WO2023120434A1

WO2023120434A1 - Base station and communication method

Info

Publication number: WO2023120434A1
Application number: PCT/JP2022/046498
Authority: WO
Inventors: 樹長野; 秀明 ▲高▼橋
Original assignee: 株式会社デンソー; トヨタ自動車株式会社
Priority date: 2021-12-23
Filing date: 2022-12-16
Publication date: 2023-06-29

Abstract

A base station (200) comprises: a communication unit (210) that transmits a specific system information block including a TRS resource configuration, which is a configuration for a tracking reference signal (TRS); and a control unit (230) that updates the TRS resource configuration at the timing of a boundary of a correction period at which system information may be updated. The control unit (230) updates the TRS resource configuration only at a timing when a boundary of an acquisition period, which serves as a trigger for acquisition of updated system information by a communication device in which an enhanced discontinuous reception is configured, matches the boundary of the correction period.

Description

Base station and communication method

Cross-references to related applications

This application is based on and claims the benefit of priority from patent application number 2021-209674, filed December 23, 2021, the entire contents of which are incorporated by reference. incorporated herein by.

The present disclosure relates to base stations and communication methods used in mobile communication systems.

A communication device in a radio resource control (RRC) connected state in a mobile communication system conforming to the technical specifications of the 3GPP (registered trademark; the same shall apply hereinafter) (3rd Generation Partnership Project), which is a standardization project for mobile communication systems. On the other hand, there is a tracking reference signal (TRS) in the reference signal (reference signal: RS) that is set for each communication device. TRS is a reference signal for performing time/frequency synchronization (time/frequency tracking).

　3GPP is discussing standardization of techniques for reducing power consumption for communication devices in RRC idle state or RRC inactive state. In such technology, TRS resources (also referred to as "TRS opportunities") configured for communication devices in RRC connected state can be used by communication devices in RRC idle state or RRC inactive state. (For example, see Non-Patent Document 1). Specifically, the base station broadcasts TRS resource settings (TRS configurations) through system information blocks (also referred to as "broadcast information").

A communication device in RRC idle state or RRC inactive state receives TRS using the TRS resource configuration set by the system information block, thereby synchronizing without receiving SSB (SS/PBCH Block). can reduce the wake-up duration between establishing synchronization and monitoring paging. By not receiving the SSB, an increase in power consumption due to the reception of the SSB is suppressed.

It should be noted that the system information block (system information) is maintained without being updated within a modification period, which is the period in which the system information block can be updated. The system information is changed at the timing of the boundary between the current correction cycle and the next correction cycle. The communication device may acquire the system information only once within the modification cycle in which the TRS resource setting as system information is updated.

By the way, a communication device in RRC idle state or RRC inactive state performs discontinuous reception (DRX). Specifically, the communication device wakes up in the set DRX cycle and attempts to receive paging. Also known as such a DRX cycle is extended discontinuous reception (eDRX), which uses a long DRX cycle in units of hyperframes consisting of 1024 system frames. According to eDRX, the period during which the communication device can turn off reception can be extended, so power consumption can be further reduced.

A base station according to a first aspect includes: a communication unit that transmits a specific system information block including TRS resource settings that are settings for a tracking reference signal (TRS); and a control unit for updating the TRS resource settings with. The control unit updates the TRS resource setting only at a timing when a boundary of an acquisition cycle that triggers acquisition of updated system information by a communication device set to enhanced discontinuous reception coincides with a boundary of the correction cycle. .

A communication method according to the second aspect is a communication method executed by a base station. The communication method includes transmitting a specific system information block containing a TRS resource setting that is a setting for a tracking reference signal (TRS); and updating. In the step of updating the TRS resource setting, only at the timing when the boundary of the acquisition cycle that triggers acquisition of updated system information by the communication device in which the enhanced discontinuous reception is set coincides with the boundary of the correction cycle, the TRS Update resource settings.

Objects, features, advantages, etc. of the present disclosure will become clearer from the following detailed description with reference to the accompanying drawings.
FIG. 1 is a diagram showing the configuration of a mobile communication system according to an embodiment. FIG. 2 is a diagram showing a configuration example of a protocol stack in the mobile communication system according to the embodiment. FIG. 3 is a diagram illustrating an example operation for a UE in RRC idle state or RRC inactive state. FIG. 4 illustrates an example operation for a UE in RRC idle state or RRC inactive state to receive a TRS. FIG. 5 is a diagram for explaining an overview of eDRX. FIG. 6 is a diagram for explaining problems related to eDRX. FIG. 7 is a diagram illustrating the configuration of a UE according to the embodiment; FIG. 8 is a diagram showing the configuration of a base station according to the embodiment. FIG. 9 is a flowchart for explaining the base station 200 according to the first operation example. FIG. 10 is a diagram for explaining the base station 200 according to the first operation example. FIG. 11 is a flowchart (Part 1) for explaining the base station 200 according to the second operation example. FIG. 12 is a flowchart (part 2) for explaining the base station 200 according to the second operation example.

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.

A correction cycle for eDRX communication devices (hereinafter referred to as an eDRX acquisition cycle) that is longer than the normal correction cycle is set in a communication device in which eDRX is set (hereinafter referred to as an eDRX communication device). For the eDRX communication device, the timing of the boundary between the current eDRX acquisition cycle and the next eDRX acquisition cycle triggers the acquisition of updated system information.

Here, assume a case where one eDRX acquisition period includes a modification period boundary, and the base station updates the TRS resource configuration at the modification period boundary. Since the eDRX communication device has not had an opportunity to acquire updated system information (that is, the timing of the boundary of the eDRX acquisition cycle has not been reached), after the timing of the boundary of the modification cycle, the updated TRS resource There is a concern that the TRS based on the setting cannot be properly received. An eDRX communication device that has failed to receive a TRS cannot perform time/frequency tracking using the TRS, and thus has a problem of being unable to monitor paging efficiently.

Therefore, one object of the present disclosure is to provide a base station and a communication method that enable communication devices to appropriately receive TRS.

(Configuration of mobile communication system)
A configuration of a mobile communication system 1 according to an embodiment will be described with reference to FIG. The mobile communication system 1 is, for example, a system conforming to 3GPP Technical Specifications (TS). Hereinafter, as the mobile communication system 1, a mobile communication system based on the 3GPP standard 5th Generation System (5GS), that is, NR (New Radio) will be described as an example.

The mobile communication system 1 has a network 10 and user equipment (UE) 100 communicating with the network 10 . The network 10 includes an NG-RAN (Next Generation Radio Access Network) 20, which is a 5G radio access network, and a 5GC (5G Core Network) 30, which is a 5G core network.

The UE 100 is an example of a communication device. The UE 100 may be a mobile wireless communication device. UE 100 may be a device used by a user. The UE 100 may be a user equipment defined by 3GPP technical specifications. The UE 100 is, for example, a portable device such as a mobile phone terminal such as a smart phone, a tablet terminal, a notebook PC, a communication module, or a communication card. The UE 100 may be a vehicle (eg, car, train, etc.) or a device provided therein (eg, Vehicle UE). The UE 100 may be a transport body other than a vehicle (eg, a ship, an airplane, etc.) or a device provided thereon (eg, an Aerial UE). The UE 100 may be a sensor or a device attached thereto. Note that the UE 100 includes 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, and a remote terminal. , remote device, or remote unit.

NG-RAN 20 includes multiple base stations 200 . Each base station 200 manages at least one cell. A cell constitutes the minimum unit of a communication area. For example, one cell belongs to one frequency (carrier frequency) and is configured by one component carrier. The term “cell” may represent a radio communication resource and may also represent a communication target of UE 100 . Each base station 200 can perform radio communication with the UE 100 residing in its own cell. The base station 200 communicates with the UE 100 using the RAN protocol stack. Base station 200 provides NR user plane and control plane protocol termination towards UE 100 and is connected to 5GC 30 via NG interface. Such an NR base station 200 is sometimes referred to as a gNodeB (gNB).

The 5GC 30 includes a core network device 300. The core network device 300 includes, for example, AMF (Access and Mobility Management Function) and/or UPF (User Plane Function). AMF performs mobility management of UE100. UPF provides functions specialized for user plane processing. The AMF and UPF are connected with the base station 200 via the NG interface.

A configuration example of a protocol stack in the mobile communication system 1 according to the embodiment will be described with reference to FIG.

The protocol of the wireless section between the UE 100 and the base station 200 includes a physical (PHY) layer, a MAC (Medium Access Control) layer, an RLC (Radio Link Control) layer, a PDCP (Packet Data Convergence Protocol) layer, It has an RRC (Radio Resource Control) layer.

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 physical channels.

A physical channel is composed of multiple OFDM (Orthogonal Frequency Division Multiplexing) symbols in the time domain and multiple subcarriers in the frequency domain. One subframe consists of a plurality of OFDM symbols in the time domain. A resource block is a resource allocation unit, and is composed of a plurality of OFDM symbols and a plurality of subcarriers. A frame may consist of 10 ms and may include 10 subframes of 1 ms. A subframe can include a number of slots corresponding to the subcarrier spacing.

Among physical channels, the physical downlink control channel (PDCCH) plays a central role, for example, for purposes such as downlink scheduling assignments, uplink scheduling grants, and transmission power control.

In NR, the UE 100 can use a narrower bandwidth than the system bandwidth (that is, the cell bandwidth). The base station 200 configures the UE 100 with a bandwidth part (BWP) made up of consecutive PRBs. UE 100 transmits and receives data and control signals on the active BWP. Up to four BWPs can be set in the UE 100, for example. Each BWP may have different subcarrier spacing and may overlap each other in frequency. If multiple BWPs are configured for the UE 100, the base station 200 can specify which BWP to activate through downlink control. This allows the base station 200 to dynamically adjust the UE bandwidth according to the amount of data traffic of the UE 100, etc., and reduce UE power consumption.

For example, the base station 200 can configure up to 3 control resource sets (CORESET) for each of up to 4 BWPs on the serving cell. CORESET is a radio resource for control information that the UE 100 should receive. UE 100 may be configured with up to 12 CORESETs on the serving cell. Each CORESET has an index from 0 to 11. For example, a CORESET consists of 6 resource blocks (PRBs) and 1, 2 or 3 consecutive OFDM symbols in the time domain.

The MAC layer performs data priority control, retransmission processing by hybrid ARQ (Hybrid Automatic Repeat Quest: HARQ), random access procedures, and the like. Data and control information are transmitted between the MAC layer of the UE 100 and the MAC layer of the base station 200 via transport channels. The MAC layer of base station 200 includes a scheduler. The scheduler determines uplink and downlink transport formats (transport block size, modulation and coding scheme (MCS)) and allocation resources to the UE 100 .

The RLC layer uses the functions of the MAC layer and PHY layer to transmit data to the RLC layer on the receiving side. 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.

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

An SDAP (Service Data Adaptation Protocol) layer may be provided as an upper layer of the PDCP layer. The SDAP (Service Data Adaptation Protocol) layer performs mapping between an IP flow, which is the unit of QoS control performed by the core network, and a radio bearer, which is the unit of QoS control performed by the AS (Access Stratum).

The RRC layer controls logical channels, transport channels and physical channels according to radio bearer establishment, re-establishment and release. RRC signaling for various settings is transmitted between the RRC layer of UE 100 and the RRC layer of base station 200 . When there is an RRC connection between the RRC of UE 100 and the RRC of base station 200, UE 100 is in the RRC connected state. If 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 RRC idle state. When the RRC connection between the RRC of UE 100 and the RRC of base station 200 is suspended, UE 100 is in RRC inactive state.

The NAS layer located above the RRC layer performs session management and mobility management for UE100. NAS signaling is transmitted between the NAS layer of the UE 100 and the NAS layer of the core network device 300 (AMF). Note that the UE 100 has an application layer and the like in addition to the radio interface protocol.

(Assumed scenario)
An assumed scenario in the mobile communication system 1 according to the embodiment will be described with reference to FIGS. 3 to 6. FIG.

FIG. 3 shows an operation example of the UE 100 in RRC idle state or RRC inactive state.

UE 100 in RRC idle state or RRC inactive state monitors paging from base station 200 . Specifically, UE 100 receives PDCCH (Physical Downlink Control Channel) from base station 200 to check whether there is a paging addressed to UE 100 . For example, the UE 100 performs paging by receiving (decoding) downlink control information (DCI) to which CRC (Cyclic Redundancy Check) parity bits scrambled by P-RNTI (Paging Radio Network Temporary Identifier) are added on the PDCCH. You may receive messages from Here, base station 200 may configure P-RNTI for UE 100 . Also, the DCI may be a DCI format used for PDSCH (Physical Downlink Shared Channel) scheduling. That is, paging messages may be sent on the PDSCH. Here, the DCI to which the CRC parity bits scrambled by the P-RNTI are added is also called paging DCI.

Here, in order to reduce power consumption, the UE 100 intermittently monitors paging using discontinuous reception (DRX). A period for monitoring such paging is called a DRX period. Also, a frame in which the UE 100 should monitor paging is called a paging frame (PF), and a subframe in this PF in which the UE 100 should monitor paging is called a paging occasion (PO).

In step S21, the base station 200 transmits the SSB to the UE100. SSB is another example of a downlink reference signal. The SSB includes a primary synchronization signal (PSS), a secondary synchronization signal (SSS), a PBCH (Physical Broadcast Channel), and a demodulation reference signal (DMRS). For example, an SSB may consist of four consecutive OFDM symbols in the time domain. Also, the SSB may consist of 240 consecutive subcarriers (ie, 20 resource blocks) in the frequency domain. PBCH is a physical channel that carries a Master Information Block (MIB). The UE 100 performs time/frequency synchronization by receiving the SSB.

At step S22, the UE 100 monitors and receives paging at the PO. Note that the UE 100 maintains the wake-up state from the reception of the SSB in step S21 to the PO. Therefore, the longer the time from the SSB reception timing to the PO timing, the longer the wakeup duration, and the more power consumption of the UE 100 increases.

　3GPP is discussing standardization of technology for reducing power consumption for UE 100 in RRC idle state or RRC inactive state. In such technology, TRS resources (also referred to as "TRS opportunities") configured for UE 100 in RRC connected state are made available to UE 100 in RRC idle state or RRC inactive state. is being considered. Specifically, the base station 200 broadcasts TRS resource settings (TRS configurations), which are settings for TRS resources, using a system information block (also referred to as “broadcast information”).

FIG. 4 shows an operation example for UE 100 in RRC idle state or RRC inactive state to receive TRS. Note that the TRS may be a CSI-RS used for tracking purposes. That is, in this embodiment, TRS resources may include CSI-RS resources.

In step S31, the base station 200 transmits a specific system information block containing TRS resource settings. Specifically, the base station 200 transmits a system information block containing one or more TRS resource configuration parameters on a broadcast channel. The particular system information block may be an existing system information block other than system information block type 1 (SIB1) or a newly introduced type of system information block. UE 100 receives a specific system information block and obtains TRS resource configuration parameters (ie, TRS resource set configuration).

Here, the TRS resource setting for setting TRS for UE 100 in RRC idle state or RRC inactive state is CSI-ResourceConfig/NZP-CSI-RS-ResourceSet, bwp-ID, resourceType, trs-Info , repetition, powerControlOffset, powerControlOffsetSS, requencyDomainAllocation, firstOFDMSymbolInTimeDomain, Density, startingRB, nrofRBs, and subcarrierSpacing as parameters (3G PP TS38.331 reference). TRS resource configuration may be only part of the parameter group configured in UE 100 in the RRC connected state.

In step S32, the base station 200 transmits TRS. UE 100 receives TRS using TRS resource configuration. By receiving the TRS, the UE 100 can achieve time/frequency synchronization without receiving the SSB.

At step S33, the UE 100 monitors and receives paging at the PO. Note that the UE 100 maintains the wake-up state from the reception of the TRS in step S31 to the PO. When the time from the TRS reception timing to the PO timing is short, the wakeup duration is short, and the power consumption of the UE 100 is reduced. In addition, the UE 100 can reduce power consumption accompanying reception of SSB by not receiving SSB.

FIG. 5 shows an operation example of an extended DRX communication device in which extended discontinuous reception (eDRX) is set. As an example of an enhanced DRX communication device, an eDRX UE (that is, an eDRX user device) will be described below.

eDRX is a technology that uses a longer DRX cycle than normal DRX in order to achieve further power saving of the UE 100 . The UE 100 configured with DRX wakes up every DRX cycle to monitor the PDCCH, and when this monitoring ends, it goes to sleep until the next DRX cycle. Therefore, by using a DRX cycle that is longer than normal DRX (hereinafter referred to as an “eDRX cycle”), the period during which the receiver of the UE 100 can be turned off is lengthened, and further power saving is achieved. be.

In normal DRX, the DRX cycle is set to a time length of, for example, 32 radio frames, 64 radio frames, 128 radio frames, or 256 radio frames. On the other hand, the eDRX cycle used in eDRX is set to a time length that is an integral multiple of a hyperframe consisting of 1024 radio frames.

On the other hand, the UE 100 for which eDRX is configured (that is, the eDRX UE) attempts to receive paging in a specific hyperframe (Paging Hyperframe: PH) in each eDRX cycle. At this time, the time span for monitoring paging is called PTW (Paging Timing Window), and PO (Paging Occasion) is monitored according to normal DRX during the PTW period.

Since the TRS resources configured for UE 100 in RRC idle state or RRC inactive state can obtain power saving effects as described above, it is desirable that they can also be used by eDRX UEs. Here, the TRS resource is configured by a specific system information block, but there is a problem that the eDRX UE may not be able to receive the TRS if the configuration of the TRS resource is updated.

The above problems will be described with reference to FIG. A normal DRX-configured UE (hereinafter referred to as "DRX UE") monitors the PDCCH in the PO for each DRX cycle. The DRX UE performs time/frequency tracking by receiving the TRS just before each PO. The configuration of the TRS resource is notified from the base station 200 to the UE 100 by a specific system information block (hereinafter referred to as a specific SIB as appropriate). A period in which system information such as a specific SIB can be updated is called a modification period. That is, the system information is maintained without being updated within one modification period. When updating the TRS resource configuration (that is, the specific SIB), the base station 200 notifies the UE 100 that the system information will be changed in the next modification period (so-called short message), and the current modification period (modification period #n) and the next modification period (modification period #n+1), the system information (specific SIB) is changed.

On the other hand, the eDRX UE monitors the PDCCH in the PO within the PTW every DRX cycle. The eDRX UE performs time/frequency tracking by receiving the TRS immediately before each PTW or each PO. The eDRX UE is set with a modification cycle for the eDRX UE that is longer than the normal modification cycle. Such an amendment period for eDRX UEs is sometimes referred to as an eDRX acquisition period. For the eDRX UE, the timing of the boundary between the current eDRX acquisition cycle and the next eDRX acquisition cycle triggers the acquisition of updated system information.

Here, assume a case where one eDRX acquisition period includes a modification period boundary, and the base station 200 updates the TRS resource configuration at the modification period boundary. eDRX UE does not have an opportunity to acquire updated system information (that is, the eDRX acquisition cycle boundary timing has not been reached), so after the modification cycle boundary timing, the updated TRS resource configuration There is a concern that the TRS based on An eDRX UE that has TRS reception failure cannot perform time/frequency tracking using TRS, and there is a problem that efficient PO monitoring cannot be performed. In one embodiment described later, an operation for enabling the UE 100 to appropriately receive the TRS will be described.

(Configuration of user device)
A configuration of the UE 100 according to the embodiment will be described with reference to FIG. UE 100 includes communication unit 110 and control unit 120 .

The communication unit 110 performs wireless communication with the base station 200 by transmitting and receiving wireless signals to and from the base station 200 . The communication unit 110 has at least one transmitter 111 and at least one receiver 112 . The transmitter 111 and receiver 112 may be configured to include multiple antennas and RF circuits. The antenna converts a signal into radio waves and radiates the radio waves into space. Also, the antenna receives radio waves in space and converts the radio waves into signals. The RF circuitry performs analog processing of signals transmitted and received through the antenna. The RF circuitry may include high frequency filters, amplifiers, modulators, low pass filters, and the like.

The control unit 120 performs various controls in the UE 100. Control unit 120 controls communication with base station 200 via communication unit 110 . The operations of the UE 100 described above and below may be operations under the control of the control unit 120 . The control unit 120 may include at least one processor capable of executing a program and a memory that stores the program. The processor may execute a program to operate the control unit 120 . The control unit 120 may include a digital signal processor that performs digital processing of signals transmitted and received through the antenna and RF circuitry. The digital processing includes processing of the protocol stack of the RAN. Note that the memory stores programs executed by the processor, parameters related to the programs, and data related to the programs. The memory is ROM (Read Only Memory), EPROM (Erasable Programmable Read Only Memory), EEPROM (Electrically Erasable Programmable Read Only Memory), RAM (Random Access Mem ory) and flash memory. All or part of the memory may be included within the processor.

(Base station configuration)
A configuration of the base station 200 according to the embodiment will be described with reference to FIG. The base station 200 has a communication section 210 , a network communication section 220 and a control section 230 .

For example, the communication unit 210 receives radio signals from the UE 100 and transmits radio signals to the UE 100. The communication unit 210 has at least one transmitter 211 and at least one receiver 212 . The transmitting section 211 and the receiving section 212 may be configured including an RF circuit. The RF circuitry performs analog processing of signals transmitted and received through the antenna. The RF circuitry may include high frequency filters, amplifiers, modulators, low pass filters, and the like.

The network communication unit 220 transmits and receives signals to and from the network. The network communication unit 220, for example, receives signals from adjacent base stations connected via an Xn interface, which is an interface between base stations, and transmits signals to the adjacent base stations. Also, the network communication unit 220 receives a signal from the core network device 300 connected via the NG interface, for example, and transmits the signal to the core network device 300 .

The control unit 230 performs various controls in the base station 200. The control unit 230 controls communication with the UE 100 via the communication unit 210, for example. Also, the control unit 230 controls communication with a node (for example, an adjacent base station, the core network device 300) via the network communication unit 220, for example. The operations of the base station 200 described above and below may be operations under the control of the control unit 230 . The control unit 230 may include at least one processor capable of executing programs and a memory storing the programs. The processor may execute a program to operate the controller 230 . Control unit 230 may include a digital signal processor that performs digital processing of signals transmitted and received through the antenna and RF circuitry. The digital processing includes processing of the protocol stack of the RAN. Note that the memory stores programs executed by the processor, parameters related to the programs, and data related to the programs. All or part of the memory may be included within the processor.

In the base station 200 configured in this way, the communication unit 210 transmits a specific system information block including TRS resource settings, which are settings for tracking reference signals (TRS). The control unit 230 updates the TRS resource setting at the timing of the boundary of the modification period in which the system information can be updated. The control unit 230 updates the TRS resource setting only at the timing when the boundary of the eDRX acquisition cycle and the boundary of the correction cycle coincide with each other, which triggers the eDRX UE in which eDRX is configured to acquire updated system information. As a result, even if the UE 100 uses an extended DRX cycle that is longer than the modified cycle due to the extended DRX being configured, the eDRX acquisition cycle is set to the eDRX acquisition cycle while the receiving unit 112 of the UE 100 is turned off. No TRS resource settings are updated before the boundary is reached. UE 100, which is an eDRX UE, can acquire the updated TRS resource configuration with the timing of the boundary of the eDRX acquisition cycle as a trigger. As a result, the UE 100 can appropriately receive the TRS based on the updated TRS resource settings.

(First operation example)
A first operation example will be described with reference to FIGS. 9 and 10. FIG. This operation is premised on the configuration and operation described above.

In step S101, the control unit 230 of the base station 200 determines whether or not to update TRS resource settings. The control unit 230 may determine whether to update the system information included in the specific SIB.

Note that the specific SIB may contain TRS resource settings commonly used for DRX UEs and eDRX UEs, or contain TRS resource settings for DRX UEs and TRS resource settings for eDRX UEs respectively. good too.

When the control unit 230 determines to update the TRS resource setting, it executes the process of step S102. On the other hand, when the control unit 230 determines not to update the TRS resource setting (or system information), it ends the process.

In step S102, the control unit 230 updates the TRS resource setting only at the timing when the boundary of the modification cycle coincides with the boundary of the eDRX acquisition cycle.

As shown in FIG. 10, for example, at the timing Tn of the boundary between the correction cycle #n and the next correction cycle #n+1, the boundary of the correction cycle does not match the boundary of the eDRX acquisition cycle. Therefore, the control unit 230 performs control so as not to update the TRS resource setting at the timing Tn of the boundary of the modification cycle. The control unit 230 may omit updating the TRS resource settings.

After that, the boundary between the modified cycle #n+m and the next modified cycle #n+m+1 and the boundary between the eDRX acquisition cycle #p+q and the next modified cycle #p+q+1 coincide. Therefore, the control unit 230 updates the TRS resource setting at the timing Tn+m of the boundary of the modification cycle. The control unit 230 may update the TRS resource configuration at the timing of the boundary of the eDRX acquisition cycle (that is, every eDRX acquisition cycle).

Even when updating system information other than the TRS resource setting among the system information included in the specific SIB, the control unit 230 updates the system information only at the timing when the boundary of the correction cycle coincides with the boundary of the eDRX acquisition cycle. may

After that, the communication unit 210 of the base station 200 starts transmitting the updated TRS resource setting after the timing Tn+m of the boundary of the correction cycle.

Note that the control unit 230 may update the TRS resource setting at the timing Tn+m on the boundary of the correction period. Therefore, the control unit 230 does not transmit the TRS resource configuration updated from the TRS resource configuration transmitted within the modification cycle #n+m before the timing Tn+m of the boundary of the modification cycle. After Tn+m, it may start sending updated TRS resource settings.

As described above, the control unit 230 of the base station 200 updates the TRS resource setting only at the timing when the boundary of the correction cycle coincides with the boundary of the eDRX acquisition cycle. As a result, even when the UE 100 uses an extended DRX cycle longer than the correction cycle due to the extended DRX being set, the receiver of the UE 100 (that is, the receiving unit 112) is turned off The TRS resource configuration is never updated before reaching the boundary of the eDRX acquisition period. UE 100, which is an eDRX UE, can acquire the updated TRS resource configuration with the timing of the boundary of the eDRX acquisition cycle as a trigger. As a result, the UE 100 can appropriately receive the TRS based on the updated TRS resource settings.

(Second operation example)
A second operation example will be described with reference to FIGS. 11 and 12 . Descriptions similar to those of the above operation example are omitted as appropriate. In the second operation example, the control unit 230 of the base station 200 switches the update method for updating the TRS resource configuration.

As shown in FIG. 11, in step S201, the network communication unit 220 of the base station 200 receives eDRX UE information (hereinafter referred to as eDRX UE information) from the core network device 300 (eg, AMF).

The eDRX UE information is, for example, information indicating whether an eDRX UE exists within the tracking area to which the base station 200 belongs, information on the eDRX UE within the tracking area to which the base station 200 belongs, and information on the RAN paging area to which the base station 200 belongs. information indicating whether or not an eDRX UE exists in the base station 200, or information on the eDRX UE in the RAN paging area to which the base station 200 belongs. Note that the RAN paging area is an area narrower than the tracking area. The eDRX UE information may include, for example, the identifier of the UE 100 using the extended DRX cycle.

At step S202, the control unit 230 of the base station 200 selects an update method. Specifically, control unit 230 selects one of the first update method and the second update method.

The first update method is a method that can update the TRS resource setting at the timing of the boundary of the correction period regardless of whether the boundary of the correction period coincides with the boundary of the acquisition period. Therefore, the control unit 230 can update the TRS resource configuration at the timing of the boundary of the modification period (that is, every modification period).

The second update method is a method that can update the TRS resource setting only at the timing when the boundary of the correction period matches the boundary of the acquisition period. Therefore, the control unit 230 may update the TRS resource configuration at the timing of the boundary of the eDRX acquisition cycle (ie, every eDRX acquisition cycle).

The control unit 230 may select one of the first update method and the second update method based on the eDRXUE information. The control unit 230 may determine, for example, based on the eDRX UE information, whether an eDRX UE exists within the cell managed by the base station 200. When the control unit 230 determines that there is no eDRX UE in the cell, it selects the first update method. On the other hand, when the control unit 230 determines that there is an eDRX UE in the cell, it selects the second update method.

For example, based on the eDRX UE information, the control unit 230 may determine whether or not there are at least a predetermined number of eDRX UEs in the cell managed by the base station 200. If the control unit 230 determines that there are not more than a predetermined number of eDRX UEs in the cell, it selects the first update method. On the other hand, if the control unit 230 determines that there are more than the predetermined number of eDRX UEs in the cell, it selects the second update method. For example, when the control unit 230 determines that there is no eDRX UE in the RRC inactive state based on information indicating whether or not there is an eDRX UE in the RAN paging area to which the base station 200 belongs, the first Select the update method for On the other hand, when the control unit 230 determines that there is an eDRX UE in the RRC inactive state in the cell, it selects the second update method.

In step S203, the control unit 230 switches the update method for updating the TRS resource settings to the selected update method. It should be noted that the control unit 230 maintains the used updating method when controlling the updating of the TRS resource setting using the method already selected.

Next, with reference to FIG. 12, the control operation for updating TRS resource settings according to the second operation example will be described.

Step S211 is the same as step S101.

In step S212, the control unit 230 determines whether or not the second update method is used. When switching to the second update method, the control unit 230 determines that the second update method is used. When switching to the first update method, the control unit 230 determines that the second update method is not used.

The control unit 230 executes the process of step S213 when the second update method is used. On the other hand, when the second update method is not used, control unit 230 executes the process of step S214.

Note that the control unit 230 may determine whether or not the first update method is used. When switching to the first update method, the control unit 230 determines that the first update method is used. When switching to the second update method, the control unit 230 determines that the first update method is not used. If the first update method is not used, control unit 230 executes the process of step S213. On the other hand, when the first update method is used, control unit 230 executes the process of step S214.

Step S213 is the same as step S102. The control unit 230 controls the updating of TRS resource settings using the second updating method.

In step S214, the control unit 230 updates the TRS resource setting at the timing of the boundary of the modification period. Specifically, the control unit 230 can update the TRS resource configuration at the timing of the boundary of the modification period (that is, every modification period) regardless of whether the boundary of the modification period coincides with the boundary of the acquisition period. . Thus, the control unit 230 controls updating of TRS resource settings using the first updating method.

As described above, the control unit 230 may control the updating of the TRS resource settings using one of the first updating method and the second updating method. Since the control unit 230 can change the TRS resource setting update method, flexible system operation is possible.

Also, the network communication unit 220 may receive eDRXUE information from the core network device 300 . The control unit 230 may switch between the first update scheme and the second update scheme based on the eDRXUE information. As a result, the control unit 230 can change the TRS resource configuration update method based on the eDRX UE, enabling flexible system operation.

Also, when the control unit 230 determines that there is no eDRX UE in the cell managed by the base station 200, it may control the updating of the TRS resource configuration using the first updating method. As a result, since there are no eDRX UEs in the cell, even if the TRS resource configuration update cycle is shorter than the eDRX acquisition cycle, there is no impact on the eDRX UEs. Since the control unit 230 can make the update cycle of the TRS resource configuration shorter than the eDRX acquisition cycle, flexible system operation is possible.

(Other embodiments)
In the second operation example described above, the control unit 230 of the base station 200 may select one of the first update method and the second update method based on information other than the eDRXUE information. good. Also, the control unit 230 may control updating of the TRS resource configuration using an updating method different from the first updating method and the second updating method.

The operation sequences (and operation flows) in the above-described embodiments do not necessarily have to be executed in chronological order according to the order described in the flow diagrams or sequence diagrams. For example, the steps in the operations may be performed out of order or in parallel with the order illustrated in the flow diagrams or sequence diagrams. Also, some steps in the operation may be omitted and additional steps may be added to the process. Further, the operation sequences (and operation flows) in the above-described embodiments may be implemented independently, or two or more operation sequences (and operation flows) may be combined and implemented. For example, some steps of one operation flow may be added to another operation flow, or some steps of one operation flow may be replaced with some steps of another operation flow.

In the above-described embodiment, the mobile communication system 1 based on NR has been described as an example. However, the mobile communication system 1 is not limited to this example. The mobile communication system 1 may be a TS-compliant system of either LTE (Long Term Evolution) or another generation system (for example, 6th generation) of the 3GPP standards. Base station 200 may be an eNB that provides E-UTRA user plane and control plane protocol termination towards UE 100 in LTE. The mobile communication system 1 may be a system conforming to a TS of a standard other than the 3GPP standard. The base station 200 may be an IAB (Integrated Access and Backhaul) donor or an IAB node.

A program that causes a computer to execute each process performed by the UE 100 or the base station 200 may be provided. The program may be recorded on a computer readable medium. A computer readable medium allows the installation of the program on the 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, but may be, for example, a recording medium such as CD-ROM (Compact Disk Read Only Memory) or DVD-ROM (Digital Versatile Disc Read Only Memory). good. Also, 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 (chipset, SoC (System On Chip)).

In the above embodiments, "transmit" may mean performing at least one layer of processing in the protocol stack used for transmission, or physically transmitting the signal wirelessly or by wire. may mean sending to Alternatively, "transmitting" may mean a combination of performing the at least one layer of processing and physically transmitting the signal wirelessly or by wire. Similarly, "receive" may mean performing processing of at least one layer in the protocol stack used for reception, or physically receiving a signal wirelessly or by wire. may mean that Alternatively, "receiving" may mean a combination of performing the at least one layer of processing and physically receiving the signal wirelessly or by wire. Similarly, "obtain/acquire" may mean obtaining information among stored information, and may mean obtaining information among information received from other nodes. Alternatively, it may mean obtaining the information by generating the information. Similarly, references to "based on" and "depending on/in response to" are used unless otherwise specified. does not mean The phrase "based on" means both "based only on" and "based at least in part on." Similarly, the phrase "depending on" means both "only depending on" and "at least partially depending on." Similarly, "include" and "comprise" are not meant to include only the recited items, and may include only the recited items or in addition to the recited items. Means that it may contain further items. Similarly, in the present disclosure, "or" does not mean exclusive OR, but means logical OR. Furthermore, any references to elements using the "first," "second," etc. designations used in this disclosure do not generally limit the quantity or order of those elements. These designations may be used in this disclosure as a convenient method of distinguishing between two or more elements. Thus, reference to a first and second element does not imply that only two elements can be employed therein or that the first element must precede the second element in any way. In this disclosure, when articles are added by translation, such as a, an, and the in English, these articles are used in plural unless the context clearly indicates otherwise. shall include things.

Although the present disclosure has been described with reference to examples, it is understood that the present disclosure is not limited to those examples or structures. The present disclosure also includes various modifications and modifications within the equivalent range. In addition, various combinations and configurations, as well as other combinations and configurations, including single elements, more, or less, are within the scope and spirit of this disclosure.

(Appendix)
Features related to the above-described embodiments are added.

(Appendix 1)
A base station (200),
a communication unit (210) for transmitting a specific system information block containing TRS resource settings, which are settings for a tracking reference signal (TRS);
a control unit (230) for updating the TRS resource settings at the timing of the boundary of a modification period in which system information can be updated;
The control unit (230) controls the TRS only at the timing when the boundary of the acquisition cycle that triggers acquisition of updated system information by the enhanced DRX communication device set to the enhanced discontinuous reception coincides with the boundary of the modification cycle. A base station (200) that updates resource settings.

(Appendix 2)
The control unit (230) controls updating of the TRS resource configuration using one of a first updating scheme and a second updating scheme,
The first update method is a method that can update the TRS resource setting at the timing of the boundary of the modification period regardless of whether the boundary of the modification period coincides with the boundary of the acquisition period,
The base station (200) according to appendix 1, wherein the second update method is a method that can update the TRS resource configuration only at timings when the boundary of the correction period coincides with the boundary of the acquisition period.

(Appendix 3)
further comprising a network communication unit that receives information of the enhanced DRX communication device from a core network device;
The base station (200) according to appendix 2, wherein the control unit (230) switches between the first update method and the second update method based on the information.

(Appendix 4)
When the control unit (230) determines that the enhanced DRX communication device does not exist in the cell managed by the base station (200), the control unit (230) updates the TRS resource configuration using the first update method. A base station (200) according to appendix 2 or 3.

(Appendix 5)
A communication method performed in a base station (200), comprising:
transmitting a specific system information block containing TRS resource settings, which are settings for a tracking reference signal (TRS);
updating the TRS resource settings at the timing of revision period boundaries at which system information may be updated;
In the step of updating the TRS resource setting, only at the timing when the boundary of the acquisition cycle that triggers acquisition of updated system information by the communication device in which the enhanced discontinuous reception is set coincides with the boundary of the correction cycle, the TRS Communication method to update resource settings.

Claims

A base station (200),
a communication unit (210) for transmitting a specific system information block containing TRS resource settings, which are settings for a tracking reference signal (TRS);
a control unit (230) for updating the TRS resource settings at the timing of the boundary of a modification period in which system information can be updated;
The control unit (230) controls the TRS only at the timing when the boundary of the acquisition cycle that triggers acquisition of updated system information by the enhanced DRX communication device set to the enhanced discontinuous reception coincides with the boundary of the modification cycle. A base station (200) that updates resource settings.
The control unit (230) controls updating of the TRS resource configuration using one of a first updating scheme and a second updating scheme,
The first update method is a method that can update the TRS resource setting at the timing of the boundary of the modification period regardless of whether the boundary of the modification period coincides with the boundary of the acquisition period,
The base station (200) according to claim 1, wherein the second update scheme is a scheme that can update the TRS resource configuration only at timings when the boundary of the modification period coincides with the boundary of the acquisition period.
further comprising a network communication unit that receives information of the enhanced DRX communication device from a core network device;
The base station (200) according to Claim 2, wherein the control unit (230) switches between the first update scheme and the second update scheme based on the information.
When the control unit (230) determines that the enhanced DRX communication device does not exist in the cell managed by the base station (200), the control unit (230) updates the TRS resource configuration using the first update method. A base station (200) according to claim 2 or 3 for controlling.
A communication method performed in a base station (200), comprising:
transmitting a specific system information block containing TRS resource settings, which are settings for a tracking reference signal (TRS);
updating the TRS resource settings at the timing of revision period boundaries at which system information may be updated;
In the step of updating the TRS resource setting, only at the timing when the boundary of the acquisition cycle that triggers acquisition of updated system information by the communication device in which the enhanced discontinuous reception is set coincides with the boundary of the correction cycle, the TRS Communication method to update resource settings.