KR20210054721A - Method and apparatus for performing stepwise measurement procedures in next generation mobile communication system - Google Patents

Abstract

The present disclosure relates to a communication method for converging a 5G communication system for supporting higher data rates beyond a 4G system with a technology for IoT, and a system thereof. The present disclosure can be applied to intelligent services based on the 5G communication technology and the IoT-related technology, such as smart home, smart building, smart city, smart car, connected car, health care, digital education, smart retail, security and safety services, and the like. In addition, the present invention discloses a method and device for relaxed measurement of a terminal.

Description

Method and apparatus for performing a stepwise measurement operation in a next-generation mobile communication system {METHOD AND APPARATUS FOR PERFORMING STEPWISE MEASUREMENT PROCEDURES IN NEXT GENERATION MOBILE COMMUNICATION SYSTEM}

The present disclosure relates to a next-generation mobile communication system. Specifically, the present disclosure relates to a method and apparatus for performing stepwise measurement in order to save power of a terminal in a next-generation mobile communication system.

Efforts are being made to develop an improved 5G communication system or a pre-5G communication system in order to meet the increasing demand for wireless data traffic after the commercialization of 4G communication systems. For this reason, a 5G communication system or a pre-5G communication system is called a Beyond 4G Network communication system or an LTE system and a Post LTE system. The 5G communication system defined by 3GPP is called the New Radio (NR) system.

In order to achieve a high data rate, the 5G communication system is being considered for implementation in the ultra-high frequency (mmWave) band (eg, such as the 60 Giga (60 GHz) band). In order to mitigate the path loss of radio waves in the ultra-high frequency band and increase the transmission distance of radio waves, 5G communication systems include beamforming, massive MIMO, and Full Dimensional MIMO (FD-MIMO). ), array antenna, analog beam-forming, and large scale antenna techniques were discussed and applied to NR systems.

In addition, in order to improve the network of the system, in 5G communication systems, evolved small cells, advanced small cells, cloud radio access networks (cloud RAN), and ultra-dense networks. , Device to Device communication (D2D), wireless backhaul, moving network, cooperative communication, CoMP (Coordinated Multi-Points), and interference cancellation And other technologies are being developed.

In addition, in 5G systems, advanced coding modulation (ACM) methods such as Hybrid FSK and QAM Modulation (FQAM) and SWSC (Sliding Window Superposition Coding), advanced access technologies such as Filter Bank Multi Carrier (FBMC), NOMA (non-orthogonal multiple access), and sparse code multiple access (SCMA) have been developed.

Meanwhile, the Internet is evolving from a human-centered connection network in which humans create and consume information, to an Internet of Things (IoT) network that exchanges and processes information between distributed components such as objects. Internet of Everything (IoE) technology, which combines IoT technology with big data processing technology through connection with cloud servers, is also emerging. In order to implement IoT, technological elements such as sensing technology, wired/wireless communication and network infrastructure, service interface technology, and security technology are required. , M2M), and MTC (Machine Type Communication) technologies are being studied. In the IoT environment, intelligent IT (Internet Technology) services that create new value in human life by collecting and analyzing data generated from connected objects can be provided. IoT is the field of smart home, smart building, smart city, smart car or connected car, smart grid, healthcare, smart home appliance, advanced medical service, etc. through the convergence and combination of existing IT (Information Technology) technology and various industries. Can be applied to.

Accordingly, various attempts have been made to apply a 5G communication system to an IoT network. For example, 5G communication such as a sensor network, machine to machine (M2M), and machine type communication (MTC) is implemented by techniques such as beamforming, MIMO, and array antenna. The application of a cloud radio access network (cloud RAN) as the big data processing technology described above can be said as an example of the convergence of 5G technology and IoT technology.

Meanwhile, with the development of communication systems, there is an increasing demand for a method to reduce power consumption when performing measurement of a terminal.

The present disclosure aims to save power of a terminal when performing measurement by proposing a step-by-step measurement operation of a terminal. In particular, for each of the intra-frequency and inter-frequency measurements, the goal is to efficiently reduce the power consumption of the terminal by proposing a criterion for relaxed measurement for each parameter provided for radio resource management (RRM) measurement.

The method of the present disclosure for solving the above problem includes the steps of: receiving, from a base station, first setting information related to stopping measurement and second setting information related to relaxed measurement; Determining whether a condition determined by the first setting information is satisfied; Determining whether the condition determined by the second setting information is satisfied if the measurement cannot be stopped because the condition determined by the first setting information is not satisfied; And if the condition determined by the second setting information is satisfied, performing the relaxed measurement.

According to various embodiments proposed in the present disclosure, power consumption for performing measurement by the terminal may be reduced through the stepwise measurement operation of the terminal. In addition, according to embodiments of the present disclosure, power consumption of a terminal can be efficiently reduced by separately providing parameters for relaxed measurement for intra frequency measurement and inter frequency measurement, respectively.

1A is a diagram showing the structure of a next-generation mobile communication system.
1B is a terminal in which priority information for each frequency for cell reselection is broadcast through a system information block (SIB) or an RRC Connection Release message, which is a dedicated radio resource control (RRC) signaling, in relation to an embodiment of the present disclosure. It is a diagram for explaining the process of being transmitted to.
1C is a diagram illustrating a method of performing cell reselection by a terminal in relation to an embodiment of the present disclosure.
1D is a flowchart of a process of performing relaxed RRM measurement in relation to an embodiment of the present disclosure.
1E is a flowchart of a terminal operation according to an embodiment of the present disclosure.
1F is a flowchart of a process of performing a first operation and a second operation step by step according to an embodiment of the present disclosure.
1H is a block diagram illustrating an internal structure of a terminal according to an embodiment of the present disclosure.
1I is a block diagram showing a configuration of a base station according to an embodiment of the present disclosure.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the following description of the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, a detailed description thereof will be omitted.

For the same reason, some elements in the accompanying drawings are exaggerated, omitted, or schematically illustrated. In addition, the size of each component does not fully reflect the actual size. The same reference numerals are assigned to the same or corresponding components in each drawing.

Advantages and features of the present invention, and a method of achieving them will become apparent with reference to the embodiments described below in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms, and only these embodiments make the disclosure of the present invention complete, and the general knowledge in the technical field to which the present invention pertains. It is provided to completely inform the scope of the invention to the possessor, and the invention is only defined by the scope of the claims. The same reference numerals refer to the same elements throughout the specification.

At this time, it will be appreciated that each block of the flowchart diagrams and combinations of the flowchart diagrams may be executed by computer program instructions. Since these computer program instructions can be mounted on the processor of a general purpose computer, special purpose computer or other programmable data processing equipment, the instructions executed by the processor of the computer or other programmable data processing equipment are described in the flowchart block(s). It creates a means to perform functions. These computer program instructions can also be stored in computer-usable or computer-readable memory that can be directed to a computer or other programmable data processing equipment to implement a function in a particular way, so that the computer-usable or computer-readable memory It is also possible for the instructions stored in the flow chart to produce an article of manufacture containing instruction means for performing the functions described in the flowchart block(s). Since computer program instructions can also be mounted on a computer or other programmable data processing equipment, a series of operating steps are performed on a computer or other programmable data processing equipment to create a computer-executable process to create a computer or other programmable data processing equipment. It is also possible for instructions to perform processing equipment to provide steps for executing the functions described in the flowchart block(s).

In addition, each block may represent a module, segment, or part of code that contains one or more executable instructions for executing the specified logical function(s). In addition, it should be noted that in some alternative execution examples, the functions mentioned in the blocks may occur out of order. For example, two blocks shown in succession may in fact be executed substantially simultaneously, or the blocks may sometimes be executed in the reverse order depending on the corresponding function.

In this case, the term'~ unit' used in this embodiment refers to software or hardware components such as FPGA or ASIC, and'~ unit' performs certain roles. However,'~ part' is not limited to software or hardware. The'~ unit' may be configured to be in an addressable storage medium, or may be configured to reproduce one or more processors. Thus, as an example,'~ unit' refers to components such as software components, object-oriented software components, class components, and task components, processes, functions, properties, and procedures. , Subroutines, segments of program code, drivers, firmware, microcode, circuitry, data, database, data structures, tables, arrays, and variables. Components and functions provided in the'~ units' may be combined into a smaller number of elements and'~ units', or may be further separated into additional elements and'~ units'. In addition, components and'~ units' may be implemented to play one or more CPUs in a device or a security multimedia card.

1A is a diagram showing the structure of a next-generation mobile communication system.

Referring to FIG. 1A, as shown, a radio access network of a next-generation mobile communication system (New Radio, NR) includes a next-generation base station (New Radio Node B, hereinafter referred to as gNB) (1a-10) and an AMF (Access Management Function, 1a-). 05, that is, the entity of the New Radio Core Network). The user terminal (New Radio User Equipment, hereinafter referred to as NR UE or terminal) 1a-15 accesses the external network through the gNB 1a-10 and the AMF 1a-05.

In FIG. 1A, the gNB corresponds to an evolved node B (eNB) of an existing LTE system. The gNB is connected to the NR UE through a radio channel and can provide a service superior to that of the existing Node B (1a-20). In the next-generation mobile communication system, since all user traffic is serviced through a shared channel, a device that collects and schedules status information such as buffer status, available transmission power status, and channel status of UEs is required. 1a-10) is in charge. One gNB typically controls multiple cells. In order to implement ultra-high-speed data transmission compared to the existing LTE, it may have more than the existing maximum bandwidth, and an orthogonal frequency division multiplexing (hereinafter referred to as OFDM) may be used as a radio access technology, and an additional beamforming technology may be applied. . In addition, an adaptive modulation and coding method (hereinafter referred to as AMC) that determines a modulation scheme and a channel coding rate according to a channel state of the terminal is applied. AMF (1a-05) performs functions such as mobility support, bearer configuration, and quality of service (QoS) configuration. The AMF is a device responsible for various control functions as well as a mobility management function for a terminal, and is connected to a plurality of base stations. In addition, the next-generation mobile communication system can be interlocked with the existing LTE system, and the AMF is connected to the MME (Mobility Management Entity, 1a-25) through a network interface. The MME is connected to the eNB (1a-30), which is an existing base station. A terminal supporting LTE-NR Dual Connectivity can transmit and receive data while maintaining connection to not only the gNB but also the eNB (1a-35).

FIG. 1B is a diagram for explaining a process in which frequency-specific priority information for cell reselection in LTE is broadcast through SIB or applied to a specific terminal through an RRC Connection Release message, which is dedicated RRC signaling. Cell reselection is a process of reselecting a serving cell so that a mobile terminal can be connected to a cell having the best channel state. The network assigns priority for each frequency to control cell reselection of terminals in the standby mode. For example, if one terminal receives priority information for two frequencies f1 and f2, and f1 has a higher priority than f2, the probability that the terminal will stay at f1 increases. Also, even if the terminal is in f2, if the channel state of f2 is not good, it will try to change to f1. Priority information for a frequency is broadcasted through SIB or provided to a specific terminal through an RRC Connection Release message, which is dedicated RRC signaling. Even if the UE already has priority information for frequencies through the SIB, if the UE receives UE-specific priority information through RRC signaling, the priority information of the SIB is ignored. The priority information of each frequency is transmitted through the cellReselectionPriority IE of Table 1 (CellReselectionPriority information element) below, and is given one of the priorities of a total of X+1 steps. The lower the value, the lower the priority. That is, '0' means the lowest priority.

- ASN1START
- TAG-CELLRESELECTIONPRIORITY-START

CellReselectionPriority ::= INTEGER (0..7)

- TAG-CELLRESELECTIONPRIORITY-STOP
- ASN1STOP

Frequencies between radio access technology (RAT) cannot be given the same priority. If the IDLE state of the terminal is'camped on any cell state', the terminal applies the frequency priority information received through the SIB, and can only store the priority information received through RRC signaling without using it. cellReselectionPriority IE is an optional IE and may not be included in RRC signaling. In this case, priority information for the frequency is not assigned. In this case, the UE regards the priority of the corresponding frequency as the lowest level. In steps 1b-00, the UE receives priority information for frequencies used by other RATs as well as EUTRA through the SIB. However, priority information is not necessarily provided for all frequencies, and priority information on frequencies of the serving cell currently camped to the terminal may not be provided. The terminal checks whether such priority information is provided in steps 1b-05. If priority information on the frequency of the current serving cell is not provided, the priority of the frequency is regarded as the lowest level. The UE applies priority information of each frequency in step 1b-15. When the terminal receives the RRC Connection Release message from the base station, the terminal switches from the connected mode to the idle mode (IDLE mode). The RRC message may include frequency priority information. This is UE-specific information, and is generally applied preferentially to the frequency priority information provided from the SIB. Accordingly, the UE checks whether there is frequency priority information in the RRC message in step 1b-20. If present, the first timer is driven in steps 1b-25 by applying the included first timer value. The terminal determines whether the current standby mode state is'camped on any cell state' or'camped normally state' in steps 1b-35. The'camped normally state' refers to a state in which the terminal is camping in a suitable cell. A suitable cell is a cell that can provide a normal service to a terminal, and is a cell that satisfies the detailed conditions as follows.

-A cell corresponds to a selected PLMN, registered PLMN, or one PLMN in the equivalent PLMN list

-Cells not barring

-Cell that satisfies the Cell selection criterion

-'camped on any cell state' refers to a state in which the terminal is camping on an acceptable cell because it cannot camp on a suitable cell. In an acceptable cell, general services are not possible, and only an emergency call can be attempted by the terminal. Acceptable cell is a cell that satisfies the following conditions.

-Cells not barring

-Cell that satisfies the Cell selection criterion

If the terminal is in the'camped on any cell state' standby state, instead of the priority information provided from the RRC Connection Release message, it returns to step 1b-15 and applies the frequency priority information provided from the SIB. If the terminal is in the'camped normally' standby state, the terminal determines whether at least one of the following three conditions is satisfied in steps 1b-35. The three conditions are,

-The terminal is switched to the connected mode

-The first timer has expired

-According to NAS request, PLMN selection process is performed

If any of the above conditions are satisfied, the UE discards the priority information provided from the RRC Connection Release message in step 1b-40, returns to step 1b-15, and returns the frequency priority information provided from the SIB. Apply. Otherwise, if none of the conditions are satisfied, the UE applies the priority information provided from the RRC Connection Release message in steps 1b-45.

The frequency priority information influences the UE to measure a specific frequency. For frequencies having a higher priority than the current serving cell, the UE always performs measurement. On the other hand, the same frequency as the serving cell (intra-frequency) or another frequency having the same or lower priority than that of the serving cell does not always perform measurement for the corresponding frequency in order to save terminal power. Whether to perform measurement is performed when the channel QoS of the serving cell is less than or equal to a specific threshold. Cell reselection is performed in order to move to a cell having a good channel state. Although the channel QoS of the current serving cell is good, there is no reason to move to a frequency with the same or lower priority. Therefore, in order to reduce power consumption due to unnecessary channel measurement, it is determined whether to perform measurement based on a specific threshold. In the case of the same frequency (intra-frequency), when the QoS (i.e., Srxlev or Squal) of the serving cell is the same or lower than the specific threshold Sintrasearch (s-IntraSearchP and s-IntraSearchQ), channel measurement for other cells of the same frequency Perform. s-IntraSearchP is an RSRP-based threshold, and s-IntraSearchQ is an RSRQ-based threshold. When both the measured RSRP and RSRQ of the serving cell are greater than the threshold value, intra-frequency measurement is not performed. For other frequencies with the same or lower priority, if the QoS (i.e., Srxlev or Squal) of the serving cell is the same or lower than the specific threshold Snonintrasearch (s-NonIntraSearchP and s-NonIntraSearchQ), the corresponding other frequency Channel measurements are performed on the cells of. s-NonIntraSearchP is a reference signal received power (RSRP)-based threshold, and s-NonIntraSearchQ is a reference signal received quality (RSRQ)-based threshold. When both the measured RSRP and RSRQ of the serving cell are greater than the threshold value, inter-frequency measurement is not performed. In the present invention, a state in which channel measurement is performed at an intra-frequency or inter-frequency through comparison with the threshold values is referred to as a normal measurement state, and a state otherwise is referred to as a no measurement state. Regardless of the measurement state, the serving cell measurement is always performed.

While performing this measurement, if the channel QoS of the cell having a high priority frequency is higher than a specific threshold ThreshX-high, the UE reselects the cell having a high priority frequency as the serving cell. When the channel QoS of the cell with a lower priority frequency is higher than the specific threshold ThreshX-low and the QoS of the serving cell is lower than ThreshServing-low, the UE reselects the cell with the lower priority frequency as the serving cell.

1C is a diagram illustrating a method of performing cell reselection by a UE in connection with the present disclosure.

The UE always performs inter-freq/RAT measurement for a high-priority frequency or RAT regardless of the strength of the measurement signal for the serving cell. If the measurement signal strength for the serving cell is lower than SintraSearch (1c-25), the UE performs intra-freq measurement. If the measured signal strength for the serving cell is lower than SnonintraSearch (1c-30), the UE performs inter-freq/RAT measurement for a frequency equal to or lower than the frequency of the current serving cell. The reason for triggering the terminal measurement operation is to reduce power consumption of the terminal due to measurement of neighboring cells. When the channel QoS of the cell (1c-10) having a high priority frequency is higher than the specific threshold ThreshX-high (1c-35), the UE reselects the cell having a high priority frequency as the serving cell. When the channel QoS of the cell (1c-00) of a frequency with a low priority is higher than a specific threshold ThreshX-low (1c-15) and the QoS of the serving cell is lower than ThreshServing-low (1c-20), the UE is A cell of a frequency having a priority is reselected as a serving cell.

In cell reselection, received signal strength (RSRP) or received signal quality (RSRQ) may be considered. The received signal strength or received signal quality means a value calculated by S-criteria. That is, it is Srxlev or Squal, and each parameter is shown in Table 2 below.

Srxlev = Q _rxlevmeas- (Q _rxlevmin + Q _{rxlevminoffset} )-P _compensation -Qoffset _temp

Squal = Q _qualmeas- (Q _qualmin + Q _{qualminoffset} )-Qoffset _temp

Srxlev Cell selection RX level value (dB) Squal Cell selection quality value (dB) Qoffset _temp Offset temporarily applied to a cell as specified in TS 38.331 [3] (dB) Q _rxlevmeas Measured cell RX level value (RSRP) Q _qualmeas Measured cell quality value (RSRQ) Q _rxlevmin Minimum required RX level in the cell (dBm). If the UE supports SUL frequency for this cell, Qrxlevmin is obtained from q-RxLevMinSUL, if present, in SIB1, SIB2 and SIB4, additionally, if Q _{rxlevminoffsetcellSUL} is present in SIB3 and SIB4 for the concerned cell, this cell specific offset is added to the corresponding Qrxlevmin to achieve the required minimum RX level in the concerned cell;
else Qrxlevmin is obtained from q-RxLevMin in SIB1, SIB2 and SIB4, additionally, if Q _{rxlevminoffsetcell} is present in SIB3 and SIB4 for the concerned cell, this cell specific offset is added to the corresponding Qrxlevmin to achieve the required minimum RX level in the concerned cell. Q _qualmin Minimum required quality level in the cell (dB). Additionally, if Q _{qualminoffsetcell} is signaled for the concerned cell, this cell specific offset is added to achieve the required minimum quality level in the concerned cell. Q _{rxlevminoffset} Offset to the signaled Q _rxlevmin taken into account in the Srxlev evaluation as a result of a periodic search for a higher priority PLMN while camped normally in a VPLMN, as specified in TS 23.122 [9]. Q _{qualminoffset} Offset to the signaled Q _qualmin taken into account in the Squal evaluation as a result of a periodic search for a higher priority PLMN while camped normally in a VPLMN, as specified in TS 23.122 [9]. P _compensation If the UE supports the additionalPmax in the NR-NS-PmaxList, if present, in SIB1, SIB2 and SIB4:
max(P _EMAX1 -P _PowerClass , 0)-(min(P _EMAX2 , P _PowerClass )-min(P _EMAX1 , P _PowerClass ))(dB);
else:
max(P _EMAX1 -P _PowerClass , 0) (dB) P _EMAX1 , P _EMAX2 Maximum TX power level of a UE may use when transmitting on the uplink in the cell (dBm) defined as P _EMAX in TS 38.101 [15]. If UE supports SUL frequency for this cell, P _EMAX1 and P _EMAX2 are obtained from the p-Max for SUL in SIB1 and NR-NS-PmaxList for SUL respectively in SIB1, SIB2 and SIB4 as specified in TS 38.331 [3], else P _EMAX1 and P _EMAX2 are obtained from the p-Max and NR-NS-PmaxList respectively in SIB1, SIB2 and SIB4 for normal UL as specified in TS 38.331 [3]. P _PowerClass Maximum RF output power of the UE (dBm) according to the UE power class as defined in TS 38.101-1 [15].

1D is a flowchart of a process of performing relaxed RRM measurement in accordance with the present disclosure.

The terminal 1d-05 receives system information including the UE mobility and configuration parameters necessary to determine the location of the terminal from the base station 1d-10 (1d-15). Configuration parameters related to relaxed RRM measurement are stored in the system information. The parameters may all be stored in one SIB, but may be divided and transmitted through a plurality of SIBs according to their use. An indicator indicating whether the cell supports RRM measurement relaxation is stored in SIB1. SIB1 is always broadcast, and since the UE must always receive SIB1 when reselecting one cell, it is reasonable that at least the indicator is accommodated in the SIB1. If the terminal itself receiving SIB1 supports the relaxed RRM measurement operation and the indicator is stored in SIB1, it will receive other SIBs containing different configuration parameters to trigger the relaxed RRM measurement operation. In addition to SIB1, the other SIBs, unlike SIB1, are not always broadcast, but have a feature that can be broadcast on-demand.

Alternatively, parameters related to the relaxed monitoring criterion used to evaluate the terminal mobility state and the terminal location may be stored in SIB1 and transmitted to the terminal. In this case, since the parameters can serve the purpose of the indicator, the indicator is not required in the method. A detailed description of the setting parameters will be described later.

The terminal applies the configuration parameters provided by the base station to a predetermined equation to evaluate whether it is moving at a stop or at a low speed and whether it is located in a cell boundary region (1d-20). In this embodiment, the following Equation 1 is applied to evaluate the mobility of the terminal.

[Equation 1]

(Srxlev _Ref -Srxlev) <S _SearchDeltaP

In addition, the following Equation 2 is applied to evaluate whether the UE is located in the cell boundary region. Several options may be considered in Equation 2, and one of the following options is applied in the present invention.

Option 1: Srxlev _Ref > S _SearchDeltaP + Q _{offsetRelaxed}

Option 2: Srxlev > Q _{offsetRelaxed}

Option 3:

-Srxlev > SrelaxedIntraSearchP and

-Squal > SrelaxedIntraSearchQ

Option 4:

-Q _rxlevmeas > SrelaxedIntraSearchP

Option 5:

-Q _rxlevmeas > SrelaxedIntraSearchP

-Q _qualmeas > SrelaxedIntraSearchQ

As there are SintraSearch corresponding to intra-frequency and SnonintraSearch corresponding to inter-frequency, parameters corresponding to intra-frequency or inter-frequency may be provided in Equation 2 as well. For example, SrelaxedIntraSearchP and SrelaxedIntraSearchQ are applied to Equation 2 to determine relaxation of the intra-frequency measurement, and SrelaxedInterSearchP and SrelaxedInterSearchQ are applied to Equation 2 to determine relaxation of the intrer-frequency measurement. However, it goes without saying that in the present disclosure, the case of applying Equation 2 without discriminating intra-/inter-frequency may also be considered.

In Equations 1 and 2, each parameter may be defined as follows.

-Srxlev = current Srxlev value of the serving cell (dB).

-Srxlev _Ref = reference Srxlev value of the serving cell (dB), set as follows:

-After selecting or reselecting a new cell, or

-If (Srxlev-Srxlev _Ref )> 0, or

-After switching RRC_INACTIVE to RRC_IDLE, or

_-If the relaxed monitoring criterion has not been met for T SearchDeltaP:

-the UE shall set the value of Srxlev _Ref to the current Srxlev value of the serving cell;

-T _SearchDeltaP = X minutes, or the eDRX cycle length if eDRX is configured and the eDRX cycle length is longer than X minutes.

-Q _{offsetRelaxed} = offset used to derive the relaxed monitoring criterion (dB)

_{- SrelaxedIntraSearchP = Minimum required RX level to} indicate that UE is not in cell edge (dBm). It is applicable for relaxed intra-frequencies measurement only

-SrelaxedIntraSearchQ = Minimum required quality level to indicate that UE is not in cell edge (dB). It is applicable for relaxed intra-frequencies measurement only

_{- SrelaxedInterSearchP = Minimum required RX level to} indicate that UE is not in cell edge (dBm). It is applicable for relaxed inter-frequencies measurement only

-SrelaxedInterSearchQ = Minimum required quality level to indicate that UE is not in cell edge (dB). It is applicable for relaxed inter-frequencies measurement only

-Q _rxlevmeas = Measured cell RX level value (RSRP)

A value of configuration information related to relaxed measurement such as T _SearchDeltaP may be predetermined, or may be set through system information or dedicated signaling from a base station. Among the setting information related to the relaxed measurement, valid time information (validity timer) and a valid condition (validity condition) of the above-described setting information may be added. For example, when the validity timer is provided with the information from the base station, it starts driving, and when the timer expires, it is considered that the provided configuration information is no longer valid. The timer is stopped when the terminal enters the connected mode.

The terminal determines whether to perform the intra-/inter-/inter-RAT frequency relaxed RRM measurement based on the result derived from the equations (1d-25), and at this time, a longer measurement compared to the normal RRM measurement operation Terminal power consumption is reduced by applying a period or reducing the number of cells or frequencies to be measured (1d-30).

As described above, the base station may provide frequency priority information to the terminal by using system information or dedicated signaling (eg, RRCRelease message). The reason for providing the frequency priority is to reflect network deployment/policy such as load balancing. Therefore, it is necessary for the UE to continuously measure a frequency having a higher priority than the serving cell currently camp-on. Accordingly, in the present disclosure, even if the relaxed monitoring criterion is satisfied, a general RRM measurement operation is performed instead of a relaxed measurement operation for a frequency having a higher priority than a serving cell currently camped on. Therefore, if the UE has received frequency priority information through system information or a dedicated signaling message, and there is a frequency with a higher priority than the serving cell currently camping among the frequencies for which the priority information is set, the corresponding The frequency should perform a general RRM measurement operation regardless of whether the relaxed monitoring criterion is established. In addition, whether or not a general RRM measurement operation should always be performed for the priority frequency may be selectively set through the dedicated signaling.

In the present invention, in relation to a measurement operation for reducing power consumption of a terminal, an operation of determining whether to measure an intra-frequency or inter-frequency cell by applying the first configuration information and the first configuration information to the SintraSearch and SnonintraSearch is a first. It is called motion. For the first operation, the contents described above with reference to FIG. 1C may be applied. In addition, an operation of determining whether to measure a relaxed intra-frequency or inter-frequency cell by applying the setting information related to the relaxed measurement described above and the second setting information is referred to as a second operation. The second setting information is largely divided into a parameter related to Equation 1 and a parameter related to Equation 2. In the present invention, the parameter related to Equation 1 is referred to as 2-1 setting information (Configuration 2-1), and the parameter related to Equation 2 is referred to as 2-2 setting information (Configuration 2-2). Depending on whether 1 or 2-2 configuration information is provided, an equation used to determine whether to measure a relaxed intra-frequency or inter-frequency cell is determined.

That is, if the 2-1 setting information is provided, the terminal considers Equation 1, and when the 2-2 setting information is provided, the terminal considers Equation 2, and the 2-1 setting information and the 2-2 If all of the configuration information is provided, the UE determines whether to measure a relaxed intra-frequency or inter-frequency cell by considering both Equations 1 and 2.

In the same manner as SintraSearch corresponding to intra-frequency and SnonintraSearch corresponding to inter-frequency in the first configuration information, parameters corresponding to intra-frequency or inter-frequency may also be provided for the second configuration information. For example, SrelaxedIntraSearchP and SrelaxedIntraSearchQ are applied to Equation 2 to determine relaxation of the intra-frequency measurement, and SrelaxedInterSearchP and SrelaxedInterSearchQ are applied to Equation 2 to determine relaxation of the intrer-frequency measurement.

1E is a flowchart of a terminal operation for a second operation related to the present disclosure.

In steps 1e-05, the UE receives configuration parameters for the second operation from the serving cell. The configuration information is provided to the terminal through system information or a dedicated RRC message. For example, the dedicated RRC message is an RRCRelease message transmitted from the base station to switch the terminal to a standby mode or an inactive mode. When the configuration information is provided as a dedicated RRC message, one validity timer is driven. The timer value is also provided in the dedicated RRC message. When the timer expires, the provided parameters are no longer valid. The timer stops when the terminal switches to the connected mode.

In step 1e-10, the terminal determines the property of the provided parameter.

In step 1e-15, if the 2-1 setting information is provided, the terminal determines whether to measure relaxation by considering Equation 1.

In step 1e-20, if the 2-2 setting information is provided, the terminal determines whether to measure relaxation by considering Equation 2.

In step 1e-25, if both the 2-1 setting information and the 2-2 setting information are provided, the terminal determines whether to measure relaxation by considering both Equation 1 and Equation 2.

In steps 1e-30, the terminal determines whether the considered equation holds.

If it is established in steps 1e-35, the terminal relaxtion the intra-frequency or inter-frequency measurement to save power consumption of the terminal.

If not established in step 1e-40, the UE performs a normal intra-frequency or inter-frequency measurement.

1F is a flow chart of a process of performing a first operation and a second operation step by step according to the present disclosure.

The first operation and the second operation described above may be set at the same time. When the above operations are set at the same time, the present invention is characterized in that the first operation and the second operation are performed in order. The first operation is to stop the intra-frequency or inter-frequency measurement, thereby saving the most power consumption of the terminal. On the other hand, the second operation is somewhat inferior to the first operation. Accordingly, it is determined whether or not to stop through the first operation, and if it cannot be stopped, power consumption of the terminal is saved through the second operation.

In steps 1f-05, the UE receives configuration parameters related to the first operation and the second operation from the serving cell.

In step 1f-10, the UE determines whether to consider intra-frequency or inter-frequency measurement.

When considering intra-frequency measurement in step 1f-15, the UE determines whether to stop intra-frequency measurement through a first operation.

In step 1f-20, if the condition in the first operation is satisfied, the terminal stops intra-frequency measurement.

If it cannot be stopped in step 1f-25, the UE determines whether to relax the intra-frequency measurement through the second operation.

In step 1f-30, if the condition in the second operation is satisfied, the terminal relaxes the intra-frequency measurement.

If relaxation cannot be performed in steps 1f-35, the UE performs intra-frequency measurement.

When considering inter-frequency measurement in step 1f-40, the UE determines whether to stop inter-frequency measurement through the first operation.

In steps 1f-45, if the condition in the first operation is satisfied, the terminal stops inter-frequency measurement.

If it cannot be stopped in step 1f-50, the UE determines whether to relax the inter-frequency measurement through the second operation.

In steps 1f-55, if the condition in the second operation is satisfied, the terminal relaxes the inter-frequency measurement.

If relaxation cannot be performed in step 1f-60, the UE performs inter-frequency measurement.

The base station may set the frequency range (FR) to which the relaxed measurement is applied.

The base station may configure a relaxed measurement for UEs or a specific UE in a cell and at the same time set an FR capable of performing the relaxed measurement through system information or a dedicated RRC message. At a frequency belonging to the indicated FR, when the above-described equation of the second operation is satisfied, relaxed measurement may be performed.

The terminal receives configuration information for relaxed measurement from system information broadcast from the base station or a dedicated RRC message. The terminal determines whether there is FR information capable of performing the relaxed measurement in the configuration information. If the information is present and the equation for the second operation described above is established, the terminal performs a relaxed measurement on a frequency belonging to the FR.

The base station may configure the RRC state of the terminal capable of performing relaxed measurement.

The base station may set relaxed measurement for UEs or specific UEs in a cell through system information or a dedicated RRC message, and at the same time set an RRC state capable of performing the relaxed measurement. When the UE is in the indicated RRC state and satisfies the equation of the second operation described above, relaxed measurement may be performed. The RRC state is RRC_IDLE or RRC_INACTIVE. If the information is not provided, it means that relaxed measurement can be performed in both RRC states.

The terminal receives configuration information for relaxed measurement from system information broadcast from the base station or a dedicated RRC message. The terminal determines whether there is RRC state information capable of performing the relaxed measurement in the configuration information. If the information is present, the current RRC state of the UE matches the configured RRC state, and the equation for the second operation described above is established, the UE performs a relaxed measurement.

1G is a block diagram showing an internal structure of a terminal according to the present disclosure.

Referring to the drawing, the terminal includes a radio frequency (RF) processing unit 1g-10, a baseband processing unit 1g-20, a storage unit 1g-30, and a control unit 1g-40. .

The RF processing unit 1g-10 performs a function of transmitting and receiving a signal through a wireless channel such as band conversion and amplification of a signal. That is, the RF processing unit (1g-10) up-converts the baseband signal provided from the baseband processing unit (1g-20) to an RF band signal and then transmits it through an antenna, and an RF band signal received through the antenna. Is down-converted to a baseband signal. For example, the RF processing unit 1g-10 may include a transmission filter, a reception filter, an amplifier, a mixer, an oscillator, a digital to analog convertor (DAC), an analog to digital convertor (ADC), and the like. I can. In the drawing, only one antenna is shown, but the terminal may include a plurality of antennas. In addition, the RF processing unit 1g-10 may include a plurality of RF chains. Furthermore, the RF processing unit 1g-10 may perform beamforming. For the beamforming, the RF processing unit 1g-10 may adjust a phase and a magnitude of each of signals transmitted/received through a plurality of antennas or antenna elements. In addition, the RF processor may perform MIMO, and may receive multiple layers when performing the MIMO operation.

The baseband processing unit 1g-20 performs a function of converting between a baseband signal and a bit stream according to the physical layer standard of the system. For example, when transmitting data, the baseband processing unit 1g-20 generates complex symbols by encoding and modulating a transmission bit stream. In addition, when receiving data, the baseband processing unit 1g-20 restores a received bit stream through demodulation and decoding of the baseband signal provided from the RF processing unit 1g-10. For example, in the case of the OFDM (orthogonal frequency division multiplexing) method, when transmitting data, the baseband processor 1g-20 generates complex symbols by encoding and modulating a transmission bit stream, and subcarriers of the complex symbols After mapping to, OFDM symbols are constructed through an inverse fast Fourier transform (IFFT) operation and a cyclic prefix (CP) insertion. In addition, when receiving data, the baseband processing unit 1g-20 divides the baseband signal provided from the RF processing unit 1g-10 in units of OFDM symbols, and applies a fast Fourier transform (FFT) operation to subcarriers. After restoring the mapped signals, the received bit stream is restored through demodulation and decoding.

The baseband processing unit 1g-20 and the RF processing unit 1g-10 transmit and receive signals as described above. Accordingly, the baseband processing unit 1g-20 and the RF processing unit 1g-10 may be referred to as a transmission unit, a reception unit, a transmission/reception unit, or a communication unit. Furthermore, at least one of the baseband processing unit 1g-20 and the RF processing unit 1g-10 may include a plurality of communication modules to support a plurality of different wireless access technologies. In addition, at least one of the baseband processing unit 1g-20 and the RF processing unit 1g-10 may include different communication modules to process signals of different frequency bands. For example, the different wireless access technologies may include a wireless LAN (eg, IEEE 802.11), a cellular network (eg, LTE), and the like. In addition, the different frequency bands may include a super high frequency (SHF) (eg, 2.NRHz, NRhz) band, and a millimeter wave (eg, 60GHz) band.

The storage unit 1g-30 stores data such as a basic program, an application program, and setting information for the operation of the terminal. In particular, the storage unit 1g-30 may store information related to a second access node performing wireless communication using a second wireless access technology. In addition, the storage unit 1g-30 provides stored data according to the request of the control unit 1g-40.

The control unit 1g-40 controls overall operations of the terminal. For example, the control unit 1g-40 transmits and receives signals through the baseband processing unit 1g-20 and the RF processing unit 1g-10. In addition, the control unit 1g-40 writes and reads data in the storage unit 1g-40. To this end, the control unit 1g-40 may include at least one processor. For example, the control unit 1g-40 may include a communication processor (CP) that controls communication and an application processor (AP) that controls an upper layer such as an application program. In addition, the control unit 1g-40 may further include a multiple connection processing unit 1g-42 for supporting multiple connections.

1H is a block diagram showing the configuration of a base station according to the present disclosure.

As shown in the figure, the base station includes an RF processing unit (1h-10), a baseband processing unit (1h-20), a backhaul communication unit (1h-30), a storage unit (1h-40), and a control unit (1h-50). Consists of including.

The RF processing unit 1h-10 performs a function of transmitting and receiving a signal through a wireless channel such as band conversion and amplification of a signal. That is, the RF processing unit 1h-10 up-converts the baseband signal provided from the baseband processing unit 1h-20 to an RF band signal, and then transmits it through an antenna, and an RF band signal received through the antenna. Downconvert to a baseband signal. For example, the RF processing unit 1h-10 may include a transmission filter, a reception filter, an amplifier, a mixer, an oscillator, a DAC, an ADC, and the like. In the drawing, only one antenna is shown, but the first access node may include a plurality of antennas. In addition, the RF processing unit 1h-10 may include a plurality of RF chains. Furthermore, the RF processing unit 1h-10 may perform beamforming. For the beamforming, the RF processing unit 1h-10 may adjust a phase and a magnitude of each of signals transmitted and received through a plurality of antennas or antenna elements. The RF processor may perform a downlink MIMO operation by transmitting one or more layers.

The baseband processing unit 1h-20 performs a function of converting between a baseband signal and a bit stream according to the physical layer standard of the first wireless access technology. For example, when transmitting data, the baseband processing unit 1h-20 generates complex symbols by encoding and modulating a transmission bit stream. In addition, when receiving data, the baseband processing unit 1h-20 restores a received bit stream through demodulation and decoding of the baseband signal provided from the RF processing unit 1h-10. For example, in the case of the OFDM scheme, when transmitting data, the baseband processor 1h-20 generates complex symbols by encoding and modulating a transmission bit stream, mapping the complex symbols to subcarriers, and then IFFT OFDM symbols are configured through calculation and CP insertion. In addition, when receiving data, the baseband processing unit 1h-20 divides the baseband signal provided from the RF processing unit 1h-10 in units of OFDM symbols, and reconstructs signals mapped to subcarriers through FFT operation. After that, the received bit stream is restored through demodulation and decoding. The baseband processing unit 1h-20 and the RF processing unit 1h-10 transmit and receive signals as described above. Accordingly, the baseband processing unit 1h-20 and the RF processing unit 1h-10 may be referred to as a transmission unit, a reception unit, a transmission/reception unit, a communication unit, or a wireless communication unit.

The backhaul communication unit 1h-30 provides an interface for performing communication with other nodes in the network. That is, the backhaul communication unit 1h-30 converts a bit stream transmitted from the main station to another node, for example, an auxiliary base station, a core network, etc. Convert to heat.

The storage unit 1h-40 stores data such as a basic program, an application program, and setting information for the operation of the main station. In particular, the storage unit 1h-40 may store information on bearers allocated to the connected terminal, measurement results reported from the connected terminal, and the like. In addition, the storage unit 1h-40 may store information that is a criterion for determining whether to provide or stop providing multiple connections to the terminal. In addition, the storage unit 1h-40 provides stored data according to the request of the control unit 1h-50.

The control unit 1h-50 controls overall operations of the main station. For example, the control unit 1h-50 transmits and receives signals through the baseband processing unit 1h-20 and the RF processing unit 1h-10 or through the backhaul communication unit 1h-30. In addition, the control unit 1h-50 writes and reads data in the storage unit 1h-40. To this end, the control unit 1h-50 may include at least one processor. The control unit 1h-50 may further include a multiple connection processing unit 1h-52 for supporting multiple connections.

The embodiments disclosed in the present specification and drawings are merely provided specific examples for easy explanation and understanding of the present disclosure, and are not intended to limit the scope of the present disclosure. Therefore, the scope of the present disclosure should be construed as including all changes or modified forms derived from the present disclosure in addition to the embodiments disclosed herein are included in the scope of the present disclosure.

Claims (1)

In a method of performing measurement of a terminal in a wireless communication system,
Receiving, from the base station, first configuration information related to stopping measurement and second configuration information related to relaxed measurement;
Determining whether a condition determined by the first setting information is satisfied;
Determining whether the condition determined by the second setting information is satisfied if the measurement cannot be stopped because the condition determined by the first setting information is not satisfied; And
And performing a relaxed measurement if the condition determined by the second setting information is satisfied.

Images