary criterion and the non-cell edge criterion are satisfied based on the measurement result included in the measurement report message. Control unit 240 can determine whether or not both the stationary criterion and the non-cell edge criterion are satisfied, for example, from the stationary threshold T1 and the non-cell edge threshold T2 transmitted to UE 100 and the measurement result.

[0165] When the conditions for joining the stationary and non-cell edge events are satisfied, the control unit 240 may determine that the mitigation measurement conditions for causing the UE 100 to perform the mitigation measurement are satisfied, and may select to cause the UE 100 to perform the mitigation measurement. When the control unit 240 selects to cause the UE 100 to perform the mitigation measurement, the control unit 240 can execute the process of step S104.

[0166] Step S104: The radio communication unit 220 of the base station 200 transmits a mitigation measurement instruction to the UE 100 to cause the UE 100 to perform the mitigation measurement. The communication unit 120 of the UE 100 receives the mitigation measurement instruction from the serving cell.

[0167] The relaxed measurement instruction may be, for example, an instruction to relax measurement more than in the first operation example. The relaxed measurement instruction may be, for example, an instruction to increase the parameter for multiplying the allowed time by a predetermined factor higher than in the first operation example. The relaxed measurement instruction may be an instruction to allow no measurement on neighboring cells.

[0168] Step S105: Control unit 140 of UE 100 performs mitigation measurement on neighboring cells in accordance with the mitigation measurement instruction.

[0169] Step S106: The control unit 140 of the UE 100 performs measurement and determination in the same manner as in step S102. The control unit 140 may execute the process of step S107 when the stationary condition and the condition for leaving the non-cell edge event are satisfied. Therefore, the control unit 140 may execute the process of step S107 when at least one of the stationary criterion and the non-cell edge criterion is no longer satisfied.

[0170] The control unit 140 may execute the process of step S107 based on the leave report information (reportOnLeave) included in the event identifier (eventId) indicating the stationary and non-cell edge event. The control unit 140 may execute the process of step S107 when the leave report information (reportOnLeave) indicates that the UE 100 should start the measurement report procedure when the leave condition is satisfied for the serving cell.

[0171] Step S107: The communication unit 120 of the UE 100 transmits the measurement report message to the serving cell (base station 200, network) in the same manner as in step S103. The radio communication unit 220 of the base station 200 receives the measurement report message.

[0172] The communication unit 120 can transmit a measurement report message to the serving cell (network) in response to at least one of the stationary criterion and the non-cell edge criterion no longer being satisfied. The measurement report message may indicate that at least one of the stationary criterion and the non-cell edge criterion no longer being satisfied.

[0173] When the conditions for leaving the stationary and non-cell edge events are met, the control unit 140 may include a measurement identifier associated with the identifier (event identifier) ​​of the stationary and non-cell edge event in the measurement report message.

[0174] Similar to step S103, the control unit 240 of the base station 200 may select whether or not to cause the UE 100 to perform mitigation measurement based on the measurement report message.

[0175] When the control unit 240 selects not to cause the UE 100 to perform mitigation measurement, the control unit 240 can execute the process of step S108. When the measurement report message includes a measurement identifier associated with an identifier (event identifier) ​​of the stationary and non-cell edge event and the UE 100 is performing mitigation measurement (for example, when the control unit 240 has caused the UE 100 to perform mitigation measurement), the control unit 240 can determine that the condition for leaving the stationary and non-cell edge event is satisfied. Furthermore, the control unit 240 may determine whether at least one of the stationary criterion and the non-cell edge criterion is no longer satisfied, based on the measurement result included in the measurement report message.

[0176] When the condition for leaving the stationary event is satisfied, the control unit 240 may determine that the mitigation measurement condition for causing the UE 100 to perform the mitigation measurement is no longer satisfied, and may select not to cause the UE 100 to perform the mitigation measurement. When the control unit 240 selects not to cause the UE 100 to perform the mitigation measurement, the control unit 240 can execute the following process.

[0177] Step S108: This is the same as step S108 in the first operation example.

[0178] (4) Fourth operation example 12 and 17 to 19, the third operation example will be described, focusing mainly on the differences from the above operation examples. In the fourth operation example, a case will be described in which UE 100 transmits a UE assistance information message to base station 200 depending on whether both the stationary criterion and the non-cell edge criterion are satisfied, or whether the stationary criterion and the non-cell edge criterion are satisfied. The sequence in this operation example is the same as that in the second operation example.

[0179] Step S201: 12, similarly to step S101, radio communication unit 220 of base station 200 transmits the setting information to UE 100. Communication unit 120 of UE 100 receives the setting information from base station 200 (serving cell).

[0180] In this operation example, as shown in Fig. 13 , the configuration information may include status configuration information (stationaryAndNot-at-cell-edgeStatusConfig) for configuring UE 100 to report auxiliary information to notify base station 200 of the stationary state and non-cell edge state detected by UE 100. The status configuration information may include a setting value (stationaryAndNot-at-cell-edgeStatusProhibitTimer) of a prohibit timer for reporting status information. The prohibit timer (Tyyy) starts in response to transmission of a UE auxiliary information message including status information described below. The prohibit timer (Tyyy) stops in response to release of the status configuration information (stationaryAndNot-at-cell-edgeStatusConfig) or reception of information for releasing the status configuration information (stationaryAndNot-at-cell-edgeStatusConfig).

[0181] Furthermore, the configuration information may include a stationary threshold T1 and a non-cell edge threshold T2. The status configuration information (stationaryAndNot-at-cell-edgeStatusConfig) may include a stationary threshold T1 and a non-cell edge threshold T2.

[0182] Control unit 140 of UE 100 sets the information included in the setting information. UE 100 can perform the following operations based on the set information.

[0183] Step S202: The control unit 140 of the UE 100 performs measurement and determination in the same manner as in step S102. The control unit 140 may determine that the UE 100 is in a stationary state when the stationary criterion is satisfied. On the other hand, the control unit 140 may determine that the UE 100 is not in a stationary state when the stationary criterion is not satisfied. Furthermore, the control unit 140 may determine that the UE 100 is in a non-cell edge state when the non-cell edge criterion is satisfied. On the other hand, the control unit 140 may determine that the UE 100 is not in a non-cell edge state when the non-cell edge criterion is not satisfied.

[0184] As shown in FIG. 18 , control unit 140 of UE 100 capable of providing status information (stationary and not-at-cell-edge status information) indicating whether or not the UE is in a stationary state and whether or not the UE is in a non-at-cell-edge state in the RRC connected state may perform the following operation when UE 100 is configured to provide the status information and enters or leaves the stationary state. Note that UE 100 may be configured to provide the status information based on the status setting information.

[0185] The control unit 140 may start transmitting a UE assistance information message if no UE assistance information message has been transmitted since receiving the state setting information. Furthermore, if the UE assistance information message last transmitted to the network included state information indicating that the UE 100 is not in a stationary state or a non-cell edge state, the control unit 140 may start transmitting a UE assistance information message in response to both the stationary criterion and the non-cell edge criterion being satisfied. Furthermore, if the UE assistance information message last transmitted to the network included state information indicating that the UE 100 is in a stationary state and a non-cell edge state, the control unit 140 may start transmitting a UE assistance information message in response to at least one of the stationary criterion and the non-cell edge criterion no longer being satisfied.

[0186] Furthermore, the control unit 140 may start a prohibition timer in response to transmission of a UE assistance information message including the status information. If the prohibition timer is running, the communication unit 120 may not transmit the next UE assistance information message including the status information.

[0187] 18, the control unit 140 may start a prohibit timer with a timer value set to a setting value (StationaryAndNot-at-cell-edgeStatusProhibitTimer) if (i) a UE assistance information message including status information has not been transmitted since being configured to provide status information, or (ii) the current stationary or non-cell edge status is different from the status indicated by the last transmitted UE assistance information message including status information and the prohibit timer is not running. Also, the control unit 140 may start transmission of a UE assistance information message to provide the status information.

[0188] 18 and 19, when control unit 140 starts transmission of a UE assistance information message to provide state information, control unit 140 includes the state information in the UE assistance information message. The state information indicates that UE 100 is in a stationary state and a non-cell edge state, or that UE 100 is not in a stationary state or a non-cell edge state. Furthermore, the state information may indicate that UE 100 is no longer in a state of being in a stationary state and a non-cell edge state, or may indicate that UE 100 is in at least one of a state of not being in a stationary state and a state of not being in a non-cell edge state.

[0189] Step S203: The communication unit 120 of the UE 100 transmits the UE assistance information message to the serving cell (base station 200, network). The communication unit 120 can transmit the UE assistance information message to the serving cell (network) when both the stationary criterion and the non-cell edge criterion are satisfied. The radio communication unit 220 of the base station 200 receives the UE assistance information message.

[0190] The UE assistance information message may indicate that the status information indicates that both the stationary criterion and the non-cell edge criterion are met.

[0191] Based on the UE assistance information message, control unit 240 of base station 200 may select whether to cause UE 100 to perform mitigation measurement. If control unit 240 selects to cause UE 100 to perform mitigation measurement, it can execute the process of step S204. If the UE assistance information message includes state information indicating that UE 100 is in a stationary state and a non-cell edge state, control unit 240 may select to cause UE 100 to perform mitigation measurement.

[0192] Steps S204 and S205: This is the same as steps S104 and S105.

[0193] Step S206: Control unit 140 of UE 100 performs measurement and determination in the same manner as in step S202. Here, the description will proceed assuming that control unit 140 determines that at least one of the stationary criterion and the non-cell edge criterion is no longer satisfied.

[0194] The control unit 140 may start transmitting the UE assistance information message if (ii) the prohibit timer is not running because the current stationary state or non-cell edge state is different from the state indicated by the last transmitted UE assistance information message including the state information. The control unit 140 includes state information indicating that the UE 100 is not in the stationary state or non-cell edge state in the UE assistance information message.

[0195] Step S207: The communication unit 120 of the UE 100 transmits a UE assistance information message to the serving cell (base station 200, network). The communication unit 120 can transmit the UE assistance information message to the serving cell (network) in response to at least one of the stationary criterion and the non-cell edge criterion no longer being satisfied. The radio communication unit 220 of the base station 200 receives the UE assistance information message.

[0196] Based on the UE assistance information message, control unit 240 of base station 200 may select whether to cause UE 100 to perform mitigation measurement. If control unit 240 selects not to cause UE 100 to perform mitigation measurement, it can execute the process of step S208. If the UE assistance information message includes state information indicating that UE 100 is not in a stationary state or a non-cell edge state, control unit 240 may select not to cause UE 100 to perform mitigation measurement.

[0197] Steps S208 and S209: This is the same as steps S108 and S109.

[0198] (5) Fifth operation example 20 to 22, the fifth operation example will be described, mainly focusing on differences from the above-described operation examples. In the fifth operation example, the UE 100 selects to perform measurements on neighboring cells according to the measurement relaxation method depending on whether the stationary criterion is satisfied.

[0199] Steps S301 and S302: This is the same as steps S101 and S102 or S201 and S202.

[0200] The control unit 140 may determine whether to select to perform relaxation measurements in the following manner.

[0201] As shown in FIG. 21 , when the configuration information (lowMobilityEvaluation) for selecting the execution of mitigated measurement based on the low mobility criterion is configured in the UE 100 and the configuration information (cellEdgeEvaluation) for selecting the execution of mitigated measurement based on the non-cell edge criterion is not configured in the UE 100, the control unit 140 performs a power threshold (S SearchDeltaP_stationary ) and period information (T SearchDeltaP_stationary ) are configured in the UE 100, if the following conditions are met, it may choose to perform measurement of radio quality for intra-frequency cells according to the measurement relaxation method.

[0202] The above conditions are: (i) at least a predetermined period (T SearchDeltaP_stationary ), a normal measurement of radio quality for an intra-frequency cell, a normal measurement of radio quality for an NR inter-frequency cell, or a normal measurement of radio quality for an inter-RAT cell has been performed, and (ii) a predetermined period (T SearchDeltaP_stationary ), the stationary criterion may be met.

[0203] The control unit 140 determines whether the radio quality of the serving cell satisfies "Srxlev > S nonIntraSearchP " and "Squal > S nonIntraSearchQ " is satisfied, the control unit 140 may select not to measure the radio quality of the inter-frequency cell or the inter-RAT cell within one hour since the last radio quality measurement. If relaxed measurement on a high priority frequency is permitted, that is, if highPriorityMeasRelax is set to "true", the control unit 140 may select not to measure the radio quality of the inter-frequency cell or the inter-RAT cell.

[0204] The control unit 140 determines whether the radio quality of the serving cell satisfies "Srxlev > S nonIntraSearchP " and "Squal > S nonIntraSearchQ " is not met, it may choose to perform radio quality measurements for inter-frequency or inter-RAT cells according to the same or different mitigation measurements as those described above.

[0205] Furthermore, as shown in FIG. 22 , when both the configuration information (lowMobilityEvaluation) for selecting the execution of mitigated measurement based on the low mobility criterion and the configuration information (cellEdgeEvaluation) for selecting the execution of mitigated measurement based on the non-cell edge criterion are configured in the UE 100, the control unit 140 determines whether or not the power threshold (S SearchDeltaP_stationary ) and period information (T SearchDeltaP_stationary) is set in UE100, if the following condition is met, it may be possible to choose not to measure the radio quality of an intra-frequency cell, an inter-frequency cell, or an inter-RAT cell for which one hour has not yet elapsed since the radio quality measurement.

[0206] The above conditions are: (i) at least a predetermined period (T SearchDeltaP_stationary ), a normal measurement of radio quality for an intra-frequency cell, a normal measurement of radio quality for an NR inter-frequency cell, or a normal measurement of radio quality for an inter-RAT cell has been performed; and (ii) a predetermined period (T SearchDeltaP_stationary ), the stationary criterion is met, and (iii) the non-cell edge criterion is met.

[0207] The control unit 140 (i) SearchDeltaP_stationary ), perform normal radio quality measurements for intra-frequency cells, normal radio quality measurements for NR inter-frequency cells, or normal radio quality measurements for inter-RAT cells, and if (ii) the non-cell edge criteria are met and (iii) relaxation measurements on high-priority frequencies are not allowed, may choose to perform radio quality measurements for low-priority intra-frequency cells, low-priority inter-frequency cells, or low-priority inter-RAT cells according to the same or different relaxation measurements as those described above.

[0208] The control unit 140 determines whether the radio quality of the serving cell satisfies the condition "Srxlev ≦ S nonIntraSearchP " or "Squal ≦ S nonIntraSearchQ " is satisfied, it may choose to perform radio quality measurements for high priority inter-frequency cells or high priority inter-RAT cells according to the same or different mitigation measurements as those described above.

[0209] Steps S303 and S306: This is the same as step S103 or S203, and step S106 or S206. For example, after the selection, if UE 100 receives an instruction from base station 200, UE 100 may execute the selected operation in accordance with the instruction from base station 200.

[0210] Steps S304, S305, and S307: This is the same as step S104 or S204, step S106 or S206, or step S104 or S204.

[0211] (Other embodiments) In the above-described embodiment, the UE 100 may be a specific UE 100B. The specific UE 100B is expected to be stationary compared to the general UE 100A, and is therefore more likely to satisfy the stationary criterion.

[0212] In the above-described embodiment, the UE 100 may perform the above-described operations only when in the RRC connected state. Furthermore, the UE 100 may perform any of the operations of the first to fifth operation examples when in the RRC connected state, and may perform the operations of the first to fifth operation examples when in the RRC idle state or the RRC inactive state.

[0213] In the above-described embodiment, base station 200 may select whether to cause UE 100 to perform mitigation measurement in accordance with the conditions described in the fifth operation example, or whether to not cause UE 100 to perform measurement on a predetermined neighboring cell (not to perform measurement). Base station 200 may transmit an instruction based on the selection result to UE 100. UE 100 may select whether to perform mitigation measurement or not to perform measurement based on the instruction from base station 200.

[0214] In the above-described embodiment, the UE 100 may use another message (for example, a new RRC message) instead of the measurement report message and the UE assistance information message.

[0215] In the above-described embodiment, the base station 200 may include multiple units. The multiple units may include a first unit hosting a higher layer included in a protocol stack and a second unit hosting a lower layer included in the protocol stack. The higher layer may include an RRC layer, an SDAP layer, and a PDCP layer, and the lower layer may include an RLC layer, a MAC layer, and a PHY layer. The first unit may be a central unit (CU), and the second unit may be a distributed unit (DU). The multiple units may include a third unit performing processing below the PHY layer. The second unit may perform processing above the PHY layer. The third unit may be a radio unit (RU). The base station 200 may be one of the multiple units or may be connected to other units of the multiple units. Furthermore, the base station 200 may be an integrated access and backhaul (IAB) donor or an IAB node.

[0216] In the above-described embodiment, an NR-based mobile communication system has been described as an example of the mobile communication system 1. However, the mobile communication system 1 is not limited to this example. The mobile communication system 1 may be a system compliant with a TS of either LTE or another generation system (e.g., 6th generation) of the 3GPP standard. The base station 200 may be an eNB that provides E-UTRA user plane and control plane protocol termination for the UE 100 in LTE. The mobile communication system 1 may be a system compliant with a TS of a standard other than the 3GPP standard.

[0217] The steps in the operations of the above-described embodiments do not necessarily have to be executed in chronological order according to the order depicted in the flow diagrams or sequence diagrams. For example, the steps in the operations may be executed in an order different from that depicted in the flow diagrams or sequence diagrams, or may be executed in parallel. Some of the steps in the operations may be deleted, or additional steps may be added to the process. Furthermore, the above-described operational flows are not limited to being executed independently, but may be executed by combining two or more operational flows. For example, some steps of one operational flow may be added to another operational flow, or some steps of one operational flow may be replaced with some steps of another operational flow.

[0218] A program may be provided that causes a computer to execute each process performed by the UE 100 or the base station 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. Furthermore, circuits that execute each process performed by the UE 100 or the base station 200 may be integrated, and at least a part of the UE 100 or the base station 200 may be configured as a semiconductor integrated circuit (chip set, SoC).

[0219] In the above-described embodiments, "transmit" may mean performing processing at least one layer in a protocol stack used for transmission, or may mean physically transmitting a signal wirelessly or via a wire. Alternatively, "transmit" may mean a combination of performing processing at least one layer and physically transmitting a signal wirelessly or via a wire. Similarly, "receive" may mean performing processing at least one layer in a protocol stack used for reception, or may mean physically receiving a signal wirelessly or via a wire. Alternatively, "receive" may mean a combination of processing at least one layer and physically receiving a signal wirelessly or via a wire.

[0220] The above describes the embodiments in detail with reference to the drawings, but the specific configuration is not limited to that described above, and various design changes can be made within the scope that does not deviate from the gist of the invention. [Explanation of symbols]

[0221] 1: Mobile communication system 10: Network 120: Communications Department 121: Receiving unit 122: Transmitter 140: Control unit 200:Base station 220: Radio Communication Department 230: Network Communication Department 240: Control unit 300: Core network equipment

Claims

1. a receiver configured to receive, from a base station (200) using a radio resource control (RRC) message, configuration information for configuring transmission of a UE assistance information message, the configuration information including information specifying a time period used to determine whether a stationary criterion for measurement relaxation is satisfied; a transmitter configured to transmit the UE assistance information message to the base station based on the configuration information; The transmission unit If the stationary criterion is satisfied during the period, transmitting the UE assistance information message to the base station, the message including information indicating that the stationary criterion is satisfied; If the stationary criterion is not satisfied during the period, transmitting the UE assistance information message to the base station, the message including information indicating that the stationary criterion is not satisfied; If the information included in the last transmitted UE assistance information message indicates that the stationary criterion is not satisfied, transmit the UE assistance information message to the base station including the information indicating that the stationary criterion is satisfied. A communication device (100).

2. A receiver that receives configuration information from a base station using a radio resource control (RRC) message, the configuration information including information for configuring the transmission of a UE assistance information message, the information specifying a time period used to determine whether a stationary criterion for measurement relaxation is satisfied; A transmitting unit that transmits the UE assistance information message to the base station (200) based on the setting information, The transmission unit If the stationary criterion is satisfied during the period, transmitting the UE assistance information message to the base station, the message including information indicating that the stationary criterion is satisfied; If the stationary criterion is not satisfied during the period, transmitting the UE assistance information message to the base station, the message including information indicating that the stationary criterion is not satisfied; When the information included in the last transmitted UE assistance information message indicates that the stationary criterion is satisfied, the transmitter transmits the UE assistance information message including the information indicating that the stationary criterion is not satisfied to the base station. Communication equipment.

3. The communication device is capable of transmitting the information indicating that the stationary criterion has been met and the information indicating that the stationary criterion has not been met.

3. The communication device according to claim 1 or 2.

4. a transmitter configured to transmit, to a communication device (100), configuration information for configuring transmission of a UE assistance information message, the configuration information including information used to specify a period during which a stationary criterion for measurement relaxation is satisfied, using a radio resource control (RRC) message; a receiving unit configured to receive the UE assistance information message from the communication device based on the configuration information; The receiving unit receiving, from the communication device, the UE assistance information message including information indicating that the stationary criterion is satisfied if the stationary criterion is satisfied during the period; receiving, from the communication device, the UE assistance information message including information indicating that the stationary criterion is not satisfied if the stationary criterion is not satisfied during the period; If the information included in the last received UE assistance information message indicates that the resting criterion is not met, receive from the communication device a UE assistance information message including the information indicating that the resting criterion is met. Base station.

5. A transmitter that transmits configuration information to a communication device (100) using a Radio Resource Control (RRC) message, the configuration information including information for configuring the transmission of a UE auxiliary information message, the information being used to specify a period during which a quiescence criterion for measurement relaxation is satisfied; a receiving unit configured to receive the UE assistance information message from the communication device based on the configuration information; The receiving unit receiving, from the communication device, the UE assistance information message including information indicating that the stationary criterion is satisfied if the stationary criterion is satisfied during the period; receiving, from the communication device, the UE assistance information message including information indicating that the stationary criterion is not satisfied if the stationary criterion is not satisfied during the period; The receiving unit receives, from the communication device, the UE assistance information message including the information indicating that the resting criterion is not satisfied, when the information included in the last received UE assistance information message indicates that the resting criterion is satisfied. Base station.

6. A communication method executed in a communication device (100), comprising: receiving configuration information from a base station (200) using a Radio Resource Control (RRC) message, the configuration information including information for configuring transmission of a UE assistance information message, the information being used to specify a period during which a quiescence criterion for measurement relaxation is satisfied; transmitting the UE assistance information message to the base station based on the configuration information; In the transmitting step, If the stationary criterion is satisfied during the period, transmitting the UE assistance information message to the base station, the message including information indicating that the stationary criterion is satisfied; If the stationary criterion is not satisfied during the period, transmitting the UE assistance information message to the base station, the message including information indicating that the stationary criterion is not satisfied; If the information included in the last transmitted UE assistance information message indicates that the stationary criterion is not satisfied, transmit the UE assistance information message to the base station including the information indicating that the stationary criterion is satisfied. Communication method.

7. A communication method executed by a communication device (100), comprising: receiving configuration information from a base station using a Radio Resource Control (RRC) message, the configuration information including information for configuring transmission of a UE assistance information message, the information being used to specify a period during which a quiescence criterion for measurement relaxation is satisfied; transmitting the UE assistance information message to the base station (200) based on the configuration information; In the transmitting step, If the stationary criterion is satisfied during the period, transmitting the UE assistance information message to the base station, the message including information indicating that the stationary criterion is satisfied; If the stationary criterion is not satisfied during the period, transmitting the UE assistance information message to the base station, the message including information indicating that the stationary criterion is not satisfied; If the information included in the last transmitted UE assistance information message indicates that the stationary criterion is met, transmit the UE assistance information message to the base station including the information indicating that the stationary criterion is not met. Communication method.

8. The communication device is capable of transmitting the information indicating that the stationary criterion has been met and the information indicating that the stationary criterion has not been met. The communication method according to claim 6 or 7.

Images