Base station and control method

The base station design addresses the challenge of integrating 6G with 5G by using a first-generation distributed unit to transmit control messages to a second-generation radio unit, ensuring compatibility through supported modulation and channel coding, thus enabling efficient multi-RAT spectrum sharing.

WO2026115741A1PCT designated stage Publication Date: 2026-06-04NTT DOCOMO INC

Patent Information

Authority / Receiving Office
WO · WO
Patent Type
Applications
Current Assignee / Owner
NTT DOCOMO INC
Filing Date
2024-11-29
Publication Date
2026-06-04

Smart Images

  • Figure JP2024042428_04062026_PF_FP_ABST
    Figure JP2024042428_04062026_PF_FP_ABST
Patent Text Reader

Abstract

This base station includes a first-generation distributed unit and a second-generation radio unit and performs multi-RAT (radio access technology) spectrum sharing using first-generation RAT and second-generation RAT, wherein: the first-generation distributed unit includes a transmitting unit that transmits, to the second-generation radio unit, a control message based on a second-generation format including a field indicating information to be used in the first generation; and the second-generation radio unit includes a receiving unit that receives the control message from the first-generation distributed unit, and a control unit that ignores the field and acquires information included in the control message.
Need to check novelty before this filing date? Find Prior Art

Description

Base Station and Control Method

[0001] The present invention relates to a base station and a control method in a communication system.

[0002] In a wireless communication system NR (New Radio) (also referred to as "5G") and a successor system of NR (for example, "6G") based on the 3GPP (registered trademark) standard, as requirements, technologies that satisfy a large-capacity system, high data transmission speed, low latency, simultaneous connection of a large number of terminals, low cost, power saving, etc. are being studied (for example, Non-Patent Document 1).

[0003] Also, the network architecture in 5GC (5G Core Network) or 5GS (5G System), which is the core network in 5G, and 6GC (6G Core Network) or 6GS (6G System), which is a successor to 5G, is being studied.

[0004] In addition, in O-RAN (Open-Radio Access Network), as technologies for realizing 6G, an AI-Native RAN (Artificial Intelligence - Native Radio Access Network) architecture, multi-RAT (Radio Access Technology) spectrum sharing (Multi-RAT Spectrum Sharing (MRSS)), enhanced massive MIMO (Multiple Input Multiple Output) considering 1000 or more antenna elements, and distributed MIMO, etc. are being studied. The technology is closely related to an open fronthaul interface that connects a distributed unit (O-DU (Distribution Unit)) responsible for the functions of the physical upper layer (PHY-high) and a radio unit (O-RU (Radio Unit)) responsible for the functions of the physical lower layer (PHY-low). For example, the performance and implementation complexity in the technology are affected by the low-layer division options that determine the functions of PHY-high and PHY-low.

[0005] 3GPP TS 38.300 V18.3.0 (2024-09) 3GPP TS 38.214 V18.4.0 (2024-09)

[0006] One of the technologies being considered for 6G at O-RAN is Multi-RAT Spectrum Sharing (MRSS). This technology improves spectral efficiency by allowing different radio access technologies (RATs), such as 5G RATs and 6G RATs, to share the same frequency band. Here, it is necessary to provide new 6G-specific functions by utilizing existing 5G functions, particularly the functions of the radio unit (O-RU).

[0007] This invention has been made in view of the above points, and aims to utilize existing functions in multi-RAT spectrum sharing where a new generation of RATs has been introduced.

[0008] The disclosed technology provides a base station that performs multi-RAT spectrum sharing using a first-generation RAT (Radio Access Technology) and a second-generation radio unit, wherein the first-generation distributed unit has a transmitting unit that transmits a control message to the second-generation radio unit based on the second-generation format, which includes a field indicating information used in the first generation, and the second-generation radio unit has a receiving unit that receives the control message from the first-generation distributed unit and a control unit that acquires the information contained in the control message, ignoring the field.

[0009] According to the disclosed technology, existing functionality can be leveraged in multi-RAT spectrum sharing with the introduction of a new generation of RATs.

[0010] This figure shows an example configuration (1) of a wireless communication system according to an embodiment of the present invention. This figure shows an example configuration (2) of a wireless communication system according to an embodiment of the present invention. This figure shows an example of a logical architecture in O-RAN. This figure shows an example configuration of a base station 10 according to an embodiment of the present invention. This figure shows an example of a control message definition according to an embodiment of the present invention. This figure shows an example of the functional configuration of a base station 10 and a network node 30 according to an embodiment of the present invention. This figure shows an example of the functional configuration of a terminal 20 according to an embodiment of the present invention. This figure shows an example of the hardware configuration of a base station 10 and a terminal 20 according to an embodiment of the present invention. This figure shows an example of the configuration of a vehicle 2001 according to an embodiment of the present invention.

[0011] Embodiments of the present invention will be described below with reference to the drawings. Note that the embodiments described below are examples, and the embodiments to which the present invention applies are not limited to those described below.

[0012] In the operation of the wireless communication system according to the embodiment of the present invention, existing technologies may be used as appropriate. However, such existing technologies may include, for example, existing LTE or existing NR, but are not limited to existing LTE or NR.

[0013] Furthermore, in the embodiments of the present invention described below, terms such as SS (Synchronization signal), PSS (Primary SS), SSS (Secondary SS), PBCH (Physical broadcast channel), PRACH (Physical random access channel), PDCCH (Physical Downlink Control Channel), PDSCH (Physical Downlink Shared Channel), PUCCH (Physical Uplink Control Channel), and PUSCH (Physical Uplink Shared Channel), which are used in existing LTE systems, will be used. This is for convenience of description, and similar signals, functions, etc., may be called by other names. Also, the above terms in NR correspond to NR-SS, NR-PSS, NR-SSS, NR-PBCH, NR-PRACH, etc. However, even if a signal is used in NR, it is not necessarily explicitly stated as "NR-".

[0014] Furthermore, in the embodiments of the present invention, the duplex system may be a TDD (Time Division Duplex) system, an FDD (Frequency Division Duplex) system, or any other system (for example, a Flexible Duplex).

[0015] Furthermore, in embodiments of the present invention, "configuring" wireless parameters means that predetermined values ​​are pre-configured, or that wireless parameters notified from the base station 10 or terminal 20 are configured. Also, in the following description, " / " means "and / or" unless otherwise specified, or unless it is clear from the context that it has a different meaning.

[0016] Figure 1 shows an example configuration (1) of a wireless communication system according to an embodiment of the present invention. The wireless communication system according to an embodiment of the present invention includes a base station 10 and a terminal 20, as shown in Figure 1. Figure 1 shows one base station 10 and one terminal 20, but this is an example, and there may be multiple base stations 10 and terminals 20.

[0017] Base station 10 is a communication device that provides one or more cells and communicates wirelessly with terminal 20. The physical resources of the wireless signal are defined in the time domain and the frequency domain. The time domain may be defined by the number of OFDM (Orthogonal Frequency Division Multiplexing) symbols, and the frequency domain may be defined by the number of subcarriers or resource blocks. Base station 10 transmits synchronization signals and system information to terminal 20. Synchronization signals are, for example, NR-PSS and NR-SSS. System information is transmitted, for example, in NR-PBCH and is also called broadcast information. Synchronization signals and system information may also be called SSB (SS / PBCH block). As shown in Figure 1, base station 10 transmits control signals or data to terminal 20 via DL (Downlink) and receives control signals or data from terminal 20 via UL (Uplink). Both base station 10 and terminal 20 are capable of transmitting and receiving signals using beamforming. Furthermore, both the base station 10 and the terminal 20 can apply MIMO (Multiple Input Multiple Output) communication to DL or UL. Also, both the base station 10 and the terminal 20 may communicate via Carrier Aggregation (CA) through secondary cells (SCell) and primary cells (PCell). Additionally, the terminal 20 may communicate via Dual Connectivity (DC) through the primary cell of base station 10 and the primary secondary cell group cell (PSCell) of another base station 10.

[0018] Terminal 20 is a communication device equipped with wireless communication capabilities, such as a smartphone, mobile phone, tablet, wearable device, or M2M (Machine-to-Machine) communication module. As shown in Figure 1, Terminal 20 receives control signals or data from the base station 10 via DL and transmits control signals or data to the base station 10 via UL, thereby utilizing various communication services provided by the wireless communication system. Terminal 20 also receives various reference signals transmitted from the base station 10 and performs propagation path quality measurement based on the reception results of said reference signals.

[0019] Furthermore, various requirements are being considered for the next generation of 6G. For example, these requirements may include ultra-broadband communication, mission-critical communication, ultra-massive connection, universal coverage, intelligent connection, and ubiquitous sensing.

[0020] Furthermore, these requirements may include ultra-high-speed communication, large-capacity communication, ultra-wide coverage, ultra-low power consumption, low cost, ultra-low latency, ultra-high reliability communication, ultra-high connectivity, and sensing.

[0021] To meet these requirements, the new concept aims for extensibility (e.g., making it more effective for future use), ease of operation, customizability (e.g., making it easier to operate), and sustainability (e.g., cost reduction, a more robust configuration, and resilience). Furthermore, guaranteed communication, ensuring a minimum level of performance at all times, is being considered.

[0022] Figure 2 shows an example configuration (2) of a wireless communication system according to an embodiment of the present invention. Figure 2 shows an example configuration of a wireless communication system when DC (Dual connectivity) is performed. As shown in Figure 2, a base station 10A that will be an MN (Master Node) and a base station 10B that will be an SN (Secondary Node) are provided. Base stations 10A and 10B are each connected to the core network. Terminal 20 can communicate with both base station 10A and base station 10B.

[0023] A cell group provided by base station 10A, which is an MN (Mobile Network), is called an MCG (Master Cell Group), and a cell group provided by base station 10B, which is an SN (Mobile Network), is called an SCG (Secondary Cell Group). In a data center, an MCG consists of one PCell and one or more SCells, and an SCG consists of one PSCell (Primary SCG Cell) and one or more SCells.

[0024] Figure 3 shows an example of the logical architecture in O-RAN. As shown in Figure 3, at base station 10, distributed units (O-DUs) and radio units (O-RUs) are connected via an open fronthaul interface. This interface also transmits and receives control signals, user data, and synchronization signals in the open fronthaul control / user / synchronization plane (Open FH CUS-Plane), and management signals in the open fronthaul management plane (Open FH M-Plane). Furthermore, Service Management and Orchestration (SMO) communicates with the O-RUs via the Open FH M-Plane, with the O-DUs via the O1 interface, and with the O-Cloud via the O2 interface. Furthermore, in SMO, the non-real-time control unit (Non-RT (Real Time) RIC (RAN Intelligent Controller)) communicates with the near-real-time control unit (Near-RT (Real Time) RIC) via the A1 interface. The O-CU control plane (O-CU-CP) and the O-CU user plane (O-CU-UP) communicate with the O-DU via the F1-c and F1-u interfaces, respectively. The Near-RT RIC communicates with the O-DU and O-CU-CP, etc., via the E2 interface.

[0025] O-DU, O-CU, O-RU, SMO, and RIC may be deployed on the same base station, on different base stations, or in different locations other than base stations (nearby, remote, etc.). They may be treated as base station equipment or as network nodes. Furthermore, O-DU and O-CU may be deployed on a virtualization infrastructure and may be denoted as vDU (virtual DU) and vCU (virtual CU), for example.

[0026] Figure 4 shows an example of the configuration of a base station 10 in an embodiment of the present invention. Figure 4(a) shows a configuration in which one O-RU (5G+6G O-RU) that supports both 5G and 6G is connected to a 5G O-DU that supports 5G and a 6G O-DU that supports 6G, and communicates by dynamically switching between 5G and 6G or by using 5G and 6G simultaneously. In this configuration, the case in which the 5G O-DU and 6G O-DU are from the same vendor or a multi-vendor configuration may also be considered. Furthermore, since one O-RU (5G+6G O-RU) that supports both 5G and 6G is shared and used by the 5G and 6G O-DUs, it may be called a Shared O-RU.

[0027] Furthermore, Figure 4(b) shows a configuration in which one O-RU (5G+6G O-RU) that supports both 5G and 6G is connected to one O-DU (5G+6G O-DU) that supports both 5G and 6G, and communicates by dynamically switching between 5G and 6G or using 5G and 6G simultaneously. In this configuration, for example, a case may be considered in which a 5G-compatible O-DU and a 6G-compatible O-DU are in the same housing, and a 6G-compatible O-DU from a different vendor is installed in the 5G-compatible O-DU.

[0028] The following describes how to utilize existing functions in multi-RAT spectrum sharing that introduces next-generation technology. In the following methods, requests / instructions / notifications / reports sent and received by O-DUs and O-RUs may be messages that include requests / instructions / notifications / reports. Furthermore, multiple methods shown below may be used in combination. In addition, the network generations described are 5G and 6G, but they are not limited to a combination of 5G and 6G, and may be replaced with 4G or 7G or later. Also, when written as "first generation and second generation (RAT)", for example, "first generation" may be 5G and "second generation" may be 6G, or other combinations of generations may be used. Furthermore, O-DUs and O-RUs corresponding to 5G (5G RAT) and 6G (6G RAT) may be written as 5G O-DU, 5G O-RU, 6G O-DU, and 6G O-RU. Furthermore, O-DUs and O-RUs that support both 5G and 6G may be described as 5G+6G O-DUs and 5G+6G O-RUs, respectively. Interface may be abbreviated as IF.

[0029] (Method 1) 6G-Specific Control Messages (Extension of Existing Section Types) In the new generation (e.g., 6G), the O-DU / O-RU in the RAT may be assumed to include newly defined section types / section extensions used in the new generation, where the format of control messages transmitted and received in the Open Fronthaul IF, etc., between the O-DU and O-RU was used in the previous generation (e.g., 5G). Here, the section type may indicate an area defined for each type of information in the control message format. The section extension may be an area added to the existing section type for information about functions used for the new generation (e.g., information about advanced beamforming / antenna control in 6G).

[0030] This makes it possible to efficiently define the format of new-generation control messages by utilizing the format of older-generation control messages.

[0031] Furthermore, older generation RAT O-DU / O-RU may analyze the format of control messages transmitted and received in the Open Fronthaul IF between O-DU and O-RU, ignoring newly defined section types / section extensions used in the new generation, and obtain the information contained in the control messages.

[0032] Figure 5 shows an example of the definition of a control message in an embodiment of the present invention. As shown in Figure 5, in the O-RAN specification, in addition to the section types for control messages for 5G, section types for control messages for 6G may also be defined.

[0033] (Use of Reserved Fields) The O-DU / O-RU of the new generation RAT may assume that reserved fields in the control message format that were not used in the previous generation will contain information used in the new generation. Alternatively, the O-DU / O-RU of the previous generation RAT may assume that the information contained in the reserved fields may be ignored.

[0034] (Use of Version Information) The O-DU of the new generation RAT may be expected to include newly defined section types / section extensions used in the new generation in the control message, if the field indicating the version in the control message, which is based on the format used in the old generation, contains information indicating the version for the new generation. This makes it possible for both the new generation (6G, etc.) O-RU and the old generation (5G, etc.) O-RU to perform appropriate processing based on the same control data.

[0035] (Backward Compatibility) It may be assumed that the O-DU / O-RU of older generation RATs can obtain older generation information from control messages containing information indicating the version for the 6G generation, using the same method as for older generation control messages.

[0036] (Example of implementation of Method 1) (O-RU software update) It is also possible to assume that the 6G O-RU uses software that is an updated version of the existing 5G O-RU software and is capable of recognizing and processing newly defined 6G control messages.

[0037] (Enhancement of message analysis function) With the introduction of the enhanced message analysis function, O-RUs that support both 5G RATs and 6G RATs may be able to appropriately process / ignore 6G control messages based on the format used in 5G.

[0038] (Ensuring backward compatibility) A 5G O-RU may be able to parse control messages based on the format used in 5G, including information for 6G, without errors. For example, a 5G O-RU may be able to ignore section types / section extensions in 6G control messages that are undefined in 5G control messages.

[0039] (Method 2) Modulation scheme conversion (Modulation scheme conversion on the O-DU side) Instead of using a modulation scheme used in the new generation (6G, etc.) that is not supported in the old generation (5G, etc.), the O-DU may perform modulation processing using a modulation scheme supported in the old generation that can be processed / transmitted by the old generation O-RU, and then transmit the processed signal to the O-RU. This makes it possible to utilize the existing hardware in the old generation O-RU. The modulation scheme may be, for example, QPSK (Quadrature Phase Shift Keying), 16-QAM (Quadrature Amplitude Modulation), 64-QAM, and 256-QAM.

[0040] (Use of Modulation Method Mapping Table) Based on the modulation method mapping table, the O-DU may perform modulation processing using a modulation method supported in the previous generation that can be processed / transmitted by the previous generation O-RU, instead of using a modulation method used in the new generation (6G, etc.) that is not supported in the previous generation (5G, etc.), and then transmit the processed signal to the O-RU. The mapping table may, for example, include a correspondence between the Channel Quality Indicator (CQI) and the modulation method (see Section 5.2.2 of Non-Patent Document 2) for converting a modulation method not supported in the previous generation to a modulation method supported in the previous generation. By using the mapping table and performing an appropriate conversion according to the CQI, it is possible to ensure compatibility while suppressing degradation of signal quality.

[0041] (Signal processing in O-RU) The O-RU may receive a signal from the O-DU that has been processed using a modulation scheme supported by the previous generation (such as 5G), and perform processing on that signal.

[0042] (Example of implementation of Method 2) The O-RU may transmit capability information regarding supported modulation schemes to the O-DU, and the O-DU may use a modulation scheme mapping table generated based on said capability information.

[0043] (Method 3) Channel coding scheme conversion (Channel coding scheme conversion on the O-DU side) Instead of using a channel coding scheme / coding conditions (coding rate, etc.) used in the new generation (6G, etc.) that is not supported in the old generation (5G, etc.), the O-DU may perform channel coding processing using a channel coding scheme / coding conditions (coding rate, etc.) that is supported in the old generation O-RU and can be processed / transmitted by the old generation O-RU, and then transmit the processed signal to the O-RU. This makes it possible to utilize existing hardware in the old generation O-RU. The channel coding scheme is an coding scheme for error detection / correction, and may be, for example, LDPC (Low Density Parity Check) and Polar coding.

[0044] (Use of Channel Encoding Method Mapping Table) The O-DU may, based on the channel encoding method mapping table, use the channel encoding method / encoding conditions (such as encoding rate) used in the new generation (such as 6G) that are not supported in the old generation (such as 5G), and instead use the channel encoding method / encoding conditions (such as encoding rate) supported in the old generation that can be processed / transmitted in the old generation O-RU to perform processing related to channel encoding, and then transmit the processed signal to the O-RU. The mapping table may include, for example, a correspondence relationship for converting the channel encoding method / encoding conditions (such as encoding rate) not supported in the old generation to the channel encoding method / encoding conditions (such as encoding rate) supported in the old generation according to the network situation (such as error rate). By using the mapping table to perform appropriate conversion according to the network situation, it is possible to ensure compatibility while suppressing the deterioration of signal quality.

[0045] (Signal Processing in O-RU) The O-RU may receive the signal processed by the channel encoding method / encoding conditions (such as encoding rate) supported in the old generation (such as 5G) from the O-DU and perform processing on the signal.

[0046] (Effect) By the above method, it is possible to efficiently realize multi-RAT spectrum sharing with the introduction of the new generation RAT while utilizing the existing 5G O-RU. Also, in order to support the functions required in 6G, as changes to the Open Fronthaul specification in O-RAN, by performing header extension, introduction of new section types and section extensions, and changes to existing procedures, it is possible to meet the 6G requirements without impairing the compatibility with the existing 5G infrastructure.

[0047] That is, by the above method, in multi-RAT spectrum sharing with the introduction of the new generation RAT, the existing functions can be utilized.

[0048] (Device Configuration) Next, an example of the functional configuration of the base station 10, network node 30, and terminal 20 that perform the processes and operations described so far will be described. The base station 10, network node 30, and terminal 20 include functions for implementing the above-described embodiments. However, the base station 10, network node 30, and terminal 20 may each have only some of the functions in the embodiments.

[0049] <Base Station 10 and Network Node 30> FIG. 6 is a diagram showing an example of the functional configuration of the base station 10 and network node 30. As shown in FIG. 6, the base station 10 includes a transmission unit 110, a reception unit 120, a setting unit 130, and a control unit 140. The functional configuration shown in FIG. 6 is merely an example. As long as the operations according to the embodiments of the present invention can be performed, the functional classification and the names of the functional units may be any. Note that the network node 30 may have the same functional configuration as the base station 10. Also, the network node 30 having a plurality of different functions in the system architecture may be composed of a plurality of network nodes 30 separated by function.

[0050] The transmission unit 110 includes a function of generating a signal to be transmitted to the terminal 20 or another network node 30 and transmitting the signal by wire or wirelessly. The reception unit 120 includes a function of receiving various signals transmitted from the terminal 20 or another network node 30 and obtaining information of, for example, a higher layer from the received signals. A communication unit including the transmission unit 110 and the reception unit 120 may be configured.

[0051] The setting unit 130 stores setting information set in advance and various setting information to be transmitted to the terminal 20 in a storage device and reads it out from the storage device as necessary.

[0052] The control unit 140 performs the processes and the like described in the embodiments. A functional unit related to signal transmission in the control unit 140 may be included in the transmission unit 110, and a functional unit related to signal reception in the control unit 140 may be included in the reception unit 120.

[0053] Furthermore, the base station 10 may include a distributed unit (O-DU), a radio unit (O-RU), and a central unit (O-CU). Also, the SMO, the non-real-time control device (Non-RT RIC) in the SMO, and the near-real-time control device (Near-RT RIC) may be functions of the network node 30. In addition, the O-DU, O-RU, O-CU, SMO, Non-RT RIC, and Near-RT RIC may each have a transmitting unit 110, a receiving unit 120, a setting unit 130, and a control unit 140, and the transmitting unit 110 and the receiving unit 120 may communicate with each other.

[0054] <Terminal 20> Figure 7 is a diagram showing an example of the functional configuration of terminal 20. As shown in Figure 7, terminal 20 has a transmitting unit 210, a receiving unit 220, a setting unit 230, and a control unit 240. The functional configuration shown in Figure 7 is merely an example. Any functional classification and name of functional unit is acceptable as long as it can perform the operations according to the embodiment of the present invention. Furthermore, a communication device that acts as a resource holder may have a functional configuration similar to that of terminal 20.

[0055] The transmitting unit 210 creates a transmission signal from the transmission data and transmits the transmission signal wirelessly. The receiving unit 220 wirelessly receives various signals and obtains signals from higher layers from the received physical layer signals. The receiving unit 220 also has the function of receiving NR-PSS, NR-SSS, NR-PBCH, DL / UL control signals or reference signals transmitted from the network node 30. A communication unit including the transmitting unit 210 and the receiving unit 220 may be configured.

[0056] The setting unit 230 stores various setting information received from the network node 30 by the receiving unit 220 in its storage device and reads it from the storage device as needed. The setting unit 230 also stores pre-configured setting information.

[0057] The control unit 240 performs the processing described in the embodiment. The signal transmission function in the control unit 240 may be included in the transmission unit 210, and the signal reception function in the control unit 240 may be included in the reception unit 220.

[0058] (Hardware Configuration) The block diagrams (Figures 6 and 7) used in the description of the above embodiments show functional units. These functional blocks (components) are realized by any combination of at least one of hardware and software. Furthermore, the method of realizing each functional block is not particularly limited. That is, each functional block may be realized using one device that is physically or logically coupled, or it may be realized using two or more physically or logically separated devices that are directly or indirectly connected (for example, using wired or wireless connections). A functional block may be realized by combining the one device or the multiple devices with software.

[0059] Functions include, but are not limited to, judgment, decision, determination, calculation, calculation, processing, derivation, investigation, exploration, confirmation, reception, transmission, output, access, resolution, selection, selection, establishment, comparison, assumption, expectation, assumption, broadcasting, notifying, communicating, forwarding, configuring, reconfiguring, allocating (mapping), and assigning. For example, a functional block (configuration part) that enables transmission is called a transmitting unit or transmitter. In all cases, as mentioned above, the method of implementation is not particularly limited.

[0060] For example, the network node 30, terminal 20, etc. in one embodiment of the present disclosure may function as a computer that processes the wireless communication method of the present disclosure. Figure 8 is a diagram showing an example of the hardware configuration of a base station 10 and terminal 20 according to one embodiment of the present disclosure. The network node 30 may have the same hardware configuration as the base station 10. The base station 10 and terminal 20 described above may be physically configured as a computer device including a processor 1001, a storage device 1002, an auxiliary storage device 1003, a communication device 1004, an input device 1005, an output device 1006, a bus 1007, etc.

[0061] In the following explanation, the term "device" can be read as "circuit," "device," "unit," etc. The hardware configuration of the base station 10 and terminal 20 may include one or more of the devices shown in the figure, or it may be configured without some of the devices.

[0062] Each function in the base station 10 and terminal 20 is realized by loading predetermined software (programs) onto hardware such as the processor 1001 and storage device 1002, which allows the processor 1001 to perform calculations, control communication by the communication device 1004, and control at least one of data reading and writing in the storage device 1002 and auxiliary storage device 1003.

[0063] The processor 1001 controls the entire computer, for example, by running an operating system. The processor 1001 may consist of a central processing unit (CPU) that includes interfaces with peripheral devices, control devices, arithmetic units, registers, etc. For example, the control unit 140, control unit 240, etc., described above may be implemented by the processor 1001.

[0064] Furthermore, the processor 1001 reads programs (program code), software modules, or data from at least one of the auxiliary storage device 1003 and the communication device 1004 into the storage device 1002, and executes various processes accordingly. The program used is one that causes the computer to execute at least a part of the operations described in the above embodiment. For example, the control unit 140 of the base station 10 shown in Figure 6 may be implemented by a control program stored in the storage device 1002 and operated by the processor 1001. Also, for example, the control unit 240 of the terminal 20 shown in Figure 7 may be implemented by a control program stored in the storage device 1002 and operated by the processor 1001. Although the above-described processes have been explained as being executed by one processor 1001, they may be executed simultaneously or sequentially by two or more processors 1001. The processor 1001 may be implemented by one or more chips. The program may also be transmitted from the network via a telecommunications line.

[0065] The storage device 1002 is a computer-readable recording medium and may consist of at least one of the following: ROM (Read Only Memory), EPROM (Erasable Programmable ROM), EEPROM (Electrically Erasable Programmable ROM), RAM (Random Access Memory), etc. The storage device 1002 may also be called a register, cache, main memory, etc. The storage device 1002 can store executable programs (program code), software modules, etc., for implementing a communication method according to one embodiment of the present disclosure.

[0066] The auxiliary storage device 1003 is a computer-readable recording medium and may consist of at least one of the following: an optical disc such as a CD-ROM (Compact Disc ROM), a hard disk drive, a flexible disk, a magneto-optical disk (e.g., a compact disk, a digital multipurpose disk, a Blu-ray® disk), a smart card, flash memory (e.g., a card, a stick, a key drive), a floppy® disk, a magnetic strip, etc. The above-mentioned storage medium may also be a database, server, or other suitable medium that includes at least one of the storage device 1002 and the auxiliary storage device 1003.

[0067] The communication device 1004 is hardware (transmitting / receiving device) for communicating between computers via at least one of a wired network and a wireless network, and is also referred to as a network device, network controller, network card, communication module, etc. The communication device 1004 may be configured to include, for example, a high-frequency switch, duplexer, filter, frequency synthesizer, etc., in order to implement at least one of frequency division duplex (FDD) and time division duplex (TDD). For example, the transmitting and receiving antenna, amplifier section, transmitting and receiving section, transmission path interface, etc., may be implemented by the communication device 1004. The transmitting and receiving section may be implemented in a physically or logically separated manner, with a transmitting section and a receiving section.

[0068] The input device 1005 is an input device that accepts input from an external source (e.g., a keyboard, mouse, microphone, switch, button, sensor, etc.). The output device 1006 is an output device that outputs to an external source (e.g., a display, speaker, LED lamp, etc.). The input device 1005 and the output device 1006 may be configured as an integrated unit (e.g., a touch panel).

[0069] Furthermore, each device, such as the processor 1001 and the storage device 1002, is connected by a bus 1007 for communicating information. The bus 1007 may be configured using a single bus, or different buses may be configured for each device.

[0070] Furthermore, the base station 10 and terminal 20 may be configured to include hardware such as a microprocessor, a digital signal processor (DSP), an ASIC (Application Specific Integrated Circuit), a PLD (Programmable Logic Device), and an FPGA (Field Programmable Gate Array), and some or all of each functional block may be realized by such hardware. For example, the processor 1001 may be implemented using at least one of these hardware components.

[0071] Figure 9 shows an example of the configuration of vehicle 2001. As shown in Figure 9, vehicle 2001 includes an operating unit 2002, a steering unit 2003, an accelerator pedal 2004, a brake pedal 2005, a shift lever 2006, front wheels 2007, rear wheels 2008, an axle 2009, an electronic control unit 2010, various sensors 2021 to 2029, an information service unit 2012, and a communication module 2013. Each aspect / embodiment described in this disclosure may be applied to a communication device mounted on vehicle 2001, for example, to the communication module 2013.

[0072] The operating unit 2002 consists of, for example, an engine, a motor, or a hybrid of an engine and a motor. The steering unit 2003 includes at least a steering wheel (also called a handle) and is configured to steer at least one of the front wheels and the rear wheels based on the operation of the steering wheel, which is operated by the user.

[0073] The electronic control unit 2010 consists of a microprocessor 2031, memory (ROM, RAM) 2032, and communication ports (IO ports) 2033. Signals from various sensors 2021 to 2029 installed in the vehicle 2001 are input to the electronic control unit 2010. The electronic control unit 2010 may also be called an ECU (Electronic Control Unit).

[0074] Signals from various sensors 2021 to 2029 include current signals from current sensor 2021 for sensing motor current, front and rear wheel rotation speed signals acquired by rotation speed sensor 2022, front and rear wheel air pressure signals acquired by air pressure sensor 2023, vehicle speed signals acquired by vehicle speed sensor 2024, acceleration signals acquired by acceleration sensor 2025, accelerator pedal depression signals acquired by accelerator pedal sensor 2029, brake pedal depression signals acquired by brake pedal sensor 2026, shift lever operation signals acquired by shift lever sensor 2027, and detection signals acquired by object detection sensor 2028 for detecting obstacles, vehicles, pedestrians, etc.

[0075] The Information Service Unit 2012 consists of various devices for providing (outputting) various types of information such as driving information, traffic information, and entertainment information, including a car navigation system, audio system, speakers, television, and radio, and one or more ECUs that control these devices. The Information Service Unit 2012 uses information acquired from external devices via a communication module 2013, etc., to provide various multimedia information and multimedia services to the occupants of the vehicle 2001. The Information Service Unit 2012 may include input devices that accept input from the outside (e.g., keyboard, mouse, microphone, switch, button, sensor, touch panel, etc.) and output devices that perform output to the outside (e.g., display, speaker, LED lamp, touch panel, etc.).

[0076] The driver assistance system unit 2030 consists of various devices that provide functions to prevent accidents or reduce the driver's workload, such as millimeter-wave radar, LiDAR (Light Detection and Ranging), cameras, positioning locators (e.g., GNSS), map information (e.g., high-definition (HD) maps, autonomous vehicle (AV) maps), gyro systems (e.g., IMU (Inertial Measurement Unit), INS (Inertial Navigation System)), AI (Artificial Intelligence) chips, and AI processors, as well as one or more ECUs that control these devices. The driver assistance system unit 2030 also transmits and receives various information via the communication module 2013 to realize driver assistance functions or autonomous driving functions.

[0077] The communication module 2013 can communicate with the microprocessor 2031 and components of the vehicle 2001 via its communication port. For example, the communication module 2013 sends and receives data via the communication port 2033 between the moving parts 2002, steering parts 2003, accelerator pedal 2004, brake pedal 2005, shift lever 2006, front wheels 2007, rear wheels 2008, axle 2009, the microprocessor 2031 and memory (ROM, RAM) 2032 in the electronic control unit 2010, and sensors 2021-29 provided in the vehicle 2001.

[0078] The communication module 2013 is a communication device that can be controlled by the microprocessor 2031 of the electronic control unit 2010 and can communicate with external devices. For example, it can send and receive various types of information with external devices via wireless communication. The communication module 2013 may be located either inside or outside the electronic control unit 2010. The external device may be, for example, a base station or a mobile station.

[0079] The communication module 2013 may transmit at least one of the following to an external device via wireless communication: signals from the various sensors 2021-2028 input to the electronic control unit 2010, information obtained based on said signals, and information based on input from an external source (user) obtained via the information service unit 2012. The electronic control unit 2010, the various sensors 2021-2028, the information service unit 2012, etc., may also be called input units that accept input. For example, the PUSCH transmitted by the communication module 2013 may include the information based on the above input.

[0080] The communication module 2013 receives various information (traffic information, signal information, inter-vehicle information, etc.) transmitted from an external device and displays it on the information service unit 2012 provided in the vehicle 2001. The information service unit 2012 may also be called an output unit, which outputs information (for example, outputs information to devices such as displays and speakers based on the PDSCH (or data / information decoded from the PDSCH) received by the communication module 2013). The communication module 2013 also stores the various information received from the external device in a memory 2032 that can be used by the microprocessor 2031. Based on the information stored in the memory 2032, the microprocessor 2031 may control the operating unit 2002, steering unit 2003, accelerator pedal 2004, brake pedal 2005, shift lever 2006, front wheels 2007, rear wheels 2008, axles 2009, sensors 2021-2029, etc., provided in the vehicle 2001.

[0081] <Notes> (Note 1) A base station that performs multi-RAT spectrum sharing using a first-generation RAT (Radio Access Technology) and a second-generation RAT, the first-generation distributed unit having a transmitting unit that transmits a control message to the second-generation radio unit based on the second-generation format, which includes a field indicating information used in the first generation; the second-generation radio unit having a receiving unit that receives the control message from the first-generation distributed unit, and a control unit that acquires the information contained in the control message, ignoring the field. (Note 2) The base station according to Note 1, wherein the transmitting unit includes information used in the first generation in a reserved field in the control message that was not used in the second generation. (Appendix 3) A base station that performs multi-RAT spectrum sharing using a first-generation RAT (Radio Access Technology) and a second-generation RAT, the first-generation distributed unit comprising: a control unit that performs modulation processing using a modulation scheme supported in the second generation instead of a modulation scheme used in the first generation that is not supported in the second generation; and a transmitting unit that transmits the modulated signal to the second-generation radio unit. (Appendix 4) A base station that performs multi-RAT spectrum sharing using a first-generation RAT (Radio Access Technology) and a second-generation radio unit, wherein the first-generation distributed unit comprises: a control unit that performs channel coding using a channel coding scheme supported in the second generation instead of a channel coding scheme used in the first generation that is not supported in the second generation; and a transmitting unit that transmits a channel-coded signal to the second-generation radio unit.(Appendix 5) A control method to be performed by a base station that performs multi-RAT spectrum sharing by a first-generation RAT (Radio Access Technology) and a second-generation RAT, including a first-generation distributed unit and a second-generation wireless unit, comprising: the first-generation distributed unit transmitting a control message to the second-generation wireless unit based on the second-generation format, which includes a field indicating information used in the first generation; the second-generation wireless unit receiving the control message from the first-generation distributed unit; and the second-generation wireless unit ignoring the field and obtaining the information contained in the control message.

[0082] In any of the above supplementary notes, existing functions can be utilized in multi-RAT spectrum sharing with the introduction of the new generation of RATs.

[0083] (Supplement to Embodiments) Embodiments of the present invention have been described above, but the disclosed invention is not limited to such embodiments, and those skilled in the art will understand various modifications, alterations, alternatives, substitutions, etc. Specific numerical examples have been used to facilitate understanding of the invention, but unless otherwise specified, these numerical values ​​are merely examples, and any appropriate values ​​may be used. The division of items in the above description is not essential to the present invention, and matters described in two or more items may be combined as needed, and matters described in one item may be applied to matters described in another item (as long as they do not contradict each other). The boundaries of functional units or processing units in the functional block diagram do not necessarily correspond to the boundaries of physical parts. The operation of multiple functional units may be physically performed by one part, or the operation of one functional unit may be physically performed by multiple parts. The processing procedures described in the embodiments may be rearranged as long as they do not contradict each other. For the convenience of explaining the processing, the base station 10 and terminal 20 have been described using functional block diagrams, but such devices may be realized in hardware, software, or a combination thereof. The software operated by the processor of the base station 10 according to an embodiment of the present invention and the software operated by the processor of the terminal 20 according to an embodiment of the present invention may be stored in any suitable storage medium such as random access memory (RAM), flash memory, read-only memory (ROM), EPROM, EEPROM, register, hard disk (HDD), removable disk, CD-ROM, database, server, or other appropriate storage medium.

[0084] Furthermore, notification of information is not limited to the embodiments described herein and may be carried out by other means. For example, notification of information may be carried out by physical layer signaling (e.g., DCI (Downlink Control Information), UCI (Uplink Control Information)), upper layer signaling (e.g., RRC (Radio Resource Control) signaling, MAC (Medium Access Control) signaling), broadcast information (MIB (Master Information Block), SIB (System Information Block)), other signals, or combinations thereof. Also, RRC signaling may be called RRC messages, and may be, for example, RRC Connection Setup messages, RRC Connection Reconfiguration messages, etc.

[0085] Each aspect / embodiment described in this disclosure refers to LTE (Long Term Evolution), LTE-A (LTE-Advanced), SUPER 3G, IMT-Advanced, 4G (4th generation mobile communication system), 5G (5th generation mobile communication system), 6th generation mobile communication system (6G), xth generation mobile communication system (xG) (xG (where x is, for example, an integer or decimal)), FRA (Future Radio Access), NR (new Radio), New radio access (NX), Future generation radio access (FX), W-CDMA (registered trademark), GSM (registered trademark), CDMA2000, UMB (Ultra Mobile Broadband), IEEE 802.11 (Wi-Fi (registered trademark)), IEEE 802.16 (WiMAX (registered trademark)), IEEE 802.20 may apply to at least one system utilizing UWB (Ultra-WideBand), Bluetooth®, or other appropriate systems, and to next-generation systems extended, modified, created, or defined based thereon. Alternatively, multiple systems may be applied in combination (e.g., a combination of at least one of LTE and LTE-A with 5G).

[0086] The processing procedures, sequences, flowcharts, etc., of each aspect / embodiment described herein may be reordered, provided they are consistent with each other. For example, the methods described herein present various step elements in an exemplary order and are not limited to that specific order.

[0087] In this specification, specific operations performed by the base station 10 may, in some cases, be performed by its upper node. In a network consisting of one or more network nodes having a base station 10, it is clear that various operations performed for communication with the terminal 20 can be performed by the base station 10 and at least one of the other network nodes (for example, an MME or S-GW, but not limited to these). Although the above example illustrates the case where there is one other network node besides the base station 10, the other network node may be a combination of multiple other network nodes (for example, an MME and an S-GW).

[0088] The information or signals described in this disclosure may be output from a higher layer (or lower layer) to a lower layer (or higher layer). They may also be input and output via multiple network nodes.

[0089] Input and output information may be stored in a specific location (e.g., memory) or managed using a management table. Input and output information may be overwritten, updated, or appended to. Output information may be deleted. Input information may be transmitted to other devices.

[0090] The determination in this disclosure may be made by a value represented by one bit (0 or 1), by a Boolean value (true or false), or by a numerical comparison (for example, a comparison with a predetermined value).

[0091] Software should be broadly interpreted to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executable files, execution threads, procedures, functions, and so on, whether they are called software, firmware, middleware, microcode, hardware description languages, or by any other name.

[0092] Furthermore, software, instructions, information, etc., may be transmitted and received via a transmission medium. For example, if software is transmitted from a website, server, or other remote source using at least one of wired technology (such as coaxial cable, fiber optic cable, twisted pair, or digital subscriber line (DSL)) and wireless technology (such as infrared or microwave), then at least one of these wired and wireless technologies is included in the definition of a transmission medium.

[0093] The information, signals, etc. described in this disclosure may be represented using any of the various different techniques. For example, the data, instructions, commands, information, signals, bits, symbols, chips, etc. that may be referred to throughout the above description may be represented by voltage, current, electromagnetic waves, magnetic fields or magnetic particles, optical fields or photons, or any combination thereof.

[0094] In addition, terms used in this disclosure and terms necessary for understanding this disclosure may be replaced with terms having the same or similar meanings. For example, at least one of the channel and symbol may be a signal (signaling). Also, a signal may be a message. Furthermore, a component carrier (CC) may be called a carrier frequency, cell, frequency carrier, etc.

[0095] The terms “system” and “network” as used in this disclosure are interchangeable.

[0096] Furthermore, the information, parameters, etc., described in this disclosure may be expressed using absolute values, relative values ​​from a given value, or other corresponding information. For example, wireless resources may be indicated by an index.

[0097] The names used for the parameters described above are not restrictive in any way. Furthermore, the formulas and other expressions using these parameters may differ from those expressly disclosed in this disclosure. Various channels (e.g., PUCCH, PDCCH, etc.) and information elements can be identified by any suitable name, and therefore, the various names assigned to these various channels and information elements are not restrictive in any way.

[0098] In this disclosure, terms such as "Base Station (BS)", "wireless base station", "base station equipment", "fixed station", "NodeB", "eNodeB (eNB)", "gNodeB (gNB)", "access point", "transmission point", "reception point", "transmission / reception point", "cell", "sector", "cell group", "carrier", and "component carrier" may be used interchangeably. Base stations may also be referred to by terms such as macrocell, small cell, femtocell, and picocell.

[0099] A base station can accommodate one or more (e.g., three) cells. If a base station accommodates multiple cells, the entire coverage area of ​​the base station can be divided into multiple smaller areas, each of which may also be provided with communication services by a base station subsystem (e.g., a Remote Radio Head (RRH)). The terms “cell” or “sector” refer to part or all of the coverage area of ​​at least one of the base station and / or base station subsystems that provide communication services in that coverage.

[0100] In this disclosure, the transmission of information by a base station to a terminal may be interpreted as the base station instructing the terminal to perform control or operation based on the information.

[0101] In this disclosure, terms such as "Mobile Station (MS)," "user terminal," "User Equipment (UE)," and "terminal" may be used interchangeably.

[0102] A mobile station may also be referred to by those skilled in the art as a subscriber station, mobile unit, subscriber unit, wireless unit, remote unit, mobile device, wireless device, wireless communication device, remote device, mobile subscriber station, access terminal, mobile terminal, wireless terminal, remote terminal, handset, user agent, mobile client, client, or several other appropriate terms.

[0103] At least one of the base station and the mobile station may be called a transmitting device, a receiving device, a communication device, etc. At least one of the base station and the mobile station may also be a device mounted on a mobile body, the mobile body itself, etc. The mobile body refers to a movable object, and its speed of movement is arbitrary. This also includes the case when the mobile body is stationary. The mobile body includes, but is not limited to, vehicles, transport vehicles, automobiles, motorcycles, bicycles, connected cars, excavators, bulldozers, wheel loaders, dump trucks, forklifts, trains, buses, handcarts, rickshaws, ships and other watercraft, airplanes, rockets, satellites, drones (registered trademark), multicopters, quadcopters, balloons, and items mounted on them. The mobile body may also be a mobile body that moves autonomously based on operation commands. It may be a vehicle (e.g., a car, an airplane, etc.), an unmanned mobile body (e.g., a drone, an autonomous vehicle, etc.), or a robot (manned or unmanned). Furthermore, at least one of the base station and the mobile station may include devices that do not necessarily move during communication operations. For example, at least one of the base station and the mobile station may be an IoT (Internet of Things) device such as a sensor.

[0104] Furthermore, the term "base station" in this disclosure may be interpreted as "user terminal." For example, the various aspects / embodiments of this disclosure may be applied to a configuration in which communication between a base station and a user terminal is replaced with communication between multiple terminals 20 (which may be called, for example, D2D (Device-to-Device), V2X (Vehicle-to-Everything), etc.). In this case, the terminals 20 may have the functions that the base station 10 has. Also, terms such as "uplink" and "downlink" may be interpreted as terms corresponding to terminal-to-terminal communication (for example, "side"). For example, uplink channel, downlink channel, etc., may be interpreted as side channel.

[0105] Similarly, the term "user terminal" in this disclosure may be replaced with "base station." In this case, the base station may be configured to have the same functions as the user terminal described above.

[0106] As used in this disclosure, the terms “determining” and “determining” may encompass a wide variety of actions. “Determining” may include, for example, judging, calculating, computing, processing, deriving, investigating, looking up, searching, or inquiring (e.g., searching in a table, database, or other data structure), or ascertaining. “Determining” may also include receiving (e.g., receiving information), transmitting (e.g., sending information), inputting, outputting, or accessing (e.g., accessing data in memory). Furthermore, "judgment" and "decision" can include considering something as having been "judged" or "decided" after resolving, selecting, choosing, establishing, comparing, etc. In other words, "judgment" and "decision" can include considering something as having been "judged" or "decided" after some action. Also, "judgment (decision)" can be reinterpreted as "assuming," "expecting," or "considering."

[0107] The terms “connected,” “coupled,” or any variation thereof, mean any direct or indirect connection or coupling between two or more elements, and may include the presence of one or more intermediate elements between two elements that are “connected” or “coupled” with each other. The coupling or connection between elements may be physical, logical, or a combination thereof. For example, “connection” may be reinterpreted as “access.” As used in this disclosure, two elements may be considered to be “connected” or “coupled” with each other using at least one of one or more wires, cables, and printed electrical connections, and, in some non-limiting and non-exclusive examples, electromagnetic energy having wavelengths in the radio frequency domain, microwave domain, and optical (both visible and invisible) domain.

[0108] The reference signal can also be abbreviated as RS (Reference Signal), and may be called a pilot depending on the applicable standard.

[0109] In this disclosure, the phrase "based on" does not mean "based solely on" unless otherwise specified. In other words, the phrase "based on" means both "based solely on" and "based at least on."

[0110] Any reference to elements using the designations “first,” “second,” etc., as used in this disclosure does not generally limit the quantity or order of those elements. These designations may be used in this disclosure as a convenient way to distinguish between two or more elements. Accordingly, references to the first and second elements do not imply that only two elements may be employed, or that the first element must precede the second element in any way.

[0111] In the configuration of each of the above devices, "means" may be replaced with "part," "circuit," "device," etc.

[0112] Where the terms “include,” “including,” and variations thereof are used in this disclosure, these terms are intended to be inclusive, as is the term “comprising.” Furthermore, the term “or” as used in this disclosure is not intended to mean exclusive OR.

[0113] In this disclosure, if articles are added through translation, such as a, an, and the in English, this disclosure may include the fact that the noun following these articles is plural.

[0114] In this disclosure, the term "A and B are different" may mean "A and B are different from each other." The term may also mean "A and B are each different from C." Terms such as "separate" and "combine" may be interpreted similarly to "different."

[0115] Each aspect / embodiment described in this disclosure may be used individually, in combination, or switched between as needed during implementation. Furthermore, notification of specific information (e.g., notification that "X is") is not limited to explicit notification, but may also be implicit (e.g., by not providing such notification).

[0116] Although the present disclosure has been described in detail above, it will be clear to those skilled in the art that the present disclosure is not limited to the embodiments described herein. The present disclosure can be implemented in modified and altered forms without departing from the intent and scope of the present disclosure as defined by the claims. Therefore, the descriptions in the present disclosure are illustrative and not intended to be restrictive in any way.

[0117] 10 Base station 110 Transmitter 120 Receiver 130 Setting unit 140 Control unit 20 Terminal 210 Transmitter 220 Receiver 230 Setting unit 240 Control unit 30 Network node 1001 Processor 1002 Storage device 1003 Auxiliary storage device 1004 Communication device 1005 Input device 1006 Output device

Claims

A base station that performs multi-RAT spectrum sharing using the first-generation RAT (Radio Access Technology) and the second-generation RAT, including a first-generation distributed unit and a second-generation wireless unit, The first generation distributed unit is, The second generation wireless unit has a transmitting unit that transmits a control message based on the second generation format, which includes a field indicating information used in the first generation. The aforementioned second-generation wireless unit is A receiving unit that receives the control message from the first generation distributed unit, A control unit that ignores the aforementioned field and acquires the information contained in the control message, A base station having   The transmitting unit includes information used in the first generation in the reserved fields of the control message that were not used in the second generation. The base station according to claim 1.   A base station that performs multi-RAT spectrum sharing using the first-generation RAT (Radio Access Technology) and the second-generation RAT, including a first-generation distributed unit and a second-generation wireless unit, The first generation distributed unit is, A control unit that performs modulation processing using a modulation scheme supported in the second generation, instead of a modulation scheme used in the first generation that is not supported in the second generation, The second generation wireless unit includes a transmitting unit that transmits a modulated signal, A base station having   A base station that performs multi-RAT spectrum sharing using the first-generation RAT (Radio Access Technology) and the second-generation RAT, including a first-generation distributed unit and a second-generation wireless unit, The first generation distributed unit is, A control unit that performs channel coding using a channel coding scheme supported in the second generation, instead of a channel coding scheme used in the first generation that is not supported in the second generation, The second generation wireless unit includes a transmitting unit that transmits channel-coded signals, A base station having   A control method performed by a base station that performs multi-RAT spectrum sharing using a first-generation RAT (Radio Access Technology) and a second-generation RAT, including a first-generation distributed unit and a second-generation wireless unit, The first generation distributed unit transmits to the second generation wireless unit a control message based on the second generation format, which includes a field indicating information used in the first generation. The second generation wireless unit receives the control message from the first generation distributed unit, The second generation wireless unit obtains information contained in the control message, ignoring the field, A control method having