WO2024019396A1 - Initial connection method and apparatus for network-controlled repeater in next generation mobile communication system - Google Patents

Abstract

The present disclosure relates to: a communication technique for merging IoT technology with a 5G communication system for supporting a data transmission rate higher than that of a 4G system; and a system therefor. The present disclosure can be applied to intelligent services (for example, smart homes, smart buildings, smart cities, smart cars or connected cars, healthcare, digital education, retail businesses, security- and safety-related services, and the like) on the basis of 5G communication technology and IoT-related technology. The present disclosure provides an apparatus and a method related to a network-controlled repeater system.

Description

The first connection method and device for a network control repeater in a next-generation mobile communication system

This disclosure relates to a network controlled repeater system.

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

Meanwhile, the Internet is evolving from a human-centered network where humans create and consume information to an IoT (Internet of Things) network that exchanges and processes information between distributed components such as objects. IoE (Internet of Everything) technology, which combines IoT technology with big data processing technology through connection to cloud servers, etc., is also emerging. In order to implement IoT, technological elements such as sensing technology, wired and wireless communication and network infrastructure, service interface technology, and security technology are required. Recently, sensor networks for connection between things, and machine to machine communication (Machine to Machine) are required to implement IoT. , M2M), and MTC (Machine Type Communication) technologies are being researched. In an IoT environment, intelligent IT (Internet Technology) services that create new value in human life can be provided by collecting and analyzing data generated from connected objects. IoT is used in fields such as smart home, smart building, smart city, smart car or connected car, smart grid, healthcare, smart home appliances, and advanced medical services through the convergence and combination of existing IT (information technology) technology and various industries. It 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 Machine Type Communication (MTC) are implemented through 5G communication technologies such as beam forming, MIMO, and array antennas. There is. 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 the convergence of 5G technology and IoT technology.

As described above, with the development of mobile communication systems, various services can be provided, and a method for effectively providing these services is required.

One purpose of the present disclosure is to provide a method for a network control repeater to connect to a network and configure necessary operations.

Additionally, one purpose of the present disclosure is to provide an apparatus and method that can effectively provide services in a mobile communication system.

In a method of a terminal in a wireless communication system according to an embodiment of the present disclosure to solve the above problem, the method includes receiving system information from a base station; Checking whether the system information includes an indicator indicating support for a network controlled repeater (NCR); and transmitting a random access preamble for a random access procedure to the base station based on the indicator being included in the system information, and the terminal may be a terminal supporting the NCR function.

Additionally, in a method of a base station in a wireless communication system according to an embodiment of the present disclosure, the method includes generating an indicator indicating support for a network controlled repeater (NCR); Broadcasting system information including the indicator; And it may include receiving a random access preamble from the terminal based on the system information.

Additionally, in a wireless communication system according to an embodiment of the present disclosure, a terminal includes: a transceiver; And from a base station, control the transceiver to receive system information, check whether the system information includes an indicator indicating support for NCR (network controlled repeater), and based on the indicator being included in the system information, and a control unit that controls the transceiver to transmit a random access preamble for a random access procedure to the base station, and the terminal can support the NCR function.

Additionally, in a wireless communication system according to an embodiment of the present disclosure, a base station includes a transceiver; and generating an indicator indicating support for NCR (network controlled repeater), controlling the transceiver to broadcast system information including the indicator, and receiving a random access preamble from a terminal based on the system information. It may include a control unit that controls the unit.

According to an example of the present disclosure, a specific method of operating a network control repeater by attempting to connect to a base station and receiving necessary configuration information from the network can be provided.

More specifically, according to an example of the present disclosure, when a network control repeater connects to a serving cell, the serving cell distinguishes between cells that can operate a control repeater and cells that cannot operate the control repeater, and then performs an operation to selectively allow access, After the control repeater is connected, it performs an operation to inform the corresponding cell that it is a network control repeater, which has the effect of allowing signals for controlling the control repeater to be properly transmitted/received between the cell and the network control repeater.

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

Figure 2 is a diagram showing the wireless protocol structure of an LTE system according to an embodiment of the present disclosure.

Figure 3 is a diagram showing the structure of a next-generation mobile communication system according to an embodiment of the present disclosure.

Figure 4 is a diagram showing the wireless protocol structure of a next-generation mobile communication system according to an embodiment of the present disclosure.

Figure 5 is a block diagram showing the internal structure of a terminal according to an embodiment of the present disclosure.

Figure 6 is a block diagram showing the configuration of a base station according to an embodiment of the present disclosure.

Figure 7 is a diagram showing the configuration of a network control repeater according to an embodiment of the present disclosure.

Figure 8a is a flowchart of how NCR-MT announces that it is an NCR entity using the RRCSetupComplete message.

Figure 8b is a flowchart of how NCR-MT announces that it is an NCR entity using the RRCSetupComplete message.

Figure 9a is a flowchart of how NCR-MT uses the RRCSetupRequest message to announce that it is an NCR entity.

Figure 9b is a flowchart of how NCR-MT uses the RRCSetupRequest message to announce that it is an NCR entity.

Hereinafter, the operating principle of the present disclosure will be described in detail with reference to the attached drawings. In the following description of the present disclosure, if a detailed description of a related known function or configuration is determined to unnecessarily obscure the gist of the present disclosure, the detailed description will be omitted. In addition, the terms described below are terms defined in consideration of the functions in the present disclosure, and may vary depending on the intention or custom of the user or operator. Therefore, the definition should be made based on the contents throughout this specification.

Terms used in the following description to identify a connection node, a term referring to network entities, a term referring to messages, a term referring to an interface between network objects, and a term referring to various types of identification information. The following are examples for convenience of explanation. Accordingly, the present disclosure is not limited to the terms described below, and other terms referring to objects having equivalent technical meaning may be used.

For convenience of description below, 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 can be equally applied to systems complying with other standards.

The advantages and features of the present disclosure and methods for achieving them will become clear by referring to the embodiments described in detail below along with the accompanying drawings. However, the present disclosure is not limited to the embodiments disclosed below and may be implemented in various different forms, and the present embodiments are merely intended to ensure that the disclosure is complete and to provide common knowledge in the technical field to which the present disclosure pertains. It is provided to fully inform those who have 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 the specification.

At this time, it will be understood that each block of the processing flow diagrams and combinations of the flow diagram diagrams can be performed by computer program instructions. These computer program instructions can be mounted on a processor of a general-purpose computer, special-purpose computer, or other programmable data processing equipment, so that the instructions performed through the processor of the computer or other programmable data processing equipment are described in the flow chart block(s). It creates the means to perform functions. These computer program instructions may also be stored in computer-usable or computer-readable memory that can be directed to a computer or other programmable data processing equipment to implement a function in a particular manner, so that the computer-usable or computer-readable memory It is also possible to produce manufactured items containing instruction means that perform the functions described in the flowchart block(s). Computer program instructions can also be mounted on a computer or other programmable data processing equipment, so that a series of operational steps are performed on the computer or other programmable data processing equipment to create a process that is executed by the computer, thereby generating a process that is executed by the computer or other programmable data processing equipment. Instructions that perform processing equipment may also provide steps for executing the functions described in the flow diagram 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). Additionally, it should be noted that in some alternative execution examples, it is possible for the functions mentioned in the blocks to occur out of order. For example, it is possible for two blocks shown in succession to be performed substantially simultaneously, or it is possible for the blocks to be performed in reverse order depending on the corresponding function.

At this time, the term '~unit' used in this embodiment refers to 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 '~ part' may be configured to reside in an addressable storage medium and may be configured to reproduce on one or more processors. Therefore, as an example, '~ part' refers to components such as software components, object-oriented software components, class components, and task components, processes, functions, properties, and procedures. , subroutines, segments of program code, drivers, firmware, microcode, circuitry, data, databases, data structures, tables, arrays, and variables. The functions provided within the components and 'parts' may be combined into a smaller number of components and 'parts' or may be further separated into additional components and 'parts'. Additionally, components and 'parts' may be implemented to regenerate one or more CPUs within a device or a secure multimedia card. Additionally, in an embodiment, '~ part' may include one or more processors.

In the following description of the present disclosure, if a detailed description of a related known function or configuration is determined to unnecessarily obscure the gist of the present disclosure, the detailed description will be omitted. Hereinafter, embodiments of the present disclosure will be described with reference to the attached drawings.

Terms used in the following description to identify a connection node, a term referring to network entities, a term referring to messages, a term referring to an interface between network objects, and a term referring to various types of identification information. The following are examples for convenience of explanation. Accordingly, the present disclosure is not limited to the terms described below, and other terms referring to objects having equivalent technical meaning may be used. For example, in the following description, the terminal may refer to a MAC entity within the terminal that exists for each Master Cell Group (MCG) and Secondary Cell Group (SCG), which will be described later.

For convenience of description below, 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 can be equally applied to systems complying with other standards.

Hereinafter, the base station is the entity that performs resource allocation for the terminal and may be at least one of gNode B, eNode B, Node B, BS (Base Station), wireless access unit, base station controller, or node on the network. A terminal may include a UE (User Equipment), MS (Mobile Station), a cellular phone, a smartphone, a computer, or a multimedia system capable of performing communication functions. 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, this disclosure provides intelligent services (e.g., smart home, smart building, smart city, smart car or connected car, healthcare, digital education, retail, 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 explanation. That is, a base station described as an eNB may represent a gNB. Additionally, the term terminal can refer to mobile phones, NB-IoT devices, sensors, as well as other wireless communication devices.

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

As a representative example of a broadband wireless communication system, the LTE system uses Orthogonal Frequency Division Multiplexing (OFDM) in the downlink (DL), and Single Carrier Frequency Division Multiple Access (SC-FDMA) in the uplink (UL). ) method is adopted. Uplink refers to a wireless link in which a terminal (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 wireless link in which the base station transmits data or control signals to the terminal. It refers to a wireless link that transmits signals. The multiple access method described above differentiates each user's data or control information by allocating and operating the time-frequency resources to carry data or control information for each user so that they do not overlap, that is, orthogonality is established. .

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

According to some embodiments, eMBB may aim to provide more improved data transmission rates than those supported by existing LTE, LTE-A, or LTE-Pro. For example, in a 5G communication system, eMBB must be able to provide a peak data rate of 20Gbps in the downlink and 10Gbps in the uplink from the perspective of one base station. In addition, the 5G communication system may need to provide the maximum transmission rate and at the same time provide an increased user perceived data rate. In order to meet these requirements, the 5G communication system may require improvements in various transmission and reception technologies, including more advanced multi-antenna (MIMO; Multi Input Multi Output) transmission technology. In addition, while the current LTE transmits signals using a maximum of 20 MHz transmission bandwidth in the 2 GHz band, the 5G communication system uses a frequency bandwidth wider than 20 MHz in the 3 to 6 GHz or above 6 GHz frequency band, meeting the requirements of the 5G communication system. Data transfer speed can be satisfied.

At the same time, mMTC is being considered to support application services such as Internet of Things (IoT) in 5G communication systems. In order to efficiently provide the Internet of Things, mMTC may require support for access to a large number of terminals within a cell, improved coverage of terminals, improved battery time, and reduced terminal costs. Since the Internet of Things provides communication functions by attaching various sensors and various devices, it must be able to support a large number of terminals (for example, 1,000,000 terminals/km ² ) within a cell. Additionally, due to the nature of the service, terminals supporting mMTC are likely to be located in shadow areas that cannot be covered by cells, such as the basement of a building, so wider coverage may be required compared to other services provided by the 5G communication system. Terminals that support mMTC must be composed of low-cost terminals, and since it is difficult to frequently replace the terminal's battery, a very long battery life time, such as 10 to 15 years, may be required.

Lastly, in the case of URLLC, it is a cellular-based wireless communication service used for specific purposes (mission-critical), such as remote control of robots or machinery, industrial automation, It can be used for services such as unmanned aerial vehicles, remote health care, and emergency alerts. Therefore, the communication provided by URLLC may need to provide very low latency (ultra-low latency) and very high reliability (ultra-reliability). For example, a service supporting URLLC must satisfy an air interface latency of less than 0.5 milliseconds and may have a packet error rate of 10 ^-5 or less. Therefore, for services supporting URLLC, the 5G system must provide a smaller Transmit Time Interval (TTI) than other services, and at the same time, a design that requires allocating wide resources in the frequency band to ensure the reliability of the communication link. Specifications may be required.

The three services considered in the above-described 5G communication system, namely eMBB, URLLC, and mMTC, can be multiplexed and transmitted in one system. At this time, different transmission/reception techniques and transmission/reception parameters can be used between services to satisfy the different requirements of each service. However, the above-described mMTC, URLLC, and eMBB are only examples of different service types, and the service types to which this disclosure is applied are not limited to the above-described examples.

In addition, hereinafter, embodiments of the present invention will be described using LTE, LTE-A, LTE Pro or 5G (or NR, next-generation mobile communication) systems as examples, but the present invention can also be applied to other communication systems with similar technical background or channel type. Examples of may be applied. In addition, the embodiments of the present invention may be applied to other communication systems through some modifications without significantly departing from the scope of the present invention at the discretion of a person with skilled technical knowledge.

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

Referring to FIG. 1, as shown, the wireless access network of the LTE system includes a next-generation base station (Evolved Node B, hereinafter referred to as ENB, Node B or base station) (1-05, 1-10, 1-15, 1-20) and It may be composed of a Mobility Management Entity (MME) (1-25) and S-GW (1-30, Serving-Gateway). User equipment (hereinafter referred to as UE or terminal) (1-35) can access an external network through ENB (1-05 to 1-20) and S-GW (1-30).

In FIG. 1, ENBs 1-05 to 1-20 may correspond to the existing Node B of the UMTS system. The ENB is connected to the UE (1-35) through a wireless channel and can perform a more complex role than the existing Node B. In the LTE system, all user traffic, including real-time services such as VoIP (Voice over IP) through the Internet protocol, can be serviced through a shared channel. Therefore, a device that collects status information such as buffer status, available transmission power status, and channel status of UEs and performs scheduling may be needed, and the ENB (1-05 to 1-20) may be responsible for this. One ENB can typically control multiple cells. For example, in order to implement a transmission speed of 100 Mbps, the LTE system can use Orthogonal Frequency Division Multiplexing (OFDM) as a wireless access technology in, for example, a 20 MHz bandwidth. Additionally, the ENB can apply the Adaptive Modulation & Coding (AMC) method, which determines the modulation scheme and channel coding rate according to the channel status of the terminal. The S-GW (1a-30) is a device that provides a data bearer, and can create or remove a data bearer under the control of the MME (1-25). The MME is a device that handles various control functions as well as mobility management functions for the terminal and can be connected to multiple base stations.

Figure 2 is a diagram showing the wireless protocol structure of an LTE system according to an embodiment of the present disclosure.

Referring to Figure 2, the wireless protocols of the LTE system are Packet Data Convergence Protocol (PDCP) (2-05, 2-40) and Radio Link Control (RLC) (Radio Link Control, RLC) in the terminal and ENB, respectively. 2-10, 2-35) and Medium Access Control (MAC) (2-15, 2-30). PDCP may be responsible for operations such as IP (internet protocol) header compression/restoration. The main functions of PDCP can be summarized as follows. Of course, it is not limited to the examples below.

- Header compression and decompression (ROHC only)

- Transfer of user data

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

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

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

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

- Encryption and decryption function (Ciphering and deciphering)

- Timer-based SDU discard in uplink.

According to one embodiment, the Radio Link Control (RLC) (2-10, 2-35) reconfigures the PDCP Packet Data Unit (PDU) to an appropriate size to perform an automatic repeat request (ARQ) operation. etc. can be performed. The main functions of RLC can be summarized as follows. Of course, it is not limited to the examples below.

- Data transfer function (Transfer of upper layer PDUs)

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

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

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

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

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

- Error detection function (Protocol error detection (only for AM data transfer))

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

- RLC re-establishment function

According to one embodiment, MAC (2-15, 2-30) is connected to several RLC layer devices configured in one terminal, and performs an operation of multiplexing RLC PDUs to MAC PDUs and demultiplexing RLC PDUs from MAC PDUs. can do. The main functions of MAC can be summarized as follows. Of course, this is not limited to the examples below.

- Mapping function (Mapping between logical channels and transport channels)

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

- Scheduling information reporting

- HARQ function (Error correction through HARQ)

- Priority handling between logical channels of one UE

- Priority handling between UEs by means of dynamic scheduling

- MBMS service identification function

- Transport format selection function

- Padding function

According to one embodiment, the physical layer (2-20, 2-25) channel codes and modulates upper layer data, creates an OFDM symbol and transmits it over a wireless channel, or demodulates an OFDM symbol received through a wireless channel and transmits it to the channel. You can decode and transmit it to the upper layer. Of course, this is not limited to the examples below.

Figure 3 is a diagram showing the structure of a next-generation mobile communication system according to an embodiment of the present disclosure.

Referring to Figure 3, the radio access network of the next-generation mobile communication system (hereinafter referred to as NR or 5g) includes a next-generation base station (New Radio Node B, hereinafter referred to as NR gNB or NR base station) (3-10) and a next-generation wireless core network (New Radio Core). Network, NR CN) (3-05). The next-generation wireless user equipment (New Radio User Equipment, NR UE or UE) (3-15) can access an external network through NR gNB (3-10) and NR CN (3-05).

In FIG. 3, the NR gNB (3-10) may correspond to an Evolved Node B (eNB) of the existing LTE system. NR gNB is connected to NR UE (3-15) through a wireless channel and can provide superior services than the existing Node B. In the next-generation mobile communication system, all user traffic can be serviced through a shared channel. Therefore, a device that collects status information such as buffer status, available transmission power status, and channel status of UEs and performs scheduling may be needed, and the NR gNB 3-10 may be responsible for this. One NR gNB (3-10) can control multiple cells. In the next-generation mobile communication system, in order to implement ultra-fast data transmission compared to the current LTE, a bandwidth exceeding the current maximum bandwidth may be applied. Additionally, beamforming technology may be additionally used using Orthogonal Frequency Division Multiplexing (OFDM) as a wireless access technology.

Additionally, according to one embodiment, the NR gNB (3-10) uses Adaptive Modulation & Coding (hereinafter referred to as Adaptive Modulation & Coding) to determine the modulation scheme and channel coding rate according to the channel status of the terminal. (referred to as AMC) method may be applied. NR CN (3-05) can perform functions such as mobility support, bearer setup, and QoS setup. NR CN (3-05) is a device responsible for various control functions as well as mobility management functions for the terminal and can be connected to multiple base stations. Additionally, the next-generation mobile communication system can be linked to the existing LTE system, and NR CN can be connected to the MME (3-25) through a network interface. MME (3-25) can be connected to eNB (3-30), which is an existing base station.

Figure 4 is a diagram showing the wireless protocol structure of a next-generation mobile communication system according to an embodiment of the present disclosure.

Referring to FIG. 4, the wireless protocols of the next-generation mobile communication system are NR Service Data Adaptation Protocol (SDAP) (4-01, 4-45) and NR PDCP (4-05, 4-05) in the terminal and NR base station, respectively. 4-40), NR RLC (4-10, 4-35), and NR MAC (4-15, 4-30).

According to one embodiment, the main functions of NR SDAP (4-01, 4-45) may include some of the following functions. However, it is not limited to the examples below.

- Transfer of user plane data

- Mapping function of QoS flow and data bearer for uplink and downlink (mapping between a QoS flow and a DRB for both DL and UL)

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

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

For SDAP layer devices, the terminal uses a Radio Resource Control (RRC) message to determine whether to use the header of the SDAP layer device for each PDCP layer device, for each bearer, or for each logical channel, or whether to use the function of the SDAP layer device. can be set. In addition, when the SDAP layer device has an SDAP header set, the terminal sets a 1-bit indicator (NAS reflective QoS) that reflects the Non-Access Stratum (NAS) QoS (Quality of Service) in the SDAP header and the access layer (Access Stratum). Stratum, AS) QoS reflection setting 1-bit indicator (AS reflective QoS) can indicate that the terminal can update or reset mapping information for uplink and downlink QoS flows and data bearers. According to one embodiment, the SDAP header may include QoS flow ID information indicating QoS. According to one implementation, QoS information can be used as data processing priority, scheduling information, etc. to support smooth service.

According to one embodiment, the main functions of NR PDCP (4-05, 4-40) may include some of the following functions. However, it is not limited to the examples below.

- Header compression and decompression (ROHC only)

- Transfer of user data

- In-sequence delivery of upper layer PDUs

- Out-of-sequence delivery of upper layer PDUs

- Order reordering function (PDCP PDU reordering for reception)

- Duplicate detection of lower layer SDUs

- Retransmission of PDCP SDUs

- Encryption and decryption function (Ciphering and deciphering)

- Timer-based SDU discard in uplink.

In the above description, the reordering function of the NR PDCP device may mean the function of reordering PDCP PDUs received from the lower layer in order based on PDCP sequence number (SN). The reordering function of the NR PDCP device may include the function of delivering data to a higher layer in the reordered order, or may include the function of delivering data directly without considering the order, and may include the function of transmitting data directly without considering the order, and reordering the data may cause loss. It may include a function to record lost PDCP PDUs, it may include a function to report the status of lost PDCP PDUs to the transmitting side, and it may include a function to request retransmission of lost PDCP PDUs. there is.

According to one embodiment, the main functions of NR RLC (4-10, 4-35) may include some of the following functions. However, it is not limited to the examples below.

- Data transfer function (Transfer of upper layer PDUs)

- In-sequence delivery of upper layer PDUs

- Out-of-sequence delivery of upper layer PDUs

- ARQ function (Error Correction through ARQ)

- Concatenation, segmentation and reassembly of RLC SDUs

- Re-segmentation of RLC data PDUs

- Reordering of RLC data PDUs

- Duplicate detection function

- Protocol error detection

- RLC SDU deletion function (RLC SDU discard)

- RLC re-establishment function

In the above description, the in-sequence delivery function of the NR RLC device may mean the function of delivering RLC SDUs received from the lower layer to the upper layer in order. When one RLC SDU is originally received by being divided into multiple RLC SDUs, the in-sequence delivery function of the NR RLC device may include the function of reassembling and delivering it.

The in-sequence delivery function of the NR RLC device may include a function to rearrange the received RLC PDUs based on the RLC SN (sequence number) or PDCP SN (sequence number), and rearrange the order to prevent loss. It may include a function to record lost RLC PDUs, it may include a function to report the status of lost RLC PDUs to the transmitting side, and it may include a function to request retransmission of lost RLC PDUs. there is.

The in-sequence delivery function of the NR RLC device may include a function of delivering only the RLC SDUs up to the lost RLC SDU in order when there is a lost RLC SDU to the upper layer.

The in-sequence delivery function of the NR RLC device may include a function of delivering all RLC SDUs received before the timer starts to the upper layer in order if a predetermined timer expires even if there are lost RLC SDUs. there is.

The in-sequence delivery function of the NR RLC device may include a function of delivering all RLC SDUs received to date to the upper layer in order if a predetermined timer expires even if there are lost RLC SDUs.

The NR RLC device can process RLC PDUs in the order they are received and deliver them to the NR PDCP device, regardless of the order of the sequence number (out-of sequence delivery).

When the NR RLC device receives a segment, it can receive segments stored in a buffer or to be received later, reconstruct them into one complete RLC PDU, and then transmit it to the NR PDCP device.

The NR RLC layer may not include a concatenation function, and may perform the function in the NR MAC layer or replace it with the multiplexing function of the NR MAC layer.

In the above description, the out-of-sequence delivery function of the NR RLC device may refer to the function of directly delivering RLC SDUs received from a lower layer to the upper layer regardless of their order. The out-of-sequence delivery function of the NR RLC device may include a function of reassembling and delivering when one RLC SDU is originally received by being divided into several RLC SDUs. The out-of-sequence delivery function of the NR RLC device may include a function of storing the RLC SN or PDCP SN of received RLC PDUs, sorting the order, and recording lost RLC PDUs.

According to one embodiment, the NR MAC (4-15, 4-30) may be connected to several NR RLC layer devices configured in one terminal, and the main functions of the NR MAC may include some of the following functions. . However, it is not limited to the examples below.

- Mapping function (Mapping between logical channels and transport channels)

- Multiplexing and demultiplexing function (Multiplexing/demultiplexing of MAC SDUs)

- Scheduling information reporting

- HARQ function (Error correction through HARQ)

- Priority handling between logical channels of one UE

- Priority handling between UEs by means of dynamic scheduling

- MBMS service identification function

- Transport format selection function

- Padding function

The NR PHY layer (4-20, 4-25) channel-codes and modulates the upper layer data, creates OFDM symbols and transmits them to the wireless channel, or demodulates and channel decodes the OFDM symbols received through the wireless channel and transmits them to the upper layer. The transfer operation can be performed.

Figure 5 is a block diagram showing the internal structure of a terminal to which the present invention is applied.

Referring to Figure 5, the terminal may include an RF (Radio Frequency) processing unit 5-10, a baseband processing unit 5-20, a storage unit 5-30, and a control unit 5-40. there is. Of course, it is not limited to the above example, and the terminal may include fewer or more components than those shown in FIG. 5.

The RF processing unit 5-10 can perform functions for transmitting and receiving signals through a wireless channel, such as band conversion and amplification of signals. That is, the RF processing unit 5-10 up-converts the baseband signal provided from the baseband processing unit 5-20 into an RF band signal and transmits it through an antenna, and converts the RF band signal received through the antenna into a baseband signal. It can be down-converted into a signal. For example, the RF processing unit 5-10 may include a transmission filter, a reception filter, an amplifier, a mixer, an oscillator, a digital to analog convertor (DAC), an analog to digital convertor (ADC), etc. there is. Of course, it is not limited to the above example. In FIG. 5, only one antenna is shown, but the terminal may be equipped with multiple antennas. Additionally, the RF processing unit 5-10 may include a plurality of RF chains. Additionally, the RF processing unit 5-10 can perform beamforming. For beamforming, the RF processing unit 5-10 can adjust the phase and size of each signal transmitted and received through a plurality of antennas or antenna elements. Additionally, the RF processing unit 5-10 can perform MIMO (Multi Input Multi Output) and can receive multiple layers when performing a MIMO operation.

The baseband processing unit 5-20 performs a conversion function between baseband signals and bit strings according to the physical layer specifications of the system. For example, when transmitting data, the baseband processing unit 5-20 generates complex symbols by encoding and modulating the transmission bit string. Additionally, when receiving data, the baseband processing unit 5-20 can restore the received bit stream by demodulating and decoding the baseband signal provided from the RF processing unit 5-10. For example, when following the OFDM (orthogonal frequency division multiplexing) method, when transmitting data, the baseband processing unit 5-20 generates complex symbols by encoding and modulating the transmission bit string, and maps the complex symbols to subcarriers. Afterwards, OFDM symbols are configured through IFFT (inverse fast Fourier transform) operation and CP (cyclic prefix) insertion. In addition, when receiving data, the baseband processing unit 5-20 divides the baseband signal provided from the RF processing unit 5-10 into OFDM symbol units, and signals mapped to subcarriers through FFT (fast Fourier transform). After restoring the received bit string, the received bit string can be restored through demodulation and decoding.

The baseband processing unit 5-20 and the RF processing unit 5-10 transmit and receive signals as described above. The baseband processing unit 5-20 and the RF processing unit 5-10 may be referred to as a transmitting unit, a receiving unit, a transceiving unit, or a communication unit. Furthermore, at least one of the baseband processing unit 5-20 and the RF processing unit 5-10 may include a plurality of communication modules to support a plurality of different wireless access technologies. Additionally, at least one of the baseband processing unit 5-20 and the RF processing unit 5-10 may include different communication modules to process signals in different frequency bands. For example, different wireless access technologies may include wireless LAN (eg, IEEE 802.11), cellular network (eg, LTE), etc. Additionally, the different frequency bands may include a super high frequency (SHF) (e.g., 2.NRHz, NRhz) band and a millimeter wave (e.g., 60GHz) band. The terminal can transmit and receive signals with the base station using the baseband processing unit 5-20 and the RF processing unit 5-10, and the signals may include control information and data.

The storage unit 5-30 stores data such as basic programs, application programs, and setting information for operation of the terminal. In particular, the storage unit 5-30 may store information related to an access node that performs wireless communication using a second wireless access technology. Additionally, the storage unit 5-30 provides stored data upon request from the control unit 5-40. The storage unit 5-30 may be composed of a storage medium such as ROM, RAM, hard disk, CD-ROM, and DVD, or a combination of storage media. Additionally, the storage unit 5-30 may be composed of a plurality of memories.

The control unit 5-40 controls the overall operations of the terminal. For example, the control unit 5-40 transmits and receives signals through the baseband processing unit 5-20 and the RF processing unit 5-10. Additionally, the control unit 5-40 writes and reads data into the storage unit 5-30. For this purpose, the control unit 5-40 may include at least one processor. For example, the control unit 5-40 may include a communication processor (CP) that performs control for communication and an application processor (AP) that controls upper layers such as application programs. Additionally, at least one component within the terminal may be implemented with one chip.

Figure 6 is a block diagram showing the configuration of a base station according to an embodiment of the present disclosure.

Referring to FIG. 6, the base station may include an RF processing unit 6-10, a baseband processing unit 6-20, a backhaul communication unit 6-30, a storage unit 6-40, and a control unit 6-50. You can. 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. 6.

The RF processing unit 6-10 can perform functions for transmitting and receiving signals through a wireless channel, such as band conversion and amplification of signals. That is, the RF processing unit 6-10 up-converts the baseband signal provided from the baseband processing unit 6-20 into an RF band signal and transmits it through an antenna, and converts the RF band signal received through the antenna into a baseband signal. Downconvert it to a signal. For example, the RF processing unit 6-10 may include a transmission filter, a reception filter, an amplifier, a mixer, an oscillator, a DAC, an ADC, etc. In Figure 6, only one antenna is shown, but the RF processing unit 6-10 may be equipped with a plurality of antennas. Additionally, the RF processing unit 6-10 may include a plurality of RF chains. Additionally, the RF processing unit 6-10 can perform beamforming. For beamforming, the RF processing unit 6-10 can adjust the phase and size of each signal transmitted and received through a plurality of antennas or antenna elements. The RF processing unit can perform downward MIMO operation by transmitting one or more layers.

The baseband processing unit 6-20 may perform a conversion function between a baseband signal and a bit string according to the physical layer standard of the first wireless access technology. For example, when transmitting data, the baseband processing unit 6-20 may generate complex symbols by encoding and modulating the transmission bit stream. Additionally, when receiving data, the baseband processing unit 6-20 can restore the received bit stream by demodulating and decoding the baseband signal provided from the RF processing unit 6-10. For example, when following the OFDM method, when transmitting data, the baseband processing unit 6-20 generates complex symbols by encoding and modulating the transmission bit string, maps the complex symbols to subcarriers, and performs IFFT operation and OFDM symbols are configured through CP insertion. In addition, when receiving data, the baseband processing unit 6-20 divides the baseband signal provided from the RF processing unit 6-10 into OFDM symbols, restores the signals mapped to subcarriers through FFT operation, and then , the received bit string can be restored through demodulation and decoding. The baseband processing unit 6-20 and the RF processing unit 6-10 can transmit and receive signals as described above. Accordingly, the baseband processing unit 6-20 and the RF processing unit 6-10 may be referred to as a transmitting unit, a receiving unit, a transceiving unit, a communication unit, or a wireless communication unit. The base station can transmit and receive signals with the terminal using the baseband processing unit 6-20 and the RF processing unit 6-10, and the signals can include control information and data.

The backhaul communication unit 6-30 provides an interface for communicating with other nodes in the network. In other words, the backhaul communication unit 6-30 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 backhaul communication unit 6-30 may be included in the communication unit.

The storage unit 6-40 stores data such as basic programs, application programs, and setting information for operation of the base station. The storage unit 6-40 can store information about bearers assigned to the connected terminal, measurement results reported from the connected terminal, etc. Additionally, the storage unit 6-40 may store information that serves as a criterion for determining whether to provide or suspend multiple connections to the terminal. Additionally, the storage unit 6-40 provides stored data upon request from the control unit 6-50. The storage unit 6-40 may be composed of a storage medium such as ROM, RAM, hard disk, CD-ROM, and DVD, or a combination of storage media. Additionally, the storage unit 6-40 may be composed of a plurality of memories. According to some embodiments, the storage unit 6-40 may store a program for performing the buffer status reporting method according to the present disclosure.

The control unit 6-50 controls the overall operations of the base station. For example, the control unit 6-50 transmits and receives signals through the baseband processing unit 6-20 and the RF processing unit 6-10 or through the backhaul communication unit 6-30. Additionally, the control unit 6-50 writes and reads data into the storage unit 6-40. For this purpose, the control unit 6-50 may include at least one processor. Additionally, at least one component of the base station may be implemented with one chip.

In this disclosure, a network controlled repeater (NCR) is referred to as one entity, and in terms of operation, one NCR is referred to as NCR-MT (mobile termination) and NCR-FWD (forwarding).

Figure 7 is a diagram showing the configuration of a network control repeater according to an embodiment of the present disclosure.

The network controlled repeater consists of NCR (network controlled repeater) - MT and NCR-FWD. MT stands for mobile termination, and can receive control signals for NCR operation from the serving base station and transmit control information to NCR-FWD. NCR-FWD stands for forwarding and performs the role of amplifying the RF signal received from the base station and transmitting it to the terminal. NCR-FWD can perform additional operations through control information received from NCR-MT. For example, NCR-FWD can deliver a signal amplified using a specific beam to the terminal or receive a signal transmitted by the terminal. Additionally, as an example, NCR-FWD may or may not receive/amplify/transmit a signal from a base station according to a specific time division duplex (TDD) pattern, or receive/amplify/transmit a signal from a terminal.

In order to perform the above operations, NCR and the network must be able to distinguish between each other. Below, we will explain how the NCR and the network, that is, the serving base station, distinguish between each other and how to exchange configuration information specific to the NCR accordingly.

The cell may include a separate cell for controlling NCR. The NCR can perform operations required when accessing the separate cell, and for this purpose, it can receive control information from the separate cell. The separate cell needs to provide an indicator indicating that it is a cell for NCR use, and the NCR that confirms that it is a cell for NCR use can continue attempting to connect to the separate cell. As an example, the serving base station can support a general terminal and may be a base station that simultaneously supports a general terminal and NCR, or it may be a base station that cannot support a general terminal and NCR at the same time. Depending on the example, it can be divided into the following cases.

A base station supporting NCR or the NCR function may broadcast including an NCR support indicator in a master information block (MIB) or system information block (SIB).

In another example, the base station may introduce intraFreqReselection-NCR bit (IFR bit) in SIB. The bit can have the value of allowed or not-allowed. The presence of this bit may mean that this cell supports NCR. After cell selection/reselection, NCR-MT can attempt to access the cell by performing random access if this bit is included in the SIB. When selecting/reselecting a cell, if this bit does not exist in the SIB of the cell, the NCR-MT considers this cell as barred and the intraFreqReselection-NCR bit is set to allowed, and selects/reselects another cell. When reselecting, you can select/reselect another cell with the same frequency as the barred cell.

As a more specific example, if this bit is present in the SIB and its value is not-Allowed, the NCR-MT can attempt to access this cell, and if it is barred while trying to access, it can use a frequency other than the frequency of the barred cell. Frequency must be considered when selecting/reselecting cells. In other words, the corresponding frequency is also considered barred.

On the other hand, if this bit is present in the SIB and its value is allowed, the NCR-MT can attempt to access this cell, and if it is barred while attempting access, it will cell a cell on the same frequency as the frequency of the barred cell. This can be taken into consideration when selecting/reselecting.

In the same way as above, the NCR-MT can selectively attempt to connect to an NCR-supporting cell during the cell selection/reselection process. After that, if there is a process of establishing an RRC connection, the NCR-MT must inform the corresponding cell that it is an NCR entity or NCR-MT. Here's how to do this:

Case 1: Notification method during RACH (random access channel) preamble transmission process.

NCR-MT may receive a dedicated random access preamble and/or rach occasion (RO) and/or RACH resources in advance. Alternatively, the NCR-MT can receive RACH-related settings from the MIB or SIB of the cell it is attempting to connect to. After selecting/reselecting a cell, the NCR-MT may attempt random access to access the cell. In this process, if RACH is attempted using the NCR dedicated RACH preamble/RO/resource, the gNB may attempt the access. The terminal attempting can identify that it is NCR, and then the base station can transmit control information for NCR-FWD through NCR-MT.

Case 2: How to inform the rest of the RACH process

During the RACH process, in the case of 4 step RACH, MSG (Message) 3, or in the case of 2 step RACH, MSG A may include an NCR-specific LCID (logical channel ID). This LCID is used to identify the common control channel (CCCH) included in the MSG3 or MSGA MAC PDU, and this LCID may be included in the MAC subheader in the MAC PDU. In this case, the UL CCCH may be, for example, RRCSetupRequest. According to this method, the base station that successfully receives MSG 3 or MSG A learns that the corresponding terminal is NCR based on this. Afterwards, the base station can transmit control information for NCR-FWD through NCR-MT.

Case 3: How to notify during RRC connection setup process after RACH is successful

Case 3-1: How to notify with RRCSetupComplete message

After cell selection/reselection, when the NCR-MT receives a UL (uplink) grant with a successful RACH procedure, it delivers MSG3 to the serving base station through the RRCSetupRequest message, and when the serving base station delivers the RRCSetup message, the settings are applied. Afterwards, the RRCSetupComplete message is delivered to the serving base station. At this time, the RRCSetupComplete message may be delivered by including an indicator indicating that it is NCR. The following shows the detailed flow, which can correspond to the procedures shown in FIGS. 8A and 8B. In this example, the NCR support bit is included in the MIB/SIB as an example, but it is also possible to utilize the intra-Frequency Reselection bit.

8A and 8B are flowcharts of how the NCR-MT uses the RRCSetupComplete message to announce that it is an NCR entity.

Referring to FIG. 8A, the NCR-MT 810 can be switched from an idle state to a connected state or powered on (S801).

The NCR-MT (810) is a synchronization signal block (SSB) radiated from surrounding cells (e.g., base station 1 (gNB 1 (830)) and base station 2 (gNB 2 (820)) as shown in FIG. 8A. ) is received to derive the signal strength of the cell, and based on this measurement, a cell that satisfies the cell selection conditions is selected (S802). Here, the cell selected by the NCT-MT (810) is gNB. Assume it is a cell of 2 (820).

And, when the NCR-MT (810) receives the MIB or SIB1 of the selected cell and confirms that the cell is not an NCR support cell, it assumes a cell barred state (S803) and assumes a cell barred state (S803), and determines that another cell (e.g., gNB Cell 1 (cell of 830) is selected (S804), and MIB/SIB1 of the corresponding cell is received to check whether it is an NCR-supporting cell (S805).

If it is confirmed that the corresponding cell is an NCR support cell, the NCR-MT 810 can perform a random access procedure to the corresponding cell (S806). For example, in this procedure, the NCR-MT (810) transmits MSG 3 through an RRCSetupRequest message to the corresponding cell (830) (S806a) and receives an RRCsetup message from the cell (830) in response (S806b). You can. At this time, the RRCSetupRequest message may include information about the connection establishment cause (EstablishmentCause) specific to NCR.

Based on this, the NCR-MT 810, which has received the RRCSetup message, can apply the master cell group (MCG) settings for the MAC and PHY obtained from the corresponding cell 830, as shown in FIG. 8b (S807). . In addition, the NCR-MT 810 may transmit an RRCSetupComplete message to the corresponding cell to complete RRC connection setup (S808). Here, the RRCSetupComplete message includes an indicator indicating that the NCR-MT 810 is an NCR, NCR- At least one of an MT ID or a NAS registration request may be included.

Meanwhile, the following specific operations/contents may be applied to the above-mentioned procedures and the procedures to be described later.

1) gNB supporting NCR broadcasts the NCR-support indication in MIB or SIB.2) When UE which is NCR-MT is powered on(or UE is in Idle/inactive), it can first search frequency to camp and select the cell based on measurement result (i.e., do legacy cell(re)selection procedure).

3) If the above selected cell is providing or broadcasting NCR-support bit in MIB or SIB, UE (NCR-MT), then finally select the cell to set RRC connection up with.

A> NCR-MT applies the configurations in MIB and SIB1 of the selected cell.

B> When NCR-MT tries to setup RRC connection, NCR-MT does random access procedure with gNB. NCR-MT sends RRCSetupRequest msg to gNB, and gNB responds with RRCSetup msg to NCR-MT. Within RRCSetupRequest msg, there is new cause value for Establishment indicating NCR control traffic. After NCR-MT configures the received RRCsetup msg, UE can add NCR-MT indication within RRCSetupComplete message and transmit it upon successful RRC setup procedure.

i. with or without above NCR-MT indication,　RRCSetupComplete msg can also include: NCR specific entity ID (and/or (MT) ID , and/or FWD ID) either in legacy　NAS msg 'Registration Request' or out, and transfer this.

C> Serving gNB identifies that the accessed UE is NCR-MT, and some UE ID visible in CN can be transferred to CN for authorization (like 5G TMSI or 5G-GUTI, or NCR-FWD ID).

i. NCR-FWD ID is transferred to CN within IE 'NCR', then CN can identify NCR-FWD.

4) Else UE (NCR-MT) considers the cell as barred.

A> for the frequency of this barred cell:

i. bar the frequency as well

ii. (assuming that NCR-MT does not ignore the other cell reservation bits including IFRI bit in MIB) bar the frequency if IFRI bit in MIB is set to not-Allowed. Otherwise, do not bar the frequency

iii. do not bar the frequency

Referring again to FIG. 8B, after establishing an RRC connection with the NCR-MT 810, the serving base station 830 may transmit a Registration Request to the AMF 840 using the NGAP initial UE message (S808). At this time, the NGAP initial UE message may include an Establishment cause indicating that it is an RRC connection indicator for NCR control, obtained during the RRC connection process. Additionally, the ID of the NCR-MT or NCR entity, or NCR-Fwd ID may be included in the message. This information can be transmitted from the serving base station 830 to the AMF 840 (S809) and used for authorization and authentication of the NCR entity in the core network 850 (S810, S811).

More specifically, whether the terminal is authorized as an NCR node is determined by the AMF 840 receiving an indicator that identifies the terminal as an NCR node through an Initial UE message from the serving base station 830 (e.g. , NCR MT's terminal ID) can be confirmed by transmitting it to a separate server on the core network (850) that holds the ID or to the AMF (840) and co-located server (850). If it is confirmed that the terminal is authenticated as an NCR node, a separate server on the core network 850 or a server co-located with the AMF 840 may transmit an indication that it has been authorized to the AMF 840. The AMF 840 that receives this is the serving base station 830 and can provide an indication that the corresponding terminal has been authorized through an initial UE context setup request message. The NCR authorization confirmation operation of the AMF and co-located server described above can be replaced by the implementation of AMF.

After receiving information related to authorization and authentication of the NCR entity, the serving base station 830 may transmit control information for operation of the NCR-Fwd to the NCR-MT 810. The configuration information of the L1/L2 channel for transmitting this control information may be transmitted to the NCR-MT 810 through a DL RRC message or RRCReconfiguration message (S812). More detailed settings transmitted at this time may be as follows.

NCR specific configurations i.e., PDCCH/PDSCH configuration for side control information channel, PUCCH/PUSCH configuration for side control information channel, configuration for DCI/UCI and MAC CE for side control information reception and transmission.

By applying the above settings, the NCR-MT (810) can receive side control information for NCR-Fwd from the serving base station (830) through the L1/L2 control signal (S813).

Case 3-2: Notification method with RRCSetupRequest message

After cell selection/reselection, when the NCR-MT receives a UL grant through a successful RACH procedure, it delivers MSG3 to the serving base station through the RRCSetupRequest message, and when the serving base station delivers the RRCSetup message in response, the settings are applied. Afterwards, the RRCSetupComplete message is delivered to the serving base station. At this time, the RRCSetupRequest message may be delivered with an indicator indicating that it is NCR. The following shows the detailed flow, which can correspond to the procedures shown in FIGS. 9A and 9B. In this example, the case of including the NCR support bit in the MIB/SIB is explained, but it is also possible to utilize the intra-Frequency Reselection bit.

9A and 9B are flowcharts of how the NCR-MT uses the RRCSetupRequest message to announce that it is an NCR entity.

Referring to FIG. 9A, the NCR-MT (910) may be converted from an idle state to a connected state or may be powered on (S901).

The NCR-MT (910) receives SSBs radiated from surrounding cells (e.g., base station 1 (gNB 1 (930)) and base station 2 (gNB 2 (920)) as shown in FIG. 9A and connects the cell to the cell. The signal strength of is derived, and based on this measurement, a cell that satisfies the cell selection conditions is selected (S902). Here, the cell selected by the NCT-MT (910) is that of gNB 2 (920). Assume it is a cell.

Then, when the NCR-MT (910) receives the MIB or SIB1 of the selected cell and confirms that the cell is not an NCR support cell, it assumes a cell barred state (S903) and connects to another cell (e.g., gNB 1). A cell of (830) is selected (S904), and the MIB/SIB1 of the corresponding cell is received to check whether it is an NCR-supporting cell (S905). For example, the MIB/SIB1 may include an NCR support indicator indicating that the corresponding cell supports NCR.

If it is confirmed that the corresponding cell is an NCR support cell, the NCR-MT 910 can perform a random access procedure to the corresponding cell (S906). In this procedure, the NCR-MT 910 may, for example, transmit (S906a) MSG 3 to the corresponding cell 930 through an RRCSetupRequest. At this time, the RRCSetupRequest message includes an NCR-MT indicator indicating that it is an NCR-MT. , NCR-specific connection establishment cause (EstablishmentCause), and/or NCR-related ID may be included.

Meanwhile, the following specific operations/contents may be applied to the above-mentioned procedures and the procedures to be described later.

1) gNB supporting NCR broadcasts the NCR-support indication in MIB or SIB.

2) When UE which is NCR-MT is powered on (or UE is in Idle/inactive), it can first search frequency to camp and select the cell based on measurement result (i.e., do legacy cell(re)selection procedure).

3) If the above selected cell is providing or broadcasting NCR-support bit in MIB or SIB, UE (NCR-MT), then finally select the cell to set RRC connection up with.

A> NCR-MT applies the configurations in MIB and SIB1 of the selected cell

B> When NCR-MT tries to setup RRC connection, UE can add 1-bit indication to indicate NCR-MT or NCR entity within RRCSetupRequest msg and transmit it upon obtaining UL grant.

i. with or without above NCR-MT indication, in RRCSetupRequest msg, legacy 'InitialUE-Identity' field can indicate NCR specific UE ID, or NCR specific UE ID can be further indicated in separate IE than 'initialUE-Identity' field.

ii. Independent with above indication, in RRCSetupRequest msg, 'EstablishmentCause' can further indicate 'NCR MT access' value

C> Upon receiving above RRCSetupRequest msg, Serving gNB identifies that the accessed UE is NCR-MT, and select the radio resource and schedule the resource accordingly for NCR MT (frequency /time domain resource assignment, MCS selection etc.) via PDCCH

D> serving gNB setup SRB1 and send RRCSetup msg to NCR-MT.

E> UE (NCR-MT) applies the received RRCSetup configuration, and generates RRCSetupComplete msg which can include: NCR specific entity ID (and/or UE ID, and/or FWD ID) either in legacy　NAS msg 'Registration Request' or out , and transmit this.

4) Else UE (NCR-MT) considers the cell as barred.

A> for the frequency of this barred cell:

i. bar the frequency as well

ii. (assuming that NCR-MT does not ignore the other cell reservation bits including IFRI bit in MIB) bar the frequency if IFRI bit in MIB is set to not-Allowed. Otherwise, do not bar the frequency

iii. do not bar the frequency

Referring to Figure 9b, the serving base station 930, based on the information received from the NCR-MT 910, confirms that the connected terminal is an NCR-MT and sets the NCR-specific master cell group (e.g., mac-CellGroupConfig, PhysicalCellGroupConfig) can be provided (S907). Such settings can be transmitted to the NCR-MT (910) through an RRCSetup message (S907a). The NCR-MT 910, which has received NCR specific cell group settings for the MAC layer or PHY layer from the serving base station 930, can apply the corresponding cell group settings (S908).

In addition, the NCR-MT (910) can transmit (S909) a NAS message including a registration request to the serving base station (930) through the RRCSetupComplete message, and after establishing an RRC connection with the NCR-MT (910), The serving base station 930 may transmit a Registration Request to the AMF 940 using the NGAP initial UE message (S910). At this time, the NGAP initial UE message may also include an Establishment cause indicating that it is an RRC connection indicator for NCR control, obtained during the RRC connection process. Additionally, the ID of the NCR-MT or NCR entity, or NCR-Fwd ID may be included in the message. This information can be transmitted from the serving base station 930 to the AMF 940 and used for authorization and authentication of the NCR entity in the core network 950 (S911, S912). Here, the authentication procedure between the AMF (940) and the core network (950) is the same as described above in FIGS. 8A and 8B.

After receiving information related to authorization and authentication of the NCR entity, the serving base station 930 may transmit control information for operation of the NCR-Fwd to the NCR-MT 910. The configuration information of the L1/L2 channel for transmitting this control information may be transmitted to the NCR-MT 910 through a DL RRC message or RRCReconfiguration message (S913). More detailed settings transmitted at this time may be as follows.

NCR specific configurations i.e., PDCCH/PDSCH configuration for side control information channel, PUCCH/PUSCH configuration for side control information channel, configuration for DCI/UCI and MAC CE for side control information reception and transmission.

By applying the above settings, the NCR-MT 910 can receive side control information for NCR-Fwd from the serving base station 930 through the L1/L2 control signal (S914).

Meanwhile, the embodiments of the present disclosure disclosed in the specification and drawings are merely provided as specific examples to easily explain the technical content of the present disclosure and aid understanding of the present disclosure, and are not intended to limit the scope of the present disclosure. In other words, it is obvious to those skilled in the art that other modifications based on the technical idea of the present disclosure can be implemented. Additionally, each of the above embodiments can be operated in combination with each other as needed. For example, a base station and a terminal may be operated by combining parts of one embodiment of the present disclosure and another embodiment. Additionally, the embodiments of the present disclosure can be applied to other communication systems, and other modifications based on the technical idea of the embodiments may also be implemented. For example, embodiments may also be applied to LTE systems, 5G, NR systems, or 6G systems. Therefore, the scope of the present disclosure should not be limited to the described embodiments, but should be determined not only by the scope of the patent claims described later, but also by the scope of this patent claim and equivalents.

Claims (14)

1. In a terminal method in a wireless communication system,

   Receiving system information from a base station;

   Checking whether the system information includes an indicator indicating support for a network controlled repeater (NCR); and

   Based on the indicator being included in the system information, transmitting a random access preamble for a random access procedure to the base station,

   A method of a terminal, characterized in that the terminal supports the NCR function.
2. According to paragraph 1,

   Receiving a random access response to the random access preamble from the base station;

   Transmitting a radio resource control (RRC) Setup Request message to the base station based on the uplink grant included in the random access response;

   Receiving an RRC Setup message from the base station in response to the RRC Setup Request message; and

   Including transmitting an RRC Setup Complete message to the base station based on the RRC Setup message,

   The RRC Setup Complete message is a terminal method characterized in that it includes indication information indicating that the terminal supports the NCR function.
3. According to paragraph 2,

   The RRC Setup Complete message further includes a registration request for AMF (access and mobility management function),

   A method of a terminal, characterized in that NCR authentication for the terminal is performed by the AMF based on the indication information.
4. In a method of a base station in a wireless communication system,

   Creating an indicator indicating support for a network controlled repeater (NCR);

   Broadcasting system information including the indicator; and

   A method of a base station comprising receiving a random access preamble from a terminal based on the system information.
5. According to paragraph 4,

   Transmitting, to the terminal, a random access response to the random access preamble;

   Receiving a radio resource control (RRC) Setup Request message from the terminal, based on an uplink grant included in the random access response;

   Transmitting, to the terminal, an RRC Setup message in response to the RRC Setup Request message; and

   Comprising the step of receiving an RRC Setup Complete message from the terminal based on the RRC Setup message,

   The RRC Setup Complete message is a method of a base station, characterized in that it includes indication information indicating that the terminal supports the NCR function.
6. According to clause 5,

   Transmitting an initial UE (user equipment) message to an access and mobility management function (AMF) based on the RRC Setup Complete message; and

   Further comprising receiving, from the AMF, a message containing NCR authentication information for the terminal, based on the initial UE message,

   The RRC setup Complete message further includes a registration request for the terminal,

   The initial UE message includes the indication information,

   The method of the base station, characterized in that the NCR authentication information is determined based on the indication information.
7. According to clause 6,

   The method of the base station further comprising transmitting a message containing control information for controlling the operation of the terminal to the terminal based on the NCR authentication information.
8. In a terminal in a wireless communication system,

   Transmitter and receiver; and

   From a base station, control the transceiver to receive system information, check whether the system information includes an indicator indicating support for NCR (network controlled repeater), and based on the inclusion of the indicator in the system information, and A control unit that controls the transceiver to transmit a random access preamble for a random access procedure to the base station,

   The terminal is characterized in that it supports the NCR function.
9. According to clause 8,

   The control unit controls the transceiver to receive a random access response to the random access preamble from the base station, and sets up RRC (radio resource control) setup to the base station based on the uplink grant included in the random access response. Controlling the transceiver to transmit a Request message, controlling the transceiver to receive an RRC Setup message in response to the RRC Setup Request message from the base station, and based on the RRC Setup message to the base station, RRC Controls the transceiver to transmit a Setup Complete message,

   The RRC Setup Complete message is a terminal characterized in that it includes indication information indicating that the terminal supports the NCR function.
10. According to clause 9,

    The RRC Setup Complete message further includes a registration request for AMF (access and mobility management function),

    A terminal, characterized in that NCR authentication for the terminal is performed by the AMF based on the indication information.
11. In a base station in a wireless communication system,

    Transmitter and receiver; and

    Generate an indicator indicating support for NCR (network controlled repeater), control the transceiver to broadcast system information including the indicator, and configure the transceiver to receive a random access preamble from a terminal based on the system information. A base station comprising a control unit for controlling.
12. According to clause 11,

    The control unit controls the transceiver to transmit a random access response to the random access preamble to the terminal, and provides radio resource control (RRC) from the terminal based on the uplink grant included in the random access response. Controlling the transceiver to receive a Setup Request message, controlling the transceiver to transmit an RRC Setup message in response to the RRC Setup Request message to the terminal, and controlling the RRC based on the RRC Setup message from the terminal Controls the transceiver to receive a Setup Complete message,

    The RRC Setup Complete message is a base station characterized in that it includes indication information indicating that the terminal supports the NCR function.
13. According to clause 12,

    The control unit controls the transceiver to transmit an initial UE (user equipment) message using an access and mobility management function (AMF) based on the RRC Setup Complete message, and from the AMF, based on the initial UE message. Thus, controlling the transceiver to receive a message containing NCR authentication information for the terminal,

    The RRC setup Complete message further includes a registration request for the terminal,

    The initial UE message includes the indication information,

    A base station wherein the NCR authentication information is determined based on the indication information.
14. According to clause 13,

    The control unit,

    A base station further comprising controlling the transceiver to transmit a message containing control information for controlling the operation of the terminal to the terminal based on the NCR authentication information.

Images