RU2778486C1 - Base station, user equipment, and method for transmission - Google Patents

Abstract

FIELD: wireless communication.

SUBSTANCE: terminal comprises: a reception configured to receive interconnection information from the base station to calculate the reference time of the external system; a control unit configured to calculate the reference time of the external system based on the interconnection information; and a transmitting unit configured to transmit the calculated reference time to a slave apparatus in the external system; wherein the interconnection information indicates the correspondence between the reference time of the 5G system and the reference time of the external system.

EFFECT: possibility for the 3GPP network to send a reference time, different from the reference time supported by the 3GPP network, to the user equipment.

5 cl, 10 dwg

Description

Technical field

The present invention relates to a base station, a user equipment and a transmission method in a radio communication system.

State of the art

In accordance with the Third Generation Partnership Project (3GPP, from the English. 3 ^rd Generation Partnership Project), research is ongoing on the method of radio communication, referred to as the new radio communication (NR, from the English. New Radio) or 5G, with the aim of further increasing the system capacity, increasing data rate and delay reduction in the radio section (for example, see non-patent document No. 1). For NR, various radio technologies are being studied to meet the requirements for providing a throughput of 10 Gbps or more and reducing the delay in the radio section so that it is less than or equal to 1 ms.

Currently, 3GPP Release 16 considers TSN (Time Sensitive Networking) / Ultra-Reliable and Low-Latency Communication (Ultra-Reliable and Low-Latency Communication). URLLC aims to provide communication with high reliability and low latency.

Basically, URLLC covers services such as traffic control and remote control that require both high reliability and low latency. Use cases for URLLC include vehicle traffic control and traffic management; robot control and 3D drone connection, etc.; and remote surgery.

All of the use cases described above require high reliability and low latency, it being assumed that the radio communication systems used are primarily used for control signaling.

Accordingly, in a 5G system, instead of requiring high data rates and multiple end connections, URLLC needs to meet stringent conditions in terms of reliability, low latency, and mobility.

In accordance with 3GPP, for URLLC, the following values are set as specific target values to be achieved: radio section delay must be less than or equal to 1 ms; and the probability of successful reception of data packets should be greater than or equal to 99.999% when transmitting data packets of 32 bits.

In the NR (New Radio) system, several different types of subcarrier spacing (15, 30, 60, 120, 240 kHz) of orthogonal frequency division multiplexing (OFDM, from the English Orthogonal) are used as a technology that can meet the requirements of URLLC frequency division multiplexing). By using a large subcarrier spacing, such as 240 kHz, the bandwidth per subcarrier is increased and the same amount of information can be transmitted in a shorter period of time. As a result, the transmission time of the radio signal can be reduced as well as the delay.

Prior Art Documents

Non-Patent Documents

Non-Patent Document No. 1: 3GPPTR 22.804 V16.1.0 (2018-09)

Non-Patent Document No. 2: 3GPP TSG-RAN WG2 Meeting No. 103-Bis, R2-1813967, Chengdu, China, October 8-12, 2018

Disclosure of invention

Technical problem

At present, the interworking between 5G and TSN systems introduced by the manufacturer, etc. is being studied in 3GPP.

It is assumed that several independent reference times are supported by several manufacturers. However, with the current broadcast information specified in 3GPP, the 3GPP network is only allowed to send UTC information to the user equipment.

Thus, there is a need for a technology that, in the 3GPP network, will allow the 3GPP network to send to the user equipment at least one time reference different from its own time reference.

Solution

According to one aspect of the present invention, a base station is provided, comprising: a receiving unit configured to receive, from an external system, a time reference of the external system; a control unit configured to generate, based on the reference time of the external system, relationship information for the user equipment to calculate the reference time of the external system to which the user equipment belongs; and a transmission unit configured to transmit the relationship information to the user equipment.

Positive results of the invention

According to one embodiment of the present invention, a technology is provided that, in a 3GPP network, allows the 3GPP network to send to user equipment at least one time reference different from the time reference supported by the 3GPP network itself.

Brief description of the drawings

FIG. 1 is a diagram illustrating one example of a timing accuracy requirement.

2 is a diagram illustrating one example of a time synchronization process.

Figure 3 is a diagram illustrating one example of a transparent approach.

4 is a diagram illustrating one example of a black box approach.

5 is a diagram illustrating one example of a network system configuration.

6 is a diagram illustrating one example of broadcast information.

7 is a diagram illustrating one example of a time reference transmission process.

Fig. 8 is a diagram illustrating one example of the functional configuration of the user equipment 10.

9 is a diagram illustrating one example of the functional configuration of the base station 20.

10 is a diagram illustrating one example of the hardware configuration of the user equipment 10 and the base station 20.

Implementation of the invention

Next, with reference to the accompanying drawings, various embodiments (specific embodiment) of the present invention are disclosed. It should be noted that the embodiments described below are merely examples, and the embodiments to which the present invention may be applied are not limited to the following embodiments.

It is assumed that the radio communication system in the following embodiments substantially conforms to NR. However, this is just an example, and the radio communication system in this embodiment may conform, in part or in full, to a non-NR radio communication system (eg, LTE).

At present, the interworking between 5G and TSN systems introduced by the manufacturer, etc. is being studied in 3GPP.

As disclosed in Non-Patent Document No. 2, the implementation of interworking between TSN and 5G system in 3GPP is currently being studied. In Non-Patent Document No. 2, as a method for implementing interworking between TSN and a 5G system, two methods are being studied in 3GPP, one of which is referred to as a transparent approach and the other is referred to as a black box approach. Further in the text, the main principles of the transparent approach and the approach based on the "black box" are given. The transparent and black box approaches outlined below involve processing to synchronize time between master clocks and slave clocks specified in the Precision Time Protocol (PTP). Accordingly, first, with reference to FIG. 2, the basic principles of the PTP time synchronization process are given.

2 is a diagram illustrating one example of processing for time synchronization between a master clock and a slave clock. As shown in FIG. 2, four types of timestamps are exchanged between the master clock and the slave clock, which are separately referred to as T1, T2, T3, and T4. These timestamps are required to calculate the slave clock offset.

The first timestamp T1 represents the exact time at which a message of type "Sync" was sent from the master. The time at which a Sync message is sent to the Ethernet port is referred to as T1. T1 is transmitted from the master to the slave using a follow up message.

The second time stamp T2 is the exact time at which the slave device receives a message of type "Sync".

The third time stamp T3 is the exact time at which a message of type "Delay Request" is transmitted from the slave.

The fourth time stamp T4 is the exact time at which the master device receives a Delay Request message from the slave device. T4 is sent to the slave using a Delay Response message.

In this case, it is assumed that the propagation delay from the master to the slave is equal to the propagation delay from the slave to the master (the transmission line is symmetrical). In this case, the offset between the time maintained by the clock of the slave device and the time maintained by the clock of the master device can be calculated as follows.

Bias

= (time supported by slave clock) -

(time supported by master clock)

= T2 - T1 - (propagation delay from master to slave)

\u003d T2-T1 - ((T2 - T1) + (T4 - T3)) / 2

= ((T2 - T1) - (T4 - T3)) / 2.

When calculating the offset described above, it is assumed that the transmission line is symmetrical. If the transmission line is symmetrical, ((T2 - T1) + (T4 - T3))/2 is the average of the master-to-slave propagation delay and the slave-to-master propagation delay.

Since (time supported by the clock of the master) = (time supported by the clock of the slave) is an offset, by calculating the offset described above, it is possible to achieve time synchronization between the master clock and the slave clock.

Next, the basic principles of the transparent approach presented in non-patent document No. 2 are given.

Transparent approach

In this method, the user equipment receives a plurality of Precise Time Protocol (PTP) packets via radio, including a precise time reference, and the received plurality of PTP packets is transmitted to all devices connected to the Ethernet port of the user equipment. As shown in Figure 3, several master ports (labeled M) of a clock source must be mapped to slave ports (labeled S) of multiple devices.

In this case, the 3GPP system serves as a "transparent switch" in the IEEE, with the "transparent switch" updating the "Correction Time" header field of the PTP packet in the master-to-slave direction and in the slave-to-master direction. The user equipment (UE) and the base station (gNB) are required to update the CT to include the time that the PTP packet is held in the UE/gNB (referred to as "residence time"). In order for time synchronization to satisfy the 1 microsecond requirement, the residence time should be updated in the PTP packet at the time of transmission.

In this case, in a transparent approach, to update the "correction time" field, it is required to perform a detailed analysis of the packets just before sending the PTP packet in the upstream and downstream data exchange. In order to perform an accurate CT update, it is necessary that the PTP packets take precedence so that they are transmitted with known delays. In addition, to update the CT, the latency due to HARQ retransmission and the radio propagation delay must be taken into account, whereby the calculated CT becomes unreliable.

Accordingly, due to the unreliability of the residence time data, the transparent approach does not allow timing accuracy to be less than 1 microsecond.

Next, with reference to FIG. 4, the black box approach is summarized.

In this approach, as shown in FIG. 4, TSN provides an accurate time reference for the 5G system in 3GPP. The 5G system in 3GPP, serving as a "black box", corresponds to the IEEE's "boundary clock (BC)" and acts as the master clock for all connected nodes. The reference time supported by the user equipment is delivered as PTP packets to all devices connected to the Ethernet port.

In the black box method, the accurate time obtained from the TSN can be delivered by the 5G system in 3GPP to all user equipment units connected to the 5G system in 3GPP. The black box approach can provide timing accuracy of 1 microsecond.

Moreover, in the black box approach, the 3GPP system is independent from the IEEE system, and the 3GPP system can maintain accurate time within the 3GPP system.

Problems

4, the reference time is provided by the master clock to the base station of the 3GPP system. However, in practice, it is assumed that the base station of the 3GPP system receives multiple time references by connecting to multiple systems (multiple master clocks) having different clocks.

For example, as shown in FIG. 5, it is assumed that there are systems from multiple manufacturers (factories A and B in FIG. 5), with each manufacturer providing time references from their own master clocks. In this case, in the example of Fig. 5, the number of factory systems is two. However, the number of factory systems is not limited to two. The number of factory systems may be one, or the number of factory systems may be greater than or equal to three. In the situation illustrated in FIG. 5, a case is assumed in which the user equipment units 10 belonging to different manufacturers receive the reference time from different master clocks. Namely, the user equipment 10 belonging to manufacturer A receives the reference time from the master clock of manufacturer A, and the user equipment 10 belonging to manufacturer B receives the reference time from the master clock of manufacturer B. In this case, time synchronization is established for multiple units of user equipment 10 at manufacturer A. Additionally, time synchronization is established for several units of user equipment 10 at manufacturer B. However, synchronization should not be established between user equipment 10 at manufacturer A and user equipment 10 at the factory B.

In version 15 of the NR scheme, similar to LTE, time information is set as broadcast information. Fig. 6 is a diagram illustrating a System Information Block (SIB) as broadcast information reflecting time information.

As shown in FIG. 6, in the current broadcast information, in the 3GPP network, only common common time information is allowed to be sent to the user equipment 10. Accordingly, when using the current broadcast information, the 3GPP network is unable to send to the user equipment 10 a reference time different from the reference time supported by the 3GPP network.

As a way to solve this problem, one can consider a method in which additional information is sent from the 3GPP network to the user equipment 10, so that the user equipment 10 can obtain at least one reference time provided by at least one clock and different from the reference time, supported by the 3GPP network. Hereinafter, method 1 and method 2 are disclosed for forwarding additional information from the 3GPP network to the user equipment 10.

Method 1

In method 1, the 3GPP network sends, to the user equipment 10, relationship information defining a correspondence between a time reference supported by the 3GPP network and a time reference of another system. The user equipment 10 that receives the relationship information compares the identifier of another system to which the user equipment 10 belongs (for example, system of manufacturer A or system of manufacturer B) with the identifier of at least one system included in the received relationship information. , wherein the user equipment 10 retrieves information for calculating the reference time of another system to which the user equipment 10 belongs.

The 3GPP network may send, as the relationship information disclosed above, the identifier of the other system and information for calculating the time reference of the other system from the time reference supported by the 3GPP network. For example, information for calculating the other system reference signal from the reference signal supported by the 3GPP network may be an offset between the time reference supported by the 3GPP network and the other system time reference.

Alternatively, for example, information for calculating the time reference of another system from the time reference supported by the 3GPP network may be a function for calculating the time reference of the other system with the time reference supported by the 3GPP network as a variable.

Alternatively, in the user equipment 10 and in the 3GPP network, namely in each of them, a database can be prepared containing at least one correspondence between the identifier of the other system, the time reference supported by the 3GPP network, and the time reference of the other system. The 3GPP network may transmit, as the relationship information disclosed above, an identifier reflecting at least one of the above-disclosed matches to the user equipment 10, where the user equipment 10 may calculate the time reference of the other system based on the received identifier.

The association information may be sent from the 3GPP network to the user equipment 10 as a Non-Access Stratum (NAS) message, or it may be sent as an Access Stratum (AS) message. , for example, RRC messages.

Method 2

In method 2, the 3GPP network identifies a system from at least one other system (e.g., system of manufacturer A or system of manufacturer B) to which user equipment 10 belongs (or a PTP terminal connected to user equipment 10), when The 3GPP network then sends relationship information to the user equipment 10 for the user equipment 10 to calculate the reference time of the identified system.

The 3GPP network (base station 20) may send, in advance, at least one identifier to identify at least one of the other systems. In this case, the 3GPP network may contain, in the relationship information, the identifier of the identified system disclosed above, and the 3GPP network may transmit the relationship information to the user equipment 10. The user equipment 10 that receives the relationship information may identify, based on the identifier, contained in the relationship information, the system to which the reference time calculated by the user equipment 10 belongs. In this case, the relationship information from the base station 20 can be sent not only by broadcast information, but also by a dedicated RRC message, and so on. per user equipment 10 or per group of UEs.

The identifier disclosed above may be a relationship information identifier; temporary network identifier (RNTI); logical channel identifier (LCID, from English Logical Channel Identifier); resource block identifier (RB-ID, from the English Resource Block Identifier); broadcast information identifier; assigned RRC signal identifier; identifier (ID) segmentation; PLMN ID; information reflecting QoS, such as QFI or QCI; AS (access class); or an identifier implicitly identified based on the frequency and/or time information at which the relationship information is received. If the identifier or relationship information is not sent by the base station 20, the user equipment 10 may apply the default identifier or relationship information by default. In addition, when multiple timing references are sent according to timing requirements, information may be sent to identify different requirements (QoS, QFI, etc.).

In addition, as the identifier disclosed above, an identifier that has been associated with the user equipment 10 (eg, an identifier associated based on contract information) may be reported from the base station 20 (or CN). The identifier may be signaled when sending the identifier of the user equipment 10 (eg, RACH Msg3 or Msg5 (eg, as a complete RRC establishment message)) during initial access, and so on.

The identifier may be transferred between and used by multiple base stations 20 and CNs. The identifier may also have an effective period, wherein the user equipment may request to re-allocate the identifier or extend the effective period if the effective period of the identifier is about to expire. For example, the expiration of the effective period may imply the case in which the measurement of the period of time starts from the moment of the last reception of one or more items of valid time information, and the specified period of time exceeds a predetermined value. In addition, if the RRC connection or connection to the CN is dropped (eg, release or release of the RRC connection), the identifier may be discarded or retained (an indication from the base station 20 may specify whether it should be discarded or retained).

In addition, when the ID needs to be changed or updated in order to eliminate the mismatch between the base station 20 (or CN) and the user equipment 10, a handover ("ReconfigurationWithSync") or an RRC connection release (RRC connection release) can be performed.

Functional example

Next, with reference to FIG. 7, one example of a processing operation for time synchronization according to one embodiment is disclosed. In step S101, the base station 20 of the 3GPP network performs time synchronization processing with the master device of manufacturer A, which maintains the master clock of the system of manufacturer A, and the base station 20 obtains the time reference A of the system of manufacturer A.

In step S103, the base station 20 of the 3GPP network performs time synchronization processing with the master device of manufacturer B, which maintains the master clock of the system of manufacturer B, and the base station 20 obtains the reference time B of the system of manufacturer B.

In step S105, the base station 20 generates information A for the user equipment 10 to calculate the reference time A of the system of manufacturer A, and associates the information A with the ID of A of the system of manufacturer A. In addition, the base station 20 generates information B for the user equipment 10 to calculate the reference time B of the system of manufacturer B, and associate information B with the identifier B of the system of manufacturer B. The base station 20 generates relationship information containing information A for the user equipment 10 to calculate the reference time A of the system of manufacturer A, and identifier A associated with information A; and containing information B for the user equipment 10 for calculating the reference time B of the system of the manufacturer B, and an identifier B associated with the information B.

In step S107, the base station 20 transmits the generated relationship information to the user equipment 10.

In step S109, in response to receiving the relationship information from the base station 20, the user equipment 10 compares (i) an identifier to identify the system to which the user equipment 10 belongs (in this example, one of the system of manufacturer A and the system of manufacturer B), which is stored by the user equipment 10, with (ii) the identifier contained in the received relationship information, and then the user equipment 10 obtains information for calculating the reference time of the system to which the user equipment 10 belongs.

For example, suppose that the identifier stored in the user equipment 10 is the identifier A. In this case, the user equipment 10 extracts from the relationship information information for calculating the reference time A of the system of the manufacturer A, wherein the user equipment 10 calculates the reference time A system of manufacturer A. Therefore, in step S111, the user equipment 10 transmits the calculated reference time A of the system of manufacturer A to the slave of manufacturer A.

In step S109, assume that the identifier stored in the user equipment 10 is the identifier B. Here, the user equipment 10 extracts information for calculating the reference time B of the system of the manufacturer B from the relationship information, and the user equipment 10 calculates the reference time B of the system of manufacturer B. Therefore, in step S111', the user equipment 10 transmits the calculated reference time B of the system of manufacturer B to the slave of manufacturer B.

Through the processing disclosed above, time synchronization can be established within the system of manufacturer A and/or the system of manufacturer B.

Device Configurations

Next, examples of functional configurations of user equipment 10 and base station 20 for performing the procedures disclosed above are disclosed. User equipment 10 and base station 20 have all of the functions described in the various embodiments. However, the user equipment 10 and the base station 20 may contain only some of the functions disclosed in the various embodiments. User equipment 10 and base station 20 may be collectively referred to as a communication device.

User Equipment

FIG. 8 is a diagram illustrating one example of the functional configuration of the user equipment 10. As shown in FIG. 8, the user equipment 10 includes a transmitting unit 110, a receiving unit 120, a control unit 130, and a data storage unit 140. The functional configuration illustrated in Fig. 8 is just one of the possible examples. The functional division and function block names may include any division and name, as long as operations can be performed according to various embodiments. Transmitting unit 110 may be referred to as a transmitter, and receiving unit 120 may be referred to as a receiver.

The transmission unit 110 generates a transmission signal based on the transmission data, and transmits the transmission signal via radio communication. The transmitter unit 110 may form one or more beams. The receiving unit 120 receives various types of signals via radio communication and obtains a high-level signal from the received physical layer signal.

The control unit 130 controls the user equipment 10. The transmission function of the control unit 130 may be included in the transmit unit 110, and the function of the control unit 130 related to the reception may be included in the receive unit 120. For example, configuration information is stored in the unit 140 data storage. The configuration information related to transmission may be stored in the transmitting unit 110, and the configuration information related to receiving may be stored in the receiving unit 120.

For example, the receiving unit 120 receives relationship information specifying a correspondence between the time reference supported by the 3GPP network and the time reference of another system from the base station 20, and the receiving unit 120 transmits the received relationship information to the control unit 130. The control unit 130 extracts, from the relationship information, information for calculating the reference time of another system to which the user equipment 10 belongs, by comparing the ID of the other system to which the user equipment 10 belongs (for example, system of manufacturer A or system of manufacturer B) , and an identifier of at least one system included in the received relationship information, after which the control unit 130 calculates the reference time of the specified other system. The control unit 130 causes the transmitting unit 110 to transmit the calculated time reference to the other system.

Base station 20

FIG. 9 is a diagram illustrating one example of the functional configuration of the base station 20. As shown in FIG. 9, the base station 20 includes a transmitting unit 210, a receiving unit 220, a control unit 230, and a data storage unit 240. The functional configuration shown in Fig. 9 is just one of the possible examples. The functional division and function block names may include any division and any names, as long as operations can be performed according to various embodiments. The transmitting unit 210 may be referred to as a transmitter, and the receiving unit 220 may be referred to as a receiver.

The transmission unit 210 has a function of generating a signal transmitted to the user equipment 10 and transmitting the signal via radio communication. In addition, the transmitter unit 210 generates one or more beams. The receiving unit 220 has a function of receiving various types of signals transmitted from the user equipment 10 and obtaining higher level information from, for example, the received signal. The receiving unit 220 includes a measurement unit that measures the received signal and obtains the received power, and so on.

The control unit 230 controls the base station 20. The function of the control unit 230 relating to transmission may be included in the transmitting unit 210, and the function of the control unit 230 relating to receiving may be included in the receiving unit 220. For example, configuration information is stored in the unit 240 data storage. The configuration information related to the transmission may be stored in the transmitting unit, and the configuration information related to the reception may be stored in the receiving unit 220.

For example, the receiving unit 220 performs processing for time synchronization with another system (eg, the system of manufacturer A and the system of manufacturer B) to which the user equipment 10 belongs, where the receiving unit 220 obtains the reference time of the other system, and the receiving unit 220 transmits the reference signal to the block 230 control. The control unit 230 generates relationship information by generating information for the user equipment 10 to calculate the reference time of said other system to which the user equipment 10 belongs based on the reference time of said other system, and associating the identifier of said other system with the generated information. The control unit 230 transmits the relationship information to the transmission unit, and the transmission unit 210 transmits the relationship information to the user equipment 10.

Hardware configuration

The block diagrams (FIGS. 8 - 9) used to describe the above embodiments illustrate the blocks in functional units. These functional blocks (components) are implemented by any combination of at least one of hardware and software. In addition, the implementation method of each function block is not limited to a specific method. That is, each functional block may be implemented by a single device that is physically or logically combined, or may be implemented by directly or indirectly connecting two or more devices that are physically or logically separated from each other (using, for example, a wired, wireless connections, etc.) and through these several devices. A functional block may be implemented by combining software with a single device described above, or a plurality of devices disclosed above.

Functions include, but are not limited to, evaluating, deciding, determining, calculating, calculating, processing, deriving, exploring, searching, verifying, receiving, transmitting, inferring, accessing, refining, selecting, selecting, establishing, comparing, assuming , waiting, acknowledging, broadcasting, notifying, establishing a connection, forwarding, configuring, reconfiguring, extracting, displaying, assigning, etc. For example, a functional unit (component) whose function is to transmit is referred to as a transmitting unit or transmitter. In any case, as disclosed above, the implementation method is not limited to a specific method.

For example, base station 20, user equipment 10, and so on. according to one of the embodiments of the present invention can perform the functions of a computer for implementing the radio communication method according to the present invention. FIG. 10 is a diagram illustrating one example of a hardware configuration of base station 20 and user equipment 10 according to one embodiment of the present invention. Each of the devices disclosed above, base station 20 and user equipment 200, may be physically configured as a computing device including a processor 1001, a memory 1002, a storage device 1003, a communication device 1004, an input device 1005, an output device 1006, a bus 1007, etc. d.

In the following description, the term "device" can be interpreted as a loop, device, block, etc. The hardware configuration of each of the following devices: base station 20 and user equipment 10 may be configured to include each of the illustrated devices, or may be configured without some of the devices.

Each function of each of the following devices: the base station 20 and the user equipment 10 is implemented such that the predetermined software (program) is read by the hardware, for example, the processor 1001, the memory 1002, etc., and the processor 1001 operates and controls communication via the communication device 1004 and at least one of the following processes: reading and writing data in the memory 1002 and the drive 1003.

For example, processor 1001 powers the operating system and controls the entire computer. The processor 1001 may have a central processing unit (CPU, from the English Central Processing Unit), containing an interface with peripheral devices, a control device, a computing device, a register, etc. For example, the above-disclosed control unit 130, control unit 230, and so on. may be implemented by the processor 1001.

In addition, the processor 1001 reads a program (program code), a program module, data, and so on. from at least one of the storage device 1003 and the communication device 1044 to the memory 1002 and perform various types of processes in accordance with them. As said program, a program is used that causes the computer to perform at least some of the operations disclosed in the above embodiments. For example, the control unit 130 of the base station 20 illustrated in FIG. 8 may be implemented by a control program stored in the memory 1002 and executed in the processor 1001. In addition, for example, the control unit 230 of the user equipment 10 illustrated in FIG. may be implemented by a control program stored in memory 1002 and executed on processor 1001. It is disclosed that various types of processes may be performed by a single processor 1001, but may also be performed simultaneously or sequentially by two or more processors 1001. The processor 1001 may be implemented by one or more chips. The program may be transmitted from the network via an electrical communication line.

The memory 1002 is a computer-readable storage medium and has at least one of read-only memory (ROM), erasable programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), random access memory (RAM), and so on. Memory 1002 may also be referred to as "register", "cache", "main memory", etc. The memory 1002 may store programs (program codes), program modules, etc., executable to implement the communication method according to one embodiment of the present invention.

The drive 1003 is a computer-readable storage medium and may have, for example, at least one of the following devices: an optical disk, such as a compact disc ROM (CD-ROM), a hard disk drive, a floppy disk, a magneto-optical disk (for example, CD, Digital Versatile Disc or Blu-Ray Disc (registered trademark)), smart card, flash memory (such as a card, mass storage or flash drive), floppy disk (registered trademark), magnetic stripe, etc. The drive 1003 may also be referred to as "auxiliary storage". The storage medium mentioned above may, for example, be a database, a server, or any other suitable medium containing at least one of the following devices: a memory 1002 and a drive 1003.

Communication device 1004 is a hardware (transmitter and receiver) 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 a high frequency switch, a duplexer, a filter, a frequency synthesizer, etc., to implement at least one of a frequency division duplex (FDD) and a frequency division duplex. connections with time division (TDD, from the English. Time Division Duplex). For example, transmitting and receiving antennas, amplifier, transceiver, transmission line interface, etc. may be implemented by the communication device 1004. The transceiver may be implemented such that the transmitter and receiver are physically or logically separated from each other.

The input device 1005 is an input device that receives input from outside (eg, keyboard, mouse, microphone, switch, button, sensor, etc.). The output device 1006 is an output device that performs a process of outputting data to the outside (eg, a display, a speaker, an LED lamp, etc.). The input device 1005 and the output device 1006 may be integrated into a single device (eg, touch panel).

Devices such as processor 1001 and memory 1002 are connected to each other via bus 1007 to communicate information to each other. Bus 1007 may be a single bus, or devices may be connected to each other using different buses.

In addition, each of the base station 20 and the user equipment 10 may be configured to contain hardware such as a microprocessor, a digital signal processor (DSP), Application Specific Integrated Circuit), a programmable logic device (PLD, from the English Programmable Logic Device) or a user-programmable gate array (FPGA, from the English Field Programmable Gate Array) or all or some of the functional blocks can be implemented by hardware. For example, processor 1001 may be implemented by at least one of these hardware components.

Conclusion on Embodiments

As disclosed above, according to various embodiments, a base station is provided, comprising: a receiving unit configured to receive, from an external system, an external system time reference; a control unit configured to generate, based on the reference time of the external system, relationship information for the user equipment to calculate the reference time of the external system to which the user equipment belongs; and a transmission unit configured to transmit the relationship information to the user equipment.

According to the configuration disclosed above, the base station can obtain an external system time reference different from the time reference maintained by the base station itself from the external system and transmit the time reference to the user equipment. Namely, it can be ensured that the communication system formed by the base station and the user equipment functions as a boundary clock.

The receiving unit may receive, from each external system of the plurality of external systems, the external system reference time, and the control unit may generate, for each external system of the plurality of external systems, relationship information by generating information for the user equipment to calculate the external system reference time by linking generated information with an external system identifier, and by including the generated information and an associated external system identifier.

According to the above configuration, even if multiple external systems are provided, the base station can obtain the reference time of each external system and transmit information for the user equipment belonging to the external system to calculate the external system time reference.

The receiving unit may receive, from each external system of the plurality of external systems, the external system reference time and the ID of the user equipment that belongs to the external system, and the control unit can generate, for each user equipment of one or more user equipment units belonging to the base station, information about for the user equipment to calculate the reference time of the external system to which the user equipment belongs, and the transmitting unit can transmit the relationship information to each user equipment of one or more user equipment units belonging to the base station.

According to the above configuration, the base station can determine the external system of the plurality of external systems to which the specific user equipment belongs, and the base station can transmit information for the specific user equipment to calculate the time reference of the external system to which the specific user equipment belongs.

Further, according to various embodiments, a user equipment is provided, comprising: a receiving unit configured to receive relationship information for calculating an external system reference time; a control unit configured to calculate the reference time of the external system based on the relationship information; and a transmitting unit configured to transmit the calculated reference time.

According to the configuration disclosed above, the user equipment can obtain information for calculating an external system time reference different from the time reference supported by the base station.

The receiving unit may receive, as the relationship information, the relationship information including, for each external system of the plurality of external systems, information for the user equipment to calculate the external system reference time, and the external system identifier associated with the information, and the control unit may extract, from the relationship information, information for the user equipment to calculate the reference time of the external system to which the user equipment belongs, wherein the control unit can calculate the reference time of the external system to which the user equipment belongs, by comparing (i) an ID of the external system to which the user equipment belongs, wherein the identifier is stored in the user equipment, and (ii) the identifier of each external system included in the relationship information.

According to the configuration disclosed above, even if multiple external systems are provided, the user equipment can obtain information for calculating the reference time of the external system to which the user equipment belongs.

In addition, according to various embodiments, a transmission method is provided, including: receiving, from an external system, an external system time reference; generating, based on the reference time of the external system, relationship information for the user equipment to calculate the reference time of the external system to which the user equipment belongs; and transmitting the relationship information to the user equipment.

According to the configuration disclosed above, the base station can receive an external system time reference different from the time reference maintained by the base station itself from the external system and transmit the time reference to the user equipment. Namely, it is possible to ensure that the communication system formed by the base station and the user equipment functions as a boundary clock.

Auxiliary Embodiment

The exemplary embodiment of the present invention has been described above, however, the present invention is not limited to the above embodiments, and one skilled in the art will appreciate that various modified examples, revised examples, alternative examples, substitute examples, etc. are possible. To facilitate understanding of the present invention, specific examples of numerical values are used in this specification, but the numerical values are only examples, and unless otherwise indicated, suitable specific values may be used. The classification of concepts in the above description is not essential to the present invention. Questions discussed in two or more sections can be combined and used as needed, and a question considered in one of the sections can be applied to a question disclosed in another section (unless there is a contradiction). The boundaries between functional units or processing units in a function block diagram do not necessarily correspond to boundaries between physical parts. The operations of a plurality of functional units may be physically performed by a single component, or the operation of a single functional unit may be physically performed by a plurality of parts. In the processing procedure disclosed in the various embodiments, the order of the processes may change as long as there is no conflict. For convenience in describing processes, base station 20 and user equipment 10 are disclosed using functional block diagrams, but such devices may be implemented in hardware, software, or a combination of both. The software executable by the processor included in the base station 20 according to the exemplary embodiment of the present invention and the software executed by the processor included in the user equipment 10 according to the exemplary embodiment of the present invention may be stored in random access memory (RAM), flash -memory, read-only memory (ROM), EPROM, EEPROM, register, hard disk drive (HDD), removable disk, CD-ROM, database, server, or any other suitable storage medium.

In addition, notification of information is in no way limited to the aspect or embodiment disclosed herein, and may be carried out using any other method. For example, the forwarding of information can be implemented through physical layer signaling (for example, downlink control information (DCI) and uplink control information (UCI)), higher layer signaling (for example, radio resource control signaling (RRC, from the English Radio Resource Control), medium access control signaling (MAC, from the English Medium Access Control), broadcast information (main information block (MIB, from the English Master Information Block), system information block (SIB)), other signals, or combinations thereof.Furthermore, RRC signaling may be referred to as an RRC message, and may, for example, be an RRC Connection Setup message or an RRC Connection Reconfiguration message, etc.

Each aspect and embodiment disclosed herein can be applied to at least one of the following systems: LTE (Long Term Evolution; Long Term Evolution) schemes, LTE Advanced (LTE-A) schemes, SUPER 3G schemes, IMT schemes -A (IMT-Advanced), 4G (fourth generation mobile communication systems), 5G (fifth generation mobile communication systems), Future Radio Access (FRA), NR (New Radio) systems, W-CDMA (registered trademark), Global System for Mobile Communications (GSM) (registered trademark), CDMA2000, Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi (registered trademark) ), IEEE 802.16 (WiMAX (registered trademark)), IEEE 802.20, Ultra-Wide Band (UWB), Bluetooth (registered trademark), systems using any other suitable system, and future generation systems that have functionality enhanced based on these systems. In addition, multiple systems (eg, combinations of at least one of the LTE scheme and the 5G LTE-A scheme) can be combined for application.

The order of processing procedures, sequences, flowcharts, etc. relevant aspects/embodiments disclosed in this description may be changed, provided there is no conflict. For example, the method disclosed in this specification has the elements of the various steps listed in exemplary order, and is not limited to the proposed specific order.

In this description, the specific operation performed by the base station 20 may be performed by the top node in some cases. In a network containing one or more network nodes, including base station 20, various operations performed for communication with user equipment 10 can obviously be performed by one of the following devices: base station 20 and any network node (which, as is assumed to be, for example, a mobility management node (MME), a serving gateway (S-GW, from the English Serving-Gateways, etc., without limitation to these examples), other than the base station 20. Above as An example is the case where one network node other than the base station 20 is provided. One network node may be a combination of a plurality of other network nodes (eg, MME and S-GW).

The information, signal, etc. disclosed in the present description can be derived from a higher level (or lower level) to a lower level (or higher level). The information, signal, etc. disclosed in the present description can be input and output via a plurality of network nodes.

Input and output information, etc. may be stored in a dedicated location (eg memory) or may be controlled via a control table. Input and output information, etc. can be overwritten, updated, or overwritten. Output information, etc. can be removed. Input information, etc. can be transferred to another device.

The determination in the present invention may be performed based on a value (0 or 1) expressed as 1 bit, may be performed based on a boolean value (true or false), or may be performed based on a comparison with numerical values (e.g. , comparisons with a preset value).

Whether software is referred to as software, firmware, middleware, microcode, hardware description language, or some other name, software should be interpreted broadly to mean an instruction, set of instructions, code, codename. segment, program code, program, subroutine, program module, application, program application, program package, routine, subprogram, object, executable, thread of execution, procedure, function, etc.

In addition, software, instructions, information, etc. can be transmitted and received via the transmission medium. When, for example, software is transmitted from websites, a server, or any other remote source using wired technology (such as coaxial cable, fiber optic cable, twisted pair, or Digital Subscriber Line) and radio technology (such as , infrared radiation or microwaves), at least one of the following technologies: wired technology and wireless technology is part of the definition of the transmission medium.

The information, signals, etc. disclosed in the present invention may be expressed using any of various technologies. For example, the data, instructions, commands, information, signals, bits, symbols, microcircuits, etc. mentioned throughout the above description may be expressed as voltages, currents, electromagnetic waves, magnetic particles, optical fields, or photons, or their combinations.

Terms disclosed in this specification and terms necessary for understanding the present invention may be replaced by terms having the same or similar meanings. For example, at least one of a channel and a symbol may be a signal. In addition, the signal may be a message. Also, the carrier component (CC, from the English Component Carrier) can be referred to as "carrier frequency", "hundredth", etc.

The terms "system" and "network" as used herein may be used interchangeably.

In addition, the information, parameters, etc. disclosed in this description may be expressed using absolute values, may be expressed using relative values from predetermined values, or may be expressed using other relevant information. For example, radio resources may be designated by an index.

The names used for the parameters disclosed above are by no means limited. In addition, mathematical formulas, etc., which use these parameters may differ from the mathematical formulas set forth explicitly in this description. Since different channels (eg, PUCCH, PDCCH, etc.) and information items can be designated with any suitable names, these different names associated with different channels and information items are by no means limited.

In this description, the terms "base station (BS)", "radio base station", "base station device", "fixed station", node "NodeB", node "eNodeB (eNB)", node "gNodeB (gNB)", "access point", "transmitting point", "receiving point", "transmitting/receiving point", "cell", "sector", "cell group", "carrier", "carrier component", etc. can be used synonymously. Base stations may also be referred to as macro cell, small cell, femto cell, and pico cell.

The base station eNB can accommodate one or multiple (eg, three) cells. If the base station accommodates a plurality of cells, the entire coverage area of the base station can be divided into a plurality of small areas, where each small area can also provide a communication service via a subsystem of the base station (for example, an indoor small base station (PRH: Remote Radio Node)). The term "cell" or "sector" refers to part of the coverage area or the entire coverage area of at least one of the base station and the base station subsystem that provides a communication service in this coverage.

In this description, the terms "mobile station MS (Mobile Station)", "user terminal", "user equipment UE (User Equipment)", "terminal", etc. can be used synonymously.

A mobile station may also be referred to by those skilled in the art in some cases as a user terminal, mobile unit, subscriber station, wireless unit, remote unit, mobile device, wireless device, wireless communication device, remote device, mobile user terminal, access terminal, mobile terminal, wireless terminal, remote terminal, handset, user agent, mobile client, client, or other suitable names.

At least one of the base station and the mobile station may also be referred to as a transmitter, a receiver, a communication device, and so on. At least one of the base station and the mobile station may be a device mounted on the movable body, the movable body itself, and so on. The mobile body can be a vehicle (for example, a car, an aircraft, etc.), a body that moves without a crew (for example, an unmanned aerial vehicle, a self-driving car, etc.), or a robot (with a manual with or without an operator). At least one of the base station and the mobile station includes a device that does not need to move during a communication operation. For example, at least one of the base station and the mobile station may be a loT (Internet of Things) device such as a sensor.

In addition, the base station in this description can be replaced by a user terminal. For example, each aspect/embodiment of the present invention can be applied to a configuration in which communication between a base station and a user terminal is replaced by communication between multiple units of user equipment 10 (which may be referred to, for example, as D2D: device-to-device or V2X ( Vehicle-to-Everything; connection of the car with "everything")). In this case, the user equipment 10 may have the functions of the aforementioned base station 20. In addition, words such as "uplink" and "downlink" can be replaced by terms (eg, "side") corresponding to communication between terminals. For example, uplink, downlink, etc. can be replaced with side channels.

By analogy, the user terminal in this description can be replaced by a base station. In this case, the base station may have the functions of the user terminal mentioned above.

The term "definition" used in the present description may include a variety of operations. For example, the concept of "determination" may include, for example, events in which events such as decision making, calculation, calculation, processing, receiving, exploring, viewing, searching, and querying (for example, searching in a table, database, or other data structure) and establishment are treated as "definition". In addition, the concept of "determination" may include, for example, events in which events such as receiving (for example, receiving information), transmitting (for example, transmitting information), inputting, outputting, or accessing (for example, accessing data in memory) are treated as a "definition". In addition, the concept of "determination" may include, for example, events in which events such as resolution, selection, selection, establishment or comparison are considered as "determination". In other words, the concept of "definition" may include events in which a particular operation is considered as a "definition". In addition, the concept of "definition" can be replaced by such concepts as "assumption", "expectation", "consideration", etc.

The words "connected", "connected", or variations of these words, may refer to any direct or indirect connection or connection between two or more elements, which may involve the presence of one or more intermediate elements between two elements that are "connected" or "connected" to each other. . The relationship or connection between elements can be physical, logical, or a combination of both. For example, "connection" can be replaced by the concept of "access". In this description, in the case of a connection, two elements can be considered "connected" or "connected" to each other using at least one of one or more electrical cables, wires and/or printed electrical connections, or in some non-limiting and non-exhaustive examples , using electromagnetic energy having a wavelength in the radio frequency range, microwave range, or optical (both visible and invisible) region.

The reference signal may be abbreviated to "RS" (Reference Signal) and may be referred to as a pilot signal depending on the applicable standard.

The term "based on" as used herein is not limited to "based only on" unless otherwise indicated. In other words, the phrase "based on" means both "based only on" and "based at least on".

Any reference to an element for which terms such as "first", "second", etc. are used in the present invention does not generally limit the number or order of these elements. These designations are used here for convenience only, as a way to distinguish two or more elements from one another. Thus, referring to the first and second elements does not mean that only two elements can be used, or that the first element must precede the second element in some way.

In addition, "means" in the configuration of each of the devices mentioned above can be replaced by terms such as "block", "loop", "device", etc.

When the terms "include", "including" and variations thereof are used in the present description, these terms should be understood as inclusive, by analogy with the concept of "equipped" ("comprising"). In addition, the word "or" used in the present description is not an exclusive "or".

A radio frame may consist of one or more frames in the time domain. In the time domain, each of one or more frames may be referred to as a subframe. In addition, a subframe may consist of one or more slots in the time domain. A subframe may have a fixed time duration (eg, 1 ms) that is independent of numerology.

Numerology may be a communication parameter applicable to at least one of the following processes: the transmission and reception of a particular signal or channel. For example, numerology may indicate at least one of the following parameters: subcarrier spacing (SCS), bandwidth, symbol length, cyclic prefix length, transmission time interval (TTI, from English. Transmission Time Interval), number of characters per TTI, configuration radio frame, specific filtering processing performed by the transceiver in the frequency domain, specific framing processing performed by the transceiver in the time domain, and so on.

A slot may be composed of one or more symbols (OFDM (Orthogonal Frequency Division Multiplexing) symbols, SC-FDMA (Single Carrier Frequency Division Multiple Access), etc.) symbols in the time domain. A slot may be a unit of time based on numerology.

A slot may contain a plurality of minislots. Each minislot may consist of one or more symbols in the time domain. In addition, a minislot may be referred to as a subslot. A minislot may contain fewer symbols than a slot. A PDSCH (or PUSCH) to be transmitted in larger units of time compared to a minislot may be referred to as PDSCH (or PUSCH) mapping type A. The PDSCH (or PUSCH) to be transmitted with the minislot may be referred to as PDSCH Map Type B (PUSCH).

All of the following concepts: radio frame, subframe, slot, minislot, and symbol, denote a unit of time for signal transmission. Other appropriate names may be used to refer to the radio frame, subframe, slot, minislot, and symbol.

For example, one subframe may be referred to as a transmission time interval (TTI), or a plurality of adjacent subframes may be referred to as TTIs, or one slot or one minislot may be referred to as a TTI. In other words, at least one of the subframe and the TTI may be a subframe (1 ms) in the existing LTE scheme, may be a period shorter than 1 ms (eg, 1 to 13 symbols), or may be a period longer than 1 ms. , which reflects the TTI, may be referred to as a slot, a minislot, and so on. instead of a subframe.

In this case, TTI refers to, for example, the minimum unit of time for radio scheduling. For example, in the LTE system, the base station performs scheduling to allocate a radio resource (transmit power bandwidth, etc. that can be used in each user equipment 10) in units of TTI for each user equipment 10. The definition of TTI is not limited to the above example.

A TTI may be a unit of transmission time, such as a data packet (transport block) that undergoes channel coding, a code block, or a codeword, or may be a unit of processing, such as link scheduling or adaptation. In addition, given the TTI, the time interval (eg, the number of symbols) in which the transport block, code block, codeword, etc. is actually displayed may be shorter than the TTI.

In addition, when one slot or one minislot is referred to as a TTI, one or more TTIs (ie, one or more slots or one or more minislots) may represent a minimum unit of scheduling time. In addition, the number of slots (number of minislots) that constitutes the minimum unit of scheduling time can be controlled.

A TTI having a time duration of 1 ms may be referred to as a general TTI (TTI according to versions 8-12 of the LTE scheme), a normal TTI, a long TTI, a common subframe, a normal subframe, a long subframe, a slot, and so on. A TTI shorter than the overall TTI may be referred to as a short TTI, a short TTI, a partial TTI (partial or fractional TTI), a shortened subframe, a short subframe, a minislot, a subslot, a slot, and so on.

In addition, a long TTI (eg, normal TTI, subframe, etc.) can be replaced by a TTI having a time duration exceeding 1 ms, and a short TTI (eg, short TTI, etc.) can be replaced by a TTI having a length The TTI is shorter than the length of the TTI of the long TTI and is equal to or greater than 1 ms.

A resource block (RB) is a unit of resource allocation in the time domain and frequency domain, and may contain one or more contiguous sub-carriers in the frequency domain. The number of sub-carriers contained in the RB may be the same regardless of the numerology, and may, for example, be 12. The number of sub-carriers contained in the RB may be determined based on the numerology.

In addition, the RB time domain may contain one or more symbols, or may be one slot, one minislot, one subframe, or one TTI in length. One TTI, one subframe, etc. may contain one or more resource blocks.

In addition, one or more RBs can be referred to as a Physical Resource Block (PRB), a Sub-Carrier Group (SCG), or a Resource Element Group (REG). ), PRB pair, RB pair, etc.

In addition, a resource block may contain one or more resource elements (REs). For example, one RE may represent a radio resource area of one subcarrier and one symbol.

Partial bandwidth (BWP) (which may be referred to as partial bandwidth) may denote a subset of contiguous common resource blocks (RB) for a particular numerology in a particular carrier. In this case, the common RB may be set by the RB index based on the common reference point of the particular carrier. The PRB may be defined based on some BWP, and may be numbered in some BWP.

The BWP may comprise an uplink BWP (UL BWP) and a downlink BWP (DL BWP). At the UE, one or more BWPs may be configured on the same carrier.

At least one of the configured BWPs may be active and the UE may prevent preset signals/channels from being transmitted and received outside of the active BWP. In addition, "cell", "carrier", etc. in this description can be replaced by the term "BWP".

The structures of the radio frame, subframe, slot, minislot, and symbol described above are only exemplary structures. For example, configurations such as the number of subframes included in a radio frame, the number of slots per subframe or radio frame, the number of minislots included in a slot, the number of symbols and RBs included in a slot or minislot, the number of subcarriers included in a RB, the number of symbols in a TTI , character length, cyclic prefix length (CP, from the English Cyclic Prefix), etc., can vary in various ways.

For example, in the present description, if in the text when translated into English an article is added to words, for example, "a", "an" or "the", then the present description may cover the case when the noun following the article is in the plural number.

In this description, the phrase that "A and B are different" may mean that "A and B are different from each other." In addition, this phrase can mean that "A and B are each different from C." Concepts such as "separate", "connected", etc. can also be interpreted by analogy with the word "various".

Each aspect/embodiment disclosed herein may be used alone, in combination, or may be switched according to the embodiment. Moreover, notification of predefined information (eg, notification of what "represents X") is not limited to explicit notification, and may be sent implicitly (eg, without notification of this predefined information).

In addition, in the present description, DL-SSB is an example of a block containing a synchronization signal and broadcast information in the downstream direction. SL-SSB is an example of a block containing a synchronization signal and broadcast information in the forward direction.

Although the present invention has been described in detail above, it will be apparent to a person skilled in the art that the present invention is not limited to the embodiments disclosed herein. The present invention may be embodied in modified and modified embodiments without departing from the spirit and scope of protection of the present invention as defined by the appended claims. Accordingly, the description of the present invention is for illustrative purposes and is not intended to be limiting to the present invention.

POSITION NUMBERS

10 user equipment

110 transmitter unit

120 receiving unit

130 control unit

140 storage unit

20 base station

210 transmitter unit

220 receiving unit

230 control unit

240 storage unit

1001 processors

1002 memory

1003 drive

1004 communication device

1005 input device

1006 output device

Claims (20)

1. Terminal containing: a receiving unit, configured to receive, from the base station, relationship information for calculating an external system reference time; a control unit configured to calculate the reference time of the external system based on the relationship information; and a transmitting unit configured to transmit the calculated reference time to a slave device in an external system, wherein the relationship information indicates a correspondence between the 5G system reference time and the external system reference time. 2. The terminal according to claim. 1, in which the receiving unit is configured to receive, as relationship information, relationship information containing, for each external system of the plurality of external systems, information for the terminal to calculate the reference time of the external system and an identifier for identifying the external system , wherein the control unit is configured to extract, from the relationship information, information for the terminal to calculate the reference time of the external system to which the terminal belongs, the control unit is configured to calculate the reference time of the external system to which the terminal belongs, by comparing (i) an identifier for identifying the external system to which the terminal belongs, the identifier being stored in the terminal, and (ii) identifiers for identifying the respective external systems included in the relationship information. 3. A communication method performed by a terminal, including the following steps: receiving from the base station information about the relationship to calculate the reference time of the external system; calculating a reference time of the external system based on the relationship information; and transferring the calculated reference time to a slave device in an external system, wherein the relationship information indicates a correspondence between the 5G system reference time and the external system reference time. 4. The method according to claim 3, wherein at the step of receiving, as the relationship information, the relationship information containing, for each external system of the plurality of external systems, information for the terminal to calculate the reference time of the external system and an identifier for identifying the external system, and in the calculation step, from the relationship information, extract information for the terminal to calculate the reference time of the external system to which the terminal belongs, and calculate the reference time of the external system to which the terminal belongs, by comparing (i) an identifier to identify the external system to which the terminal belongs, wherein the identifier stored in the terminal, and (ii) identifiers to identify the respective external systems included in the relationship information. 5. A radio communication system comprising a terminal and a base station, the terminal comprising: a receiving unit, configured to receive, from the base station, relationship information for calculating an external system reference time; a control unit configured to calculate the reference time of the external system based on the relationship information; and a transmitting unit configured to transmit the calculated reference time to a slave device in an external system, and the base station includes a transmission unit configured to transmit relationship information to the terminal, wherein the relationship information indicates a correspondence between the reference time of the 5G system to which the terminal belongs and the reference time of the external system.

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