WO2023277026A1

WO2023277026A1 - Terminal and wireless communication method

Info

Publication number: WO2023277026A1
Application number: PCT/JP2022/025803
Authority: WO
Inventors: 治彦曽我部; 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: 2021-06-30
Filing date: 2022-06-28
Publication date: 2023-01-05
Also published as: JP2023005974A

Abstract

Provided is a terminal having: a reception unit for receiving a first DRX configuration for an RRC idle state and a second DRX configuration for an RRC inactive state; and a control unit that, when prescribed information relating to an offset value for determining a paging frame is received, monitors, in the RRC inactive state, a paging opportunity that corresponds to the paging frame determined on the basis of the prescribed information.

Description

Terminal and wireless communication method

Cross-reference to related applications

This application is based on Japanese Patent Application No. 2021-108309 filed on June 30, 2021, and claims the benefit of its priority. incorporated herein by reference.

The present disclosure relates to terminals and wireless communication methods.

In the Third Generation Partnership Project (3GPP), an international standardization organization, Long Term Evolution (LTE), which is the 3.9th generation Radio Access Technology (RAT), and LTE-Advanced, which is the 4th generation RAT As a successor, Release 15 of New Radio (NR), which is a fifth generation (5G) RAT, has been specified (for example, Non-Patent Document 1).

NR introduces a technique called DRX (Discontinuous reception) that reduces the power consumption of terminals by limiting the period during which radio signals can be received. In addition to the RRC (Radio Resource Control) active state and RRC idle state, NR defines an RRC state called an RRC inactive state. A terminal in RRC idle state or RRC inactive state operates to receive radio signals during periods called paging occasions and not to receive radio signals during periods other than paging occasions.
In the current DRX specification, paging occasions may overlap in RRC idle state and RRC inactive state. Here, for some reason, the RRC state recognized by the terminal may not match the RRC state recognized by the network (base station and/or core network). Therefore, in order to quickly resolve RRC state inconsistency, it may be desirable to set paging opportunities in the RRC idle state and RRC inactive state so that they do not overlap.

One object of the present disclosure is to provide a terminal and a wireless communication method that enable more flexible DRX settings in the RRC idle state or RRC inactive state.

A terminal according to the present disclosure includes a receiver that receives a first DRX setting for RRC idle state and a second DRX setting for RRC inactive state, and an offset value for determining a paging frame as the second DRX setting. and a control unit for monitoring, in the RRC inactive state, paging opportunities corresponding to paging frames determined based on the predetermined information when predetermined information is received.

According to the present disclosure, it is possible to provide a terminal and a wireless communication method that enable more flexible DRX settings in the RRC idle state or RRC inactive state.

FIG. 1 is a diagram showing an example of an outline of a wireless communication system according to this embodiment. FIG. 2 is a diagram illustrating an example of state transition of a terminal. FIG. 3 is a diagram for explaining the DRX operation. FIG. 4 is a diagram for explaining the eDRX operation. FIG. 5 is a diagram illustrating an example of setting paging frames and paging opportunities. FIG. 6 is a sequence diagram illustrating an example of a procedure for setting DRX parameters in a terminal. FIG. 7 is a flow chart showing an example of DRX control in an inactive state. FIG. 8 is a diagram illustrating an example of DRX operation in pattern 1. In FIG. FIG. 9 is a diagram showing an example of specification change of TS38.304 in pattern 1. In FIG. FIG. 10 is a diagram showing an example of specification change of TS38.331 in pattern 1. In FIG. FIG. 11 is a diagram illustrating an example of DRX operation in pattern 2. In FIG. FIG. 12 is a diagram showing an example of specification change of TS38.304 in pattern 2. In FIG. FIG. 13 is a diagram showing an example of specification change of TS38.331 in pattern 2. In FIG. FIG. 14 is a diagram illustrating an example of DRX operation in pattern 3. In FIG. FIG. 15 is a diagram showing an example of specification change of TS38.304 in pattern 3. In FIG. FIG. 16 is a diagram showing an example of specification change of TS38.331 in pattern 3. In FIG. FIG. 17 is a diagram showing an example in which the PTW in the idle state and the PTW in the inactive state overlap. FIG. 18 is a diagram illustrating an example of the hardware configuration of each device within the wireless communication system. FIG. 19 is a diagram illustrating an example of a functional configuration of a terminal; FIG. 20 is a diagram illustrating an example of a functional configuration of a base station;

The present embodiment will be described below with reference to the accompanying drawings. In order to facilitate understanding of the description, the same constituent elements in each drawing are denoted by the same reference numerals as much as possible, and overlapping descriptions are omitted.

FIG. 1 is a diagram showing an example of an overview of a wireless communication system according to this embodiment. As shown in FIG. 1, the wireless communication system 1 may include a terminal 10, a base station 20, and a core network 30. Note that the numbers of terminals 10 and base stations 20 shown in FIG. 1 are merely examples, and are not limited to the numbers shown. In the following description, core network 30 and/or base station 20 may be referred to as "network".

As the radio access technology (Radio Access Technology: RAT) of the wireless communication system 1, for example, NR is assumed, but not limited to this, for example, LTE, LTE-Advanced or 6th generation or later RAT, etc. Various RATs are available.

The terminal 10 is, for example, a predetermined terminal or device such as a smartphone, a personal computer, an in-vehicle terminal, an in-vehicle device, a stationary device, a telematics control unit (TCU), or the like. Terminal 10 may also be called a User Equipment (UE), a Mobile Station (MS), a User Terminal, a Radio apparatus, a subscriber terminal, an access terminal, and so on. The terminal 10 may be mobile or stationary. The terminal 10 is configured to be able to communicate using, for example, NR as the RAT.

Here, in Release 17 of NR, it is lower than terminals for high-speed large capacity (enhanced Mobile Broadband: eMBB), ultra-reliable and low latency Communications (URLLC) introduced in

Release

15 or 16 It is being considered to support functions for terminals that assume performance and price ranges. The terminal is also called a reduced capability (RedCap) terminal, device, etc., and is used for, for example, industrial wireless sensors, video surveillance, wearable devices, etc. is assumed.

RedCap terminals are assumed to have higher performance than terminals for low power wide area communication (Low Power Wide Area: LPWA), and the carriers used by RedCap terminals are, for example, 20MHz, 50MHz or 100MHz bandwidth. There may be. Also, the maximum terminal bandwidth (maximum UE bandwidth) supported by RedCap terminals is, for example, 20 MHz for Frequency Range 1 (e.g., frequency bands below 6 GHz), Frequency Range 2 (e.g., frequency bands above 6 GHz). ) may be 100 MHz. Note that LPWA includes, for example, Category 1, Long Term Evolution for Machine-type-communication (LTE-M) and Narrow Band IoT (NB-IoT) that operate on LTE RAT. The maximum bandwidth of Category 1 is 20 MHz, the maximum bandwidth of LTE-M is 1.4 MHz (6 RB), and the maximum bandwidth of NB-IoT is 180 kHz (1 RB). In this way, RedCap terminals are expected to be used as middle-range terminals between those for eMBB and URLLC and those for LPWA. The terminal 10 according to this embodiment includes a RedCap terminal and a terminal for LPWA.

The base station 20 forms one or more cells C and communicates with the terminal 10 using the cell C. Cell C may be interchangeably referred to as serving cell, carrier, component carrier (CC), and the like. Base station 20 includes gNodeB (gNB), en-gNB, Next Generation-Radio Access Network (NG-RAN) node, eNB, low-power node, Central Unit (CU), Distributed Unit (DU) , gNB-DU, Remote Radio Head (RRH), Integrated Access and Backhaul/Backhauling (IAB) node, etc. The base station 20 is not limited to one node, and may be composed of a plurality of nodes (for example, a combination of a lower node such as DU and an upper node such as CU).

The core network 30 is, for example, an NR-compatible core network (5G Core Network: 5GC), but is not limited to this. A device on the core network 30 (hereinafter also referred to as “core network device”) performs mobility management such as paging and location registration of the terminal 10 . A core network device may be connected to the base station 20 via a predetermined interface (eg, S1 or NG interface).

The core network device includes, for example, AMF (Access and Mobility Management Function) for managing information related to access and mobility management, SMF (Session Management Function) for session management, and User Plane Function (UPF) for U-plane transmission control. , NSSF (Network Slice Selection Function) for managing network slices. Each of these functions is implemented in one or more physical or logical devices.

In the wireless communication system 1 , the terminal 10 receives downlink (DL) signals from the base station 20 and/or transmits uplink (UL) signals to the base station 20 . Terminal 10 may be configured with one or more carriers. Each carrier has a bandwidth of, for example, 5 MHz to 400 MHz. One carrier may be configured with one or more bandwidth parts (BWP). A BWP has the bandwidth of at least a portion of a carrier.

<UE state>
Next, the RRC state (RRC state) of the terminal 10 defined by NR will be described. The RRC state of the terminal 10 includes an RRC idle state (hereinafter referred to as "idle state"), an RRC inactive state (hereinafter referred to as "inactive state"), and an RRC connected state (hereinafter referred to as "connected state"). ”).

FIG. 2 is a diagram showing an example of state transition of the terminal 10. FIG. In FIG. 2, the idle state is a state in which an RRC connection is not established between the terminal 10 and the base station 20, and is also called RRC_IDLE, idle mode, RRC idle mode, or the like.

The idle state terminal 10 camps on a cell C selected by cell selection and/or cell reselection (hereinafter referred to as "cell selection/reselection"), and broadcasts on the cell C. receive system information The terminal 10 in the idle state transitions to the connected state when the RRC connection is established.

The inactive state is a state in which an RRC connection is established but suspended, and is also called RRC_INACTIVE, inactive mode, RRC inactive mode, and the like. A terminal 10 in an inactive state camps on a cell C selected by cell selection/reselection and receives system information broadcast on the cell C. FIG. In the inactive state, it is possible to save power in the terminal 10, as in the idle state. However, unlike the idle state, the RRC context and NAS (Non AccessStratum) context.

The core network 30 manages the position of the terminal 10 in units called TA (Tracking Area), and the core network 30 sends a paging message to a plurality of base stations 20 constituting the TA where the calling terminal 10 exists. Instruct to send. Also, one or more base stations 20 that have received the instruction transmit paging messages all at once.

In addition, in NR, a RAN Notification Area (RAN Notification Area: RNA), which is an area obtained by subdividing a TA (Tracking Area), is newly defined. manages the RAN notification area that In addition, in NR, a technique called "RAN paging (RAN paging, RAN initiated paging)" that performs paging processing in units of RAN notification areas, which is used when calling a terminal 10 in an inactive state, is introduced. In RAN paging, paging signals (also referred to as “paging messages”) are simultaneously transmitted from a plurality of base stations 20 forming a RAN notification area in which terminals 10 in an inactive state exist. The terminal 10 in the inactive state that has received the paging signal resumes the RRC connection and transitions to the connected state.

On the other hand, the process used when calling an idle terminal 10 according to an instruction from the core network 30 is called "CN paging (CN paging, CN initiated paging)". In CN paging, paging signals are simultaneously transmitted from a plurality of base stations 20 forming a TA in which idle terminals 10 exist. The idle terminal 10 that has received the paging signal notifies the upper layer (NAS layer) of the terminal 10 that it has received the paging signal. The RRC layer establishes an RRC connection according to an instruction from the NAS layer and transitions to the connected state.

In this embodiment, when CN paging and RAN paging are not distinguished, they are called "paging". In CN paging, the identifier of the terminal 10 used in the core network (eg, 5G-S-TMSI (5G S-Temporary Mobile Subscriber Identity)) is used as the identifier of the terminal 10 . Also, in RAN paging, the identifier of the terminal 10 used by the base station 20 (eg, full I-RNTI (Inactive-Radio Network Temporary Identity)) is used as the identifier of the terminal 10 . The identifier is notified from the base station 20 when the terminal 10 transitions to the inactive state. The paging message includes a paging record for each terminal 10 to be called. Each paging record contains an identifier for terminal 10 .

The connected state is a state in which the RRC connection is established, and is also called RRC_CONNECTED, connected mode, RRC connected mode, and the like. Terminal 10 in a connected state monitors a downlink control channel (PDCCH (Physical Downlink Control Channel)), and detects a downlink common channel (PDSCH (Physical Downlink Shared Channel)) based on the detected DCI (Downlink Control Information). Control reception. The terminal 10 in the connected state transitions to the idle state when the RRC connection is released, and transitions to the inactive state when the RRC connection is suspended.

<DRX and eDRX technology>
In NR, a slot with a variable length of time (eg, if the subcarrier is 15 kHz, 1 slot is 1 ms), a subframe with a length of 1 ms, and a subframe with a length of time of 1 ms A Radio Frame of 10 ms and a Hyperframe of duration 10.24 seconds are defined. The position of the radio frame is represented by an SFN (System Frame Number) from 0 to 1023. Also, in order to manage a time longer than 1024 radio frames, hyperframes with a length of SFN numbered 0 to 1023 (that is, 10.24 seconds) are defined. A hyperframe is represented by an H-SFN (Hyper-SFN) from 0 to 1023 numbers.

FIG. 3 is a diagram for explaining the DRX operation. In order to reduce the power consumption of the terminal 10, which is in an idle state or an inactive state, a downlink control channel (PDCCH) (more specifically, downlink control channel Radio signals are received by monitoring candidates (PDCCH candidates) (hereinafter referred to as "monitoring paging occasions"). The radio signals received by the terminal 10 include paging signals and/or short messages. The short message is a message transmitted by DCI1_0, and is used to notify the terminal 10 of changes in system information (systemInfoModification), ETWS (Earthquake and Tsunami Warning System) and/or CMAS (Commercial Mobile Alert Service).

When the terminal 10 is idle or inactive, the base station 20 transmits radio signals during the PO period and does not transmit radio signals during other periods. The terminal 10 that has received the paging signal establishes communication with the base station 20 and transitions to the connected state. A DRX cycle is a maximum of 2.56 seconds (2560 radio frames).

A paging frame (PF) is associated with a paging opportunity for the terminal 10 to monitor radio signals. A paging opportunity for the terminal 10 to monitor radio signals may be included in the paging frame or after the paging frame. Terminal 10 may monitor one paging opportunity per DRX cycle.

Here, the paging frame may be an SFN that satisfies Equation 1 below.

(Formula 1)
(SFN + PF_offset) mod T = (T div N)*(UE_ID mod N)
'T' indicates the DRX cycle and is set with the length of one or more radio frames. The current NR specification allows selection from T=32, 64, 128 and 256. 'N' indicates the total number of paging frames in the DRX cycle. In the current NR specifications, any one of N=T/1, T/4, T/8 and T/16 can be set. For example, if the DRX cycle is 32 and N=T/16, then N=32/16=2. "PF_offset" is an offset value used for determining the paging frame. 'UE_ID' may be, for example, the value of '5G S-TMIS mod 1024'.

Next, the paging opportunity may be determined based on the paging opportunity index (Index(i_s)) calculated by Equation 2 below.

(Formula 2)
i_s = floor (UE_ID/N) mod Ns
"Ns" indicates the number of paging opportunities in one paging frame.

FIG. 3 shows an example of paging frames and paging occasions when the DRX cycle is 32 radio frames, the value of N is 2, the PF_offset is 0, and Ns=2. Since the DRX cycle is 32 radio frames and the value of N is 2, there is a paging frame every 16 radio frames. If the value of N is 4, there will be a paging frame every 8 radio frames.

Here, the SFN of the paging frame for one terminal 10 is calculated based on Equation 1. For example, in the example of FIG. 3, there are terminals 10 whose paging frames are SFN=0, 32, and 64, and terminals 10 whose paging frames are SFN=16 and 48. FIG. The UE_ID of the terminal 10 determines which paging frame is for each terminal 10 .

The paging opportunity of terminal 10 is determined based on the value of i_s calculated based on Equation 2. If Ns=2, the value of i_s will be either 0 or 1. Whether the value of i_s of each terminal 10 is 0 or 1 is determined by the UE_ID of the terminal 10 . Each paging frame contains one or more paging opportunities or starting points of paging opportunities. In other words, each paging frame is associated with one or more paging opportunities. Also, one paging occasion is one set of a plurality of PDCCH monitoring occasions (PDCCH monitoring occasions) determined according to paging search space setting and the like. Which paging opportunity among the one or more paging occasions corresponding to each paging frame corresponds to the paging occasion that the terminal 10 should monitor is determined based on the value of i_s of each terminal 10 . For example, in the case of the terminal 10 with i_s=0, the paging opportunity corresponding to i_s=0 among the one or more paging opportunities associated with each paging frame corresponds to the paging opportunity of the terminal 10 . Similarly, for a terminal 10 with i_s=1, the paging opportunity corresponding to i_s=1 among the one or more paging opportunities associated with each paging frame corresponds to the paging opportunity of the terminal 10 .

Parameters for determining DRX operation such as DRX cycle, 'N', 'PF_offset' and 'Ns' (hereinafter referred to as 'DRX parameters') are sent in higher layer (NAS (Non Access Stratum)) messages and RRC messages. Alternatively, it is set in the terminal 10 using system information (SIB (System Information Block)) or the like. Also, the DRX parameters for the idle state (DRX parameters applied to the idle state) and the DRX parameters for the inactive state (DRX parameters applied to the inactive state) may be the same or different.

FIG. 4 is a diagram for explaining the eDRX (extended discontinuous reception) operation. As shown in FIG. 4, the eDRX-configured terminal 10 receives radio signals by monitoring paging opportunities that exist within a period called PTW (Paging Time Window) in an idle state or an inactive state. . One PTW is set in a hyperframe called PH (Paging Hyperframe). There may be one PH per eDRX cycle.

Here, PH may be H-SFN that satisfies Equation 10 below.

(Formula 10)
H-SFN mod T _eDRX,H = (UE_ID_H mod T _eDRX,H )
“T _eDRX,H ” indicates an eDRX cycle and is set with a length that is an integral multiple of a hyperframe. UE_ID_H may be the highest 10 or 12 bits of a hashed ID determined based on 5G-S-TMSI (5G S-Temporary Mobile Subscriber Identity).

The SFN, which is the PTW start position (PTW_start) (start timing), may be expressed by

Equations

11 and 12 below.

(Formula 11)
SFN = 256 * ieDRX
(Formula 12)
ieDRX=floor(UE_ID_H/TeDRX,H) mod 4
The SFN, which is the end position (PTW_end) (end timing) of the PTW, may be expressed by Equation 13 below.

(Formula 13)
SFN = (PTW_start+L*100-1) mod 1024
L is the PTW length (Paging Time Window length). Parameters that determine the eDRX operation such as the eDRX cycle and the length of time of the PTW (hereinafter referred to as "eDRX parameters") are obtained using higher layer (NAS (Non Access Stratum)) messages, RRC messages, system information, or the like. It is set in the terminal 10. The eDRX parameters for the idle state (eDRX parameters applied to the idle state) and the DRX parameters for the inactive state (eDRX parameters applied to the inactive state) may be the same or different.

<Overlapping paging opportunities>
In the current NR specifications, when the terminal 10 is in the inactive state, it is specified that both RAN paging and CN paging are monitored according to both the DRX parameters for the idle state and the DRX parameters for the inactive state. It is

Also, in the current NR specifications, the DRX parameters for the idle state are set using system information, and the DRX parameters for the inactive state are set using the RRC release message (RRC Release). Also, the DRX parameters for the idle state set in the system information include the DRX cycle, 'N', 'PF_offset' and 'Ns'. Also, the RRC release message contains only the DRX cycle. Therefore, the terminal 10 uses 'N', 'PF_offset' and 'Ns' set in the system information as DRX parameters for the inactive state. Thus, in the current NR specifications, the DRX parameters for the inactive state partially divert the DRX parameters for the idle state, so that the idle state paging opportunities and the inactive state paging opportunities overlap. sometimes.

FIG. 5 is a diagram showing an example of setting paging frames and paging opportunities. The upper part of FIG. 5 is an example DRX setting for an inactive state, and the lower part of FIG. 5 is an example DRX setting for an idle state. In FIG. 5, the paging frames in the non-active state of a terminal 10 are PF10, PF14, PF18, PF22 and PF26, and the paging frames in the idle state are PF100, PF108 and PF116. Thus, every second paging opportunity in the inactive state, ie, the paging opportunities corresponding to PF10, PF18 and PF26, will overlap with the paging opportunity in the idle state.

Normally, the RRC state managed by the terminal 10 and the RRC state managed by the network match, but for example, when the UE context (RRC context) is lost due to a software error in the base station 20, etc. For some reason the RRC state of the terminal 10 may be inconsistent between the terminal 10 and the network. The RRC state mismatch can be resolved by the terminal 10 receiving either RAN paging or CN paging and transitioning to the connected state. Therefore, in order to be able to resolve RRC state discrepancies early, paging opportunities are increased by setting so that paging opportunities do not overlap between the idle state and the inactive state, and when paging occurs, the terminal 10 It would be desirable to be able to receive CN paging or RAN paging earlier. Furthermore, if for some reason RAN paging and CN paging occur at the same time, base station 20 preferentially transmits either CN paging or RAN paging in the first paging opportunity that arrives, and the one that did not take precedence. paging signal may be transmitted at the next paging opportunity. In this case, the base station 20 needs to buffer the paging signal until the next paging opportunity, and the transmission of the paging signal is also delayed. In this way, it is conceivable that the overlapping of paging opportunities may cause pressure on the buffer of the base station 20 or delay in transmission of the paging signal. On the other hand, increasing paging opportunities also causes an increase in power consumption of the terminal 10 . Therefore, it is desirable to be able to set paging occasions more flexibly while considering the balance with power consumption.

<Processing procedure>
FIG. 6 is a sequence diagram showing an example of a processing procedure for setting DRX parameters in the terminal 10. As shown in FIG. In the following description, the positional relationship between paging frames and paging opportunities is assumed to be the same for all paging frames, including idle and inactive states (that is, the value of i_s is identical). For example, for the terminal 10 for which the 10th symbol counted from the first symbol in the paging frame corresponds to the paging opportunity, the 10th symbol counted from the first symbol corresponds to the paging opportunity in all paging frames. .

At step S100, the base station 20 transmits system information (SIB) including DRX parameter settings for the idle state.

In step S101, the terminal 10 sets the idle state DRX parameters included in the system information (that is, stores the idle state DRX parameters in the storage device). More specifically, the idle state DRX parameters included in the system information may be "defaultPagingCycle", "nAndPagingFrameOffset" and "ns" included in PCCH-Config among the information elements transmitted in SIB1. 'defaultPagingCycle' indicates the DRX cycle, and 'nAndPagingFrameOffset' indicates 'N' and 'PF_offset'. After that, it is assumed that the terminal 10 transitions to the active state.

In step S102, the base station 20 transmits an RRC release message (RRC Release) including a suspend configuration (SuspendConfig) to the terminal 10 when instructing the terminal 10 to transition from the active state to the inactive state. Suspend settings include DRX parameters for inactive states.

In step S103, the terminal 10 sets the DRX parameters for the inactive state (stores the DRX parameters in the storage device) included in the RRC release message, and transitions to the inactive state. At this time, the terminal 10 uses the DRX parameters for the idle state for the DRX parameters that are not included in the RRC release message among the DRX parameters required for the DRX operation (for example, the DRX cycle, N, PF_offset, and Ns). Diverting sets the DRX parameters for the inactive state.

A terminal 10 that has transitioned to the inactive state monitors idle and inactive paging opportunities according to both the idle DRX parameter and the inactive DRX parameter.

When the terminal 10 transitions to the idle state, the terminal 10 may monitor paging opportunities according to the DRX parameters for the idle state. Alternatively, the terminal 10 receives the idle state paging opportunity and the inactive state paging opportunity according to both the inactive state DRX parameter and the idle state DRX parameter set when the terminal 10 last transitioned to the inactive state. You may make it monitor.

The DRX parameter setting method described above is an example, and for example, the DRX parameters for the idle state and/or the DRX parameters for the inactive state may be set by NAS messages. Also, the inactive state DRX parameters are not limited to the RRC release message, and may be set in the terminal 10 using other messages. The other messages are, for example, an RRC reconfiguration message, an RRC reestablishment message, an RRC resume request (RRCResumeRequest/RRCResumeRequest1) message, an RRC resume (RRCResume) message, an RRC setup (RRCSetup) message, or It may be system information (SIB1, SIB2, etc.).

FIG. 7 is a flowchart showing an example of DRX control in an inactive state. The processing procedure of FIG. 7 details the processing procedure when the RRC message is received in step S102 of FIG.

At step S200, when the terminal 10 receives the RRC release message including the suspend setting, it transitions to the inactive state.

In step S201, the terminal 10 determines whether or not the suspend setting of the RRC release message includes a specific flag. If the specific flag is not included, the process proceeds to step S202, and if the specific flag is included, the process proceeds to step S203. A 'specific flag' may be defined as an information element that indicates to change the DRX parameters for the inactive state.

In step S<b>202 , the terminal 10 performs DRX control according to the DRX parameters for the idle state and the DRX parameters for the inactive state set by the base station 20 .

At step S203, the terminal 10 changes the DRX parameters for the inactive state according to the specific flag. In addition, the terminal 10 performs DRX control according to the DRX parameters for the idle state set by the base station 20 and the DRX parameters for the inactive state changed according to the specific flag.

<Processing when a specific flag is included>
Next, a processing procedure when a specific flag is included in the suspend setting of the RRC release message will be described.

(Pattern 1)
In the case of pattern 1, the specific flag is the "additional offset value" to be added to the idle state "PF_offset". When the RRC release message includes the "additional offset value", the terminal 10 changes the value of "PF_offset" in the idle state to a value to which the "additional offset value" is added, and converts the changed "PF_offset" into the formula By substituting 1, the paging frame is calculated. Also, when the RRC release message does not include the specific flag, the terminal 10 diverts the "PF_offset" in the idle state to the "PF_offset" in the inactive state.

FIG. 8 is a diagram explaining an example of DRX operation in pattern 1. FIG. In FIG. 8, it is assumed that PF10, PF18, and PF26 among the paging frames in the inactive state of the terminal 10 overlap with the paging frames PF100, PF108, and PF116 in the idle state, respectively.

The example of FIG. 8 shows a case where a specific flag indicating "additional offset value=Y" is set for the terminal 10 . In this case, the terminal 10 calculates its own paging frame by substituting the value obtained by adding Y to the value of "PF_offset=0", ie, "PF_offset=Y", into Equation 1. By increasing the value of "PF_offset", each paging frame is moved by the offset amount. This eliminates the overlap between the paging opportunities in the inactive state and the paging opportunities in the idle state, and allows more flexible setting of the paging opportunities.

FIG. 9 is a diagram showing an example of specification change of TS38.304 in pattern 1. FIG. 10 is a diagram showing an example of specification change of TS38.331 in pattern 1. In FIG. "ran-PagingFrameOffset-r17" shown in FIG. 10 corresponds to the specific flag.

(Pattern 2)
For pattern 2, the specific flag is a value indicating 'N' for inactive state. The value indicating "N" may be the value of N itself (for example, N = 2, 4, 8, 16, etc.), or a value indicating N indirectly (for example, N = T/1, T/4 , T/8 and T/16, etc.). When the value indicating "N" is included as the specific flag, the terminal 10 substitutes the value indicating "N" for "N" in Equation 1 to calculate the paging frame. Also, when the RRC release message does not include the specific flag, the terminal 10 uses the value indicating "N" in the idle state as the value indicating "N" in the inactive state.

FIG. 11 is a diagram explaining an example of DRX operation in pattern 2. FIG. In FIG. 11, it is assumed that PF10, PF18 and PF26 among the paging frames in the inactive state of the terminal 10 overlap with the paging frames PF100, PF108 and PF116 in the idle state.

The example of FIG. 11 shows a case where a specific flag indicating "N"=X (here, X=4) is set for the terminal 10. In this case, the terminal 10 calculates its own paging frame by substituting "N=X" into Equation 1. Here, it is assumed that N when the specific flag exists is at least a larger number than "N" in the idle state.

As "N" increases, the number of paging frames increases. For example, if "N" is changed from 2 to 4, the number of paging frames will increase by a factor of 2. For example, as shown in FIG. 11, by changing "N" from 2 to 4, PF11, PF13, PF15, PF17, PF19, PF21, PF23 and PF25 are added as new paging frames. Since the UE_ID is included in Equation 1, the paging frames assigned to each terminal 10 are distributed over the increased new paging frames. As a result, depending on the UE_ID of the terminal 10, increasing the value of N may move the paging frame in the inactive state to a paging frame that does not overlap with the paging frame in the idle state. For example, when N=2, PF10, PF18, and PF26 corresponded to the paging frame in the inactive state. There are terminals 10 that change to paging frames in the inactive state.

In this way, by increasing the value of N, there is a terminal 10 in which the paging frame in the inactive state and the paging frame in the idle state do not overlap. It is possible to eliminate the overlap with the paging opportunity and to set the paging opportunity more flexibly.

FIG. 12 is a diagram showing an example of specification change of TS38.304 in pattern 2. FIG. 13 is a diagram showing an example of specification change of TS38.331 in pattern 2. In FIG. "ran-PagingFrameN-r17" shown in FIG. 13 corresponds to the specific flag.

(Pattern 3)
In the case of pattern 3, the specific flag is a value indicating "additional offset value" to be added to "PF_offset" in the idle state and "N" in the inactive state. That is, pattern 3 is a combination of pattern 1 and pattern 2. FIG. Points not specifically mentioned in the description of pattern 3 may be the same as those of pattern 1 or pattern 2 .

FIG. 14 is a diagram explaining a DRX operation example in pattern 3. FIG. In FIG. 14, it is assumed that PF10, PF18 and PF26 among the paging frames in the inactive state of the terminal 10 overlap with the paging frames PF100, PF108 and PF116 in the idle state.

In the example of FIG. 14, a specific flag indicating "additional offset value=Y" is set for the terminal 10, and a specific flag indicating "N"=X (here, X=4) is set. indicates the case. In this case, the terminal 10 calculates its own paging frame by substituting the value obtained by adding Y to the value of 'PF_offset=0', that is, 'PF_offset=Y' and 'N=X' into Equation 1. . Here, N when the specific flag is present is at least a number greater than "N" for the inactive state when the specific flag is not present.

By increasing N, the number of paging frames will increase. Furthermore, each paging frame is moved by increasing the value of "PF_offset". This eliminates the overlap between the paging opportunities in the inactive state and the paging opportunities in the idle state, and allows more flexible setting of the paging opportunities.

FIG. 15 is a diagram showing an example of specification change of TS38.304 in pattern 3. FIG. 16 is a diagram showing an example of specification change of TS38.331 in pattern 3. In FIG. "ran-PagingFrameOffset-r17" and "ran-PagingFrameN-r17" shown in FIG. 16 correspond to specific flags.

<Modification>
The specific flag is not limited to the RRC release message, and may be set in the terminal 10 using other messages. The other messages are, for example, an RRC reconfiguration message, an RRC reestablishment message, an RRC resume request (RRCResumeRequest/RRCResumeRequest1) message, an RRC resume (RRCResume) message, an RRC setup (RRCSetup) message, or It may be system information (SIB1, SIB2, etc.).

In

patterns

1 and 3, the "specific flag" may be a value indicating "PF_offset" for the inactive state, instead of the "additional offset value" to be added to the "PF_offset" in the idle state. That is, when the RRC release message includes "PF_offset" for the inactive state, the terminal 10 may calculate the paging frame by substituting the "PF_offset" into Equation 1.

In

patterns

2 and 3, the "specific flag" may be a value to be added to "N" in the idle state. That is, when the RRC release message includes "a value to be added to N", the terminal 10 substitutes N obtained by adding "a value to be added to N" to the terminal 10 "N" into Equation 1, thereby generating a paging frame may be calculated.

The terminal 10 sets the DRX parameters described in patterns 1 to 3 in a period in which the PTW in the idle state and the PTW in the inactive state overlap, or in the PH in which the PTW in the idle state and the PTW in the inactive state overlap. You may make it perform a change process.

FIG. 17 shows an example in which the PTW in the idle state and the PTW in the inactive state overlap when the terminal 10 performs the eDRX operation. The terminal 10 changes the DRX parameter based on the specific flag in a period in which the PTW in the idle state and the PTW in the inactive state overlap, or in the PH in which the PTW in the idle state and the PTW in the inactive state overlap. DRX control may be performed using the DRX parameters obtained (that is, the processing procedure of step S203 in FIG. 7 is executed). Further, when the PTW in the idle state and the PTW in the inactive state do not overlap, the terminal 10 does not change the DRX parameters based on the specific flag, but performs DRX control using the set DRX parameters. (that is, the processing procedure of step S202 in FIG. 7 is executed).

<Hardware configuration>
FIG. 18 is a diagram illustrating an example of the hardware configuration of each device within the wireless communication system. Each device in the wireless communication system 1 (eg, terminal 10, base station 20, core network 30, etc.) includes a processor 11, a storage device 12, a communication device 13 that performs wired or wireless communication, and an input device that receives various input operations. and an input/output device 14 for outputting various information.

The processor 11 is, for example, a CPU (Central Processing Unit) and controls each device within the wireless communication system 1 . The processor 11 may read and execute the program from the storage device 12 to execute various processes described in this embodiment. Each device within the wireless communication system 1 may be configured with one or more processors 11 . Each device may also be called a computer.

The storage device 12 is composed of storage such as memory, HDD (Hard Disk Drive) and/or SSD (Solid State Drive). The storage device 12 may store various types of information necessary for execution of processing by the processor 11 (for example, programs executed by the processor 11, etc.).

The communication device 13 is a device that communicates via a wired and/or wireless network, and may include, for example, network cards, communication modules, chips, antennas, and the like. Further, the communication device 13 may include an amplifier, an RF (Radio Frequency) device that performs processing related to radio signals, and a BB (BaseBand) device that performs baseband signal processing.

The RF device, for example, performs D/A conversion, modulation, frequency conversion, power amplification, etc. on the digital baseband signal received from the BB device to generate a radio signal to be transmitted from the antenna. Further, the RF device generates a digital baseband signal by performing frequency conversion, demodulation, A/D conversion, etc. on the radio signal received from the antenna, and transmits the digital baseband signal to the BB device. The BB device performs a process of converting a digital baseband signal into a packet and a process of converting the packet into a digital baseband signal.

The input/output device 14 includes input devices such as keyboards, touch panels, mice and/or microphones, and output devices such as displays and/or speakers.

The hardware configuration described above is just an example. Each device in the wireless communication system 1 may omit part of the hardware shown in FIG. 18, or may include hardware not shown in FIG. Also, the hardware shown in FIG. 18 may be configured by one or a plurality of chips.

<Functional configuration>
(terminal)
FIG. 19 is a diagram showing an example of the functional configuration of the terminal 10. As shown in FIG. Terminal 10 includes receiver 101 , transmitter 102 , and controller 103 . All or part of the functions realized by the receiving unit 101 and the transmitting unit 102 can be realized using the communication device 13 . All or part of the functions realized by the receiving unit 101 and the transmitting unit 102 and the control unit 103 can be realized by the processor 11 executing a program stored in the storage device 12 . Also, the program can be stored in a storage medium. The storage medium storing the program may be a non-transitory computer readable medium. The non-temporary storage medium is not particularly limited, but may be a storage medium such as a USB memory or CD-ROM, for example.

The receiving unit 101 receives the downstream signal. Also, the receiving section 101 may receive information and/or data transmitted via a downlink signal. Here, "receiving" may include, for example, performing processing related to reception such as at least one of receiving, demapping, demodulating, decoding, monitoring, and measuring radio signals.

Also, receiving section 101 receives the DRX parameters for the idle state and the DRX parameters for the inactive state.

The transmission unit 102 transmits an upstream signal. Also, the transmitting section 102 may transmit information and/or data transmitted via an uplink signal. Here, "transmitting" may include performing processing related to transmission, such as at least one of encoding, modulation, mapping, and transmission of radio signals.

Based on the DRX parameters received by the receiving unit 101, the control unit 103 performs various processes related to DRX. Further, when control section 103 receives a specific flag indicating information about an offset value (PF_offset) for determining a paging frame as a DRX parameter for inactive state, in RRC inactive state, based on the specific flag, monitor paging opportunities corresponding to paging frames determined by

Here, the specific flag may indicate an additional offset value to be added to the first offset value (PF_offset) for determining the paging frame indicated by the DRX parameter for idle state. That is, the specific flag may indicate that the offset value for the inactive state (PF_offset) is determined by adding an additional offset value to the first offset value for the idle state (PF_offset). Further, in the non-active state, the control unit 103 monitors the paging opportunity corresponding to the paging frame determined based on the offset value obtained by adding the additional offset value to the first offset value indicated by the DRX parameters for the idle state. You may make it For example, the terminal 10 adds the "PF_offset" obtained by adding the additional offset value indicated by the specific flag to the "PF_offset" included in the DRX parameter applied to the idle state, and the "PF_offset" applied to the inactive state. (corresponding to pattern 1).

Also, the specific flag may indicate a second offset value (PF_offset) for determining an inactive paging frame. Also, the control unit 103 may monitor the paging opportunity corresponding to the paging frame determined based on the second offset value (PF_offset) indicated by the DRX parameter for inactive state. For example, when the DRX parameter set as the DRX parameter to be applied to the inactive state does not include "PF_offset", the terminal 10 sets the "PF_offset" indicated by the specific flag to the "PF_offset" to be applied to the inactive state. (corresponding to the modified example).

Further, when the control unit 103 does not receive the specific flag, in the inactive state, the paging frame determined based on the offset value (PF_offset) for determining the paging frame, which is indicated by the DRX parameters for the idle state. , may be monitored for paging occasions corresponding to .

Also, the specific flag may be information on the offset value (PF_offset) for determining the paging frame (additional offset value or second offset value) and information on the number of paging frames (N) per DRX cycle. . Also, in the inactive state, the control unit 103 may monitor paging opportunities corresponding to paging frames determined based on specific flags (PF_offset and N) (corresponding to pattern 3).

Further, when control section 103 receives a specific flag that is information about the number of paging frames (N) per DRX cycle as a DRX parameter for inactive state, control section 103 determines based on the specific flag in inactive state. Paging occasions corresponding to paging frames may be monitored. Further, when the control unit 103 does not receive the specific flag, in the inactive state, the paging frame determined based on the information indicating the number of paging frames per one DRX cycle indicated by the DRX parameters for the idle state. (corresponding to pattern 2).

Here, the specific flag may be a value (that is, a value directly indicating) indicating the number (N) of paging frames per DRX cycle for determining inactive paging frames. When receiving a specific flag, control section 103 monitors, in an inactive state, paging opportunities corresponding to paging frames determined based on the number of paging frames per DRX cycle indicated by the specific flag. may

Also, the specific flag may indicate the number of additional paging frames to be added to the number of paging frames per DRX cycle for determining the paging frames indicated by the DRX parameter for idle state. When the specific flag is received, control section 103 is determined based on the number obtained by adding the number of additional paging frames to the number of paging frames per DRX cycle indicated by the DRX parameter for idle state in the inactive state. A paging opportunity corresponding to a paging frame corresponding to a paging frame may be monitored (corresponding to a modification).

FIG. 20 is a diagram showing an example of the functional configuration of the base station 20. As shown in FIG. Base station 20 includes receiver 201 , transmitter 202 , and controller 203 . All or part of the functions realized by the receiving unit 201 and the transmitting unit 202 can be realized using the communication device 13 . All or part of the functions realized by the receiving unit 201 and the transmitting unit 202 and the control unit 103 can be realized by the processor 11 executing a program stored in the storage device 12 . Also, the program can be stored in a storage medium. The storage medium storing the program may be a computer-readable non-temporary storage medium. The non-temporary storage medium is not particularly limited, but may be a storage medium such as a USB memory or CD-ROM, for example.

The receiving unit 201 receives an upstream signal. Also, the receiving section 201 may receive information and/or data transmitted via the uplink signal.

The transmission unit 202 transmits a downlink signal. Also, the transmitting section 202 may transmit information and/or data transmitted via the downlink signal. Also, the transmitting unit 202 transmits DRX parameters for idle state to the terminal 10, for example, via system information. Also, the transmitting unit 202 transmits DRX parameters for inactive state to the terminal 10 via an RRC message (for example, an RRC release message). Also, transmitting section 202 transmits an RRC message (for example, an RRC release message) including a specific flag to terminal 10 .

The control unit 203 allocates uplink resources and downlink resources to the terminal 10, and the like. For example, when receiving a scheduling request from the terminal 10 , the control section 203 allocates resources for transmitting uplink data to the terminal 10 (uplink scheduling). Also, the control unit 203 transmits radio signals (paging signals and/or short messages) at paging occasions set in each terminal 10 .

<Supplement>
A DRX parameter is an example of a DRX configuration. A specific flag is an example of predetermined information. A DRX configuration for idle state is an example of a first DRX configuration. A DRX configuration for an inactive state is an example of a second DRX configuration.

DRX may also be referred to as discontinuous reception and consultation interval control. eDRX may also be referred to as enhanced discontinuous reception and enhanced reception interval control. A DRX cycle may be referred to as a paging cycle. An eDRX cycle may be referred to as an extended paging cycle. Paging occasions may also be referred to as paging reception periods, paging reception timings, and the like.

The DRX parameters for idle state may be called default DRX parameters, DRX parameters notified by system information, DRX parameters for CN paging, and the like. Also, the DRX parameters for the inactive state may be referred to as DRX parameters in suspend settings, and the like. It may also be called a DRX parameter for RAN paging. System information may be called broadcast information.

Various signals, information, and parameters in the above embodiments may be signaled in any layer. That is, the various signals, information, and parameters are replaced with signals, information, and parameters of any layer such as higher layers (eg, NAS layer, RRC layer, MAC layer, etc.), lower layers (eg, physical layer), etc. good too. Further, the notification of the predetermined information is not limited to being performed explicitly, but may be performed implicitly (for example, by not notifying the information or using other information).

Also, the names of various signals, information, parameters, IEs, channels, time units, and frequency units in the above embodiments are merely examples, and may be replaced with other names. For example, a slot may be named any unit of time having a predetermined number of symbols. Also, RB may be any name as long as it is a frequency unit having a predetermined number of subcarriers.

In addition, the use of the terminal 10 in the above embodiment (for example, for RedCap, IoT, etc.) is not limited to those illustrated, as long as it has similar functions, any use (for example, eMBB, URLLC, Device-to- Device (D2D), Vehicle-to-Everything (V2X), etc.).

In addition, the format of various information is not limited to the above embodiment, and may be appropriately changed to bit representation (0 or 1), true/false value (Boolean: true or false), integer value, character, or the like. Also, singularity and plurality in the above embodiments may be interchanged.

The present embodiment has been described above with reference to specific examples. However, the present disclosure is not limited to these specific examples. Design modifications to these specific examples by those skilled in the art are also included in the scope of the present disclosure as long as they have the features of the present disclosure. Each element included in each specific example described above and its arrangement, conditions, shape, etc. are not limited to those illustrated and can be changed as appropriate. As long as there is no technical contradiction, the combination of the elements included in the specific examples described above can be changed as appropriate.

Claims

a receiver for receiving a first DRX configuration for RRC idle state and a second DRX configuration for RRC inactive state;
When predetermined information regarding an offset value for determining a paging frame is received as the second DRX setting, in the RRC inactive state, control for monitoring paging opportunities corresponding to the paging frame determined based on the predetermined information. Department and
terminal with
the predetermined information indicates an additional offset value to be added to the first offset value for determining the paging frame indicated by the first DRX setting;
The control unit, in the RRC inactive state, monitors paging opportunities corresponding to paging frames determined based on an offset value obtained by adding the additional offset value to the first offset value indicated by the first DRX setting. do,
A terminal according to claim 1 .
The predetermined information is information indicating a second offset value for determining the RRC inactive paging frame,
the controller monitors paging opportunities corresponding to paging frames determined based on the second offset value indicated by the second DRX setting;
A terminal according to claim 1 .
The control unit corresponds to the paging frame determined based on the offset value for determining the paging frame indicated by the first DRX setting in the RRC inactive state when the predetermined information is not received. monitor paging opportunities,
The terminal according to any one of claims 1-3.
the predetermined information is information about the offset value and information about the number of paging frames per DRX cycle;
The control unit, in the RRC inactive state, monitors paging opportunities corresponding to paging frames determined based on the predetermined information.
A terminal according to any one of claims 1-4.
receiving a first DRX setting for RRC idle state and a second DRX setting for RRC inactive state;
When predetermined information regarding an offset value for determining a paging frame is received as the second DRX setting, monitoring in the RRC inactive state a paging opportunity corresponding to the paging frame determined based on the predetermined information. When,
The communication method performed by the terminal, including