Base station and control method

Abstract

This base station includes a first-generation distribution unit, a second-generation distribution unit, and a radio unit. The first-generation distribution unit comprises: a transmission unit that transmits, to the second-generation distribution unit, first timing information including at least one among a slot length, a subframe length, and a delay time between the first-generation distribution unit and the radio unit; a reception unit that receives, from the second-generation distribution unit, second timing information including at least one among a slot length, a subframe length, and a delay time between the second-generation distribution unit and the radio unit; and a control unit that executes timing synchronization on the basis of the first timing information and the second timing information. The transmission unit transmits, to the radio unit, a synchronization signal that is based on the timing synchronization and is common to the first-generation distribution unit and the second-generation distribution unit.

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 based on the 3GPP (registered trademark) standard, namely NR (New Radio) (also referred to as "5G") and a successor system of NR (for example, "6G"), technologies that meet requirements such as 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 architectures in 5GC (5G Core Network) or 5GS (5G System), which are the core networks in 5G, and 6GC (6G Core Network) or 6GS (6G System), which are successors to 5G, are being studied.

[0004] In addition, in O-RAN (Open-Radio Access Network), as technologies for realizing 6G, an AI-Native RAN (Artificial Intelligence - Radio Access Network) architecture, multi-RAT (Radio Access Technology) spectrum sharing (Multi-RAT Spectrum Sharing (MRSS)), enhanced massive MIMO (Multiple Input Multiple Output) considering more than 1000 antenna elements, and distributed MIMO, etc. are being studied. This technology is closely related to the 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 this 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) O-RAN. WG4. CUS. 0-R004-v16.00

[0006] Multi-RAT spectrum sharing, one of the technologies being considered for 6G in O-RAN, is feared to be strongly affected by the functionality and requirements of the open fronthaul interface. However, the operation of this open fronthaul interface in O-RAN is not yet clearly defined.

[0007] This invention has been made in view of the above points, and aims to clarify the operation of an open fronthaul interface related to multi-RAT spectrum sharing.

[0008] The disclosed technology provides a base station comprising a first-generation distributed unit, a second-generation distributed unit, and a radio unit, wherein the first-generation distributed unit includes a transmitting unit that transmits first timing information to the second-generation distributed unit, which includes at least one of a slot length, a subframe length, and a delay time between the first-generation distributed unit and the radio unit; a receiving unit that receives second timing information from the second-generation distributed unit, which includes at least one of a slot length, a subframe length, and a delay time between the second-generation distributed unit and the radio unit; and a control unit that performs timing synchronization based on the first timing information and the second timing information, wherein the transmitting unit transmits a synchronization signal common to the first-generation distributed unit and the second-generation distributed unit, based on the timing synchronization, to the radio unit.

[0009] The disclosed technology clarifies the operation of an open fronthaul interface for multi-RAT spectrum sharing.

[0010] This figure shows an example configuration (1) of a wireless communication system in an embodiment of the present invention. This figure shows an example configuration (2) of a wireless communication system in an embodiment of the present invention. This figure shows an example of a logical architecture in O-RAN. This figure shows an example of the configuration of a base station 10 in an embodiment of the present invention. This figure shows an example of timing difference between RATs. This figure shows an example of frequency overlap between RATs. This figure shows an example of delay time difference in the fronthaul between RATs. This figure shows an example of reception timing error between RATs. This figure illustrates the time alignment window in 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 in an embodiment of the present invention. This figure shows an example of the functional configuration of a terminal 20 in an embodiment of the present invention. This figure shows an example of the hardware configuration of a base station 10 and a terminal 20 in an embodiment of the present invention. This figure shows an example of the configuration of a vehicle 2001 in 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 is applied 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, the Non-Real Time RIC (RAN Intelligent Controller) in the SMO communicates with the Near-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-Real Time 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 be considered. Also, since one O-RU that supports both 5G and 6G (5G+6G O-RU) 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 enclosure, and a 6G-compatible O-DU from a different vendor is installed in the 5G-compatible O-DU.

[0028] Figure 5 shows an example of a timing difference between RATs. As shown in Figure 5, the slot lengths may differ between 5G and 6G RATs. In response to this, the O-RU (Shared O-RU) shared between 5G and 6G needs to appropriately process information that is transmitted and received at different timings between the 5G O-DU and the 6G O-DU.

[0029] Figure 6 shows an example of frequency overlap between RATs. When performing MRSS with different 5G and 6G RATs within the same frequency band, there are cases where the frequencies used by the 5G RAT and the 6G RAT do not overlap, as shown in Figure 6(a), and cases where the frequencies used by the 5G RAT and the 6G RAT overlap, as shown in Figure 6(b). In the latter case, frequency interference can lead to problems such as an increase in bit error rate and a decrease in throughput.

[0030] Figure 7 shows an example of a delay time difference in the fronthaul between RATs. As shown in Figure 7, when a 5G O-DU and a 6G O-DU located in different positions communicate with a 5G+6G O-RU, the fronthaul length (delay amount) X on the 5G side and the fronthaul length (delay amount) Y on the 6G side may be different values ​​(X > Y). In this case, as shown in the example of reception timing error between RATs in Figure 8, if the transmission timing of the 5G O-DU and the 6G O-DU is synchronized, an error will occur in the reception timing on the O-RU side, and if the transmission timing is synchronized on the O-RU, an error will occur in the reception timing of the 5G O-DU and the 6G O-DU. Therefore, it is necessary to process the received information appropriately. Non-patent document 2 contains a definition of the latency requirement between O-DUs and O-RUs.

[0031] The following describes methods for clarifying the operation of the open fronthaul interface regarding multi-RAT spectrum sharing. In the following methods, requests / instructions / notifications / reports sent and received by O-DUs and O-RUs may be messages containing 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 and 6G may be written as 5G O-DU, 5G O-RU, 6G O-DU, and 6G O-RU. Furthermore, O-DUs and O-RUs corresponding to both 5G and 6G may be written as 5G+6G O-DU and 5G+6G O-RU. The term "interface" can also be written as "IF".

[0032] (Method 1) Method 1 describes protocol extensions in a fronthaul interface that enable synchronization between different RATs and real-time interference management.

[0033] (Method 1-1) Integrated Timing Synchronization Mechanism The 5G O-DU, 6G O-DU, 5G+6G O-DU, and 5G+6G O-RU within the base station 10 may communicate with each other using a newly defined common synchronization signal (message) shared between different RATs. The message may be a newly defined C-Plane signal or an extension of an existing C-Plane signal. The message may also use a newly defined Section Type / Section Extension or an extension of an existing Section Type / Section Extension. Here, Section Type may be an area defined for each type of information, and Section Extension may be an extended area for a particular type of information. The message may also include, for example, time information for timing synchronization (delay time between O-DU and O-RU, slot length, and subframe length, etc.).

[0034] The following describes an example of the procedure for sending and receiving synchronization signals.

[0035] (Example 1) Timing synchronization between O-DUs In a configuration including different O-DUs (5G O-DU and 6G O-DU) as shown in Diagram 4(a), the 5G O-DU and 6G O-DU may share timing information via an interface (D2 IF, etc.) between them and perform timing synchronization using the shared timing information. This makes it possible for the 5G O-DU and 6G O-DU to transmit a common synchronization signal unified between the O-DUs to the O-RU. Here, the timing information may include, for example, time information for performing timing synchronization (slot length, subframe length, delay time between the O-DU and O-RU, etc.).

[0036] For example, a 5G O-DU may transmit first timing information to a 6G O-DU, including at least one of the slot length, subframe length, and delay time between the 5G O-DU and the O-RU, and receive second timing information from the 6G O-DU, including at least one of the slot length, subframe length, and delay time between the 6G O-DU and the O-RU. Furthermore, after performing timing synchronization based on the first and second timing information, the 5G O-DU may transmit a synchronization signal common to both the 5G O-DU and the 6G O-DU to the O-RU based on the timing synchronization.

[0037] (Example 2) Timing synchronization within the O-DU In the configuration of the O-DU (5G+6G O-DU) shown in diagram 4(b), the O-DU may integrate the timings of 5G and 6G within the O-DU to establish a common timing reference for 5G and 6G. Furthermore, the O-DU may transmit a synchronization signal to the O-RU based on the established timing reference. This timing reference may be, for example, a reference indicating the time difference between the RATs of 5G and 6G.

[0038] (Example 3) Timing synchronization on the O-RU side After the O-RU receives timing information for each RAT from the O-DU (5G O-DU / 6G O-DU / 5G+6G O-DU), the O-RU may perform timing synchronization between different RATs based on the received timing information.

[0039] For example, an O-RU may receive first timing information from a 5G O-DU, including at least one of the slot length, subframe length, and delay time between the 5G O-DU and the O-RU, and second timing information from a 6G O-DU, including at least one of the slot length, subframe length, and delay time between the 6G O-DU and the O-RU. Furthermore, the O-RU may perform timing synchronization between the 5G O-DU and the 6G O-DU based on the first and second timing information.

[0040] (Method 1-2) Elimination of timing interference The O-RU may synchronize the timing of frequency conversion processing (such as fast Fourier transform) for signals from different RATs (e.g., the position of the analysis window) based on the synchronization between different RATs as shown in Method 1-1. This makes it possible to prevent interference in the frequency domain between different RATs due to such timing mismatches.

[0041] (Real-time Interference Management Protocol) O-DUs and O-RUs may send and receive messages between O-DUs / between O-DUs and O-RUs that include newly defined message types (e.g., extended C-Plane messages / new Section Type and Section Extension) that provide real-time information about interference between different RATs.

[0042] The O-DU may dynamically adjust resource allocation in the O-RU based on information received regarding interference conditions. For example, based on such interference conditions, the O-DU may allocate radio resources so that the frequency bands used by 5G and 6G are separated in order to prevent interference caused by frequency overlap between 5G and 6G.

[0043] (Effects of Method 1) - Realization of timing synchronization between different RATs: By using a common synchronization signal between different RATs and performing timing alignment on the O-RU side, timing differences between different RATs due to differences such as slot length / sub-frame length can be absorbed, making it possible to achieve timing synchronization. - Improvement of communication quality: Through synchronization and interference management between different RATs, frequency interference and timing interference can be reduced, making it possible to improve communication quality. - Unification of message formats: With the newly defined common synchronization signal and message format, message processing between different RATs becomes easier, ensuring protocol compatibility. - Improvement of network flexibility and scalability: With the extended protocol, compatibility between different vendors is maintained, improving network flexibility and enabling flexible support not only for 5G and 6G but also for RATs after 6G. - Improvement of user experience: By eliminating interference between 5G and 6G RATs, it becomes possible to provide users with stable high-speed communication.

[0044] (Method 2) In Method 2, a timing synchronization mechanism considering the delay difference in the fronthaul interface (which may be simply referred to as the fronthaul) will be described.

[0045] (Measurement and Sharing of Delay Information) The O-DU / O-RU may use newly defined C-Plane messages to exchange delay information / timing adjustment information in the fronthaul. Here, the newly defined C-Plane messages may include delay information / timing correction information by extending existing C-Plane signals and Section Type / Section Extension. The messages may also use newly defined Section Type / Section Extension. Here, Section Type may be an area defined for each type of information, and Section Extension may be an extended area for a particular type of information. Furthermore, delay information may include, for example, the delay time between the O-DU and O-RU, and timing adjustment information may include, for example, time information for timing synchronization (slot length, subframe length, etc.).

[0046] Each O-DU (5G O-DU, 6G O-DU, etc.) / O-RU may measure the fronthaul delay between the O-DU and the O-RU and share delay information, including the measured delay, between the O-DU and the O-RU. For example, each O-DU may measure the fronthaul delay between itself and the O-RU during installation. This measurement may be performed using existing synchronization signals or dedicated delay measurement packets. Alternatively, each O-DU may share the measured delay time by transmitting it to other O-DUs via an inter-O-DU interface (e.g., D2 IF).

[0047] (Adjustment and Correction of Delay Information) An O-DU may adjust the transmission timing of the signals it sends to the O-RU based on delay information in the fronthaul of its own device and other O-DUs. For example, an O-DU may adjust its transmission timing so that the reception timing at the O-RU matches by delaying the transmission of O-DUs with short delays and advancing the transmission of O-DUs with long delays.

[0048] The O-RU may correct the reception timing of signals based on the delay information received from each O-DU (such as 5G O-DU and 6G O-DU). For example, the O-RU may buffer a plurality of signals with different delays and perform processing (for example, synchronize the times of the plurality of signals for processing) at an appropriate timing based on the delay information.

[0049] (Expansion of Time Alignment Window) The O-DU and O-RU may use a time alignment window that is dynamically expanded / adjusted to absorb the differences in the fronthaul delay for each O-DU / the differences in the frame structures of the RATs. FIG. 9 is a diagram for explaining the time alignment window in an embodiment of the present invention. As shown in FIG. 9, the minimum value of the time alignment window may be the larger value of the slot length / subframe length of both RATs in 5G and 6G. Also, the maximum value may be the sum of the slot lengths / subframe lengths of both RATs. Here, the slot length / subframe length may be a length called by another name indicating a unit of a certain length in the signal.

[0050] For example, when the slot length of 5G is 1 millisecond and the slot length of 6G is 1.5 milliseconds, the minimum value of the time alignment window may be set to 1.5 milliseconds.

[0051] Also, for example, the minimum value of the time alignment window may be set to 2.5 milliseconds, which is the sum of the slot lengths of 5G and 6G.

[0052] The O-RU may correct / adjust the timing deviation of the signals received within the time alignment window to appropriately synchronize and process the signals from different RATs. Thereby, signal interference due to timing deviation can be prevented and the communication quality can be improved.

[0053] As described above, by setting the minimum value, each RAT has its own unique frame structure, and often differs in slot length and subframe length. Therefore, timing correction can be performed based on the longest unit of time (slot / subframe), ensuring that the signals from both RATs fall within the time alignment window. Consequently, when the O-RU receives the signal, correction based on the longest timing unit is reliably performed, enabling minimum timing synchronization between different RATs.

[0054] By setting the maximum value as described above, it is possible to comprehensively cover the maximum timing difference resulting from differences in frame structure between RATs. This reduces the risk of timing differences occurring due to overlapping signals from different RATs during signal processing on the O-RU side. Therefore, the O-RU can keep all timing differences occurring between RATs with different frame structures within an acceptable range, thereby maintaining signal integrity and communication quality.

[0055] (Effects of Method 2) - Achievement of timing synchronization: By adjusting the timing to take into account the fronthaul delay difference, it is possible to absorb the delay difference and synchronize signals from different O-DUs at the O-RU. - Improved communication quality: By achieving timing synchronization, it is possible to reduce interference between different RATs and improve communication quality. - Improved system flexibility and scalability: By expanding and standardizing the protocol, it is possible to improve the flexibility and compatibility of the system.

[0056] (Method 3) Method 3 describes a method for coordinating scheduling between different RATs.

[0057] (Establishment of Common Timing Standards) O-DU / O-RU may establish common timing standards among different RATs and make adjustments (adjustments to absorb differences) for differences in fronthaul delay between different RATs and differences in the frame structure of each RAT.

[0058] (Cooperative scheduling between O-DUs) O-DUs may coordinate with other generations of O-DUs (for example, 5G O-DUs and 6G O-DUs) to perform scheduling and adjust for fronthaul delay differences and different timing requirements (such as slot length / subframe length).

[0059] For example, each O-DU (5G O-DU and 6G O-DU, etc.) may exchange scheduling information, including delay information and timing information in the fronthaul, in real time via a D2 interface / proprietary interface. The timing information may include information regarding slot length / subframe length.

[0060] For example, to minimize signal interference at O-RUs, each O-DU (such as a 5G O-DU and a 6G O-DU) may adjust its transmission timing and resource allocation to the O-RUs based on shared delay information and scheduling information.

[0061] Alternatively, for example, a 5G O-DU may transmit first scheduling information to a 6G O-DU, including information regarding fronthaul delays and slot length / subframe length information for the 5G O-DU, and receive second scheduling information from the 6G O-DU, including information regarding fronthaul delays and slot length / subframe length information for the 6G O-DU. Based on the first and second scheduling information, the 5G O-DU may then adjust the transmission timing and resource allocation for the O-RU.

[0062] (Effects of Method 3) - Optimization of resource utilization efficiency: By coordinating scheduling that takes into account the delay difference of the fronthaul and the differences in frame structure, scheduling can be optimized and resource utilization efficiency can be improved.

[0063] In other words, the above method makes it possible to clarify the operation of the open fronthaul interface regarding multi-RAT spectrum sharing.

[0064] (Device Configuration) Next, an example of the functional configuration of the base station 10, network node 30, and terminal 20 that perform the processing and operations described above will be explained. The base station 10, network node 30, and terminal 20 include the functions to perform the embodiments described above. However, the base station 10, network node 30, and terminal 20 may each be equipped with only some of the functions in the embodiments.

[0065] <Base Station 10 and Network Node 30> Figure 10 shows an example of the functional configuration of a base station 10 and a network node 30. As shown in Figure 10, the base station 10 has a transmitting unit 110, a receiving unit 120, a setting unit 130, and a control unit 140. The functional configuration shown in Figure 10 is merely an example. The functional classifications and names of the functional units can be anything as long as they can perform the operations according to the embodiment of the present invention. The network node 30 may have the same functional configuration as the base station 10. Furthermore, a network node 30 having multiple different functions on the system architecture may be composed of multiple network nodes 30 separated by function.

[0066] The transmitting unit 110 includes the function of generating a signal to be transmitted to the terminal 20 or other network node 30 and transmitting the signal by wire or wireless. The receiving unit 120 includes the function of receiving various signals transmitted from the terminal 20 or other network node 30 and obtaining information from the received signal, for example, information from a higher layer. A communication unit including the transmitting unit 110 and the receiving unit 120 may be configured.

[0067] The setting unit 130 stores pre-configured setting information and various setting information to be transmitted to the terminal 20 in a storage device, and reads them from the storage device as needed.

[0068] The control unit 140 performs the processing described in the embodiment. The signal transmission function in the control unit 140 may be included in the transmission unit 110, and the signal reception function in the control unit 140 may be included in the reception unit 120.

[0069] Furthermore, the base station 10 may include a distributed unit (O-DU), a radio unit (O-RU), a central unit (O-CU), and a near-real-time control device (Near-Real Time RIC), and the O-DU, O-RU, O-CU, and Near-Real Time RIC may each have a transmitting unit 110, a receiving unit 120, a setting unit 130, and a control unit 140. Also, the O-DU, O-RU, O-CU, and Real Time RIC may communicate with each other using the transmitting unit 110 and the receiving unit 120.

[0070] <Terminal 20> Figure 11 is a diagram showing an example of the functional configuration of terminal 20. As shown in Figure 11, 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 11 is merely an example. The functional classifications and names of the functional units can be anything as long as they can perform the operations according to the embodiment of the present invention. In addition, the communication device that becomes the resource holder may have a functional configuration similar to that of terminal 20.

[0071] 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.

[0072] 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.

[0073] 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.

[0074] (Hardware Configuration) The block diagrams (Figures 10 and 11) 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.

[0075] 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.

[0076] 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 12 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.

[0077] 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.

[0078] 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.

[0079] 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.

[0080] 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 10 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 11 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.

[0081] 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.

[0082] 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.

[0083] 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.

[0084] 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).

[0085] 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.

[0086] 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.

[0087] Figure 13 shows an example of the configuration of vehicle 2001. As shown in Figure 13, 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.

[0088] 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.

[0089] 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).

[0090] 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.

[0091] 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.).

[0092] 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.

[0093] 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.

[0094] 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.

[0095] 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.

[0096] 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.

[0097] <Note> (Note 1) A base station comprising a first generation distributed unit, a second generation distributed unit, and a radio unit, wherein the first generation distributed unit comprises: a transmitting unit that transmits first timing information to the second generation distributed unit, which includes at least one of a slot length, a subframe length, and a delay time between the first generation distributed unit and the radio unit; a receiving unit that receives second timing information from the second generation distributed unit, which includes at least one of a slot length, a subframe length, and a delay time between the second generation distributed unit and the radio unit; and a control unit that performs timing synchronization based on the first timing information and the second timing information, wherein the transmitting unit transmits a synchronization signal common to the first generation distributed unit and the second generation distributed unit, based on the timing synchronization, to the radio unit. (Appendix 2) A base station comprising a first generation distributed unit, a second generation distributed unit, and a radio unit, wherein the radio unit includes a receiving unit that receives first timing information from the first generation distributed unit, which includes at least one of a slot length, a subframe length, and a delay time between the first generation distributed unit and the radio unit, and a second timing information from the second generation distributed unit, which includes at least one of a slot length, a subframe length, and a delay time between the second generation distributed unit and the radio unit, and a control unit that performs timing synchronization between the first generation distributed unit and the second generation distributed unit based on the first timing information and the second timing information.(Appendix 3) A base station comprising a first generation distributed unit, a second generation distributed unit, and a wireless unit, wherein the wireless unit includes: a control unit that sets the minimum value of the time alignment window to the larger of the slot length or subframe length in the first generation and the second generation, and sets the maximum value of the time alignment window to the sum of the slot length or subframe length in the first generation and the second generation; and a control unit that corrects the timing difference between the first generation distributed unit and the second generation distributed unit based on the time alignment window. (Appendix 4) A base station comprising a first generation distributed unit, a second generation distributed unit, and a radio unit, wherein the first generation distributed unit includes a transmitting unit that transmits to the second generation distributed unit first scheduling information to the first generation distributed unit, including information regarding delay at the interface between the distributed unit and the radio unit, and information regarding slot length or subframe length; a receiving unit that receives from the second generation distributed unit second scheduling information to the second generation distributed unit, including information regarding delay at the interface between the distributed unit and the radio unit, and information regarding slot length or subframe length; and a control unit that performs adjustment of transmission timing and resource allocation to the radio unit based on the first scheduling information and the second scheduling information.(Appendix 5) A control method performed by a base station including a first generation distributed unit, a second generation distributed unit, and a radio unit, the first generation distributed unit transmitting first timing information to the second generation distributed unit, which includes at least one of a slot length, a subframe length, and a delay time between the first generation distributed unit and the radio unit; receiving second timing information from the second generation distributed unit, which includes at least one of a slot length, a subframe length, and a delay time between the second generation distributed unit and the radio unit; performing timing synchronization based on the first timing information and the second timing information; and transmitting a synchronization signal to the radio unit that is common to the first generation distributed unit and the second generation distributed unit, based on the timing synchronization.

[0098] Any of the appendices 1 to 5 can clarify the operation of the open fronthaul interface regarding multi-RAT spectrum sharing.

[0099] (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.

[0100] 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.

[0101] 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).

[0102] 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.

[0103] 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).

[0104] 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.

[0105] 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.

[0106] 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).

[0107] 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.

[0108] 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.

[0109] 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.

[0110] 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.

[0111] The terms “system” and “network” as used in this disclosure are interchangeable.

[0112] Furthermore, the information, parameters, etc., described in this disclosure may be expressed using absolute values, relative values ​​from a given value, or corresponding other information. For example, wireless resources may be indicated by an index.

[0113] 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.

[0114] 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.

[0115] 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.

[0116] 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.

[0117] In this disclosure, terms such as "Mobile Station (MS)," "user terminal," "User Equipment (UE)," and "terminal" may be used interchangeably.

[0118] 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.

[0119] 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.

[0120] 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.

[0121] 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.

[0122] 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."

[0123] 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.

[0124] The reference signal can also be abbreviated as RS (Reference Signal), and may be called a pilot depending on the applicable standard.

[0125] 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."

[0126] 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.

[0127] In the configuration of each of the above devices, "means" may be replaced with "part," "circuit," "device," etc.

[0128] 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.

[0129] 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.

[0130] 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."

[0131] 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).

[0132] 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.

[0133] 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

1. A base station comprising a first-generation distributed unit, a second-generation distributed unit, and a radio unit, wherein the first-generation distributed unit includes: a transmitting unit that transmits first timing information to the second-generation distributed unit, which includes at least one of a slot length, a subframe length, and a delay time between the first-generation distributed unit and the radio unit; a receiving unit that receives second timing information from the second-generation distributed unit, which includes at least one of a slot length, a subframe length, and a delay time between the second-generation distributed unit and the radio unit; and a control unit that performs timing synchronization based on the first timing information and the second timing information, wherein the transmitting unit transmits a synchronization signal common to the first-generation distributed unit and the second-generation distributed unit, based on the timing synchronization, to the radio unit.

2. A base station comprising a first-generation distributed unit, a second-generation distributed unit, and a radio unit, wherein the radio unit includes a receiving unit that receives first timing information from the first-generation distributed unit, which includes at least one of a slot length, a subframe length, and a delay time between the first-generation distributed unit and the radio unit, and a second timing information from the second-generation distributed unit, which includes at least one of a slot length, a subframe length, and a delay time between the second-generation distributed unit and the radio unit, and a control unit that performs timing synchronization between the first-generation distributed unit and the second-generation distributed unit based on the first timing information and the second timing information.

3. A base station comprising a first-generation distributed unit, a second-generation distributed unit, and a wireless unit, wherein the wireless unit includes: a control unit that sets the minimum value of the time alignment window to the larger of the slot length or subframe length in the first and second generations, and sets the maximum value of the time alignment window to the sum of the slot length or subframe length in the first and second generations; and a control unit that corrects the timing difference between the first-generation distributed unit and the second-generation distributed unit based on the time alignment window.

4. A base station comprising a first-generation distributed unit, a second-generation distributed unit, and a radio unit, wherein the first-generation distributed unit includes: a transmitting unit that transmits to the second-generation distributed unit first scheduling information to the first-generation distributed unit, including information regarding delays at the interface between the distributed unit and the radio unit, and information regarding slot length or subframe length; a receiving unit that receives from the second-generation distributed unit second scheduling information to the second-generation distributed unit, including information regarding delays at the interface between the distributed unit and the radio unit, and information regarding slot length or subframe length; and a control unit that performs adjustments to transmission timing and resource allocation for the radio unit based on the first and second scheduling information.

5. A control method performed by a base station including a first-generation distributed unit, a second-generation distributed unit, and a radio unit, the control method comprising: the first-generation distributed unit transmitting first timing information to the second-generation distributed unit, which includes at least one of a slot length, a subframe length, and a delay time between the first-generation distributed unit and the radio unit; the first-generation distributed unit receiving second timing information from the second-generation distributed unit, which includes at least one of a slot length, a subframe length, and a delay time between the second-generation distributed unit and the radio unit; performing timing synchronization based on the first-generation timing information and the second-generation timing information; and transmitting a synchronization signal common to the first-generation distributed unit and the second-generation distributed unit, based on the timing synchronization, to the radio unit.

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