KR20210143047A - Method and Apparatus for Performing Chnnel Measurement in a Wireless Communication System - Google Patents

Abstract

The present disclosure relates to a wireless communication system, and may provide a method for operating a terminal in a wireless communication system. The method comprises the steps of: receiving an RRC release message from a first base station; identifying IDLE mode measurement configuration information from the received RRC release message; transitioning to an IDLE mode based on the identified IDLE mode measurement configuration information; performing cell reselection with a second base station; and performing IDLE mode measurement when the second base station belongs to a validity area.

Description

Method and Apparatus for Performing Channel Measurement in a Wireless Communication System

The present disclosure relates to a wireless communication system, and more particularly, to a method for a terminal to perform channel measurement.

Efforts are being made to develop an improved 5G communication system or pre-5G communication system in order to meet the increasing demand for wireless data traffic after the commercialization of the 4G communication system. For this reason, the 5G communication system or the pre-5G communication system is called a system after the 4G network (Beyond 4G Network) communication system or the LTE system after (Post LTE). In order to achieve a high data rate, the 5G communication system is being considered for implementation in a very high frequency (mmWave) band (eg, such as a 60 gigabyte (60 GHz) band). In order to alleviate the path loss of radio waves and increase the propagation distance of radio waves in the very high frequency band, in the 5G communication system, beamforming, massive MIMO, full dimensional MIMO, FD-MIMO ), array antenna, analog beam-forming, and large scale antenna technologies are being discussed. In addition, for network improvement of the system, in the 5G communication system, an evolved small cell, an advanced small cell, a cloud radio access network (cloud RAN), and an ultra-dense network (ultra-dense network) , Device to Device communication (D2D), wireless backhaul, moving network, cooperative communication, Coordinated Multi-Points (CoMP), and interference cancellation Technology development is underway. In addition, in the 5G system, advanced coding modulation (ACM) methods such as FQAM (Hybrid FSK and QAM Modulation) and SWSC (Sliding Window Superposition Coding), and advanced access technologies such as FBMC (Filter Bank Multi Carrier), NOMA (non orthogonal multiple access), and sparse code multiple access (SCMA) are being developed.

On the other hand, the Internet is evolving from a human-centered connection network where 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 big data processing technology through connection with cloud servers, etc. with IoT technology, is also emerging. In order to implement IoT, technology elements such as sensing technology, wired and wireless communication and network infrastructure, service interface technology, and security technology are required, and recently, a sensor network for connection between objects, and machine to machine communication (Machine to Machine) are required. , M2M), and MTC (Machine Type Communication) are being studied. In the IoT environment, intelligent IT (Internet Technology) services that create new values in human life by collecting and analyzing data generated from connected objects can be provided. IoT is a field of smart home, smart building, smart city, smart car or connected car, smart grid, health care, smart home appliance, advanced medical service, etc. can be applied to

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

As various services can be provided according to the above-mentioned and the development of mobile communication systems, a method for efficiently measuring a channel by a terminal is required.

The disclosed embodiment is to provide an apparatus and method for a terminal to measure a channel in a wireless communication system.

The present disclosure provides a method of operating a terminal in a wireless communication system, the method comprising: receiving an RRC release message from a first base station; identifying IDLE mode measurement configuration information from the received RRC release message; transitioning to an IDLE mode based on the identified IDLE mode measurement setting information; performing cell reselection with a second base station; and if the second base station belongs to the validity area, performing IDLE mode measurement.

The disclosed embodiment may provide an apparatus and method by which the terminal can effectively perform channel measurement when the terminal reselects a cell in a wireless communication system.

1A is a diagram illustrating a structure of an LTE system according to an embodiment of the present disclosure.
1B is a diagram illustrating a radio protocol structure in an LTE system according to an embodiment of the present disclosure.
1C is a diagram illustrating a structure of a next-generation mobile communication system according to an embodiment of the present disclosure.
1D is a diagram illustrating a radio protocol structure of a next-generation mobile communication system according to an embodiment of the present disclosure.
FIG. 1E is a diagram illustrating an overall operation in which a UE transitions to a connected state and performs neighbor cell measurement and carrier aggregation in LTE and NR systems according to an embodiment of the present disclosure.
FIG. 1f shows the overall operation of measuring a neighboring cell in an IDLE state so that carrier aggregation can be quickly activated when cell reselection is performed in an LTE system or an NR system according to an embodiment of the present disclosure, and reporting it to the base station it is one drawing
1G is a diagram illustrating an operation of performing IDLE mode measurement when a UE performs cell reselection using NR as a master cell group (MCG) according to an embodiment of the present disclosure.
1H is a diagram illustrating an operation of performing IDLE mode measurement measurement when a UE performs cell reselection using LTE as an MCG according to an embodiment of the present disclosure.
1I is a block diagram illustrating an internal structure of a terminal according to an embodiment of the present disclosure.
1J is a block diagram illustrating a configuration of a base station according to an embodiment of the present disclosure.

Hereinafter, the operating principle of the present disclosure will be described in detail with reference to the accompanying drawings. In the following description of the present disclosure, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present disclosure, the detailed description thereof will be omitted. In addition, the terms described below are terms defined in consideration of functions in the present disclosure, which may vary according to intentions or customs of users and operators. Therefore, the definition should be made based on the content throughout this specification. A term for identifying an access node used in the following description, a term referring to network entities, a term referring to messages, a term referring to an interface between network objects, and a term referring to various identification information and the like are exemplified for convenience of description. Accordingly, the present disclosure is not limited to the terms described below, and other terms referring to objects having equivalent technical meanings may be used.

Advantages and features of the present disclosure, and a method of achieving them will become apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present disclosure is not limited to the embodiments disclosed below, but may be implemented in various different forms, and only the present embodiments allow the disclosure of the present disclosure to be complete, and common knowledge in the art to which the present disclosure pertains. It is provided to fully inform the possessor of the scope of the invention, and the present disclosure is only defined by the scope of the claims. Like reference numerals refer to like elements throughout.

At this time, it will be understood that each block of the flowchart diagrams and combinations of the flowchart diagrams may be performed by computer program instructions. These computer program instructions may be embodied in a processor of a general purpose computer, special purpose computer, or other programmable data processing equipment, such that the instructions performed by the processor of the computer or other programmable data processing equipment are not described in the flowchart block(s). It creates a means to perform functions. These computer program instructions may also be stored in a computer-usable or computer-readable memory that may direct a computer or other programmable data processing equipment to implement a function in a particular manner, and thus the computer-usable or computer-readable memory. It is also possible that the instructions stored in the flowchart block(s) produce an article of manufacture containing instruction means for performing the function described in the flowchart block(s). The computer program instructions may also be mounted on a computer or other programmable data processing equipment, such that a series of operational steps are performed on the computer or other programmable data processing equipment to create a computer-executed process to create a computer or other programmable data processing equipment. It is also possible that instructions for performing the processing equipment provide steps for performing the functions described in the flowchart block(s).

Additionally, each block may represent a module, segment, or portion of code that includes one or more executable instructions for executing specified logical function(s). It should also be noted that in some alternative implementations it is also possible for the functions recited in blocks to occur out of order. For example, two blocks shown one after another may in fact be performed substantially simultaneously, or it is possible that the blocks are sometimes performed in the reverse order according to the corresponding function.

In this case, the term '~ unit' used in this embodiment means software or hardware components such as FPGA (Field Programmable Gate Array) or ASIC (Application Specific Integrated Circuit), and '~ unit' performs certain roles do. However, '~part' is not limited to software or hardware. '~' may be configured to reside on an addressable storage medium or may be configured to refresh one or more processors. Thus, as an example, '~' denotes components such as software components, object-oriented software components, class components, and task components, and processes, functions, properties, and procedures. , subroutines, segments of program code, drivers, firmware, microcode, circuitry, data, databases, data structures, tables, arrays, and variables. The functions provided in the components and '~ units' may be combined into a smaller number of components and '~ units' or further separated into additional components and '~ units'. In addition, components and '~ units' may be implemented to play one or more CPUs in a device or secure multimedia card. Also, in an embodiment, '~ part' may include one or more processors.

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

A term for identifying an access node used in the following description, a term referring to a network entity (network entity), a term referring to messages, a term referring to an interface between network objects, and various identification information Reference terms and the like are exemplified for convenience of description. Accordingly, the present disclosure is not limited to the terms described below, and other terms referring to objects having equivalent technical meanings may be used.

For convenience of description, the present disclosure uses terms and names defined in the 3rd Generation Partnership Project Long Term Evolution (3GPP LTE) standard. However, the present disclosure is not limited by the above terms and names, and may be equally applied to systems conforming to other standards. In the present disclosure, eNB may be used interchangeably with gNB for convenience of description. That is, a base station described as an eNB may represent a gNB. Also, the term terminal may refer to mobile phones, NB-IoT devices, sensors, as well as other wireless communication devices.

Hereinafter, the base station is a subject that performs resource allocation of the terminal, and may be at least one of gNode B, eNode B, Node B, a base station (BS), a radio access unit, a base station controller, or a node on a network. The terminal may include a user equipment (UE), a mobile station (MS), a cellular phone, a smart phone, a computer, or a multimedia system capable of performing a communication function. Of course, it is not limited to the above example.

In particular, the present disclosure is applicable to 3GPP NR (5th generation mobile communication standard). In addition, the present disclosure provides intelligent services (eg, smart home, smart building, smart city, smart car or connected car, healthcare, digital education, retail business, security and safety-related services based on 5G communication technology and IoT-related technology) etc.) can be applied. In the present invention, eNB may be used interchangeably with gNB for convenience of description. That is, a base station described as an eNB may represent a gNB. Also, the term terminal may refer to mobile phones, NB-IoT devices, sensors, as well as other wireless communication devices.

A wireless communication system, for example, 3GPP's HSPA (High Speed Packet Access), LTE (Long Term Evolution or E-UTRA (Evolved Universal Terrestrial Radio Access)), LTE-Advanced (LTE-A), LTE-Pro, 3GPP2's High Rate Packet Data (HRPD), UMB (Ultra Mobile Broadband), and IEEE's 802.16e, such as communication standards such as communication standards such as broadband wireless that provides high-speed, high-quality packet data service It is evolving into a communication system.

As a representative example of a broadband wireless communication system, in an LTE system, an Orthogonal Frequency Division Multiplexing (OFDM) scheme is employed in a downlink (DL; DownLink), and Single Carrier Frequency Division Multiple Access (SC-FDMA) in an uplink (UL). ) method is used. Uplink refers to a radio link in which a UE (User Equipment or MS; Mobile Station) transmits data or control signals to a base station (eNode B or BS; Base Station), and downlink refers to a radio link in which the base station transmits data or control to the UE A radio link that transmits signals. The multiple access method as described above divides the data or control information of each user by allocating and operating the time-frequency resources to which data or control information is to be transmitted for each user so that they do not overlap each other, that is, orthogonality is established. .

As a future communication system after LTE, that is, the 5G communication system must be able to freely reflect various requirements such as users and service providers, so services that simultaneously satisfy various requirements must be supported. Services considered for the 5G communication system include Enhanced Mobile BroadBand (eMBB), massive Machine Type Communication (mMTC), and Ultra Reliability Low Latency Communication (URLLC). There is this.

According to some embodiments, the eMBB may aim to provide a data transmission rate that is more improved than the data transmission rate supported by the existing LTE, LTE-A, or LTE-Pro. For example, in the 5G communication system, the eMBB should be able to provide a maximum data rate of 20 Gbps in the downlink and a maximum data rate of 10 Gbps in the uplink from the viewpoint of one base station. In addition, the 5G communication system may have to provide the maximum transmission speed and at the same time provide the increased user perceived data rate of the terminal. In order to satisfy such a requirement, improvement of various transmission/reception technologies may be required in the 5G communication system, including a more advanced multi-antenna (MIMO) transmission technology. In addition, while transmitting signals using a transmission bandwidth of up to 20 MHz in the 2 GHz band currently used by LTE, the 5G communication system uses a frequency bandwidth wider than 20 MHz in the frequency band of 3 to 6 GHz or 6 GHz or more Data transfer speed can be satisfied.

At the same time, mMTC is being considered to support application services such as the Internet of Things (IoT) in the 5G communication system. In order to efficiently provide the Internet of Things, mMTC may require large-scale terminal access support, improved terminal coverage, improved battery life, and reduced terminal cost within a cell. Since the Internet of Things is attached to various sensors and various devices to provide communication functions, it must be able to support a large number of terminals (eg, 1,000,000 terminals/km2) within a cell. In addition, since the terminal supporting mMTC is highly likely to be located in a shaded area that the cell does not cover, such as the basement of a building, due to the nature of the service, wider coverage may be required compared to other services provided by the 5G communication system. A terminal supporting mMTC should be composed of a low-cost terminal, and since it is difficult to frequently exchange the battery of the terminal, a very long battery life time such as 10 to 15 years may be required.

Finally, in the case of URLLC, as a cellular-based wireless communication service used for a specific purpose (mission-critical), remote control for a robot or a machine, industrial automation, It may be used for a service used in an unmanned aerial vehicle, remote health care, emergency alert, and the like. Therefore, the communication provided by URLLC may have to provide very low latency (ultra-low latency) and very high reliability (ultra-reliability). For example, a service supporting URLLC must satisfy an air interface latency of less than 0.5 milliseconds, and at the same time may have a requirement of a packet error rate of 10-5 or less. Therefore, for a service supporting URLLC, the 5G system must provide a smaller Transmit Time Interval (TTI) than other services, and at the same time, it is a design that requires a wide resource allocation in the frequency band to secure the reliability of the communication link. items may be required.

The three services considered in the above-described 5G communication system, ie, eMBB, URLLC, and mMTC, may be multiplexed and transmitted in one system. In this case, different transmission/reception techniques and transmission/reception parameters may be used between services to satisfy different requirements of each service. However, the aforementioned mMTC, URLLC, and eMBB are only examples of different service types, and service types to which the present disclosure is applied are not limited to the above examples. For convenience of description, the present disclosure provides for 3GPP LTE The terms and names defined in the (3rd Generation Partnership Project Long Term Evolution) standard are used. However, the present disclosure is not limited by the above terms and names, and may be equally applied to systems conforming to other standards. In addition, the embodiments of the present disclosure will be described below using LTE, LTE-A, LTE Pro, or 5G (or NR, next-generation mobile communication) systems as an example, but the present disclosure also applies to other communication systems having a similar technical background or channel type. An embodiment of can be applied. In addition, the embodiments of the present disclosure may be applied to other communication systems through some modifications within a range that does not significantly depart from the scope of the present disclosure as judged by a person having skilled technical knowledge.

The present disclosure may provide a technique for improving the carrier aggregation technology and dual access technology applied to the existing LTE system and the next-generation mobile communication system. According to an embodiment of the present disclosure, after the UE in the idle state measures the neighboring cells, records the measurement value, and establishes the RRC connection procedure in a specific cell, the stored measurement value of the neighboring cells is transmitted to the base station and , the base station may instruct the terminal to set up and activate a fast carrier aggregation using the received measurement value. However, in the existing operation, since the procedure for performing the measurement of the dual access carry during cell reselection by the idle terminal is inaccurate, it is necessary to determine which terminal having the dual access capability can perform the measurement.

As a specific method for a UE in an IDLE state at the time of cell reselection proposed in the present disclosure to perform a measurement on dual connectivity, in particular, an operation of performing IDLE measurement on a dual access frequency and carrier based on the capability of the UE. Accordingly, the improvement of carrier aggregation performed by the existing terminal, that is, the measurement of the neighboring cell of the idle-state terminal for fast carrier aggregation setting can be accurately performed even in the cell reselection process.

1A is a diagram illustrating a structure of an LTE system according to an embodiment of the present disclosure.

Referring to Figure 1a, the radio access network of the LTE system as shown in the next-generation base station (Evolved Node B, hereinafter eNB, Node B or base station) (1a-05, 1a-10, 1a-15, 1a-20) and It consists of a Mobility Management Entity (MME, 1a-25) and a Serving-Gateway (S-GW, 1a-30). User equipment (hereinafter referred to as UE or terminal) 1a-35 accesses an external network through eNBs 1a-05 to 1a-20 and S-GW 1a-30.

In FIG. 1A , the eNBs 1a-05 to 1a-20 may correspond to an existing Node B of a UMTS (Universal Mobile Telecommunication System). The eNBs 1a-05 to 1a-20 are connected to the UE 1a-35 through a radio channel and may perform a more complex role than the existing Node B. In the LTE system, all user traffic, including real-time services such as VoIP (Voice over IP) through the Internet protocol, are serviced through a shared channel, so the state information such as buffer status of UEs, available transmission power status, and channel status A device for scheduling is required, and the eNBs 1a-05 to 1a-20 are responsible for this. One eNB can control a plurality of cells. For example, in order to implement a transmission rate of 100 Mbps, the LTE system may use, for example, orthogonal frequency division multiplexing (OFDM) in a 20 MHz bandwidth as a radio access technology. Of course, the radio access technology that the LTE system can use is not limited to the above example. In addition, the eNBs 1a-05 to 1a-20 determine a modulation scheme and a channel coding rate according to the channel state of the UE (Adaptive Modulation & Coding, hereinafter referred to as AMC). method can be applied. The Serving GateWay (S-GW) 1a-30 is a device that provides a data bearer, and may create or remove a data bearer under the control of the Mobility Management Entity (MME) 1a-25. The MME is a device in charge of various control functions as well as a mobility management function for the UE, and may be connected to a plurality of base stations.

1B is a diagram illustrating a radio protocol structure in an LTE system according to an embodiment of the present disclosure.

Referring to Figure 1b, in the LTE system, the radio protocol of the terminal is PDCP (Packet Data Convergence Protocol) (1b-05, 1b-40), RLC (Radio Link Control) (1b-10, 1b-35), MAC (Medium) Access Control) (1b-15, 1b-30) and may include a PHY (Physical) layer. In addition, in the LTE system, the radio protocol of the eNB is PDCP (Packet Data Convergence Protocol 1b-40), RLC (Radio Link Control, 1b-35), MAC (Medium Access Control, 1b-30) and PHY (Physical) ( 1b-25) layer may be included. The PDCPs 1b-05 and 1b-40 may be in charge of operations such as IP header compression/restore. The main functions of PDCP are summarized below. Of course, it is not limited to the following examples.

- Header compression and decompression: Robust Header Compression (ROHC) only

- Transfer of user data

- In-sequence delivery of upper layer PDUs at PDCP re-establishment procedure for RLC AM (Acknowledged Mode)

- Reordering function (For split bearers in DC (only support for RLC AM): PDCP PDU routing for transmission and PDCP PDU reordering for reception)

- Duplicate detection of lower layer SDUs at PDCP re-establishment procedure for RLC AM

- Retransmission of PDCP SDUs at handover and, for split bearers in DC, of PDCP PDUs at PDCP data-recovery procedure, for RLC AM)

- Ciphering and deciphering

- Timer-based SDU discard in uplink.

The radio link control (Radio Link Control, hereinafter referred to as RLC) 1b-10, 1b-35 may perform an ARQ operation by reconfiguring a PDCP packet data unit (PDU) to an appropriate size. The main functions of RLC are summarized below. Of course, it is not limited to the following examples.

- Data transfer function (Transfer of upper layer PDUs)

- ARQ function (Error Correction through ARQ (only for AM data transfer))

- Concatenation, segmentation and reassembly of RLC SDUs (only for UM and AM data transfer)

- Re-segmentation of RLC data PDUs (only for AM data transfer)

- Reordering of RLC data PDUs (only for UM and AM data transfer)

- Duplicate detection (only for UM and AM data transfer)

- Protocol error detection (only for AM data transfer)

- RLC SDU discard function (RLC SDU discard (only for UM and AM data transfer))

- RLC re-establishment function

The MACs 1b-15 and 1b-30 are connected to several RLC layer devices configured in one terminal, and may perform operations of multiplexing RLC PDUs into MAC PDUs and demultiplexing RLC PDUs from MAC PDUs. The main functions of MAC are summarized below. Of course, the function of the MAC is not limited to the following example.

- Mapping between logical channels and transport channels

- Multiplexing/demultiplexing of MAC SDUs belonging to one or different logical channels into/from transport blocks (TB) delivered to/from the physical layer on transport channels

- Scheduling information reporting function

- HARQ function (Error correction through HARQ)

- Priority handling between logical channels of one UE

- Priority handling between UEs by means of dynamic scheduling

- MBMS service identification

- Transport format selection

- Padding function (Padding)

The physical layer (hereinafter referred to as the PHY layer or the physical layer) (1b-20, 1b-25) channel-codes and modulates upper layer data, converts it into an OFDM symbol, and transmits it through a radio channel or receives it through a radio channel An operation of demodulating one OFDM symbol, channel decoding, and transferring the OFDM symbol to a higher layer may be performed. In addition, the physical layer uses Hybrid ARQ (HARQ) for additional error correction, and the receiving end transmits whether a packet transmitted from the transmitting end is received with 1 bit. This is called HARQ ACK/NACK information. Downlink HARQ ACK/NACK information for uplink transmission is transmitted through a PHICH (Physical Hybrid-ARQ Indicator Channel) physical channel, and uplink HARQ ACK/NACK information for downlink transmission is PUCCH (Physical Uplink Control Channel) or It may be transmitted through a Physical Uplink Shared Channel (PUSCH) physical channel.

On the other hand, the PHY layer (1b-20, 1b-25) may be configured to use one or a plurality of frequencies/carriers, and a technology for simultaneously setting and using a plurality of frequencies is referred to as carrier aggregation (CA). ) is called According to the use of CA technology, for communication between the UE (or User Equipment, UE) and the base station (E-UTRAN NodeB, eNB), the main carrier and one or more sub-carriers are additionally used and the transmission amount is equal to the number of sub-carriers. can be significantly increased. Meanwhile, in LTE, a cell in a base station using a primary carrier is called a PCell (Primary Cell), and a secondary carrier is called a SCell (Secondary Cell).

Although not shown in this figure, an RRC (Radio Resource Control, hereinafter referred to as RRC) layer may exist above the PDCP layer of the terminal and the base station, and the RRC layer provides access and measurement related configuration control messages for radio resource control. can give and receive

1C is a diagram illustrating a structure of a next-generation mobile communication system according to an embodiment of the present disclosure.

1c, as shown, the radio access network of the next-generation mobile communication system includes a next-generation base station (New Radio Node B, hereinafter NR NB, NR gNB, gNB or NR base station) 1c-10 and NR CN (New Radio CN). Core Network, or NG CN: Next Generation Core Network) (1c-05) may be configured. A user terminal (New Radio User Equipment, hereinafter NR UE or terminal) 1c-15 may access an external network through NR NB 1c-10 and NR CN 1c-05.

In FIG. 1c , NR NBs 1c-10 correspond to an Evolved Node B (eNB) of an existing LTE system. The NR NB (1c-10) is connected to the NR UE (1c-15) through a radio channel and can provide a service superior to that of the existing Node B. In the next-generation mobile communication system, since all user traffic is serviced through a shared channel, a device for scheduling by collecting status information such as buffer status, available transmission power status, and channel status of UEs is required. (1c-10) may be in charge. One NR NB 1c-10 can typically control a plurality of cells. According to an embodiment of the present disclosure, the next-generation mobile communication system may have more than the existing maximum bandwidth in order to implement ultra-high-speed data transmission compared to the existing LTE, and use an Orthogonal Frequency Division Multiplexing (hereinafter referred to as OFDM). As the wireless access technology, a beamforming technology may be additionally used. In addition, the NR NB 1c-10 applies an Adaptive Modulation & Coding (AMC) method that determines a modulation scheme and a channel coding rate according to the channel state of the terminal. can do. The NR CN 1c-05 may perform functions such as mobility support, bearer setup, QoS setup, and the like. The NR CN (1c-05) is a device in charge of various control functions as well as a mobility management function for the terminal, and may be connected to a plurality of base stations. In addition, the next-generation mobile communication system may be interlocked with the existing LTE system, and the NR CN (1c-05) may be connected to the MME (1c-25) through a network interface. The MME may be connected to the existing base station eNB (1c-30).

1D is a diagram illustrating a radio protocol structure of a next-generation mobile communication system according to an embodiment of the present disclosure.

Referring to FIG. 1d, the wireless protocols of the next-generation mobile communication system are NR SDAP (Service Data Adaptation Protocol) (1d-01, 1d-45) and NR PDCP (Packet Data Convergence Protocol) (1d-05) in the terminal and the NR base station, respectively. , 1d-40), NR RLC (Radio Link Control) (1d-10, 1d-35), NR MAC (Medium Access Control) (1d-15, 1d-30) and NR PHY (Physical) layer. have.

According to an embodiment of the present disclosure, the main functions of the NR SDAPs 1d-01 and 1d-45 may include some of the following functions. Of course, it is not limited to the following examples.

- transfer of user plane data

- For uplink and downlink, QoS (Quality Of Service) flow and data bearer mapping function (mapping between a QoS flow and a DRB for both DL and UL)

- Marking QoS flow ID in both DL and UL packets for uplink and downlink

- A function of mapping a relective QoS flow to a data bearer for uplink SDAP PDUs (reflective QoS flow to DRB mapping for the UL SDAP PDUs).

With respect to the SDAP layer device, the UE can receive a set of whether to use the header of the SDAP layer device or the function of the SDAP layer device for each PDCP layer device, for each bearer, or for each logical channel with an RRC (Radio Resource Control) message. have. When the SDAP header is set, the base station or the terminal uses the NAS QoS reflection setting 1-bit indicator (NAS reflective QoS) and the AS QoS reflection setting 1-bit indicator (AS reflective QoS) of the SDAP header to allow the UE to control uplink and downlink QoS flows and It may indicate to update or reconfigure mapping information for a data bearer. According to an embodiment of the present disclosure, the SDAP header may include QoS flow ID information indicating QoS. Also, according to an embodiment of the present disclosure, QoS information may be used as data processing priority, scheduling information, etc. to support a smooth service.

According to an embodiment of the present disclosure, the main function of the NR PDCP (1d-05, 1d-40) may include some of the following functions. Of course, it is not limited to the following examples.

- Header compression and decompression (ROHC only)

- Transfer of user data

- In-sequence delivery of upper layer PDUs

- Out-of-sequence delivery of upper layer PDUs

- Reordering function (PDCP PDU reordering for reception)

- Duplicate detection of lower layer SDUs

- Retransmission of PDCP SDUs

- Ciphering and deciphering

- Timer-based SDU discard in uplink.

According to an embodiment of the present disclosure, the reordering function of the NR PDCP device may mean a function of reordering PDCP PDUs received from a lower layer in order based on a PDCP sequence number (SN), NR PDCP The reordering function of the device may include a function of delivering data to a higher layer in the rearranged order, or may include a function of directly passing data without considering the order, and PDCP lost by rearranging the order It may include a function of recording PDUs, and may include a function of reporting a status on the lost PDCP PDUs to the transmitting side, and at least one function of a function of requesting retransmission for the lost PDCP PDUs. may include

According to an embodiment of the present disclosure, a main function of the NR RLCs 1d-10, 1d-35 may include some of the following functions. Of course, it is not limited to the following examples.

- Data transfer function (Transfer of upper layer PDUs)

- In-sequence delivery of upper layer PDUs

- Out-of-sequence delivery of upper layer PDUs

- ARQ function (Error Correction through ARQ)

- Concatenation, segmentation and reassembly of RLC SDUs

- Re-segmentation of RLC data PDUs

- Reordering of RLC data PDUs

- Duplicate detection

- Protocol error detection

- RLC SDU discard function (RLC SDU discard)

- RLC re-establishment function

In-sequence delivery of the NR RLC (1d-10, 1d-35) device may mean a function of sequentially delivering RLC SDUs received from a lower layer to a higher layer. The sequential delivery function of the NR RLC device may include a function of reassembling and delivering the divided RLC SDUs when one RLC SDU is divided into several RLC SDUs and received. It may include a function of reordering based on a sequence number (SN) or PDCP sequence number (SN), and may include a function of reordering the order to record the lost RLC PDUs, and the status of the lost RLC PDUs It may include a function of reporting to the transmitting side, and may include a function of requesting retransmission for lost RLC PDUs. It may include a function of sequentially delivering to the upper layer, or if a predetermined timer expires even if there is a lost RLC SDU, it may include a function of sequentially delivering all RLC SDUs received before the timer starts to the upper layer. Alternatively, even if there is a lost RLC SDU, if a predetermined timer has expired, at least one function among functions of sequentially transferring all RLC SDUs received so far to a higher layer may be included. In addition, according to an embodiment of the present disclosure, the NR RLC layer processes RLC PDUs in the order in which they are received (regardless of the order of serial numbers and sequence numbers, in the order of arrival) to the PDCP device regardless of the order (Out- of sequence delivery), and in the case of segments, segments stored in a buffer or to be received later are received, reconstructed into one complete RLC PDU, processed and delivered to the PDCP device. The NR RLC layer may not include a concatenation function, and the concatenation function may be performed in the NR MAC layer or replaced with a multiplexing function of the NR MAC layer.

According to an embodiment of the present disclosure, out-of-sequence delivery of the NR RLC device refers to a function of directly delivering RLC SDUs received from a lower layer to a higher layer regardless of order, and originally one When the RLC SDU is divided into several RLC SDUs and received, it may include a function of reassembling and transmitting the divided RLC SDUs, and stores the RLC SN or PDCP SN of the received RLC PDUs and arranges the order Thus, it may include at least one function among the functions of recording the lost RLC PDUs.

According to an embodiment of the present disclosure, the NR MACs 1d-15 and 1d-30 may be connected to several NR RLC layer devices configured in one terminal, and the main function of the NR MAC includes some of the following functions. can do. Of course, it is not limited to the following examples.

- Mapping between logical channels and transport channels

- Multiplexing/demultiplexing of MAC SDUs

- Scheduling information reporting function

- HARQ function (Error correction through HARQ)

- Priority handling between logical channels of one UE

- Priority handling between UEs by means of dynamic scheduling

- MBMS service identification

- Transport format selection

- Padding function (Padding)

According to an embodiment of the present disclosure, the NR PHY layers 1d-20 and 1d-25 may channel-code and modulate upper layer data, make an OFDM symbol, and transmit it over a radio channel. In addition, the NR PHY layers 1d-20 and 1d-25 may perform an operation of demodulating an OFDM symbol received through a radio channel, performing channel decoding, and transmitting the OFDM symbol to a higher layer. The operation of the NR PHY layer is not limited to the above example.

FIG. 1E is a diagram illustrating an overall operation of a terminal transitioning to a connected state and performing measurement and carrier aggregation in an LTE system according to an embodiment of the present disclosure.

Cell re-selection is when the service quality with the serving cell is lower than the service quality with the neighboring cells due to the movement of the terminal in the IDLE state (represented in the present invention as an idle state or a dormant mode, etc.), This is a procedure for determining which cell the UE will camp in. While the handover is determined by the network (MME or source eNB), the cell reselection may be determined by the UE based on the measurement value. In addition, the cell to be reselected while the terminal moves is a cell using the same LTE frequency as the serving cell currently camping, a cell using a different LTE frequency (inter-frequency), or another radio access technology. It may be a cell used (inter-RAT).

The terminal 1e-01 in the IDLE state may perform a series of operations while camping (1e-05) in the serving cell. First, system information (System Information Block, SIB) broadcast by the base station of the serving cell may be received (1e-10). For reference, MIB, SIB1, and SIB2 are system information commonly applied to all UEs, and SIB3 to SIB8 may include information necessary for a UE in an IDLE state to reselect a cell. In particular, information related to measurement of a neighboring cell in an LTE intra-frequency may be transmitted to SIB4, and information related to an inter-frequency measurement may be transmitted to SIB5. The system information may include a threshold value used when determining whether to measure a signal from a neighboring cell, a parameter used for calculating the ranking of the serving cell and neighboring cells, and the like. In addition, for intra-frequency measurement, since the carrier frequency is the same as the current serving cell, carrier frequency information is not separately signaled to SIB4, but carrier frequency information of a neighboring cell requiring measurement may be specified in SIB5.

In addition, the terminal 1e-01 in the dormant mode (RRC_IDLE) finds a suitable cell and camps at the corresponding base station (1e-05), and may access the base station for reasons such as generation of data to be transmitted (1e) -15). In the sleep mode, data cannot be transmitted because the terminal is not connected to the network for power saving, etc., and a transition to the connected mode (RRC_CONNECTED) is required for data transmission. Also, the meaning of camping may mean that the terminal stays in the corresponding cell and receives a paging message to determine whether data is coming in downlink. The UE performing the access procedure to the base station may mean performing the random access procedure to the corresponding base station and cell, that is, if the UE succeeds in the random access procedure in step 1e-15, the UE 1e-01 A preamble may be transmitted (msg1) to the base station 1e-02, and in step 1e-20, the base station 1e-02 may transmit a random access response message (msg2) for the corresponding preamble to the terminal 1e-01. In step 1e-25, the terminal 1e-01 may transmit to the base station 1e-02 an RRC connection request message (msg3) for requesting an RRC connection, including the ID of the terminal, the connection reason, and the like. In step 1e-30, the base station 1e-02 may transmit a response message (msg4) in response to the corresponding RRC connection request to the terminal 1e-01. When the UE receives the RRC connection setup message in step 1e-30, it determines that it has received permission to the RRC connection state from the base station, and transmits an RRC connection setup complete message to the base station in step 1e-40 to the RRC connection mode (RRC_CONNECTED) ) can be changed to (1e-35). Accordingly, the terminal in the connected mode can transmit and receive data with the base station.

In step 1e-45, the base station 1e-02 may transmit an RRC connection reconfiguration message including measurement settings to the terminal 1e-01. Measurement settings included in the RRC connection reconfiguration message may include information on intra/inter/inter-RAT neighboring cells requiring measurement, types of signals requiring measurement, and a method of reporting measurement values, and the like. In response to the RRC connection reconfiguration message, the terminal 1e-01 may transmit an RRC connection reconfiguration complete message in steps 1e-50. If, among the set measurement settings, the measurement result for a specific measurement object satisfies the measurement condition for reporting (1e-55), the terminal 1e-01 may report the measurement result to the base station according to the set reporting method. There is (1e-60).

In step 1e-65, the base station 1e-02 may determine the channel state of the neighboring cells based on the measurement result reported by the terminal 1e-01 in the above step, and may identify cells having a good channel state. In step 1e-70, the base station 1e-02 may set carrier aggregation (CA, carrier aggregation) to the terminal 1e-01 for reasons such as increased traffic to the corresponding terminal and better service provision, and the channel condition is good. Cells may be configured as secondary cells (SCells) for CA. The configuration may be transmitted while being included in the RRC connection reconfiguration, and when the terminal 1e-01 receives the RRC connection reconfiguration message in steps 1e-70, it may transmit a response message to the base station 1e-02. Thereafter, the base station 1e-02 may activate the CA by delivering the MAC CE for activating carrier aggregation for a specific cell in steps 1e-75.

FIG. 1f shows the overall operation of measuring a neighboring cell in an IDLE state so that carrier aggregation can be quickly activated when cell reselection is performed in an LTE system or an NR system according to an embodiment of the present disclosure, and reporting it to the base station it is one drawing

Cell re-selection is when the service quality with the serving cell is lower than the service quality with the neighboring cells due to the movement of the terminal in the IDLE state (represented in the present invention as an idle state or a dormant mode, etc.), This is a procedure for determining which cell the UE will camp in. The handover is determined by the network (MME/AMF or source eNB/gNB), whereas the cell reselection may be determined by the UE based on the measurement value. In addition, the cell to be reselected while the terminal moves is a cell using the same LTE frequency as the serving cell currently camping, a cell using a different LTE frequency (inter-frequency), or another radio access technology. It may be a cell used (inter-RAT).

The terminal 1f-01 in the IDLE state may perform a series of operations while camping (1f-05) in the serving cell 1 (1f-02). First, system information (System Information Block, SIB) broadcast by the base station of the serving cell 1f-02 may be received (1f-10). The configuration and number of system information in the LTE system and the NR system may be different. Information related to measurement of an intra-frequency neighboring cell may be transmitted as SIB4 in LTE and SIB3 in NR. In addition, information related to inter-frequency measurement may be transmitted as SIB5 in LTE and SIB4 in NR. The system information may include a threshold value used when determining whether to measure a signal from a neighboring cell, a parameter used for calculating the ranking of the serving cell and neighboring cells, and the like. In addition, carrier frequency information is not separately signaled for intra-frequency measurement because the carrier frequency is the same as the current serving cell, but carrier frequency information of a neighboring cell requiring measurement can be specified for inter-frequency measurement. Subsequent content in this figure will be described based on NR. However, in terms of functionality, it can be applied to LTE without much change. Also, in NR, in addition to SIB4, frequency setting information for IDLE mode measurement may be provided through SIB11.

The UE may transition to the connected state according to the existence of data to be transmitted or data to be received with respect to the camping serving cell, and may transition to the IDLE state when there is no longer data transmission/reception in the connected state. The corresponding state transition may be determined and indicated by the base station 1f-02, and may be indicated through an RRC release message as in step 1f-20. The RRC release message may include information instructing the base station 1f-02 to measure the neighboring cell/frequency/RAT even in the IDLE state to the terminal 1f-01, and accordingly, frequency information requiring IDLE measurement is listed as a list. may be provided. In detail, carrier frequency, bandwidth information, a valid cell list (PCI: physical cell index) that can measure neighboring cells in the IDLE mode state, a cell list to be measured (PCI), a reference signal type to be measured and a threshold value, etc. May be included in this RRC release message. A valid cell list capable of measuring a neighboring cell (validity area) may mean a list of cells capable of performing IDLE mode measurement in a cell in which the terminal 1f-01 camps on, and may measure the neighboring cell. A valid cell list (validity area) can be interpreted as indicating that IDLE mode measurement can be processed in the corresponding cells. The parameters may be referred to in the following ASN.1 code, and for reference, a setting for measuring an LTE cell may be added and configured in a similar manner.

As can be seen by referring to the above RRC ASN.1 code, the configuration to measure the neighboring cells in the IDLE state can be configured through SIB4/SIB11 or RRC release message. The difference is that in SIB4/SIB11, only inter-carrier frequency information (list) that requires measurement can be provided, and in the RRC release message, inter-carrier frequency information (list) that requires measurement and how much measurement should be performed in IDLE mode. A timer period (measIdleDuration-r16) may be set. That is, basically, the RRC release message may be used to instruct the UE to dedicated IDLE mode measurement and trigger the corresponding operation, and the corresponding setting may be provided in SIB4/SIB11 to apply the same setting to the corresponding serving cell in common. have. In this case, the base station may transmit the RRC release message by omitting the configuration of inter-carrier frequency information to be measured in the IDLE state. If the SIB4/SIB11 and RRC release messages overlap inter-carrier frequency information to be measured in the IDLE state, the information included in the RRC release message may be prioritized.

Upon receiving the RRC release message including information indicating measurement of neighboring cells in the IDLE state in step 1f-20, the terminal 1f-01 may start to measure frequencies and cells configured in the IDLE state. In addition, in step 1f-25, the terminal 1f-01 may operate the IDLE state cell measurement timer T331. The terminal can perform IDLE state cell measurement from the start of the timer T331 to the timer expiration time (measIdleDuration-r16) When measurement is supported (it can be determined after checking SIB1, SIB4/SIB11, 1f-30), measurement of neighboring cells indicated by the corresponding cell or RRC release can be started (1f-35). That is, the terminal 1f-01 may check whether the corresponding serving cell can receive the IDLE mode measurement value and process it with fast CA/DC (Carrier Aggregation/Dual Connectivity). The capability of whether the serving cell can receive the IDLE mode measurement value and process it with fast CA/DC may be indicated by the idleModeMeasurements field in SIB1, and the terminal 1f-01 receives the idleModeMeasurements of SIB1 in step 1f-35. Whether to measure in IDLE mode can be determined by whether or not the indication is indicated. When the corresponding timer expires, the terminal 1f-01 may continue to perform the measurement set in SIB4/SIB11, or the terminal 1f-01 may arbitrarily stop the measurement.

If the terminal 1f-01 transitions to the RRC connected state while the timer T331 is operating, that is, before the timer expiration time (steps 1f-40 to 1f-55), random to the serving cell 1f-03 Perform the access procedure, and transition to the RRC connected state in step 1f-60), the terminal 1f-01 stops the T331 timer, and the serving cell to which the terminal transitions to the connected state receives the IDLE mode measurement value and fast CA If it is determined that it can be processed as RRC including an indicator that the terminal 1f-01 stores the measurement values of neighboring cells measured by the terminal in the IDLE state in the corresponding serving cell 1f-03 in step 1f-65 You can send a setup complete message.

The serving cell 1f-03 that has received the RRC setup complete message can know that there are measurement values of neighboring cells measured by the terminal 1f-01 in the IDLE state, and in step 1f-70, the terminal 1f-01 A UE information request message for requesting corresponding measurement value information may be transmitted.

Upon receiving the UE information request message, the UE 1f-01 transmits the UE information response message including the channel measurement values of the serving cell and neighboring cells stored by the UE to the serving cell 1f-03 in step 1f-75. Channel measurements can be reported.

As can be seen from the ASN.1 code above, the UE information response message includes the channel measurement values of the serving cell (Reference Signal Received Power (RSRP), Reference Signal Received Quality (RSRQ)) and the measurement values of neighboring cells that have been instructed to measure. Specifically, frequency information of neighboring cells, PCI ID, and channel measurement values (RSRP, RSRQ) of the corresponding cell are included.

In step 1f-75, the base station 1f-03, having received the measurement values for neighboring cells in the IDLE state from the terminal 1f-01, sends the terminal 1f-01 to the SCell for CA and DC in step 1f-80. Configuration information alc Can provide sPCell configuration information. The base station may refer to the content reported by the terminal in the corresponding step, and may activate the CA by transmitting an activation MAC CE for the SCell for reasons such as an increase in the data transmission amount of the terminal in a later step.

1G is a diagram illustrating an operation of performing IDLE mode measurement measurement when a UE performs cell reselection using NR as a master cell group (MCG) according to an embodiment of the present disclosure.

The UE may receive the IDLE mode measurement configuration in the first RAT (NR) in step 1g-05. The IDLE mode measurement setting may be related setting information included in the RRCRelease message, and details of the setting may correspond to the above-described contents in FIG. 1F . Upon receiving the RRCRelease message, the UE transitions to the IDLE mode in step 1g-10, and then may perform a cell reselection procedure to neighboring cells. In this embodiment, it is assumed that the cell (Cell 2) performing cell reselection is also a cell belonging to the first RAT, that is, NR. The terminal receiving the system information from the base station to which the cell belongs checks whether there is an indicator indicating that IDLE mode measurement is supported in the system information, and if the indicator exists, the previously set IDLE mode setting is applied to the IDLE mode. Measurements can be performed (1g-20). The case of performing IDLE mode measurement may also include the case that the corresponding cell belongs to the validity area. The setting value applied at this time may include IDLE mode measurement configuration information provided in the RRCRelease message or IDLE mode measurement configuration information included in system information provided by the corresponding cell.

Steps 1g-25 to 1g-35 below represent steps 1g-20, that is, a detailed procedure for performing IDLE mode measurement configured by the UE, and may be performed in the following order.

In step 1g-25, the UE may perform IDLE mode measurement for the first RAT (NR). IDLE mode measurement for the first RAT (NR) may mean IDLE mode measurement for intra-frequency neighboring cells, and may mean measurement of cells for a serving frequency. In step 1g-30, the UE may perform peripheral carrier measurement for the second RAT (LTE, that is, EUTRA). In step 1g-30, the UE is limited to a UE supporting NE-DC, and may be a UE supporting dual connectivity in which the first RAT/current carrier is MCG and the second RAT/neighborhood carrier is SCG. If in step 1g-30, the terminal is named as a terminal supporting DC rather than as a terminal supporting NE-DC, the terminal supporting EN-DC can perform step 1g-30, which in turn means that the terminal supports 1g- Although it results in reporting the measurement value for the second RAT of step 30, if the base station interprets it as it is and gives the NE-DC setting, the RRC setting may not be applied properly because it does not actually have the NE-DC capability. can In the standard document, the conditions for the step can be described as the following procedure.

The UE may then perform IDLE mode measurement for the first RAT (NR) neighboring carrier in step 1g-35. IDLE mode measurement for the first RAT (NR) neighboring carrier may mean that the UE performs measurement on an inter-frequency frequency for the first RAT, and a UE having CA and NR-DC capabilities for the frequency. This may mean a case of supporting dual connectivity in which the first RAT/current carrier is MCG/ and the first RAT/neighboring carrier is SCG. That is, for the corresponding condition, the UE may perform IDLE mode measurement for set frequencies. In the standard document, the conditions for the step can be described as the following procedure.

Thereafter, the UE may transmit the corresponding measurement result to the base station according to the procedure described in FIG. 1F, and the base station may apply the fast CA/DC setting using the corresponding measurement value.

1H is a diagram illustrating an operation of performing IDLE mode measurement measurement when a UE performs cell reselection using LTE as an MCG according to an embodiment of the present disclosure.

The UE may receive the IDLE mode measurement configuration in the first RAT (NR) in step 1h-05. The IDLE mode measurement setting may be related setting information included in the RRCRelease message, and details of the setting may correspond to the above-described contents in FIG. 1F . Upon receiving the RRCRelease message, the UE transitions to the IDLE mode in steps 1h-10, and then may perform a cell reselection procedure to neighboring cells. In step 1h-10, the UE starts T331. In this embodiment, it is assumed that the cell (Cell 3) performing cell reselection is a cell belonging to the second RAT, that is, LTE. The terminal receiving the system information from the base station to which the cell belongs checks whether there is an indicator indicating support for IDLE mode measurement from the system information, and if the indicator exists, the previously set IDLE mode setting is applied to the IDLE mode. Measurements can be performed (1h-20). The case of performing IDLE mode measurement may also include a case where the corresponding cell belongs to the validity area. The setting value applied at this time may include IDLE mode measurement configuration information provided in the RRCRelease message or IDLE mode measurement configuration information included in system information provided by the corresponding cell.

Steps 1h-25 to 1h-30 below represent steps 1h-20, that is, a detailed procedure for performing IDLE mode measurement configured by the UE, and may be performed in the following order.

In step 1h-25, the UE may perform IDLE mode measurement for the second RAT (LTE) and store the corresponding value. IDLE mode measurement for the second RAT (LTE) may mean IDLE mode measurement for intra/inter-frequency neighboring cells, and may be cell/frequency measurement for a serving RAT. In standard documents, the conditions of steps 1h-25 can be described with the following procedure.

In step 1h-30, the UE may perform neighbor carrier measurement for the first RAT (NR). In step 1h-30, the UE may be a UE supporting (NG)EN-DC, and it is explained as a UE supporting dual connectivity with the second RAT/current carrier as MCG and the first RAT/neighboring carrier as SCG. can be If the name is not a terminal supporting (NG)EN-DC but a terminal supporting DC in the corresponding step, the terminal supporting NE-DC is able to perform steps 1h-30, which results in the terminal being able to perform steps 1h It brings the result of reporting the measurement value for the first RAT of step -30, but if the base station interprets it as it is and sets the (NG)EN-DC setting, in reality there is no (NG)EN-DC capability. RRC settings may not be applied properly. In the standard document, the conditions for the step can be described as the following procedure.

Thereafter, the UE may transmit the corresponding measurement result to the base station according to the procedure described in FIG. 1F, and the base station may apply the fast CA/DC setting using the corresponding measurement value.

1I is a block diagram illustrating an internal structure of a terminal according to an embodiment of the present disclosure.

Referring to FIG. 1I , the terminal may include a radio frequency (RF) processing unit 1i-10, a baseband processing unit 1i-20, a storage unit 1i-30, and a control unit 1i-40. have. Of course, the example is not limited thereto, and the terminal may include fewer or more configurations than those illustrated in FIG. 1I .

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

The baseband processing unit 1i-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 1i-20 generates complex symbols by encoding and modulating the transmitted bit stream. Also, upon data reception, the baseband processing unit 1i-20 restores the received bit stream by demodulating and decoding the baseband signal provided from the RF processing unit 1i-10. For example, in the case of orthogonal frequency division multiplexing (OFDM), when transmitting data, the baseband processing unit 1i-20 encodes and modulates a transmitted bit stream to generate complex symbols, and maps the complex symbols to subcarriers. After that, OFDM symbols are constructed through inverse fast Fourier transform (IFFT) operation and cyclic prefix (CP) insertion. In addition, when receiving data, the baseband processing unit 1i-20 divides the baseband signal provided from the RF processing unit 1i-10 into OFDM symbol units, and maps the baseband signals to subcarriers through a fast Fourier transform (FFT) operation. After restoring the signals, the received bit stream is restored through demodulation and decoding.

The baseband processing unit 1i-20 and the RF processing unit 1i-10 transmit and receive signals as described above. Accordingly, the baseband processing unit 1i-20 and the RF processing unit 1i-10 may be referred to as a transmitter, a receiver, a transceiver, or a communication unit. Furthermore, at least one of the baseband processing unit 1i-20 and the RF processing unit 1i-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 1i-20 and the RF processing unit 1i-10 may include different communication modules to process signals of different frequency bands. For example, 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 terminal may transmit/receive a signal to and from the base station using the baseband processing unit 1i-20 and the RF processing unit 1i-10, and the signal may include control information and data. The storage unit 1i-30 may be configured of a storage medium such as a ROM, a RAM, a hard disk, a CD-ROM, and a DVD, or a combination of storage media. Also, the storage unit 1i-30 may include a plurality of memories. According to an embodiment of the present disclosure, the storage unit 1i-30 may store a program for a method for the terminal according to the present disclosure to apply medium access control (MAC) configuration information.

The storage unit 1i-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 1i-30 may store information related to a second access node that performs wireless communication using a second wireless access technology. In addition, the storage unit 1i-30 provides stored data according to the request of the control unit 1i-40.

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

1J is a block diagram illustrating a configuration of a base station according to an embodiment of the present disclosure.

As shown in FIG. 1j, the base station includes an RF processing unit 1j-10, a baseband processing unit 1j-20, a backhaul communication unit 1j-30, a storage unit 1j-40, and a control unit 1j-50. may include Of course, it is not limited to the above example, and the base station may include fewer or more configurations than the configuration shown in FIG. 1J .

The RF processing unit 1j-10 may perform a function for transmitting and receiving a signal through a wireless channel, such as band conversion and amplification of the signal. That is, the RF processing unit 1j-10 up-converts the baseband signal provided from the baseband processing unit 1j-20 into an RF band signal, transmits it through the antenna, and converts the RF band signal received through the antenna to the baseband. can be down-converted to a signal. For example, the RF processing unit 1j-10 may include a transmit filter, a receive 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. Also, the RF processing unit 1j-10 may include a plurality of RF chains. Furthermore, the RF processing unit 1j-10 may perform beamforming. For beamforming, the RF processing unit 1j-10 may adjust the phase and magnitude of each of signals transmitted and received through a plurality of antennas or antenna elements. The RF processing unit may perform a downlink MIMO operation by transmitting one or more layers.

The baseband processing unit 1j-20 may perform a conversion function between a baseband signal and a bit stream according to the physical layer standard of the first radio access technology. For example, when transmitting data, the baseband processing unit 1j-20 may generate complex symbols by encoding and modulating the transmitted bit stream. Also, when receiving data, the baseband processing unit 1j-20 may restore the received bit stream by demodulating and decoding the baseband signal provided from the RF processing unit 1j-10. For example, in the OFDM scheme, when transmitting data, the baseband processing unit 1j-20 generates complex symbols by encoding and modulating the transmitted bit stream, maps the complex symbols to subcarriers, and performs IFFT operation and OFDM symbols can be configured through CP insertion. In addition, upon data reception, the baseband processing unit 1j-20 divides the baseband signal provided from the RF processing unit 1j-10 into OFDM symbol units, and restores signals mapped to subcarriers through FFT operation. , it is possible to restore the received bit stream through demodulation and decoding. The baseband processing unit 1j-20 and the RF processing unit 1j-10 may transmit and receive signals as described above. Accordingly, the baseband processing unit 1j-20 and the RF processing unit 1j-10 may be referred to as a transmitter, a receiver, a transceiver, a communication unit, or a wireless communication unit. The base station may transmit/receive a signal to/from the terminal using the baseband processing unit 1j-20 and the RF processing unit 1j-10, and the signal may include control information and data.

The backhaul communication unit 1j-30 may provide an interface for performing communication with other nodes in the network. That is, the backhaul communication unit 1j-30 converts a bit string transmitted from the main base station to another node, for example, an auxiliary base station, a core network, etc. into a physical signal, and converts the physical signal received from the other node into a bit string. can be converted

The storage unit 1j-40 may store data such as a basic program, an application program, and setting information for the operation of the main station. In particular, the storage unit 1j-40 may store information on a bearer allocated to an accessed terminal, a measurement result reported from the accessed terminal, and the like. In addition, the storage unit 1j-40 may store information serving as a criterion for determining whether to provide or stop multiple connections to the terminal. In addition, the storage unit 1j-40 may provide stored data according to the request of the control unit 1j-50. In addition, the storage unit 1j-40 provides the stored data according to the request of the control unit 1j-50. The storage unit 1j-40 may be configured of a storage medium such as a ROM, a RAM, a hard disk, a CD-ROM, and a DVD, or a combination of storage media. Also, the storage unit 1j-40 may include a plurality of memories.

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

Methods according to the embodiments described in the claims or specifications of the present disclosure may be implemented in the form of hardware, software, or a combination of hardware and software.

When implemented in software, a computer-readable storage medium storing one or more programs (software modules) may be provided. One or more programs stored in the computer-readable storage medium are configured to be executable by one or more processors in an electronic device (device). One or more programs include instructions for causing an electronic device to execute methods according to embodiments described in a claim or specification of the present disclosure.

Such programs (software modules, software) include random access memory, non-volatile memory including flash memory, read only memory (ROM), electrically erasable programmable ROM (EEPROM: Electrically Erasable Programmable Read Only Memory), magnetic disc storage device, Compact Disc-ROM (CD-ROM), Digital Versatile Discs (DVDs), or any other form of It may be stored in an optical storage device or a magnetic cassette. Alternatively, it may be stored in a memory composed of a combination of some or all thereof. In addition, a plurality of each configuration memory may be included.

In addition, the program is transmitted through a communication network consisting of a communication network such as the Internet, Intranet, Local Area Network (LAN), Wide LAN (WLAN), or Storage Area Network (SAN), or a combination thereof. It may be stored on an attachable storage device that can be accessed. Such a storage device may be connected to a device implementing an embodiment of the present disclosure through an external port. In addition, a separate storage device on the communication network may be connected to the device implementing the embodiment of the present disclosure.

In the specific embodiments of the present disclosure described above, components included in the disclosure are expressed in the singular or plural according to the specific embodiments presented. However, the singular or plural expression is appropriately selected for the situation presented for convenience of description, and the present disclosure is not limited to the singular or plural component, and even if the component is expressed in plural, it is composed of a singular or singular. Even an expressed component may be composed of a plurality of components.

Meanwhile, although specific embodiments have been described in the detailed description of the present disclosure, various modifications are possible without departing from the scope of the present disclosure. Therefore, the scope of the present disclosure should not be limited to the described embodiments and should be defined by the claims described below as well as the claims and equivalents. That is, it will be apparent to those of ordinary skill in the art to which the present disclosure pertains that other modifications may be implemented based on the technical spirit of the present disclosure. In addition, each of the above embodiments may be operated in combination with each other as needed. For example, a base station and a terminal may be operated by combining parts of the methods proposed in the present disclosure. In addition, although the above embodiments have been presented based on 5G and NR systems, other modifications based on the technical idea of the embodiments may be implemented in other systems such as LTE, LTE-A, and LTE-A-Pro systems.

Claims (1)

A method of operating a terminal in a wireless communication system, comprising:
Receiving an RRC release message from the first base station;
identifying IDLE mode measurement configuration information from the received RRC release message;
transitioning to an IDLE mode based on the identified IDLE mode measurement setting information;
performing cell reselection with a second base station; and
if the second base station belongs to a validity area, performing IDLE mode measurement.

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