KR20210125364A - Method and apparatus for reporting random access-related infromation in a mobile communication system - Google Patents

Abstract

The present disclosure relates to a method and apparatus for reporting random access information in a mobile communication system. The method for reporting random access information includes the steps of: receiving, by a terminal, an RRC message including configuration information necessary for performing a Logged MDT operation, from a base station; receiving an RRC Release message indicating a standby mode or an inactive mode, from the base station; and performing, by the terminal, Logged MDT in the standby mode or inactive mode based on the RRC Release message and configuration information.

Description

Method and apparatus for reporting random access information in a mobile communication system

The present disclosure relates to a method and apparatus for reporting random access information in a mobile communication system, and more particularly, to a method and apparatus for reporting random access information to perform a Minimization of Drive Test (MDT).

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 after the LTE system (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 reporting random access information in a mobile communication system is required.

The disclosed embodiments are intended to provide an apparatus and method for effectively reporting random access information in a mobile communication system.

According to an embodiment of the present disclosure, there is provided a method for a terminal to report random access information in a mobile communication system, the method comprising: receiving an RRC message including configuration information necessary for performing a Logged MDT operation from a base station; Receiving an RRC Release message indicating a standby mode or an inactive mode from the base station; and performing Logged MDT in standby mode or inactive mode based on the RRC Release message and the configuration information.

The disclosed embodiment provides an apparatus and method for effectively reporting random access information in a mobile communication system.

1A is a diagram illustrating a structure of a next-generation mobile communication system according to an embodiment of the present disclosure.
FIG. 1B is a diagram for explaining a wireless access state transition in a next-generation mobile communication system according to an embodiment of the present disclosure. FIG. 1C is a diagram illustrating a technology for collecting and reporting cell measurement information according to an embodiment of the present disclosure. It is a drawing.
1D is a diagram illustrating a method of collecting and reporting cell measurement information according to an embodiment of the present disclosure.
1E is a flowchart of an operation for collecting and reporting cell measurement information according to an embodiment of the present disclosure.
1F is a diagram for explaining a Radio Link Monitoring (RLM) operation according to an embodiment of the present disclosure.
1G is a diagram for explaining a Radio Link Failure (RLF) operation and an RLF report according to an embodiment of the present disclosure.
1H is a diagram for explaining a random access (RA) report according to an embodiment of the present disclosure.
1I is a flowchart of a process of storing random access related information according to an embodiment of the present disclosure.
1J is a flowchart of an operation of a terminal for storing random access related information according to an embodiment of the present disclosure.
1K is a block diagram illustrating an internal structure of a terminal according to an embodiment of the present disclosure.
11 is a block diagram illustrating a configuration of a base station according to an embodiment of the present disclosure.

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.

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 flow chart 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. The '~ unit' 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. .

In addition, although the embodiment of the present invention will be described below using an LTE, LTE-A, LTE Pro or 5G (or NR, next-generation mobile communication) system as an example, the present invention is also applied 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 invention can be applied to other communication systems through some modifications within the scope of the present invention as judged by a person having skilled technical knowledge.

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

Referring to FIG. 1A, as shown, the radio access network of a next-generation mobile communication system (New Radio, NR) includes a next-generation base station (New Radio Node B, hereinafter gNB) 1a-10 and a radio core network (New Radio Core Network). ), and the wireless core network may include an AMF (1a-05, Access Management Function), and is not limited to the above example. A user terminal (New Radio User Equipment, hereinafter NR UE or terminal) 1a-15 may access an external network through the gNB 1a-10 and the AMF 1a-05.

In FIG. 1A , gNBs 1a-10 correspond to an Evolved Node B (eNB) of an existing LTE system. The gNB (1a-10) 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 for scheduling by collecting status information such as buffer status of UEs, available transmission power status, and channel status is required, and it is 1a-10) may be in charge. One gNB 1a-10 may control a plurality of cells. In order to implement ultra-high-speed data transmission compared to existing LTE, it can have more than the existing maximum bandwidth, and additionally beamforming technology can be used by using Orthogonal Frequency Division Multiplexing (hereinafter referred to as OFDM) as a radio access technology.

In addition, according to an embodiment, the NR gNB 1a-10 determines a modulation scheme and a channel coding rate according to the channel state of the terminal (Adaptive Modulation & Coding, hereinafter AMC). d) method can be applied.

Also, according to an embodiment, the AMF 1a-05 may perform functions such as mobility support, bearer setup, QoS setup, and the like. The AMF (1a-05) is a device in charge of various control functions as well as a mobility management function for the terminal, and can 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 AMF 1a-05 may be connected to the Mobility Management Entity (MME) 1a-25 through a network interface. The MME (1a-25) may be connected to the existing base station eNB (1a-30). A UE supporting LTE-NR Dual Connectivity may transmit and receive data while maintaining a connection to not only the gNB 1a-10 but also the eNB 1a-30 (1a-35).

1B is a diagram for explaining a wireless connection state transition in a next-generation mobile communication system according to an embodiment of the present disclosure.

The next-generation mobile communication system has three radio connection states (RRC states). The connected mode (RRC_CONNECTED, 1b-05) is a wireless connection state in which the terminal can transmit and receive data. The standby mode (RRC_IDLE, 1b-30) is a radio access state in which the terminal monitors whether paging is transmitted to itself. The connected mode (1b-05) and the standby mode (1b-30) are radio access states that are also applied to the existing LTE system, and the detailed technology is the same as that of the existing LTE system.

In the next-generation mobile communication system, a new inactive (RRC_INACTIVE) radio connection state 1b-15 is defined. In the present disclosure, the RRC_INACTIVE radio access state 1b-15 newly defined in the next-generation mobile communication system may correspond to an inactive radio access state, an INACTIVE mode, an inactive mode, and the like.

In the inactive mode (1b-15) radio access state, the UE context is maintained in the base station and the terminal, and RAN (Radio Access Network) based paging is supported. The characteristics of the inactive mode (1b-15) wireless connection state are listed below.

- Cell re-selection mobility;

- CN - NR RAN connection (both C/U-planes) has been established for UE;

- The UE AS context is stored in at least one gNB and the UE;

- Paging is initiated by NR RAN;

- RAN-based notification area is managed by NR RAN;

- NR RAN knows the RAN-based notification area which the UE belongs to;

According to an embodiment, the INACTIVE radio connection state 1b-15 may transition to the connected mode 1b-05 or the standby mode 1b-30 using a specific procedure. According to the resume process, the INACTIVE mode (1b-15) is converted to the connected mode (1b-05), and the connected mode (1b-05) is converted to the INACTIVE mode (1b-15) using the Release procedure including the suspend setting information. becomes (1b-10). In the aforementioned procedure (1b-10), one or more RRC messages may be transmitted/received between the UE and the base station, and the above-described procedure (1b-10) may consist of one or more steps.

Also, through the Resume and Release procedure, the INACTIVE mode (1b-15) can be switched to the standby mode (1b-30) (1b-20).

Switching between the connected mode (1b-05) and the standby mode (1b-30) follows the existing LTE technology. That is, through an establishment or release procedure, a switch between the connected mode (1b-05) and the standby mode (1b-30) may be performed (1b-25).

1C is a diagram for describing a technique for collecting and reporting cell measurement information according to an embodiment of the present disclosure.

When constructing or optimizing a network, a mobile communication service provider (hereinafter referred to as an operator) typically measures signal strength in an expected service area, and places or readjusts base stations in the service area based on the measured signal strength. . The operator loads the signal measurement equipment on the vehicle and collects the cell measurement information in the service area, which requires a lot of time and money. The process of collecting the above-described cell measurement information is generally referred to as a drive test (1c-30) by using a vehicle.

The terminal 1c-25 is equipped with a function of measuring a signal and transmitting the measurement result to the base station in order to support operations such as cell reselection, handover, and serving cell addition when moving between cells. Therefore, instead of the above-described drive test, the terminal 1c-25 in the service area may be utilized, which may be defined as a minimization of drive test (MDT). The operator may set the MDT operation to specific terminals through various components of the network. In addition, UEs may collect and store signal strength information from the serving cell and neighboring cells in the connected mode (RRC_Connected), the standby mode (RRC_Idle), or the inactive mode (RRC_Inactive). In addition, the terminals may also store various information such as location information, time information, and signal quality information. The information that the terminal can store is not limited to the above-described example. The information stored in the terminal may be reported to the network when the terminals are in the connected mode, and the information stored in the terminal may be transmitted to a specific server.

The above-described MDT operation can be largely classified into immediate MDT and logged MDT.

Immediate MDT is characterized by reporting the collected information directly to the network. Since the terminal must immediately report the collected information to the network, only the terminal in the connected mode can perform this. As an example, Immediate MDT may be performed by recycling a Radio Resource Management (RRM) measurement process for supporting operations such as handover and serving cell addition, and location information, time information, etc. may be additionally reported to the network.

Logged MDT stores the information collected by the terminal without directly reporting the collected information to the network, and after the terminal is switched to the connected mode, the terminal reports the stored information. As an example, a terminal in a standby mode that cannot directly report the collected information to the network may perform Logged MDT. As another example, the terminal in the inactive mode introduced in the next-generation mobile communication system may perform Logged MDT. When a specific terminal is in the connected mode, the network may provide configuration information for performing the Logged MDT operation to the terminal in the connected mode. In addition, the terminal may collect and store set information after being switched to a standby mode or an inactive mode.

Table 1 below is a table summarizing the MDT mode (Immediate MDT or Logged MDT) that the UE can perform according to the RRC state of the UE.

[Table 1]

1D is a diagram illustrating a method of collecting and reporting cell measurement information according to an embodiment of the present disclosure.

The terminal 1d-05 may be switched from the standby mode or the inactive mode 1d-10 to the connected mode 1d-15. The terminal 1d-05 in the connected mode 1d-15 may collect MDT data and report it to the base station through an immediate MDT operation.

The terminal 1d-05 switched to the connected mode 1d-15 may be provided with Logged MDT configuration information (IDLE/INACTIVE MDT configuration) performed in the standby mode or inactive mode from the base station (1d-20). Logged MDT configuration information may be included in a predetermined RRC message and transmitted to the terminal. Upon receiving the RRC message, the UE may drive a first timer (1d-55).

The UE may perform the Logged MDT operation in the standby mode or the inactive mode until the first timer expires. The value of the first timer may be included in Logged MDT configuration information. When the terminal is switched to the standby mode or the inactive mode, according to the received Logged MDT configuration information, the terminal may perform Logged MDT (1d-25). The terminal may store predetermined information collected at every set period (eg, logging interval) (1d-35) (1d-30, 1d-45).

In addition, if the terminal 1d-05 has collected valid location information (eg, GNSS location information) 1d-40, the terminal 1d-05 should also store the valid location information. After the above-described location information is collected, if a predetermined time (eg, Validity period for GNSS location) 1d-50 has elapsed, the location information may be determined to be valid. The predetermined time 1d-50 for determining whether the above-described location information is valid may be shorter than or equal to the logged interval (or logging interval) 1d-35.

Even before the first timer expires, if the terminal 1d-05 is switched to the connected mode, the terminal 1d-05 may pause the Logged MDT operation being performed (1d-60). However, the first timer may be continuously driven without stopping even in the connected mode period. That is, the first timer may be continuously driven regardless of the change in the RRC state. However, when the terminal memory for storing MDT data is insufficient, when the terminal can no longer store data, or when the Logged MDT setting information is released, the first timer may be stopped. For example, when the Logged MDT configuration information is released, other Logged MDT configuration information is provided from the serving RAT (Radio Access Technology) or other RAT, or when the terminal is detached or the power is cut off. During the connection establishment process (RRC Connection Establishment) or the connection restart process (RRC Connection Resume), the terminal 1d-05 uses the RRC Setup Complete message or the RRC Resume Complete message to collect the collection information (MDT data) it stores. It can report to the base station that it has (1d-65).

The connection establishment process (RRC Connection Establishment) is a process in which the terminal 1d-05 is switched from the standby mode to the connected mode. As described below, the RRC Connection Establishment is typically composed of three steps, and three types of RRC messages are used.

- Step 1: The terminal transmits an RRC Setup Request message to the base station

- Step 2: The base station transmits the RRC Setup message to the terminal

- Step 3: The terminal transmits the RRC Setup Complete message to the base station

The connection restart process (RRC Connection Resume) is a process in which the terminal 1d-05 is switched from the inactive mode to the connected mode. As described below, the RRC Connection Resume usually consists of a process of three steps, and three types of RRC messages are used.

- Step 1: The terminal transmits an RRC Resume Request message to the base station

- Step 2: The base station transmits an RRC Resume message to the terminal

- Step 3: The UE transmits the RRC Resume Complete message to the base station

As described above, the terminal 1d-05 may report information indicating that it has the collection information (MDT data) to the base station during the connection establishment process and the connection restart process. Also, as another example, the terminal 1d-05 may report information indicating that it has the collection information (MDT data) to the target base station during the RRC Connection Reestablishment and the handover process.

According to an embodiment of the present disclosure, although the Logged MDT is configured, if there is no collected and stored information yet, the terminal 1d-05 may omit the above-described reporting process.

The base station receiving the report (information indicating that it has collection information (MDT data)) may request a report of the MDT data stored by the terminal 1d-05 if necessary. The unreported MDT data must be continuously stored by the terminal 1d-05 for a predetermined time. If the terminal 1d-05 is switched back to the standby mode or the inactive mode, and the first timer has not yet expired, the terminal 1d-05 may restart the Logged MDT operation again (1d-70).

If the first timer expires, the terminal 1d-05 may stop the Logged MDT operation (1d-75). After stopping the logged MDT operation, the terminal (1d-05) drives the second timer (1d-80), and the terminal (1d-05) may maintain the stored MDT data until the second timer expires. After the second timer expires, whether to delete the MDT data being stored may be determined by the terminal implementation. According to an embodiment of the present disclosure, the value of the second timer may be included in the Logged MDT configuration information, or a predefined value may be applied without being set.

When the terminal 1d-05 is switched back to the connected mode, the terminal 1d-05 may report to the base station that it is storing the collection information (MDT data) (1d-85). This time, the base station may request a report of the MDT data stored by the terminal 1d-05 by using a predetermined RRC message (1d-90). Accordingly, the terminal 1d-05 may receive (or include) the MDT data being stored in a predetermined RRC message, and report the message to the base station (1d-95).

1E is a flowchart of an operation for collecting and reporting cell measurement information according to an embodiment of the present disclosure.

The terminal 1e-05 may establish a connection with the base station (eg, gNB) 1e-10 (1e-15). The terminal 1e-05 provides UE capability information to the base station 1e-10 (1e-20), and can indicate whether it supports the MDT operation and whether it can measure what frequency. have. The base station 1e-10 may receive the configuration information necessary for performing the Logged MDT operation in a predetermined RRC message and transmit it to the terminal 1e-05 (1e-25). As an example, the setting information may include at least one of the following information.

- About Trace Reference

- About Trace Recording Session Reference

- Trace Collection Entity (TCE) ID information: The base station transmits the MDT data information reported from the terminal to the data server designated by the TCE ID.

- Absolute Time: Absolute time in the current cell providing Logged MDT setting information.

- Area Configuration: It means area information that can collect and store measurement information through Logged MDT operation, and is indicated in units of cells. It may also include RAT information for which measurement information should be collected. The list included in the RAT information may be a black list or a white list. If the list is a black list, cell measurement information is collected for RATs not included in the list. If the list is a White List, cell measurement information is not collected for RATs not included in the list.

- Logging Duration: As the value of the first timer described above, when the first timer is running, the terminal performs a Logged MDT operation in a standby mode or an inactive mode.

- Logging Interval: It is the interval for saving the collected information.

- plmn-IdentityList (i.e. MDT PLMN list): PLMN list information, and stores PLMN information capable of not only performing the above-described Logged MDT operation, but also reporting whether MDT data is stored and reporting MDT data.

- An indicator indicating whether to perform Logged MDT operation in standby mode, inactive mode, or both. As an example, by using this indicator, it is possible to indicate the RRC state for performing the Logged MDT operation. As another example, it can be defined to always perform the Logged MDT operation in the standby mode and the inactive mode without the above-described indicator. The UE performs the Logged MDT operation only in the RRC state indicated by this indicator.

- An indicator indicating whether to collect and store beam level measurement information. A beam antenna may be applied in a next-generation mobile communication system. As an example, without such an indicator, it may be defined that the beam level measurement measurement is always collected and stored for a frequency at which a beam-based operation is performed.

- Information on the maximum number of beams to be collected or stored, and information about the minimum signal strength of beams to be stored. The terminal may omit storage of information on a beam that is weaker than the minimum signal strength of the stored beam. If all the beams are weaker than the set minimum signal value, the terminal may store one beam information having the strongest signal strength among them, or may include an indicator that all beams are weaker than the set minimum signal value.

- An indicator indicating whether the MDT retrieval operation can be triggered in the 2-step restart process (RRC Resume).

Upon receiving the above-described Logged MDT configuration information, the terminal 1e-05 may drive a first timer (1e-30). The value of the first timer may be set to be the same as the value of Logging Duration.

The base station 1e-10 may use the RRC Release message to switch the terminal 1e-05 to the standby mode or the inactive mode (1e-35). Depending on which RRC state the UE 1e-05 is switched to, the RRC Release message may contain configuration information for the operation of the UE 1e-05 in the selected RRC state.

If the first timer is running, the terminal 1e-05 may perform Logged MDT in a standby mode or an inactive mode (1e-40).

According to an embodiment of the present disclosure, the terminal 1e-05 may measure signal strength of a serving cell and neighboring cells, and obtain location information. When the beam level measurement is set, the terminal 1e-05 may collect and store a signal strength value for a beam greater than a minimum value (minimum signal value) set in the serving cell and the adjacent cell. The maximum number of beams that can be stored may be set or predefined. In the present specification, the signal strength may mean Reference Signal Received Power (RSRP), Reference Signal Received Quality (RSRQ), or Signal-to-interference-plus-noise ratio (SINR), but is not limited thereto.

According to an embodiment of the present disclosure, the terminal 1e-05 may store the collected information every Logged Interval period. Each log information stored in each Logged Interval period may include an indicator indicating whether the stored information is collected in the standby mode of the terminal or is collected in the inactive mode of the terminal. As another example, the above-described indicator (indicator indicating in which mode of the terminal the information is collected) may be included in every first log in which the mode is switched. In this case, signaling overhead due to the indicator can be minimized.

When the first timer expires (1e-45), the terminal (1e-05) may stop the Logged MDT operation (1e-50).

If the terminal 1e-05 is in standby mode or inactive mode by the RRC Release message of step 1e-35 described above, and receives RAN or CN (Core Network) paging from the base station 1e-10, or MO (Mobile) Originated) when data transmission is activated, the terminal 1e-05 may initiate an establishment process or a resume process for switching from the standby mode or the inactive mode to the connected mode.

The establishment process or resume process

- Step 1: The terminal 1e-05 transmits an RRC Setup Request message or RRC Resume Request message to the base station 1e-10 (1e-55)

- Step 2: The base station 1e-10 transmits an RRC Setup message or an RRC Resume message to the terminal 1e-05 (1e-60)

- Step 3: The terminal (1e-05) transmits an RRC Setup Complete message or an RRC Resume Complete message to the base station (1e-10) (1e-65)

can be composed of According to an embodiment of the present disclosure, the terminal 1e-05 may accommodate an indicator indicating whether there is MDT data stored therein in the RRC Setup Complete or RRC Resume Complete message.

Upon receiving the RRC Setup Complete message, the base station 1e-10 may request a report of the MDT data to the terminal 1e-05 by using a predetermined RRC message, if necessary (1e-70). Upon receiving the request from the base station 1e-10, the terminal 1e-05 may report the MDT data to the base station 1e-10 using a predetermined RRC message (1e-75).

1F is a diagram for explaining a Radio Link Monitoring (RLM) operation according to an embodiment of the present disclosure.

The physical layer of the UE may measure the downlink signal quality from a cell-specific reference signal (CRS) of the serving cell (1f-05). The physical layer of the terminal may determine whether the downlink signal quality is lower than (or smaller than) Qout, which is a specific threshold (1f-10). In this case, as an example, the threshold may mean a signal quality value corresponding to a specific block error rate (BLER) measured in a physical downlink control channel (PDCCH).

If the downlink signal quality is lower than the specific threshold Qout, the physical layer may transmit an 'out-of-sync' indicator to the upper layer. In LTE technology, the operation is called RLM (Radio Link Monitoring). If the 'out-of-sync' indicator is delivered to the upper layer more than a certain number of times, the upper layer drives a specific timer, and when the timer expires, Radio Link Failure (RLF) may be declared (1f-15).

1G is a diagram for explaining a Radio Link Failure (RLF) operation according to an embodiment of the present disclosure.

As previously described, RLF can be declared according to the result from the RLM operation. The physical layer of the UE may determine whether the downlink signal quality is lower than a specific threshold Qout from the CRS of the serving cell at every specific period (eg, Qout evaluation period). If the downlink signal quality is lower than a specific threshold Qout, the physical layer may transmit an 'out-of-sync' indicator to a higher layer.

After the first 'out-of-sync' indicator is delivered to the upper layer (1g-05), if the 'out-of-sync' indicator is delivered to the upper layer a certain number of times (eg, N310), the upper layer is A timer (eg, T310 timer) may be driven (1g-10).

The physical layer may also determine whether the downlink signal quality is higher than a specific threshold Qin from the CRS of the serving cell. If the downlink signal quality is higher than the specific threshold Qin, the physical layer may deliver the 'in-sync' indicator to the upper layer. When the 'in-sync' indicator is delivered to the upper layer a certain number of times, the upper layer may stop the running T310 timer. If the T310 timer is not stopped and expires, the upper layer may declare an RLF (1g-15).

After RLF declaration, the UE may drive another timer T311. The UE may find a new suitable cell. If the terminal does not find a new suitable cell until the T311 timer expires, the terminal may be switched to the standby mode (1g-25).

If the UE finds a new suitable cell before the T311 timer expires, the UE may drive the T301 timer and perform a re-establishment process with the new suitable cell (1g-20).

According to an embodiment of the present disclosure, if the re-establishment is not successfully completed before the T301 timer expires, the terminal may be switched to the standby mode (1g-30).

According to an embodiment of the present disclosure, if re-establishment is successful, the terminal may continue the connected mode in the cell (the above-described new suitable cell). RLF may be declared by an RLM operation, and may be declared according to another condition. Even when random access fails, RLF may be declared (1g-35).

In addition, even if the maximum number of retransmissions is reached in the RLC (Radio Link Control) layer, RLF may be declared even if the packet is not successfully transmitted (1g-40).

The above-described timers, the T301 timer and the T311 timer, are described in the table below.

[Table 2]

Another case in which RLF is declared is when handover fails. Upon receiving the RRCConnectionReconfiguration message including the handover configuration information and the mobilityControlInfo IE (1g-45), the terminal may drive the T304 timer. The set time value of the T304 timer may be provided in the mobilityControlInfo. If the random access with the target cell is not successfully completed before the timer expires, the UE may regard it as a handover failure and declare an RLF (1g-50).

Predetermined information collected when RLF occurs in the UE is useful for optimizing the cell area. Accordingly, such information is stored in the terminal when RLF occurs, and then is reported to the base station when the terminal is successfully switched to the connected mode. In this case, the reporting of predetermined information stored in the terminal to the base station is referred to as an RLF report, and the predetermined information reported at this time is as follows. At this time, information related to the random access process is also stored.

- plmn-IdentityList

- measResultLastServCell

- measResultNeighCells

- locationInfo

- failedPCellId

- previousPCellId

- timeConnFailure

- Cell Radio-Network Temporary Identifier (C-RNTI) used in the source PCell

- connectionFailureType

- absoluteFrequencyPointA: absolute frequency position of the reference resource block (Common RB 0)

- locationAndBandwidth: Frequency domain location and bandwidth of the bandwidth part associated to the random-access resources used by the UE

- subcarrierSpacing: Subcarrier spacing used in the BWP associated to the random-access resources used by the UE

- msg1-FrequencyStart: Offset of lowest PRACH transmission occasion in frequency domain with respective to PRB 0 of the UL BWP

- msg1-SubcarrierSpacing: Subcarrier spacing of PRACH resources

- msg1-FDM: The number of PRACH (Physical Random Access Channel) transmission occasions FDMed in one time instance

- raPurpose: the Random Access (RA) scenario for which the RA report entry is triggered

- perRAInfoList: detailed information about each of the random access attempts in the chronological order of the random access attempts, for example, the SSB index related to preamble transmission, the number of preamble transmissions per SSB, whether contention occurs, etc.

When the terminal is switched to the connected mode through the RRC establishment or RRC resume process, it may report to the base station that the RLF report is being stored using a predetermined RRC message such as an RRCSetupComplete or RRCResumeComplete message (1g-55).

The base station may instruct the terminal to report the RLF report by using the UEInformationRequest message (1g-60). The UE may report the UEInformationResponse message containing the RLF report to the base station (1g-65).

1H is a diagram for explaining a random access (RA) report according to an embodiment of the present disclosure.

For the successfully completed random access, the terminal may store information related to the random access in the terminal internal variable VarRA-Report (1h-05). This is called one RA (Random Access) report. RA (Random Access) report information is as follows.

- CellId: CGI of the cell in which the associated random access procedure was performed

- absoluteFrequencyPointA: absolute frequency position of the reference resource block (Common RB 0)

- locationAndBandwidth: Frequency domain location and bandwidth of the bandwidth part associated to the random-access resources used by the UE

- subcarrierSpacing: Subcarrier spacing used in the BWP associated to the random-access resources used by the UE

- msg1-FrequencyStart: Offset of lowest PRACH transmission occasion in frequency domain with respective to PRB 0 of the UL BWP

- msg1-SubcarrierSpacing: Subcarrier spacing of PRACH resources

- msg1-FDM: The number of PRACH transmission occasions FDMed in one time instance

- raPurpose: the RA scenario for which the RA report entry is triggered

- perRAInfoList: detailed information about each of the random access attempts in the chronological order of the random access attempts

In addition, when storing the above-mentioned information, the terminal may store the EPLMN list if there is the stored Equivalent Public Land Mobile Network (EPLMN) information, otherwise, the selected PLMN information may be stored together.

After storing the RA information, if another random access process succeeds, the terminal may store information related to the newly successful random access (1h-10). At this time, if a Registered Public Land Mobile Network (RPLMN) is included in the stored PLMN information, it may be updated and stored with the currently stored EPLMN information. If the RPLMN is not included in the stored PLMN information, all information stored in the VarRA-Report may be deleted.

According to an embodiment of the present disclosure, the UE may store up to 8 RA reports. Eight RA reports are already stored, and when the new random access process is successfully completed, the UE may delete the first stored RA report and store information related to the newly successful random access process (1h-15) .

After the terminal is switched to the connected mode, the base station may request the RA report information stored in the terminal from the terminal using a predetermined RRC message (1h-20). At this time, if the terminal stores the RA report and the RPLMN is included in the stored PLMN information, the terminal may report the stored RA report to the base station using a predetermined RRC message (1h-25). All reported RA report information may be deleted from the VarRA-Report.

1I is a flowchart of a process of storing random access related information according to an embodiment of the present disclosure.

The UE 1i-05 may receive a predetermined RRC message including measurement configuration information from the source cell 1i-10 (1i-25). The terminal 1i-05 applies the measurement configuration information to measure the signal quality of the serving cell and neighboring cells, and periodically or when a set event occurs (1i-30), collects cell measurement information from the source cell 1i- 10) (1i-35).

The source cell 1i-10 may determine whether to trigger a handover operation based on the reported cell measurement information (1i-40). For example, when event A3 (Neighbor becomes offset better than SpCell) is satisfied and cell measurement information is reported, the source cell 1i-10 may determine handover. If the source cell 1i-10 decides to trigger handover, the source cell 1i-10 performs handover to one target cell 1i-20 through a predetermined inter-node message. can be requested (1i-45). Upon receiving the request, the target cell 1i-20 may accept the request and transmit handover configuration information necessary for the handover operation to the source cell 1i-10 (1i-50).

The source cell 1i-10 may store the handover configuration information and additional configuration information received from the target cell 1i-20 in a predetermined RRC message, and may transmit the RRC message to the terminal 1i-05 (1i). -55). The configuration information includes an ID of the target cell 1i-20, frequency information, configuration information necessary for a random access operation to the target cell 1i-20 (dedicated preamble information, dedicated radio resource information, etc.), transmission power information, target cell ( 1i-20) may include C-RNTI information and the like.

Upon receiving the handover configuration information, the terminal 1i-05 may immediately perform a random access process to the target cell 1i-20 and drive the T304 timer (1i-60).

The terminal 1i-05 may transmit the received preamble to the target cell 1i-20 (1i-65). If the terminal 1i-05 is not provided with the dedicated preamble, the terminal 1i-05 may transmit one of the preambles used in the contention basis. Upon receiving the preamble, the target cell 1i-20 may transmit a random access response message (RAR) to the terminal 1i-05. The terminal 1i-05 may transmit msg3 to the target cell 1i-20 by using the UL grant information contained in the random access response message (RAR). msg3 contains an RRCConnectionReconfigurationComplete message in the case of an LTE system and an RRCReconfigurationComplete message in the case of an NR system. When the random access process is successfully completed, it is considered that the handover has been successfully completed, and the terminal 1i-05 stops the running T304 timer. If the handover is not successfully completed until the T304 timer expires, the terminal 1i-05 may regard it as a handover failure and declare an RLF (1i-70).

The terminal 1i-05 recently attempted (failed) random access to the uplink of the source cell (li-10) or the target cell (li-20) for an RLF report according to the expiration of the T304 timer or radio link failure. It is possible to store valid information related to (1i -75). The random access information stored at this time is referred to as second random access information. If the RLF does not occur due to expiration of the T304 timer or radio link failure, the second random access information is not stored in the RLF report.

If the terminal li-05 succeeds in random access (1i-80), the terminal li-05 may store valid information related to random access in a terminal internal variable (eg, VarRA-Report). For example, the terminal li-05 stores, in a terminal internal variable, valid information related to random access that the terminal recently attempted in an uplink to the source cell li-10 or the target cell li-20 and was successful. can (1i-85). The random access information stored at this time is referred to as first random access information.

The second random access information is a part of the first random access information, and may mean information remaining in the first random access information except for cellId and raPurpose information. cellId is CGI information of a cell that has performed random access, and raPurpose may be used to indicate the purpose of performing random access.

1J is a flowchart of a terminal operation for storing random access related information according to an embodiment of the present disclosure.

In step 1j-05, the terminal is in an RRC connection state with the base station.

In step 1j-10, the UE may trigger random access for the purpose of handover or synchronization with a serving cell.

In step 1j-15, the terminal may determine whether the triggered random access process has been successfully completed.

If the UE has successfully completed the random access process triggered by the UE in step 1j-20, the UE may store the first random access information. Specifically, the first random access information stored in VarRA-Report is as follows.

- Stores EPLMN list information (including RPLMN) stored by the terminal in plmn-IdentityList. If there is no EPLMN information stored by the terminal, the selected PLMN selected by the terminal NAS layer among PLMN information included in SIB1 (System Information Block 1) broadcast by the cell is stored.

- CellId: Cell Global Identity (CGI) of the cell in which the associated random access procedure was performed

- absoluteFrequencyPointA: absolute frequency position of the reference resource block (Common RB 0)

- locationAndBandwidth: Frequency domain location and bandwidth of the bandwidth part associated to the random-access resources used by the UE

- subcarrierSpacing: Subcarrier spacing used in the BWP associated to the random-access resources used by the UE

- msg1-FrequencyStart: Offset of lowest PRACH transmission occasion in frequency domain with respective to PRB 0 of the UL BWP

- msg1-SubcarrierSpacing: Subcarrier spacing of PRACH resources

- msg1-FDM: The number of PRACH transmission occasions FDMed in one time instance

- raPurpose: the RA scenario for which the RA report entry is triggered

- perRAInfoList: detailed information about each of the random access attempts in the chronological order of the random access attempts

If the UE has not successfully completed the random access process triggered by the UE in step 1j-25, the UE may determine the cause of the RLF that has occurred. As an example, the UE may determine whether the cause of the generated RLF is T304 timer expiration (handover failure) or radio link failure, and the cause of the RLF is not limited to the above example.

In step 1j-30, if RLF occurs due to expiration of the T304 timer or radio link failure, the UE may store the RLF report including the second random access information. Specifically, the following information may be stored in the RLF report.

- Stores EPLMN list information (including RPLMN) stored by the terminal in plmn-IdentityList.

- RSRP, RSRQ, and SINR are stored in measResultLastServCell based on valid SSB and CSI-RS measurement until handover failure or radio link failure is detected.

- The radio link monitoring configuration information of the source cell is stored in ssbRLMConfigBitmap and/or csi-rsRLMConfigBitmap of measResultLastServCell.

- For the configured measObjectNR, if the SS/PBCH block-based measurement result is valid, the highest SS/PBCH block RSRP, highest SS/PBCH block RSRQ, and highest SS/PBCH block SINR are stored in measResultListNR of measResultNeighCell in the order of SINR.

- For the configured measObjectNR, if the CSI-RS-based measurement result is valid, the highest SS/PBCH block RSRP, highest SS/PBCH block RSRQ, and highest SS/PBCH block SINR are stored in measResultListNR of measResultNeighCell in the order of SINR.

- If there is valid location information, it configures LocationInfo with commonLocationInfo, bt-LocationInfo, wlan-LocationInfo, and sensor-LocationInfo information.

- The following information may be stored as the second random access information.

- absoluteFrequencyPointA: absolute frequency position of the reference resource block (Common RB 0)

- locationAndBandwidth: Frequency domain location and bandwidth of the bandwidth part associated to the random-access resources used by the UE

- subcarrierSpacing: Subcarrier spacing used in the BWP associated to the random-access resources used by the UE

- msg1-FrequencyStart: Offset of lowest PRACH transmission occasion in frequency domain with respective to PRB 0 of the UL BWP

- msg1-SubcarrierSpacing: Subcarrier spacing of PRACH resources

- msg1-FDM: The number of PRACH transmission occasions FDMed in one time instance

- perRAInfoList: detailed information about each of the random access attempts in the chronological order of the random access attempts

In step 1j-35, if RLF does not occur due to expiration of the T304 timer or radio link failure, the UE may store the RLF report excluding the second random access information.

In step 1j-40, the terminal may find one suitable cell capable of receiving a normal service.

In step 1j-45, the UE may perform an RRC (re)establishment operation to perform RRC connection to a suitable cell.

In step 1j-50, the UE may transmit an RRCSetupComplete or RRCReestablishmentComplete message including an rlf-InfoAvailable indicator indicating that an RLF report is stored to a suitable cell. For the RA report, there is no availability indicator for the RLF report.

In step 1j-55, the UE may receive a UEInformationRequest message including an indicator requesting a report of an RA report and an RLF report.

In step 1j-60, the UE may report the UEInformationResponse message including the stored RA report and RLF report to the cell (eg, suitable cell). When the RPLMN is one of the PLMN information stored in the RA report and the RLF report, the UE may report the stored RA report or RLF report.

When the UE reports the RA report and the RLF report, the following ASN.1 structure may be considered.

The first option is to recycle the RA-Report IE, but consider the option fields of cellId and raPurpose, which are not required in the RLF report.

The cellId and raPurpose fields may be included in the RA-Report IE according to whether the RA-Report IE belongs to the RA report or the RLF report. That is, when the RA-Report IE belongs to the RA report, the cellId and raPurpose fields may be included and provided in the RA-Report IE. When the RA-Report IE belongs to the RLF report, the cellId and raPurpose fields are not included in the RA-Report IE. The following ASN.1 structure is the structure according to the first option.

[Table 3]

[Table 4]

The second option is to define a new RA-ResourceInfo IE including the following fields. According to an embodiment of the present disclosure, the RA-ResourceInfo IE may be included in the RA report. In addition, the RA-ResourceInfo IE may be included in the RLF report generated by the expiration of the T304 timer or radio link failure.

According to an embodiment of the present disclosure, the RA-ResourceInfo IE may always be included in the RA report (mandatory). On the other hand, the RA-ResourceInfo IE may be optionally included in the RLF report. The following ASN.1 structure is the structure according to the second option.

[Table 5]

[Table 6]

The UE may delete the successfully reported RLF report.

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

Referring to FIG. 1K , the terminal may include a radio frequency (RF) processing unit 1k-10, a baseband processing unit 1k-20, a storage unit 1k-30, and a control unit 1k-40. have. Of course, it is not limited to the above example, and the terminal may include fewer or more configurations than the configuration shown in FIG. 1K .

The RF processing unit 1k-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 1k-10 may up-convert the baseband signal provided from the baseband processing unit 1k-20 into an RF band signal and then transmit it through the antenna, and convert the RF band signal received through the antenna. It can be down-converted to a baseband signal. For example, the RF processing unit 1k-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. Of course, it is not limited to the above example. Although only one antenna is shown in FIG. 1K , the terminal may include a plurality of antennas. Also, the RF processing unit 1k-10 may include a plurality of RF chains. Furthermore, the RF processing unit 1k-10 may perform beamforming. For beamforming, the RF processing unit 1k-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 1k-10 may perform MIMO, and may receive multiple layers when performing the MIMO operation.

The baseband processing unit 1k-20 may perform a function of converting between a baseband signal and a bit stream according to a physical layer standard of a system. For example, during data transmission, the baseband processing unit 1k-20 may generate complex symbols by encoding and modulating the transmitted bit stream. Also, when receiving data, the baseband processing unit 1k-20 may restore the received bit stream by demodulating and decoding the baseband signal provided from the RF processing unit 1k-10. For example, in the case of orthogonal frequency division multiplexing (OFDM), when data is transmitted, the baseband processing unit 1k-20 encodes and modulates a transmission bit stream to generate complex symbols, and convert the generated complex symbols to subcarriers. After mapping to , OFDM symbols can be configured through inverse fast Fourier transform (IFFT) operation and cyclic prefix (CP) insertion. In addition, upon data reception, the baseband processing unit 1k-20 divides the baseband signal provided from the RF processing unit 1k-10 into OFDM symbol units, and is mapped to subcarriers through a fast Fourier transform (FFT) operation. After reconstructing the signals, the received bit stream may be reconstructed through demodulation and decoding.

The baseband processing unit 1k-20 and the RF processing unit 1k-10 may transmit and receive signals as described above. Accordingly, the baseband processing unit 1k-20 and the RF processing unit 1k-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 1k-20 and the RF processing unit 1k-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 1k-20 and the RF processing unit 1k-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 1k-20 and the RF processing unit 1k-10, and the signal may include control information and data.

The storage unit 1k-30 may store data such as a basic program, an application program, and setting information for the operation of the terminal. In particular, the storage unit 1k-30 may store data information such as a basic program, an application program, and setting information for the above-described operation of the terminal. In addition, the storage unit 1k-30 may provide stored data according to the request of the control unit 1k-40.

The storage unit 1k-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 1k-30 may include a plurality of memories. According to an embodiment of the present disclosure, the storage unit 1k-30 may store a program for performing the method of reporting random access information according to the present disclosure.

The controller 1k-40 may control overall operations of the terminal. For example, the control unit 1k-40 may transmit/receive signals through the baseband processing unit 1k-20 and the RF processing unit 1k-10. Also, the control unit 1k-40 may write data to and read data from the storage unit 1k-40. To this end, the controller 1k-40 may include at least one processor. For example, the controller 1k-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. Also, according to an embodiment of the present disclosure, the controller 1k-40 may include a multi-connection processing unit 1k-42 configured to process a process operating in a multi-connection mode. In addition, at least one component in the terminal may be implemented as one chip.

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

11, the base station includes an RF processing unit 11-10, a baseband processing unit 11-20, a backhaul communication unit 11-30, a storage unit 11-40, and a control unit 11-50. 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. 11 .

The RF processing unit 11-10 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 11-10 may up-convert the baseband signal provided from the baseband processing unit 11-20 into an RF band signal and then transmit it through the antenna, and convert the RF band signal received through the antenna. It can be downconverted to a baseband signal. For example, the RF processing unit 11-10 may include a transmit filter, a receive filter, an amplifier, a mixer, an oscillator, a DAC, an ADC, and the like. Although only one antenna is shown in FIG. 11, the RF processing unit 11-10 may include a plurality of antennas.

Also, the RF processing unit 11-10 may include a plurality of RF chains. Furthermore, the RF processing unit 11-10 may perform beamforming. For beamforming, the RF processing unit 11-10 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 11-10 may perform a downlink MIMO operation by transmitting one or more layers.

The baseband processing unit 11-20 may perform a function of converting a baseband signal and a bit stream according to a physical layer standard. For example, when transmitting data, the baseband processing unit 11-20 may generate complex symbols by encoding and modulating the transmitted bit stream. Also, upon data reception, the baseband processing unit 11-20 may restore the received bit stream by demodulating and decoding the baseband signal provided from the RF processing unit 11-10. For example, in the case of OFDM, when data is transmitted, the baseband processing unit 11-20 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. Also, upon data reception, the baseband processing unit 11-20 divides the baseband signal provided from the RF processing unit 11-10 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 11-20 and the RF processing unit 11-10 may transmit and receive signals as described above. Accordingly, the baseband processing unit 11-20 and the RF processing unit 11-10 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 and from the terminal using the baseband processing unit 11-20 and the RF processing unit 11-10, and the signal may include control information and data.

The backhaul communication unit 11-30 may provide an interface for performing communication with other nodes in the network. That is, the backhaul communication unit 11-30 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 a physical signal received from another node into a bit string can do.

The storage unit 11-40 may store data such as a basic program, an application program, and setting information for the operation of the base station. In particular, the storage unit 11-40 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 11-40 may store information serving as a criterion for determining whether to provide or stop multiple connections to the terminal. In addition, the storage unit 11-40 may provide stored data according to a request of the control unit 11-50. The storage unit 11-40 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 11-40 may be composed of a plurality of memories. According to an embodiment of the present disclosure, the storage unit 11-40 may store a program for performing a method of receiving IDC information from a terminal according to the present disclosure and setting a parameter.

The controller 11-50 may control overall operations of the base station. For example, the control unit 11-50 may transmit/receive a signal through the baseband processing unit 11-20 and the RF processing unit 11-10 or through the backhaul communication unit 11-30. Also, the control unit 11-50 may write data to and read data from the storage unit 11-40. To this end, the controller 11-50 may include at least one processor. Also, according to an embodiment of the present disclosure, the controller 11-50 may include a multi-connection processing unit 11-52 configured to process a process operating in a multi-connection mode.

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 context presented for convenience of description, and the present disclosure is not limited to the singular or plural element, and even if the element is expressed in plural, it is composed of the 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 invention 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 made 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 for a terminal to report random access information in a mobile communication system, the method comprising:
Receiving an RRC message including configuration information necessary to perform a Logged MDT operation from a base station;
Receiving an RRC Release message indicating a standby mode or an inactive mode from the base station; and
Performing Logged MDT in standby mode or inactive mode based on the RRC Release message and the configuration information; including, a method.

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