KR20220053352A - Method and apparatus to log information in the mobile communication system - Google Patents

Abstract

The present invention relates to a communication technique, which is able to fuse the IoT technology with a 5th generation (5G) or pre-5G communication system for supporting a higher data transmission rate after the 4th generation (4G) communication systems such as long-term evolution (LTE), and a system thereof. The present invention can be applied to intelligent services (for instance, smart home, smart building, smart city, smart car or connected car, health care, digital education, retail, security and safety-related services etc.) based on the 5G communication technology or the IoT-related technology. According to various embodiments of the present invention, a method and apparatus for recording information in a mobile communication system can be provided. According to the present invention, a method for processing a control signal in a wireless communication system comprises the steps of: receiving a first control signal transmitted from a base station; processing the received first control signal; and transmitting a second signal generated based on the processing to the base station.

Description

METHOD AND APPARATUS TO LOG INFORMATION IN THE MOBILE COMMUNICATION SYSTEM

The present disclosure relates to operation of a terminal and a base station in a mobile communication system.

Efforts are being made to develop an improved 5th generation (5G) communication system or a pre-5G communication system in order to meet the increasing demand for wireless data traffic after commercialization of the 4G (4th generation) communication system. For this reason, the 5G communication system or the pre-5G communication system is called a 4G network after (Beyond 4G Network) communication system or an LTE (Long Term Evolution) system after (Post LTE) system.

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 ultra-high frequency band, in the 5G communication system, beamforming, massive MIMO, and Full Dimensional MIMO (FD-MIMO) are used. ), array antenna, analog beam-forming, and large scale antenna technologies are being discussed.

In addition, to improve the network of the system, in the 5G communication system, an evolved small cell, an advanced small cell, a cloud radio access network (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 reception interference cancellation Technology development is underway.

In addition, in the 5G system, FQAM (Hybrid Frequency Shift Keying and Quadrature Amplitude Modulation) and SWSC (Sliding Window Superposition Coding), which are advanced coding modulation (Advanced Coding Modulation, ACM) methods, and FBMC (Filter Bank Multi Carrier), an advanced access technology, ), Non Orthogonal Multiple Access (NOMA), and Sparse Code Multiple Access (SCMA) are being developed.

In the 5G system, support for various services is being considered compared to the existing 4G system. For example, the most representative services are the enhanced mobile broad band (eMBB), ultra-reliable and low latency communication (URLLC), and massive device-to-device communication service (mMTC). machine type communication), a next-generation broadcast service (eMBMS: evolved multimedia broadcast/multicast service), and the like. In addition, the system providing the URLLC service may be referred to as a URLLC system, and the system providing the eMBB service may be referred to as an eMBB system. Also, the terms service and system may be used interchangeably.

Among them, the URLLC service is a service newly considered in the 5G system, unlike the existing 4G system, and has ultra-high reliability (eg, about 10-5 packet error rate) and low latency (eg, about 0.5 msec) requirement to be satisfied. In order to satisfy such strict requirements, the URLLC service may need to apply a shorter transmission time interval (TTI) than the eMBB service, and various operating methods are being considered using this.

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. , M2M), and MTC (Machine Type Communication) are being studied.

In the IoT environment, an intelligent IT (Internet Technology) service that collects and analyzes data generated from connected objects and creates new values in human life 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, technologies such as sensor network, machine to machine (M2M), and MTC (Machine Type Communication) are implemented by 5G communication technologies such as beamforming, MIMO, and array antenna. will be. The application of cloud radio access network (cloud RAN) as the big data processing technology described above can be said to be an example of convergence of 5G technology and IoT technology.

When constructing or optimizing a network, a mobile communication service provider can usually measure the signal strength in an expected service area, and based on this, may go through a process of disposing or re-adjusting base stations in the service area. To this end, a mobile communication service provider collects cell measurement information in the service area by using a vehicle, which may require a lot of time and money.

Accordingly, an object of the present disclosure is to provide a method for disposing or re-adjusting base stations in a service area by utilizing a function of a terminal measuring a signal, storing valid information, and reporting to the base station.

The technical problems to be achieved in the present disclosure are not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by those of ordinary skill in the art to which the present invention belongs from the description below. will be able

The present disclosure for solving the above problems provides a control signal processing method in a wireless communication system, the method comprising: receiving a first control signal transmitted from a base station; processing the received first control signal; and transmitting a second control signal generated based on the processing to the base station.

According to an embodiment of the present disclosure, it is possible to provide a method of arranging or re-adjusting base stations in a service area by utilizing a function of the terminal measuring a signal, storing valid information, and reporting to the base station.

Effects obtainable in the present disclosure are not limited to the above-mentioned effects, and other effects not mentioned may be clearly understood by those of ordinary skill in the art to which the present disclosure belongs from the description below. will be.

1A is a diagram illustrating a structure of a next-generation mobile communication system according to an embodiment of the present disclosure.
1B is a diagram illustrating a wireless connection state transition in a next-generation mobile communication system according to an embodiment of the present disclosure.
1C is a diagram illustrating a technique for collecting and reporting cell measurement information according to an embodiment of the present disclosure.
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 diagram illustrating a flowchart of an operation of collecting and reporting cell measurement information according to an embodiment of the present disclosure.
1F is a diagram illustrating a flowchart of a general handover operation according to an embodiment of the present disclosure.
1G is a diagram illustrating a flow chart of a condition-based handover operation according to an embodiment of the present disclosure.
1H is a diagram illustrating a process of reporting successfully completed handover related information to a target cell according to an embodiment of the present disclosure.
1I is a diagram illustrating a process of reporting successfully completed handover related information to another cell according to an embodiment of the present disclosure.
1J is a diagram illustrating an operation of reporting successfully completed condition-based handover related information to another cell according to an embodiment of the present disclosure.
1K is a diagram illustrating a flow chart of a terminal operation for reporting successfully completed handover related information to a target cell according to an embodiment of the present disclosure.
11 is a diagram illustrating a flowchart of a terminal operation for reporting successfully completed handover related information to another cell according to an embodiment of the present disclosure.
1M is a diagram illustrating a DCP for a connected mode terminal to save power consumption according to an embodiment of the present disclosure.
1N is a diagram illustrating a flowchart of an operation in which a connected mode terminal sets a DCP to save power consumption according to an embodiment of the present disclosure.
1O is a diagram illustrating a procedure for notifying SystemInformation update or PWS transmission according to an embodiment of the present disclosure.
1P is a diagram illustrating a procedure for notifying a SystemInformation update or PWS transmission when DCP is applied according to an embodiment of the present disclosure.
1q is a diagram illustrating a flowchart of an operation of notifying SystemInformation update or PWS transmission according to an embodiment of the present disclosure.
1R is a block diagram illustrating an internal structure of a terminal according to an embodiment of the present disclosure.
1S 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.

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 terms and names, and may be equally applied to systems conforming to other standards.

Hereinafter, an embodiment of the present disclosure will be described with reference to the accompanying drawings.

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

Referring to Figure 1a, the radio access network of the next-generation mobile communication system (new radio, NR) is a next-generation base station (new radio node B, hereinafter gNB) (1a-10) and AMF (1a-05, new radio core network) can be configured. A user terminal (new radio user equipment, hereinafter NR UE or terminal) 1a-15 may access an external network through gNB 1a-10 and AMF 1a-05.

In FIG. 1A , a gNB may correspond to an evolved node B (eNB) of an existing LTE system. The gNB may be connected to the NR UE through a radio channel and may provide a service superior to that of the existing Node B (1a-20). In the next-generation mobile communication system, since all user traffic can be 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 may be required. The gNB (1a-10) may be responsible for this. One gNB can typically control multiple 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 grafted by using orthogonal frequency division multiplexing (hereinafter referred to as OFDM) as a radio access technology. . In addition, an adaptive modulation & coding (AMC) method for determining a modulation scheme and a channel coding rate according to the channel state of the terminal may be applied. The AMF 1a-05 may perform functions such as mobility support, bearer setup, and quality of service (QoS) setup. The AMF is a device in charge of various control functions as well as a mobility management function for a terminal, and may be connected to a plurality of base stations. In addition, the next-generation mobile communication system may be linked with the existing LTE system, and the AMF (1a-05) may be connected to the MME (1a-25) through a network interface. The MME 1a-25 may be connected to the eNB 1a-30, which is an existing base station. A UE supporting LTE-NR dual connectivity can transmit and receive data while maintaining a connection to not only the gNB but also the eNB (1a-35).

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

Referring to FIG. 1B , the next-generation mobile communication system may have three types of radio access states (RRC states). The connected mode (NR RRC_CONNECTED, 1b-05) is a wireless connection state in which the terminal can transmit and receive data. The standby mode (NR RRC_IDLE, 1b-30) is a radio access state in which the terminal monitors whether paging is transmitted to itself. The above two modes 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 newly inactive (NR RRC_INACTIVE) radio connection state 1b-15 may be defined. In the radio access state, the UE context may be maintained in the base station and the terminal, and RAN-based paging may be supported. The characteristics of the new wireless connection state may be listed as follows.

- 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;

The inactive (NR RRC_INACTIVE) radio access state may transition to a connected mode or a standby mode using a specific procedure. According to the resume process, the INACTIVE mode may be converted to the connected mode, and the connected mode may be converted to the INACTIVE mode by using the Release procedure including the suspend configuration information (1b-10). The procedure may transmit and receive one or more RRC messages between the terminal and the base station, and may consist of one or more steps. In addition, it may be possible to switch from the INACTIVE mode to the standby mode (NR RRC_IDLE) through the Release procedure after Resume (1b-20). Switching between connected mode and standby mode may follow existing LTE technology. That is, through an establishment procedure or a release procedure, the mode may be switched (1b-25).

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

Referring to FIG. 1C , when constructing or optimizing a network, a mobile communication service provider can usually measure signal strength in an expected service area, and may perform a process of disposing or re-adjusting base stations in the service area based on this. The operator loads the signal measurement equipment on the vehicle and collects the cell measurement information in the service area, which may require a lot of time and money. The process may be commonly referred to as a drive test, generally utilizing a vehicle. The UE may be equipped with a function of measuring a signal and a function of reporting to the base station in order to support operations such as cell reselection, handover operation, and serving cell addition when moving between cells. Therefore, instead of the drive test, a terminal in a service area can be used, which is called minimization of drive test (MDT). The operator may set the MDT operation to specific terminals through various components of the network. In addition, the terminals may collect signal strength information from a serving cell and neighboring cells in a connected mode (RRC_Connected), standby mode (RRC_Idle), or inactive mode (RRC_Inactive), and store the signal strength information. In addition, various information such as location information, time information, and signal quality information may be stored together. The stored information may be reported to the network when the terminals are in the connected mode, and the information may be transmitted to a specific server.

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

Immediate MDT can directly report the collected information to the network. Immediate MDT should immediately report the information collected to the network, so only the connected mode terminal can perform this. In general, a radio resources management (RRM) measurement process for supporting an operation such as a handover operation and a serving cell addition may be recycled. In addition, location information, time information, and the like may be additionally reported.

Logged MDT can store the collected information without directly reporting it to the network. Logged MDT is characterized in that the terminal reports the stored information to the network after switching to the connected mode. Usually, a terminal in standby mode that cannot directly report to the network may perform this. The terminal in the inactive mode introduced in the next-generation mobile communication system may perform Logged MDT. When a specific terminal is in a connected mode, the network may provide the terminal with configuration information for performing a Logged MDT operation, and the terminal may collect and store the configured information after switching to a standby mode or an inactive mode. The relationship between the MDT operation and the RRC state is shown in [Table 1] below.

MDT action RRC state Immediate MDT RRC_Connected Logged MDT RRC_Idle, RRC_Inactive

FIG. 1D is a diagram illustrating a method of collecting and reporting cell measurement information according to an embodiment of the present disclosure. Referring to FIG. 1D , a terminal 1d-05 operates in a standby mode or an inactive mode 1d-10. Can be switched to connection mode (1d-15). In the connected mode, MDT data may be collected and reported to the base station through an immediate MDT operation. The terminal switched to the connected mode may be provided with Logged MDT configuration information performed in the standby mode or the inactive mode from the base station (1d-20). The configuration information may be included in a predetermined RRC message and transmitted to the terminal, and the terminal receiving the message may drive a first timer (1d-55). The terminal may perform a Logged MDT operation in a standby mode or an inactive mode period until the first timer expires. The value of the first timer may be included in the Logged MDT configuration information. When the terminal switches to the standby mode or the inactive mode, the logged MDT may be performed according to the received configuration information (1d-25). The terminal may store the collected information at every logging interval (1d-35) which is a set period (1d-30, 1d-45). In addition, if valid location information 1d-40 has been collected, the information may also be stored. For example, the GNSS location means location information of a terminal derived based on location information transmitted from a satellite. Whether the location information is valid may be determined when a predetermined time (1d-50) has elapsed after the information is collected. The predetermined time may be shorter than or equal to the logging interval. Even before the first timer expires, the terminal may pause the Logged MDT operation being performed when switching to the connected mode (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 it cannot be stored anymore, or when the Logged MDT setting information is released, the first timer may be stopped. The case in which the Logged MDT configuration information is released may be when other Logged MDT configuration information is provided from a serving RAT or another RAT, or when the terminal is detached or power is cut off. During the connection establishment process (RRC Connection Establishment) or the connection restart process (RRC Connection Resume), the terminal uses the RRC Setup Complete message or the RRC Resume Complete message to know that it has the collection information (MDT data) it stores. (1d-65).

The connection establishment process may be a process in which the terminal switches from the standby mode to the connected mode. As follows, it may be configured in a typical three-step process, and three types of RRC messages may be 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 is a process in which the terminal switches from an inactive mode to a connected mode. As follows, it is usually composed 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

The terminal may report information indicating that it has the collection information to the target base station during the RRC Connection Reestablishment process and the handover process in addition to the connection establishment process or the connection restart process. Although the Logged MDT has been set, if there is no collected and stored information yet, the report may be omitted. The base station receiving the report may request a report of the MDT data stored by the terminal if necessary. The unreported MDT data may have to be continuously stored by the terminal for a predetermined time. If the terminal is switched back to the standby mode or the inactive mode, and the first timer has not yet expired, the Logged MDT operation may be restarted again (1d-70). If the first timer expires, the Logged MDT operation may be stopped (1d-75). The terminal that has stopped the operation may drive a second timer (1d-80), and may maintain the stored MDT data until the timer expires. After the timer expires, whether to delete the MDT data being stored may be determined by the terminal implementation. 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 is switched back to the connected mode, it can report to the base station that it has the collection information (MDT data) it stores (1d-85). This time, the base station may request a report of the MDT data stored by the terminal using a predetermined RRC message (1d-90). Accordingly, the terminal may include the MDT data being stored in a predetermined RRC message, and may report the message to the base station (1d-95).

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

Referring to FIG. 1E , the UE may collect cell measurement information and report it to the base station. The terminal 1e-05 may connect to the base station 1e-10 (1e-15). The terminal may provide terminal capability information to the base station (1e-20), and may indicate whether it supports the MDT operation and whether it can measure what frequency. The base station may include configuration information necessary for performing the Logged MDT operation in a predetermined RRC message and transmit it to the terminal (1e-25). For example, the setting information may include at least one of the following information.

- trace reference information

- trace recording session reference information

- Trace collection entity (TCE) ID information: The base station may transmit MDT data information reported from the terminal to a data server designated by the TCE ID.

- Absolute time information (absolute time): Absolute time in the current cell providing Logged MDT configuration information

- area configuration: Through the Logged MDT operation, area information for collecting and storing measurement information can be 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 is a black list or a white list. If it is a black list, cell measurement information may be collected for RATs not included in the list. If it 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, when the timer is running, a logged MDT operation may be performed 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, which may include PLMN information capable of performing the Logged MDT operation, reporting whether to store MDT data, and reporting MDT data.

- An indicator indicating whether to perform Logged MDT operation in standby mode, inactive mode, or both. The indicator may indicate the RRC state for performing the Logged MDT operation. Alternatively, without the indicator, it can be defined to always perform the Logged MDT operation in the standby mode and the inactive mode. The UE may perform the Logged MDT operation only in the RRC state indicated by the 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. Without the above indicator, it may be defined that beam level measurement measurements are 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 a beam to be stored. The terminal may omit storage of information on a beam weaker than the minimum signal strength. If all 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 action can be triggered in the two-step restart process (RRC Resume).

Upon receiving the Logged MDT configuration information, the terminal may drive a first timer (1e-30). The value of the first timer may be set equal to the value of the logging duration. The base station may switch the terminal to the standby mode or the inactive mode by using the RRC Release message (1e-35). Depending on which RRC state is switched to, the RRC Release message may include configuration information for operation in the RRC state. If the first timer is running, the terminal may perform Logged MDT in standby mode or inactive mode (1e-40). Signal strengths of the serving cell and neighboring cells may be measured, and location information may be obtained. When the beam level measurement is set, a signal strength value for a beam greater than the set minimum value may be collected and stored in the serving cell and the adjacent cell. The maximum number of beams that can be stored may be set or predefined. The signal strength may mean RSRP, RSRQ, or SINR. The collected information may be stored at each Logged Interval period. When the first timer expires (1e-45), the Logged MDT operation may be stopped (1e-50).

If the terminal is in standby mode or inactive mode by the RRC Release message, receives RAN or CN paging from the base station, or MO data transmission is activated, the terminal moves from standby mode or inactive mode to connected mode An establishment process or a resume process for conversion can be initialized.

The establishment process or resume process is

- Step 1: UE transmits RRC Setup Request message or RRC Resume Request message to the base station (1e-55)

- Step 2: BS transmits RRC Setup message or RRC Resume message to UE (1e-60)

- Step 3: The UE may be configured to transmit an RRC Setup Complete message or an RRC Resume Complete message to the base station (1e-65).

The UE may include 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 may request a report of the MDT data by using a predetermined RRC message, UEInformationRequest, if necessary (1e-70). Upon receiving the request, the UE may report the MDT data using a predetermined RRC message and UEInformationResponse (1e-75).

In the present disclosure, in the general handover operation, when the terminal receives configuration information instructing to perform handover from the base station, the handover operation may be performed immediately. On the other hand, in the condition-based handover operation, when the terminal receives configuration information instructing to perform a handover from the base station, the handover operation may be performed when a predetermined condition is satisfied, rather than immediately performing the handover operation. Due to the above feature, the conditional handover operation is referred to as conditional handover (CHO). Since the terminal can most quickly detect a change in the channel quality state, it may be advantageous to minimize the handover failure probability to determine when the terminal starts the handover operation. Therefore, condition-based handover compared to general handover can be considered as a more advanced technique. In the general handover, only one target cell is considered, whereas in the condition-based handover, one or more target cells may be considered. In condition-based handover, the number of the considered target cells may be determined by the network.

1F is a diagram illustrating a flowchart of a general handover operation according to an embodiment of the present disclosure.

Referring to FIG. 1F , the terminal may perform a general handover operation with base stations. The terminal 1f-05 may perform a data transmission/reception operation in the connected mode state with the source cell 1f-10 (1f-20). The UE may receive a predetermined RRC message including measurement configuration information from the source cell (1f-25). The terminal can measure the signal quality of the serving cell and neighboring cells by applying the measurement configuration information (1f-30), and reports the collected cell measurement information to the source cell periodically or when a configured event occurs Can (1f-35). The source cell may determine whether to trigger a general handover operation based on the reported cell measurement information (1f-40). For example, when event A3 (neighbor becomes offset better than SpCell) is satisfied and cell measurement information is reported, the source cell may determine a general handover. If it is decided to trigger the general handover, the source cell may request the general handover to one target cell 1f-15 through a predetermined inter-node message (1f-45). Upon receiving the request, the target cell may accept it using a predetermined admission control (1f-50), and may transmit handover configuration information necessary for the general handover operation to the source cell (1f-55). ). The source cell may include the handover configuration information and additional configuration information received from the target cell in a predetermined RRC message, and may transmit the RRC message to the terminal (1f-60). The configuration information includes the ID of the target cell, frequency information, configuration information necessary for a random access operation to the target cell (dedicated preamble information, dedicated radio resource information, etc.), transmission power information, C-RNTI information used in the target cell, etc. can

Upon receiving the handover configuration information, the terminal may immediately perform a random access process to the target cell and drive a T304 timer (1f-65). Also, the data transmission/reception operation with the source cell may be stopped (1f-70). The terminal may transmit the provided preamble (1f-75). If the dedicated preamble is not provided, one of the preambles used in the contention base can be transmitted. Upon receiving the preamble, the target cell may transmit a random access response (RAR) to the UE (1f-85). The UE may transmit msg3 to the target cell by using the UL grant information included in the RAR (1f-85). The msg3 may include an RRCReconfigurationComplete message. When the random access process is successfully completed, it can be considered that the normal handover has been successfully completed, and the running T304 timer can be stopped. In addition, data transmission/reception operation with the target cell may be performed (1f-90). If the normal handover is not successfully completed until the T304 timer expires (1f-95), the handover may be regarded as a failure. At this time, radio link failure (RLF) may be declared and a re-establishment operation may be performed (1f-98). When declaring the RLF, the UE may record useful information that can be collected at the time, and may report an RLF report when connected to one cell later.

1G is a diagram illustrating a flow chart of a condition-based handover operation according to an embodiment of the present disclosure.

Referring to FIG. 1G , the terminal may perform a condition-based handover operation between base stations. The terminal 1g-05 may report its capability information to the source cell 1g-10 (1g-16). The capability information may indicate whether the terminal supports condition-based handover. The UE may receive a predetermined RRC message including measurement configuration information from the source cell (1g-17). The terminal can apply the measurement configuration information, can measure the signal quality of the serving cell and neighboring cells (1g-18), periodically or when a configured event occurs, the collected cell measurement information is used as the source cell (1g-19). The source cell may determine whether to trigger a condition-based handover operation based on the reported cell measurement information (1g-20). In order to configure the condition-based handover, the terminal must be able to support the condition-based handover. If it is determined to trigger the condition-based handover, the source cell may request the condition-based handover to one or more target cells 1g-15 through a predetermined inter-node message (1g-25). The target cells that have received the request may accept it through a predetermined admission control (1g-30), and transmit handover configuration information necessary for the condition-based handover operation to the source cell (1g-35). ). Target cells that do not accept the request may be excluded from the condition-based handover. The source cell may include the handover configuration information and additional configuration information received from the target cells in a predetermined RRC message, and may transmit the RRC message to the UE (1g-40). The configuration information includes ID of target cells, frequency information, configuration information necessary for random access operation to target cells (dedicated preamble information for each target cell, dedicated radio resource information, etc.), transmission power information, and C used in each target cell. -RNTI information, conditions triggering a random access operation to each target cell, etc. may be included. Each of the conditions may be different for each target cell, and a plurality of conditions may be set for one target cell. The attemptCondReconfig field included in the configuration information indicates whether to perform condition-based handover to the cell if the suitable cell found in the first cell selection operation is one of the candidate target cells for condition-based handover after handover failure is an indicator

Upon receiving the handover configuration information, the terminal may evaluate whether the provided condition(s) is satisfied (1g-45). Until the condition is satisfied, the terminal may maintain the data transmission/reception operation with the source cell (1g-50). If a condition related to a specific target cell is satisfied (1g-55), a random access process may be performed to the target cell and a T304 timer may be driven (1g-60). For example, if Event A3 (neighbor becomes offset better than SpCell) is set as the above condition and satisfies this condition, the UE may transmit the provided preamble to the associated target cell (1g-65). If the dedicated preamble is not provided, one of the preambles used in the contention base can be transmitted. Upon receiving the preamble, the target cell may transmit a random access response (RAR) to the UE (1g-70). The UE may transmit msg3 to the target cell by using the UL grant information included in the RAR (1g-75). The msg3 may include an RRCReconfigurationComplete message. When the random access process is successfully completed, it can be considered that the condition-based handover has been successfully completed, and the running T304 timer can be stopped. If the condition-based handover is not successfully completed until the T304 timer expires (1g-80), it may be regarded as a handover failure. At this time, RLF may be declared and a re-establishment operation may be performed (1g-85). If the suitable cell found through the cell selection operation in the re-establishment operation is one of the candidate target cells in the condition-based handover, handover may be performed again to the cell (1g-90).

When the handover is successfully completed, the terminal may delete handover configuration information. When the source cell receives the handover success report from the target cell, the source cell may delete the context information of the terminal. The success may also be determined by a UE context release message that is an inter-node message transmitted to the target cell to the source cell. Also, the source cell may instruct other candidate target cells included in the handover configuration information to delete the handover configuration information (or UE context information) (or may inform that it is no longer valid). The candidate target cells may delete the handover configuration information by themselves when a predetermined time elapses after receiving the handover request without an instruction from the source cell.

The present disclosure proposes a method in which the terminal collects information related to a successfully completed handover and reports it to the base station.

1H is a diagram illustrating a process of reporting successfully completed handover related information to a target cell according to an embodiment of the present disclosure.

Referring to FIG. 1H , a terminal 1h-10 may receive an RRC message including handover configuration information from a source base station 1h-05. The terminal may perform a handover operation according to the handover configuration information. At this time, if the terminal does not successfully complete the handover operation, it may declare an RLF and store information valid at the time. The stored information may then be reported to the connected base station, and the network may identify a problem in the handover operation and may be used to determine optimal configuration parameter values. On the other hand, if the terminal successfully completes the handover operation, it only transmits an RRC message indicating the success to the target cell, and does not store and report other information. Accordingly, if the handover operation is not smoothly completed until the handover operation is completed, the network cannot convene information that is a basis for judging the handover operation. For example, although the handover operation is successfully completed, several random access procedures may have failed. Therefore, this embodiment proposes a method of storing valid information when the terminal successfully completes the handover operation and reporting it to the target cell 1h-15. In addition, among the information related to the handover successfully completed by the terminal, information through which the network can identify a problem in the handover is proposed. In the present disclosure, an operation of reporting information related to the successfully completed handover may be defined as successful HO reporting.

1I is a diagram illustrating a process of reporting successfully completed handover related information to another cell according to an embodiment of the present disclosure.

As described above, the information related to the successfully completed handover may be used to further optimize the configuration information related to the existing handover operation. After the handover configured by the source base station 1i-05 is completed, the terminal 1i-10 may report the handover-related information to the target base station 1i-15. However, at that time, the target base station is in a network congestion state, so it may not be an appropriate timing to receive the information. In this case, the information to be reported may not be information urgently needed for the target base station. Accordingly, the target base station may not request the information from the terminal. At this time, the terminal may consider two operations. The first operation is to immediately delete the stored handover-related information. The second operation is to keep the stored handover-related information for a certain period of time without deleting it, and to report it to the connected base station 1i-20 when there is a predetermined event. The connected base station may be a predetermined base station other than the source base station and the target base station. The base station must support the PLMN supported by the source base station or the target base station. The predetermined event may be when a setup or resume process is performed on the base station, when another handover is performed, or when a re-establishment operation is performed on the base station.

1J is a diagram illustrating an operation of reporting successfully completed condition-based handover related information to another cell according to an embodiment of the present disclosure.

Referring to FIG. 1J , the terminal 1j-05 may be in a connected state with the source base station 1j-10 (1j-20). The terminal may report its capability information to the base station (1j-25). The capability information may include an indicator indicating that the terminal has a capability to report information related to a successfully completed handover. The base station may determine whether to configure a general handover or a condition-based handover based on cell measurement information reported from the terminal (1j-30).

In the present disclosure, the following two options can be proposed for a successful HO reporting operation.

Option 1

- When the base station configures successful HO reporting, or without the configuration, the terminal supporting the successful HO reporting can always perform the above operation.

- When a normal handover succeeds or a condition-based handover succeeds, valid information can be collected and stored.

- After the handover is completed, the RRCReconfigurationComplete message transmitted to the target cell may include an availability indicator indicating that the stored information is present and may be transmitted.

- Upon receiving the availability indicator, the target cell may request a report on the information by using the UEInformationRequest message.

- The terminal receiving the request may report the stored information to the target cell.

- When the target cell does not request, the information is stored for a predetermined time and can be reported to another cell that satisfies a predetermined condition (PLMN checking, etc.). The UE may transmit RRCSetupComplete, RRCResumeComplete, RRCReconfigurationComplete, and RRCReestablishmentComplete including the availability indicator to another cell.

2nd option

- When the base station configures successful HO reporting, or without the configuration, the terminal supporting the successful HO reporting can always perform the above operation.

- When a normal handover succeeds or a condition-based handover succeeds, valid information can be collected and stored.

- After completion of the handover, the stored information may be included in the RRCReconfigurationComplete message transmitted to the target cell.

In the case of the first option, by transmitting an availability indicator to the connected cell, it may be characterized in that the cell requests the successful HO report. The cell may request the report in consideration of its own network congestion state. On the other hand, since the above procedure consists of a request and report process starting with availability indicator transmission, signaling overhead may occur.

On the other hand, in the case of the second option, since the successful HO report information is included and reported in the RRCReconfigurationComplete message when the handover is completed, the signaling overhead can be reduced. However, when network congestion occurs in the target cell, the first option may be more advantageous in improving network stability than the second option.

In the present disclosure, it may be proposed to introduce the first option or the second option as a successful HO reporting procedure, or to select and apply one of the two options according to the configuration of the base station.

In this figure, description can be made based on selecting and applying one of the two options according to the setting of the base station.

The source base station 1j-10 having determined the handover may transmit a HANDOVER REQUEST message to the target base station 1j-15 to request a handover (1j-35). The message may include an indicator indicating that successful HO reporting is configured to the terminal and an indicator indicating that the successful HO report will be reported through the first option or the second option. The successful HO reporting may be operated when the source base station, the target base station, and the terminal all support it. The target base station that has received the HANDOVER REQUEST message may finally determine the option in consideration of its own network congestion, preferences, and the like. In addition, the source base station may be notified through a HANDOVER REQUEST ACKNOWLEDGE message (1j-40). If the option proposed to the source base station is to be changed, the target base station may include the preferred option in the HANDOVER REQUEST ACKNOWLEDGE message.

During handover negotiation between the source base station and the target base station, exchanging the information each time may generate signaling overhead. Accordingly, as another method, the target base station may notify neighboring base stations of the determined option in advance in consideration of its own network congestion level, preferences, and the like. Whenever the determined option is changed, the changed option may be reported to neighboring base stations. A neighboring source base station to which a specific terminal is to be handed over to the target base station may be set to the terminal using a preference option previously notified by the target base station.

The source base station may transmit handover configuration information to the terminal (1j-45). The handover configuration information may include an indicator indicating successful HO report operation. Also, the handover configuration information may include an indicator indicating the first option or the second option. When the first option or the second option is always applied, the indicator may not be necessary.

Upon receiving the configuration information, the terminal may drive the T304 timer (1j-50). In condition-based handover, the T304 timer may be driven when at least one of set conditions is satisfied and handover is executed.

The terminal may transmit a preamble to the target base station (1j-55). Upon receiving the preamble, the target base station transmits an RAR to the terminal (1j-60). The terminal may transmit an RRCReconfigurationComplete message to the target base station (1j-65). When the transmission of the RRCReconfigurationComplete message is triggered, an operation may be different for each option. If it is the first option, the terminal may include an availability indicator indicating that successful HO report information is stored in the message. In addition, if the second option, the terminal may include the stored successful HO report in the message.

If the RRCReconfiguratioComplete message is successfully transmitted, the terminal may stop the T304 timer and delete the stored successful HO report information. If the RRCReconfigurationComplete message is not successfully transmitted, the terminal can keep running the T304 timer, and when the T304 timer expires, some or all of the stored successful HO report information is maintained, or as new information You can update some or all of them. The configured successful HO report may be deleted when the T304 timer expires. Since the expiration of T304 means the failure of the handover, there is no more reason to prepare a successful HO report.

If it is the first option, the target base station may include an indicator requesting report of the information in the UEInformationRequest message and transmit it to the terminal (1j-75). Upon receiving the message, the terminal may report to the base station including the successful HO report information stored in the UEInformationResponse message (1j-80).

Since the predetermined successful HO reporting information is information that the network does not already know and is not reported to the network through other reporting technologies, it may be as follows.

- Beam-level measurement of the source cell and of the target cell when HO command is received

- Beam-level measurement of the source cell and of the target cell when HO is executed

- Beam-level measurement of the source cell and of the target cell when HO is completed

- Beam-level measurement of the candidate target cells when HO command is received (only for CHO)

- Beam-level measurement of the candidate target cells when HO is executed (only for CHO)

- Beam-level measurement of the candidate target cells when HO is completed 　 (only for CHO)

- Logging only good beams above a (configurable) threshold

- Logging an indicator to indicate no good beam (i.e. under a (configurable) RSRP/RSRQ threshold)

- Number of ARQ or HARQ retransmissions in the target cell

- Indicator if ARQ or HARQ retransmissions exceed over a (configurable) threshold, in the target cell

- UE location and time when HO was completed (or time when successful HO content was set)

1K is a diagram illustrating a flow chart of a terminal operation for reporting successfully completed handover related information to a target cell according to an embodiment of the present disclosure.

Referring to FIG. 1K , in step 1k-05, the terminal may receive an RRCReconfiguration message including handover configuration information from the source base station. The setting information may include an indicator indicating whether it is the first option or the second option.

In step 1k-10, the terminal may determine whether it is the first option or the second option.

If it is the first option in step 1k-15, the terminal may immediately perform a random access procedure to the target base station.

In step 1k-20, the terminal may store information related to a handover successfully completed at a predetermined time point.

In step 1k-25, the terminal may transmit an RRCReconfigurationComplete message including an indicator indicating that the handover-related information is stored to the target base station.

In step 1k-30, the terminal may receive feedback information for the message, and may consider that the handover has been successfully completed.

In step 1k-35, the terminal may receive a request from the base station to report the stored successful HO report information.

In step 1k-40, the terminal may report the information to the base station.

If it is the second option in step 1k-45, the terminal may immediately perform a random access procedure to the target base station.

In step 1k-50, the terminal may store information related to a handover successfully completed at a predetermined time point.

In step 1k-55, the terminal may transmit an RRCReconfigurationComplete message including an indicator indicating that the stored successful HO report is being stored to the target base station.

11 is a diagram illustrating a flow chart of a terminal operation for reporting successfully completed handover related information to another cell according to an embodiment of the present disclosure.

Referring to FIG. 11 , the target cell may not report the successful HO report due to network congestion or the like. At this time, the terminal 11-05 may maintain the stored successful HO report for a certain period of time without immediately deleting it. The terminal may report the information after being connected to another cell. To this end, the terminal may include an indicator indicating that the successful HO report is being stored in the RRCSetupComplete or RRCResumeComplete message after a predetermined PLMN check operation (11-12) (11-15). When the terminal stores the successful HO report, it can store the RPLMN or ePLMN information at the time, and if the connected cell supports at least one of the PLMNs (or the current RPLMN matches at least one of the stored PLMNs), the The indicator may be reported to the cell. The connected cell may make a request to the UE using the UEInformationRequest message (11-20), and the UE receiving the request may report the report using the UEInformationResponse message (11-25).

As another method, some successful HO report information may be included in the RRCReconfigurationComplete message, and the remaining information may be reported to the base station using the UEInformationRequest/UEInformationResponse message. In this case, the RRCReconfigurationCmplete message may include an indicator indicating that there is remaining information. The reason for reporting information separately as described above is that information requiring high importance or urgency among successful HO report information is reported first, and other information can be reported later.

1M is a diagram illustrating DCP (DCI with CRC scrambled by PS-RNTI) for a connected mode terminal to save power consumption according to an embodiment of the present disclosure.

Referring to FIG. 1m, in the connected mode, the UE may monitor the PDCCH including scheduling information (1m-05). Upon reception of its own scheduling information, its own transmission/reception data may be transmitted or received in a radio resource indicated by the scheduling information. Since the PDCCH monitoring operation consumes terminal power, a discontinuous reception (DRX) technique has been introduced in a mobile communication system to minimize it. When DRX is configured, the UE may perform a PDCCH monitoring operation for an onDuration time period (1m-10) every DRX cycle (1m-15). The base station may provide scheduling information for the terminal according to the pattern. Since DRX prevents continuous monitoring of the PDCCH, there may be an effect of reducing terminal power consumption.

In the next-generation mobile communication system, DCP (DCI with CRC scrambled by PS-RNTI) has been introduced to more effectively reduce terminal power consumption. It may also be referred to as a wake-up signal (WUS). The base station may transmit a DCP signal before a predetermined offset period (1m-25) prior to the PDCCH occasion (1m-30) (1m-20). The DCP may include information indicating whether to perform a PDCCH monitoring operation on an upcoming PDCCH occasion. If there is no scheduling information to be included in the upcoming PDCCH occasion, the base station may include an indicator that the PDCCH monitoring operation is not required in the PDCCH occasion arriving in the DCP. Accordingly, the connected mode terminal may skip the PDCCH monitoring operation according to the information included in the DCP.

1N is a diagram illustrating a flowchart of an operation in which a connected mode terminal sets a DCP to save power consumption according to an embodiment of the present disclosure.

Referring to FIG. 1N , the connected mode terminal 1n-05 may receive the DCP configuration information along with the DRX configuration information from the base station 1n-10 (1n-15). The UE may receive DCP from the base station (1n-20), and, according to information included in the DCP, may determine whether to perform a PDCCH monitoring operation on a PDCCH occasion that comes after DCP (1n-25) .

1O is a diagram illustrating a procedure for notifying SystemInformation update or PWS transmission according to an embodiment of the present disclosure.

Referring to FIG. 1O , the base station of the mobile communication system may broadcast information such as cell information, information necessary for a standby mode or inactive mode terminal to access a cell, cell reselection parameters, and the like. This can be called SystemInformation (SI). Also, the mobile communication system may broadcast disaster information (PWS, public warning system) through the SystemInformation. After the terminal acquires SystemInformation for a specific cell, upon receiving an indicator indicating that the SystemInformation has been updated, the terminal may acquire the updated SystemInformation again from the base station.

In the LTE system, an indicator for notifying SystemInformation update or PWS transmission may be included in the paging message (1o-05), and may be provided to the terminal. In order to receive the paging message, the UE must first receive the PDCCH 1o-10 including the scheduling information of the paging message. In the paging message, the following systemInfoModification is an indicator indicating that the SI has been updated, and the following etws-Indication is an indicator indicating that disaster information is being broadcast. Therefore, in order to receive the indicators, the UE must receive both the PDCCH and the paging message. This method may be disadvantageous in receiving disaster information requiring urgency.

Paging message

-- ASN1START

Paging ::= SEQUENCE {

pagingRecordList PagingRecordList OPTIONAL, -- Need ON

systemInfoModification ENUMERATED {true} OPTIONAL, -- Need ON

etws-Indication ENUMERATED {true} OPTIONAL, -- Need ON

nonCriticalExtension Paging-v890-IEs OPTIONAL

}

In the NR system, the indicator may be included in the PDCCH (1o-25). For this purpose, Short Message indicator and Short Message were introduced. The following Short Message Indicator may be used to indicate whether the terminal should receive the short message or whether it should receive the paging message according to the scheduling information of the paging message 1o-20 included in the PDCCH. For example, if set to the bit string '01', it may indicate that there is scheduling information for the paging message. That is, since the terminal may have its own paging information, it is necessary to receive the paging message. If set to '10' bit string, it may indicate that there is only a short message. Accordingly, the terminal only checks the information of the Short Message and does not need to receive the paging message. The '11' bit string indicates that both the scheduling information for the paging message and the short message are present, and the terminal can receive both the short message and the paging message. Short message indicators according to bit strings are shown in [Table 2] below.

Short Message indicator bit field Short Message indicator 00 Reserved 01 Only scheduling information for Paging is present in the DCI 10 Only short message is present in the DCI 11 Both scheduling information for Paging and short message are present in the DCI

The following Short Message may be used to include indicators indicating whether to update SI and whether to transmit PWS. The first bit of the Short Message may indicate systemInfoModifcation information, and the second bit may indicate etwsAndCmasIndication information. Both ETWS and CMAS are types of PWS information, and one of the above information is applied for each country. In this method, since the UE only needs to receive the PDCCH to know the SI update or PWS transmission, the SI update and the PWS reception operation can be performed quickly. Information of the Short Message according to the bits is shown in [Table 3] below.

Bit Short Message One systemInfoModification
If set to 1: indication of a BCCH modification other than SIB6, SIB7 and SIB8. 2 etwsAndCmasIndication
If set to 1: indication of an ETWS primary notification and/or an ETWS secondary notification and/or a CMAS notification. 3 stopPagingMonitoring
This bit can be used for only operation with shared spectrum channel access and if nrofPDCCH-MonitoringOccasionPerSSB-InPO is present.
If set to 1: indication that the UE may stop monitoring PDCCH occasion(s) for paging in this Paging Occasion as specified in TS 38.304 [20], clause 7.1. 4 - 8 Not used in this release of the specification, and shall be ignored by UE if received.

1P is a diagram illustrating a procedure for notifying a SystemInformation update or PWS transmission when DCP is applied according to an embodiment of the present disclosure.

The DCP described above may be used to determine whether or not to perform a PDCCH monitoring operation on an upcoming PDCCH occasion for connected mode UEs.

In the present disclosure, the DCP (or WUS) concept may be used to determine whether or not to perform a paging monitoring operation on a coming paging occasion (a time interval for monitoring paging). WUS (1p-05) may be transmitted ahead of a predetermined offset time on the paging occasion, and may indicate to the WUS whether paging monitoring operation should be performed on the paging occasion. If it is to be performed, the PDCCH (1p-10) may be received on the paging occasion, and the paging message (1p-15) may be sequentially received. If the base station updates the SI or transmits the PWS, in order to notify it, it may be necessary to indicate that a paging monitoring operation should be performed on a paging occasion arriving at the WUS. Upon receiving this, the UE may check an indicator indicating SI update or PWS transmission in the Short Message included in the PDCCH, and receive the SI corresponding thereto.

In order to shorten the procedure, the present disclosure proposes a method including an indicator instructing the WUS to update SI or transmit PWS. That is, the first bit (systemInfoModifcation information) and the second bit (etwsAndCmasIndication information) of the Short Message may be included in the WUS. As another method, the Short Message may be included in the WUS. In order to notify the base station when SI is updated or PWS is transmitted, the base station may transmit an indicator indicating SI update or PWS transmission to the WUS (1p-25). Upon receiving this, the UE may receive SI corresponding thereto (1p-30).

The WUS may be a predefined sequence, not a DCI format including L1 signaling, in order to minimize signaling overhead. For example, when the first sequence is transmitted on the WUS occasion (a predetermined time point at which WUS is transmitted), it is possible to instruct the UEs belonging to the first paging group to perform paging monitoring on the arriving paging occasion, and the second sequence When is transmitted on the WUS occasion, it may instruct the UEs belonging to the second paging group to perform paging monitoring on the arriving paging occasion. When the above sequence is introduced as WUS information, a separate sequence indicating the SI update or PWS transmission may be defined. As an example, the m th sequence may be used to inform SI update, and the n th sequence may be used to indicate PWS transmission. Alternatively, the x-th sequence may be used to indicate both SI update and PWS transmission. When the m, n, and x-th sequences are received, the UE may perform an SI update or PWS reception operation indicated by the UE, and may also perform paging monitoring.

1q is a diagram illustrating a flowchart of an operation of notifying SystemInformation update or PWS transmission according to an embodiment of the present disclosure.

Referring to FIG. 1q, the terminal 1q-05 broadcasts configuration information for WUS indicating whether to perform a paging monitoring operation on a paging occasion from the base station 1q-10 using system information (SIB). Can cast (1q-15). The base station may trigger SI update or PWS transmission (1q-20). The base station may transmit a WUS including an indicator indicating SI update or PWS transmission (1q-25). Since there are terminals that do not support the WUS, a Short Message included in the PDCCH of the paging occasion may also be configured and transmitted. The terminal supporting the WUS may receive the corresponding SIB according to the indicator included in the received WUS (1q-35). Otherwise, the terminal that does not support the WUS may receive a Short Message included in the PDCCH of the paging occasion, and may receive a corresponding SIB according to an indicator included in the Short Message.

The WUS may be received by a UE in standby mode (RRC_IDLE), inactive mode (RRC_INACTIVE), and connected mode (RRC_CONNECTED). For example, the terminal in the connected mode may receive two types of WUS. One may be a WUS indicating whether PDCCH monitoring is performed on a conventional PDCCH occasion, and the other may be a WUS indicating whether or not a paging monitoring operation is performed on a paging occasion in the present disclosure.

The first bit (systemInfoModifcation information) and the second bit (etwsAndCmasIndication information) of the Short Message are additionally included in DCP (i.e. WUS) indicating whether to perform the PDCCH monitoring operation on the PDCCH occasion to the conventional connected mode terminal, or the Short Message may include In this case, the UE supporting DCP and receiving DCP configuration does not need to separately receive WUS indicating whether to monitor paging, and only needs to receive DCP.

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

Referring to the drawings, the terminal may include a radio frequency (RF) processing unit 1r-10, a baseband processing unit 1r-20, a storage unit 1r-30, and a control unit 1r-40. can

The RF processing unit 1r-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 1r-10 may up-convert the baseband signal provided from the baseband processing unit 1r-20 into an RF band signal and then transmit it through an antenna, and receive the RF signal through the antenna. A band signal can be down-converted to a baseband signal. For example, the RF processing unit 1r-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), etc. can In the figure, only one antenna is shown, but the terminal may include a plurality of antennas. Also, the RF processing unit 1r-10 may include a plurality of RF chains. Furthermore, the RF processing unit 1r-10 may perform beamforming. For the beamforming, the RF processing unit 1r-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 MIMO operation.

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

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

The storage unit 1r-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 1r-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 1r-30 may provide stored data according to the request of the control unit 1r-40.

The controller 1r-40 may control overall operations of the terminal. For example, the control unit 1r-40 may transmit/receive signals through the baseband processing unit 1r-20 and the RF processing unit 1r-10. Also, the controller 1r-40 may write data to the storage unit 1r-40 and interpret the data. To this end, the controller 1r-40 may include at least one processor. For example, the controller 1r-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.

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

As shown in the figure, the base station includes an RF processing unit 1s-10, a baseband processing unit 1s-20, a backhaul communication unit 1s-30, a storage unit 1s-40, and a control unit 1s-50. It may be composed of

The RF processing unit 1s-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 1s-10 may up-convert the baseband signal provided from the baseband processing unit 1s-20 into an RF band signal and then transmit it through an antenna, and the RF received through the antenna. A band signal can be downconverted to a baseband signal. For example, the RF processing unit 1s-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 the drawing, the first access node may include a plurality of antennas. Also, the RF processing unit 1s-10 may include a plurality of RF chains. Furthermore, the RF processing unit 1s-10 may perform beamforming. For the beamforming, the RF processing unit 1s-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 1s-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 1s-20 may generate complex symbols by encoding and modulating a transmitted bit stream. Also, when receiving data, the baseband processing unit 1s-20 may restore a received bit stream by demodulating and decoding the baseband signal provided from the RF processing unit 1s-10. For example, in the OFDM scheme, when transmitting data, the baseband processing unit 1s-20 may generate complex symbols by encoding and modulating a transmission bit stream, and after mapping the complex symbols to subcarriers , OFDM symbols can be configured through IFFT operation and CP insertion. In addition, upon data reception, the baseband processing unit 1s-20 divides the baseband signal provided from the RF processing unit 1s-10 into OFDM symbol units, and restores signals mapped to subcarriers through FFT operation. After that, the received bit stream can be restored through demodulation and decoding. The baseband processing unit 1s-20 and the RF processing unit 1s-10 may transmit and receive signals as described above. Accordingly, the baseband processing unit 1s-20 and the RF processing unit 1s-10 may be referred to as a transmitter, a receiver, a transceiver, a communication unit, or a wireless communication unit.

The backhaul communication unit 1s-30 may provide an interface for performing communication with other nodes in the network. That is, the backhaul communication unit 1s-30 may convert 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 a physical signal received from the other node. can be converted to a bit string.

The storage unit 1s-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 1s-40 may store information on a bearer assigned to an accessed terminal, a measurement result reported from the accessed terminal, and the like. In addition, the storage unit 1s-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 1s-40 may provide stored data according to the request of the control unit 1s-50.

The control unit 1s-50 may control overall operations of the main base station. For example, the control unit 1s-50 may transmit/receive a signal through the baseband processing unit 1s-20 and the RF processing unit 1s-10 or through the backhaul communication unit 1s-30. Also, the control unit 1s-50 may record data in the storage unit 1s-40 and interpret the data. To this end, the control unit 1s-50 may include at least one processor.

Claims (1)

A control signal processing method in a wireless communication system, comprising:
Receiving a first control signal transmitted from the base station;
processing the received first control signal; and
and transmitting a second control signal generated based on the processing to the base station.

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