KR102655526B1 - Apparatus and method for synchronization using wireless communication network in wireless communication system - Google Patents

Abstract

The present disclosure relates to a 5th generation (5G) or pre-5G communication system to support higher data rates after 4th generation (4G) communication systems such as Long Term Evolution (LTE). According to various embodiments of the present disclosure, a method of operating a base station in a wireless communication system includes a process of receiving information about the residence time of the terminal and the transmission time of the uplink frame from the terminal, and based on the transmission time of the uplink frame. This may include determining a wireless access network residence time and transmitting the wireless access network residence time and the terminal's residence time using a user plane function (UPF).

Description

Apparatus and method for synchronization using a wireless communication network in a wireless communication system {APPARATUS AND METHOD FOR SYNCHRONIZATION USING WIRELESS COMMUNICATION NETWORK IN WIRELESS COMMUNICATION SYSTEM}

This disclosure relates generally to wireless communication systems, and more specifically to an apparatus and method for synchronization using a wireless communication network in a wireless communication system.

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

To achieve high data rates, 5G communication systems are being considered for implementation in ultra-high frequency (mmWave) bands (such as the 60 GHz band). In order to alleviate the path loss of radio waves in the ultra-high frequency band and increase the transmission distance of radio waves, the 5G communication system uses beamforming, massive array multiple input/output (massive MIMO), and full dimension multiple input/output (FD-MIMO). ), array antenna, analog beam-forming, and large scale antenna technologies are being discussed.

In addition, to improve the network of the system, the 5G communication system uses evolved small cells, advanced small cells, cloud radio access networks (cloud RAN), and ultra-dense networks. , Device to Device communication (D2D), wireless backhaul, moving network, cooperative communication, Coordinated Multi-Points (CoMP), and interference cancellation. Technology development is underway.

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

As mobile communication technology develops, the need to provide clock synchronization technology, which was only provided in wired networks, also in wireless networks has emerged. However, it is difficult to introduce time synchronization technology in wireless networks due to the asymmetric problem of uplink (UL) and downlink (DL) propagation delay in the air link. This can be. To solve these difficulties, a method for providing time synchronization between terminals in a wireless communication network may be required.

Based on the above-described discussion, this disclosure provides an apparatus and method for synchronization using a wireless communication network in a wireless communication system.

In addition, the present disclosure provides for the uplink (UL) and downlink (DL) of the wireless section (air link) so that the clock synchronization function, which is only supported in wired networks in wireless communication systems, is also supported in wireless communication networks. Provides an apparatus and method for solving the propagation delay asymmetry problem.

According to various embodiments of the present disclosure, a method of operating a base station in a wireless communication system includes a process of receiving information about the residence time of the terminal and the transmission time of the uplink frame from the terminal, and based on the transmission time of the uplink frame. This may include determining a wireless access network residence time and transmitting the wireless access network residence time and the terminal's residence time using a user plane function (UPF).

According to various embodiments of the present disclosure, a method of operating a user plane function (UPF) in a wireless communication system includes a process of receiving information about a wireless access network stay time and a terminal's stay time from a base station, and the wireless access network stay time. It may include a process of determining the residence time of an uplink frame in a wireless communication network using time, the residence time of the terminal, and the residence time of the UPF.

According to various embodiments of the present disclosure, a method of operating a terminal in a wireless communication system includes a process of receiving information about the residence time of a user plane function (UPF) and a reception time of a downlink frame from a base station, and the downlink frame A process of determining a stay time in a wireless access network based on information about the reception time of and a process of determining a stay time of a downlink frame in a wireless communication network based on the stay time of the UPF and the stay time in the wireless access network. can do.

According to various embodiments of the present disclosure, in a wireless communication system, a base station receives information about the residence time of the terminal and the transmission time of the uplink frame from the transceiver and the terminal, and receives information about the transmission time of the uplink frame based on the transmission time of the uplink frame. It may include at least one processor that determines a wireless access network residence time and transmits the wireless access network residence time and the terminal's residence time through a user plane function (UPF).

According to various embodiments of the present disclosure, in a wireless communication system, a user plane function (UPF) receives information about the wireless access network residence time and the terminal's residence time from a transceiver and a base station, and determines the wireless access network residence time and at least one processor that determines a residence time of an uplink frame in a wireless communication network using the residence time of the terminal and the UPF.

According to various embodiments of the present disclosure, in a wireless communication system, a terminal receives information about the residence time of a user plane function (UPF) and the reception time of a downlink frame from a transceiver and a base station, and receives information about the reception time of the downlink frame. At least one processor determines a stay time in a wireless access network based on information about the reception time, and determines a stay time of a downlink frame in a wireless communication network based on the stay time of the UPF and the stay time in the wireless access network. can do.

Devices and methods according to various embodiments of the present disclosure enable synchronization to be performed using a wireless communication network.

Additionally, devices and methods according to various embodiments of the present disclosure enable wireless communication networks to be utilized in application fields that require clock synchronization between nodes, such as factory automation.

The effects that can be obtained from the present disclosure are not limited to the effects mentioned above, and other effects not mentioned can be clearly understood by those skilled in the art from the description below. will be.

1 illustrates a wireless communication system according to various embodiments of the present disclosure.
Figure 2 shows the configuration of a base station in a wireless communication system according to various embodiments of the present disclosure.
Figure 3 shows the configuration of a terminal in a wireless communication system according to various embodiments of the present disclosure.
FIG. 4 illustrates the configuration of a core network object in a wireless communication system according to various embodiments of the present disclosure.
FIG. 5 is a diagram illustrating time synchronization in a wired network that does not support time sensitive network (TSN) in a wireless communication system according to various embodiments of the present disclosure.
FIG. 6 is a diagram illustrating time synchronization in a wired network supporting TSN in a wireless communication system according to various embodiments of the present disclosure.
FIG. 7 is a diagram illustrating a problem of time synchronization using a wireless communication network in a wireless communication system according to various embodiments of the present disclosure.
Figure 8 shows a flowchart of a base station in a wireless communication system according to various embodiments of the present disclosure.
Figure 9 shows a flowchart of a terminal in a wireless communication system according to various embodiments of the present disclosure.
FIG. 10 illustrates a wireless communication network protocol for solving the problem of time synchronization using a wireless communication network in a wireless communication system according to various embodiments of the present disclosure.
FIG. 11 is a diagram illustrating a synchronization method in the uplink in a wireless communication system according to various embodiments of the present disclosure.
FIG. 12 is a diagram illustrating a synchronization method in the downlink in a wireless communication system according to various embodiments of the present disclosure.
FIG. 13 illustrates a method of measuring delay time between adjacent TSN systems in a wireless communication system according to various embodiments of the present disclosure.
FIG. 14 illustrates a method of time synchronization between TSN systems in a wireless communication system according to various embodiments of the present disclosure.
FIG. 15 illustrates a time synchronization method of a TSN bridge model in a wireless communication system according to various embodiments of the present disclosure.
FIG. 16 illustrates a time synchronization method in uplink in a wireless communication system according to various embodiments of the present disclosure.
Figure 17 illustrates a time synchronization method in the downlink in a wireless communication system according to various embodiments of the present disclosure.

Terms used in the present disclosure are merely used to describe specific embodiments and may not be intended to limit the scope of other embodiments. Singular expressions may include plural expressions, unless the context clearly indicates otherwise. Terms used herein, including technical or scientific terms, may have the same meaning as generally understood by a person of ordinary skill in the technical field described in this disclosure. Among the terms used in this disclosure, terms defined in general dictionaries may be interpreted to have the same or similar meaning as the meaning they have in the context of related technology, and unless clearly defined in this disclosure, have an ideal or excessively formal meaning. It is not interpreted as In some cases, even terms defined in the present disclosure cannot be interpreted to exclude embodiments of the present disclosure.

In various embodiments of the present disclosure described below, a hardware approach method is explained as an example. However, since various embodiments of the present disclosure include technology using both hardware and software, the various embodiments of the present disclosure do not exclude software-based approaches.

Hereinafter, the present disclosure relates to an apparatus and method for synchronization using a wireless communication network in a wireless communication system. Specifically, the present disclosure describes a technology for supporting clock synchronization in a wireless communication network by determining the residence time of the wireless communication network based on the residence time of each entity within the wireless communication network. do.

In the following description, terms referring to signals, terms referring to channels, terms referring to control information, terms referring to network entities, terms referring to device components, etc. are used for convenience of explanation. This is exemplified. Accordingly, the present disclosure is not limited to the terms described below, and other terms having equivalent technical meaning may be used.

In addition, the present disclosure describes various embodiments using terms used in some communication standards (eg, ^3rd Generation Partnership Project (3GPP)), but this is only an example for explanation. Various embodiments of the present disclosure can be easily modified and applied to other communication systems.

1 illustrates a wireless communication system according to various embodiments of the present disclosure.

Referring to FIG. 1, the wireless communication system includes a radio access network (RAN) 102 and a core network (CN) 104.

The wireless access network 102 is a network directly connected to a user device, for example, the terminal 120, and is an infrastructure that provides wireless access to the terminal 120. The wireless access network 102 includes a set of a plurality of base stations including the base station 110, and the plurality of base stations can communicate through interfaces established between them. At least some of the interfaces between the plurality of base stations may be wired or wireless. Base station 110110 may have a structure divided into a central unit (CU) and a distributed unit (DU). In this case, one CU can control multiple DUs. In addition to the base station, the base station 110 includes 'access point (AP)', 'gNB (next generation node B)', '5G node ( ^5th generation node)', 'wireless point', It may be referred to as a 'transmission/reception point (TRP)', or another term with equivalent technical meaning. Terminal 120 connects to the wireless access network 102 and communicates with the base station 110 through a wireless channel. In addition to the terminal, the terminal 120 includes 'user equipment (UE)', 'mobile station', 'subscriber station', 'remote terminal', and 'wireless terminal'. It may be referred to as ‘terminal’, ‘user device’, or other terms with equivalent technical meaning.

The core network 104 is a network that manages the entire system, controls the wireless access network 102, and processes data and control signals for the terminal 120 transmitted and received through the wireless access network 102. The core network 104 is responsible for controlling the user plane and control plane, processing mobility, managing subscriber information, billing, and other types of systems (e.g. long term evolution (LTE) systems). It performs various functions such as interlocking. In order to perform the various functions described above, the core network 104 may include a number of functionally separated entities with different NFs (network functions). For example, the core network 104 includes an access and mobility management function (AMF) 130a, a session management function (SMF) 130b, a user plane function (UPF) 130c, a policy and charging function (PCF) 130d, and a network repository function (NRF) 130e. , UDM (user data management) 130f, NEF (network exposure function) 130g, and UDR (unified data repository) 130h.

The terminal 120 is connected to the wireless access network 102 and accesses the AMF 130a, which performs the mobility management function of the core network 104. AMF 130a is a function or device that is responsible for both access to the wireless access network 102 and mobility management of the terminal 102. SMF 130b is an NF that manages sessions. AMF 130a is connected to SMF 130b, and AMF 130a routes session-related messages for terminal 120 to SMF 130b. SMF 130b connects to UPF 130c to allocate user plane resources to be provided to terminal 120 and establishes a tunnel to transmit data between base station 110 and UPF 130c. PCF 130d controls information related to policy and charging for sessions used by terminal 120. NRF 130e stores information about NFs installed in the mobile communication service provider network and performs the function of informing of the stored information. NRF 130e can be connected to all NFs. When each NF starts operating in the operator network, it registers with NRF 130e and notifies NRF 130e that the NF is operating within the network. UDM 130f is an NF that performs a similar role to the home subscriber server (HSS) of a 4G network, and stores subscription information of the terminal 120, or the context that the terminal 120 uses within the network.

NEF 130g serves to connect ^3rd party servers and NFs in the 5G mobile communication system. It also plays a role in providing data to UDR 130h, updating, or obtaining data. UDR 130h performs the function of storing subscription information of the terminal 120, storing policy information, storing data exposed to the outside, or storing information necessary for a ^3rd party application. do. Additionally, UDR 103h also plays the role of providing stored data to other NFs.

Figure 2 shows the configuration of a base station in a wireless communication system according to various embodiments of the present disclosure. The configuration illustrated in FIG. 2 can be understood as the configuration of the base station 110. Hereinafter used ‘…’ wealth', '… Terms such as 'unit' refer to a unit that processes at least one function or operation, and may be implemented as hardware, software, or a combination of hardware and software.

Referring to FIG. 2, the base station includes a wireless communication unit 210, a backhaul communication unit 220, a storage unit 230, and a control unit 240.

The wireless communication unit 210 performs functions for transmitting and receiving signals through a wireless channel. For example, the wireless communication unit 210 performs a conversion function between baseband signals and bit strings according to the physical layer specifications of the system. For example, when transmitting data, the wireless communication unit 210 generates complex symbols by encoding and modulating the transmission bit string. Additionally, when receiving data, the wireless communication unit 210 restores the received bit stream by demodulating and decoding the baseband signal.

Additionally, the wireless communication unit 210 upconverts the baseband signal into a radio frequency (RF) band signal and transmits it through an antenna, and downconverts the RF band signal received through the antenna into a baseband signal. To this end, the wireless communication unit 210 may include a transmission filter, a reception filter, an amplifier, a mixer, an oscillator, a digital to analog convertor (DAC), an analog to digital convertor (ADC), etc. Additionally, the wireless communication unit 210 may include multiple transmission and reception paths. Furthermore, the wireless communication unit 210 may include at least one antenna array composed of a plurality of antenna elements.

In terms of hardware, the wireless communication unit 210 may be comprised of a digital unit and an analog unit, and the analog unit may be comprised of a number of sub-units depending on operating power, operating frequency, etc. It can be. A digital unit may be implemented with at least one processor (eg, digital signal processor (DSP)).

The wireless communication unit 210 transmits and receives signals as described above. Accordingly, all or part of the wireless communication unit 210 may be referred to as a 'transmitter', 'receiver', or 'transceiver'. Additionally, in the following description, transmission and reception performed through a wireless channel are used to mean that the processing as described above is performed by the wireless communication unit 210.

The backhaul communication unit 220 provides an interface for communicating with other nodes in the network. That is, the backhaul communication unit 220 converts a bit string transmitted from the base station to another node, for example, another access node, another base station, upper node, core network, etc., into a physical signal, and converts the physical signal received from the other node into a bit string. Convert to

The storage unit 230 stores data such as basic programs, applications, and setting information for operation of the base station. The storage unit 230 may be comprised of volatile memory, non-volatile memory, or a combination of volatile memory and non-volatile memory. And, the storage unit 230 provides stored data according to the request of the control unit 240.

The control unit 240 controls the overall operations of the base station. For example, the control unit 240 transmits and receives signals through the wireless communication unit 210 or the backhaul communication unit 220. Additionally, the control unit 240 records and reads data into the storage unit 230. Additionally, the control unit 240 can perform protocol stack functions required by communication standards. According to another implementation example, the protocol stack may be included in the wireless communication unit 210. For this purpose, the control unit 240 may include at least one processor. According to various embodiments, the controller 240 may control synchronization using a wireless communication network. For example, the controller 240 may control the base station to perform operations according to various embodiments described later.

Figure 3 shows the configuration of a terminal in a wireless communication system according to various embodiments of the present disclosure. The configuration illustrated in FIG. 3 can be understood as the configuration of the terminal 120. Hereinafter used ‘…’ wealth', '… Terms such as 'unit' refer to a unit that processes at least one function or operation, and may be implemented as hardware, software, or a combination of hardware and software.

Referring to FIG. 3, the terminal includes a communication unit 310, a storage unit 320, and a control unit 330.

The communication unit 310 performs functions for transmitting and receiving signals through a wireless channel. For example, the communication unit 310 performs a conversion function between baseband signals and bit strings according to the physical layer specifications of the system. For example, when transmitting data, the communication unit 310 generates complex symbols by encoding and modulating the transmission bit string. Additionally, when receiving data, the communication unit 310 restores the received bit stream by demodulating and decoding the baseband signal. Additionally, the communication unit 310 upconverts the baseband signal into an RF band signal and transmits it through an antenna, and downconverts the RF band signal received through the antenna into a baseband signal. For example, the communication unit 310 may include a transmission filter, a reception filter, an amplifier, a mixer, an oscillator, a DAC, an ADC, etc.

Additionally, the communication unit 310 may include multiple transmission and reception paths. Furthermore, the communication unit 310 may include at least one antenna array composed of multiple antenna elements. In terms of hardware, the communication unit 310 may be composed of digital circuits and analog circuits (eg, radio frequency integrated circuit (RFIC)). Here, the digital circuit and analog circuit can be implemented in one package. Additionally, the communication unit 310 may include multiple RF chains. Furthermore, the communication unit 310 can perform beamforming.

The communication unit 310 transmits and receives signals as described above. Accordingly, all or part of the communication unit 310 may be referred to as a ‘transmitting unit’, a ‘receiving unit’, or a ‘transmitting/receiving unit’. Additionally, in the following description, transmission and reception performed through a wireless channel are used to mean that the processing as described above is performed by the communication unit 310.

The storage unit 320 stores data such as basic programs, applications, and setting information for operation of the terminal. The storage unit 320 may be comprised of volatile memory, non-volatile memory, or a combination of volatile memory and non-volatile memory. And, the storage unit 320 provides stored data according to the request of the control unit 330.

The control unit 330 controls the overall operations of the terminal. For example, the control unit 330 transmits and receives signals through the communication unit 310. Additionally, the control unit 330 records and reads data into the storage unit 320. Additionally, the control unit 330 can perform the functions of the protocol stack required by communication standards. To this end, the control unit 330 may include at least one processor or microprocessor, or may be part of a processor. Additionally, a portion of the communication unit 310 and the control unit 330 may be referred to as a communication processor (CP). According to various embodiments, the controller 330 may control synchronization using a wireless communication network. For example, the controller 330 may control the terminal to perform operations according to various embodiments described later.

FIG. 4 illustrates the configuration of a core network object in a wireless communication system according to various embodiments of the present disclosure. Configuration 130 illustrated in FIG. 4 may be understood as a configuration of a device having at least one function among 130a, 130b, 130c, 130d, 130e, 130f, 130g, and 130h of FIG. 1. Hereinafter used ‘…’ wealth', '… Terms such as 'unit' refer to a unit that processes at least one function or operation, and may be implemented as hardware, software, or a combination of hardware and software.

Referring to FIG. 4, the core network object includes a communication unit 410, a storage unit 420, and a control unit 430.

The communication unit 410 provides an interface for communicating with other devices in the network. That is, the communication unit 410 converts a bit string transmitted from a core network object to another device into a physical signal, and converts a physical signal received from another device into a bit string. That is, the communication unit 410 can transmit and receive signals. Accordingly, the communication unit 410 may be referred to as a modem, a transmitter, a receiver, or a transceiver. At this time, the communication unit 410 allows the core network object to communicate with other devices or systems through a backhaul connection (eg, wired backhaul or wireless backhaul) or a network.

The storage unit 420 stores data such as basic programs, applications, and setting information for the operation of core network objects. The storage unit 420 may be comprised of volatile memory, non-volatile memory, or a combination of volatile memory and non-volatile memory. Additionally, the storage unit 420 provides stored data upon request from the control unit 430.

The control unit 430 controls overall operations of core network objects. For example, the control unit 430 transmits and receives signals through the communication unit 410. Additionally, the control unit 430 records and reads data into the storage unit 420. For this purpose, the control unit 430 may include at least one processor. According to various embodiments, the control unit 430 may control to perform synchronization using a wireless communication network. For example, the control unit 430 may control a core network object to perform operations according to various embodiments described later.

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

For convenience of explanation below, this disclosure uses terms and names defined in the 5GS (5G system) and NR (new radio) standards, which are the most recent standards defined by the 3GPP organization among currently existing communication standards. However, the present disclosure is not limited by the above terms and names, and can be equally applied to wireless communication networks complying with other standards. In particular, the present disclosure can be applied to 3GPP 5th generation mobile communication standards (eg, 5GS and NR).

FIG. 5 is a diagram illustrating time synchronization in a wired network that does not support time sensitive network (TSN) in a wireless communication system according to various embodiments of the present disclosure. Time synchronization of a wired network can operate based on the IEEE 1588 version (v) 1 standard.

Referring to FIG. 5, in various embodiments, the master 510 is a node that provides a reference clock, and the slave 520 performs time synchronization (time synchronization) to set its own time to the provided reference clock. It may refer to a node that performs clock synchronization. For example, the master 510 and the slave 520 may include electronic devices for communication and electronic devices for factory automation (e.g., factory computers, robot arms). If the wired network does not support TSN, delay time estimation between the master 510 and the slave 520 may be inaccurate because the delay time depending on direction is unsymmetric. Because of this, the accuracy of time synchronization may decrease. In various embodiments, the master 510 may transmit a delay measurement request Ethernet frame recording the current time (T1) 502 in a timestamp field to the slave 520. After receiving this Ethernet frame, the slave 520 may include the time (T2) 504 at which the Ethernet frame was received in the delay measurement response Ethernet frame. The slave 520 may transmit a delay measurement response Ethernet frame to the master 510 with the transmission time (T3) 506 of the delay measurement response Ethernet frame recorded in the timestamp field. After receiving the delay measurement response Ethernet frame from the slave 520 at time (T4) 508, the master 510 can estimate the delay time (d) by averaging the delay times of the delay measurement request Ethernet frame and the delay measurement response Ethernet frame. At this time, the delay time (d) can be determined as shown in Equation 1.

Referring to <Equation 1>, d is the estimated delay time, T1 is the time when the master 510 transmitted a delay measurement request to the slave 520, T2 is the time when the slave 520 received the delay measurement request from the master 510, and T3 is the time. The time at which the slave 520 transmitted the delay measurement response to the master 510, T4, may refer to the time at which the master 510 received the delay measurement response from the slave 520. If the delay time (d) between the master 510 and the slave 520 estimated by the master 510 is accurate, the slave 520 sets the clock of the slave 520 by adding the estimated delay time (d) to the timestamp transmitted by the master 510. can be matched. Through this, time synchronization between the master 510 and the slave 520 can be obtained. In various embodiments, the delay of link 1 and link 2 is a propagation delay and is therefore symmetrical to the transmission direction. However, since the delay passing through the bridge network (NW) includes queuing delay and processing delay, it is not symmetrical to the transmission direction. In various embodiments, T1 and T4 may be times based on the clock of the master 510, and T2 and T3 may be times based on the clock of the slave 520. As described above, since delay estimation is inaccurate in various embodiments, time synchronization may be inaccurate.

FIG. 6 is a diagram illustrating time synchronization in a wired network supporting TSN in a wireless communication system according to various embodiments of the present disclosure. Time synchronization in a wired network can operate based on the IEEE 1588 version 2 standard.

Referring to FIG. 6, when the wired network supports TSN, the delay time estimation between the master 610 and the slave 620 becomes more accurate compared to the case without TSN, so the accuracy of time synchronization can be increased. In various embodiments, a TSN bridge network may provide residence time correction functionality. That is, at time (T1) 602, after the master 610 transmits a delay measurement request Ethernet frame to the slave 620, the TSN bridge network transmits the time (TB1) 604 when the delay measurement request Ethernet frame entered the TSN bridge network and the time when it left (TB2). ) 606 can be used to calculate the residence time (TB2-TB1). The TSN bridge network can record the calculated dwell time (TB2-TB1) in the correction field of the corresponding Ethernet frame. The queuing and processing delays among the delays passing through the bridge network are specified in the calculated dwell time (TB2-TB1) described above, so when the dwell time is corrected from the delay experienced by the Ethernet frame, only the propagation delay symmetrical to the transmission direction is present. You can stay. In various embodiments, the slave 620 may receive a delay measurement request at time T2. At time (T3) 612, after the slave 620 transmits the delay measurement response Ethernet frame to the master 610, the TSN bridge network determines the time (TB3) 614 when the delay measurement response Ethernet frame of the slave 620 entered the TSN bridge network and the time it left ( The residence time (TB4-TB3) can be calculated using TB4) 616. The TSN bridge network can reflect the calculated dwell time (TB4-TB3) in the correction field of the corresponding Ethernet frame. Delay Measurement Response If these dwell times (TB4-TB3) are corrected for the delay experienced by the Ethernet frame, only propagation delay symmetrical in the transmission direction is left. At time T4 618, the master 610 receives a delay measurement response Ethernet frame from the slave 620, and the delay time (d) estimated by the master can be determined as shown in Equation 2.

Referring to <Equation 2>, d is the estimated delay time, T1 is the time when the master 610 transmitted a delay measurement request to the slave 620, T2 is the time when the slave 620 received the delay measurement request from the master 610, and T3 is the time. T4 is the time when the slave 620 transmitted the delay measurement response to the master 610, T4 is the time when the master 610 received the delay measurement response from the slave 620, TB1 is the time when the delay measurement request Ethernet frame entered the TSN bridge network, and TB2 is the delay measurement request. TB3 may mean the time when the Ethernet frame left the TSN bridge network, TB3 may mean the time when the delay measurement response Ethernet frame entered the TSN bridge network, and TB4 may mean the time when the delay measurement response Ethernet frame left the TSN bridge network. In various embodiments, the slave 620 may set the clock of the slave 620 by adding an estimated delay time (d) and a correction field to the timestamp transmitted by the master 610. Through this, time synchronization between the master 610 and the slave 620 can be obtained. As described above, in various embodiments TSN may provide dwell time delay correction.

FIG. 7 is a diagram illustrating a problem of time synchronization using a wireless communication network in a wireless communication system according to various embodiments of the present disclosure.

Referring to FIG. 7, when a wireless communication network (e.g., 3GPP NW) is used with an Ethernet switch (e.g., TSN SW (switch)) 720 that provides TSN functionality, problems in providing time synchronization can be shown. there is. First, each entity of 3GPP NW, UE (e.g., UE) 120, base station (e.g., gNB) 110, and UPF 130c, may not provide dwell time correction within each entity. Second, in the wireless section (air link) between the terminal and the base station, the uplink (UL) and downlink (DL) delays may be asymmetric. In various embodiments, the master 710 may transmit a delay measurement request to the slave 730 at time (T1) 702. TSN SW 720 may perform dwell time correction, and slave 730 may receive a delay measurement request at time (T2) 704. The slave 730 may transmit a delay measurement response to the master 710 at time (T3) 706. At time T4 708, the master 710 can receive a delay measurement response from the slave 730.

Figure 8 shows a flowchart of a base station in a wireless communication system according to various embodiments of the present disclosure. Figure 8 illustrates an operation method of the base station 110 during uplink.

Referring to FIG. 8, in step 801, the base station may receive information about the residence time of the terminal and the transmission time of the uplink Ethernet frame from the terminal. For example, the terminal may calculate the time an uplink Ethernet frame stays in the terminal, that is, the stay time of the terminal, and the base station may receive information from the terminal about the stay time of the terminal and the time at which the terminal transmits the uplink Ethernet frame. can receive. In various embodiments, the time at which the terminal transmits an uplink Ethernet frame may be included in SDAP (service data application protocol) and transmitted to the base station.

In step 803, the base station may determine the wireless access network residence time using the transmission time of the uplink Ethernet frame. For example, the base station uses the transmission time of the uplink Ethernet frame and the time when the base station transmits the GTP-U (general packet radio service (GPRS) tunneling protocol - user plane) payload to the UPF to determine the stay of the wireless access network. You can decide the time.

In step 805, the base station may transmit the determined wireless access network stay time and the terminal's stay time to the UPF. In various embodiments, the base station may transmit the determined residence time of the wireless access network to the UPF by including it in the GTP-U header. The UPF can calculate the residence time of the uplink Ethernet frame in the modified wireless communication network using the residence time of the received wireless access network, the residence time of the terminal, and the residence time of the uplink Ethernet frame within the UPF, and the modified wireless communication network The residence time within the communication network can be reflected in the correction field. Through this, the asymmetry problem of wireless section delay in the uplink can be solved.

Figure 9 shows a flowchart of a terminal in a wireless communication system according to various embodiments of the present disclosure. Figure 9 illustrates an operation method of the terminal 120 during downlink.

Referring to FIG. 9, in step 901, the terminal may receive information about the residence time of the UPF and the reception time of the downlink Ethernet frame. For example, the terminal may receive information from the base station about the residence time of the downlink Ethernet frame in the UPF and the time when the base station received the downlink Ethernet frame from the UPF. In various embodiments, the residence time of the UPF may be included in the GTP-U header and transmitted to the base station.

In step 903, the terminal may determine the wireless access network stay time using the reception time of the downlink Ethernet frame. For example, the terminal can determine the residence time of the wireless access network using the time when the base station receives the GTP-U payload from the UPF and the time when the terminal receives the downlink Ethernet frame from the base station.

In step 905, the terminal may determine the wireless communication network residence time based on the UPF residence time and the determined wireless access network residence time. In various embodiments, the terminal may calculate the residence time of the downlink Ethernet frame in the modified wireless communication network using the residence time of the downlink Ethernet frame in the terminal, the residence time of the UPF, and the determined residence time of the wireless access network. , the residence time within the modified wireless communication network can be reflected in the correction field. Through this, the asymmetry problem of wireless section delay in the downlink can be solved.

FIG. 10 illustrates a wireless communication network protocol for solving the problem of time synchronization using a wireless communication network in a wireless communication system according to various embodiments of the present disclosure.

Referring to FIG. 10, after an Ethernet frame enters the wireless communication network through the terminal 120, the connection between the terminal 120 and the base station 110 may be processed by SDAP and PDCP (packet data convergence protocol). Base station 110 may not read or modify Ethernet frames. Additionally, communication between the terminal 120 and the base station 110 may be performed using media access control (MAC)/radio link control (RLC)/physical layer (PHY) frames synchronized to the clock of the base station 110. Base station 110 and UPF 130c can communicate using GTP-U, and UPF 130c also cannot read or modify Ethernet frames directly. In UPF 130c, Ethernet frames can go outside the wireless network. Even in the Ethernet switch (TSN SW) 1020 that supports TSN, Ethernet frames can enter from the outside. The entered Ethernet frame undergoes internal processing and can then be sent out again. Therefore, a wireless communication network can be modeled as an Ethernet switch supporting one TSN. In various embodiments, time-of-dwelling correction may be performed on Ethernet frames coming into the wireless communication network. In various embodiments, the master 1010 may transmit a delay measurement request to the slave 1030. The slave 1030 that has received the delay measurement request may transmit a delay measurement response to the master 1010.

FIG. 11 is a diagram illustrating a synchronization method in the uplink in a wireless communication system according to various embodiments of the present disclosure.

Referring to FIG. 11, the terminal 120, the base station 110, and the UPF 130c can perform residence time correction for each entity. Each entity can calculate the time that uplink Ethernet stays in each entity as R (residence time)_UE, R_gNB, and R_UPF. The terminal 120 can transmit to the base station 110 by including R_UE and the time T(time)_UL at which uplink Ethernet is transmitted to the base station 110 in the SDAP. In various embodiments, T_UL may be determined using the MAC/RLC/PHY frame time commonly known to the base station 110 and the terminal 120. That is, the frame time of MAC/RLC/PHY at the time when terminal 120 transmits uplink Ethernet can be recorded as T_UL. The base station 110 can calculate the dwell time R_RAN of the radio access network by adding up the delay time of the uplink radio section and the dwell time of the base station 110. If the time at which the base station 110 transmits the GTP-U payload to UPF 130c is T_TX, R_RAN can be calculated as in <Equation 3>.

Referring to <Equation 3>, R_RAN is the residence time of the wireless access network, T_TX is the time when the base station 110 transmits the GTP-U payload to UPF 130c, and T_UL is the frame when the terminal 120 transmits the uplink Ethernet. It can mean time. Base station 110 may include the R_RAN value in the GTP-U header and transmit it as UPF 130c. Since UPF 130c is where the Ethernet frame goes out of the wireless communication network, UPF 130c must reflect the residence time R_3GPP within the wireless communication network in the correction field. The residence time R_3GPP within the wireless communication network can be calculated as <Equation 4>.

Referring to <Equation 4>, R_3GPP is the residence time within the wireless communication network, R_UE is the residence time within the terminal 120, R_RAN is the residence time of the wireless access network, BH is the backhaul delay time, and R_UPF is the residence time within UPF 130c. It can mean. R_3GPP is the sum of the residence time within the entity and the delay time of the wireless section and backhaul section. In various embodiments, the delay time of the wireless section between the terminal 120 and the base station 110 may not be symmetrical to the transmission direction. However, in various embodiments, the backhaul section between the base station 110 and UPF 130c may be configured as a wired network, and this section may be assumed to be a section with only propagation delay. Therefore, the delay time of the backhaul section may be symmetrical to the transmission direction. In various embodiments, the residence time R_3GPP' in the wireless communication network modified by excluding the delay time of the backhaul section symmetrical to the transmission direction can be calculated as shown in Equation 5.

Referring to <Equation 5>, R_3GPP' may mean the residence time within the modified wireless communication network, R_UE may represent the residence time within the terminal 120, R_RAN may represent the residence time of the wireless access network, and R_UPF may represent the residence time within the UPF 130c. In various embodiments, UPF 130c may update the calculated R_3GPP' in the correction field before transmitting the Ethernet frame to the outside. In various embodiments, T_UL may mean the PHY frame time when the terminal 120 transmits uplink Ethernet to the wireless section. At this time, the PHY frame may be synchronized with the global positioning system (GPS) time of the base station 110. T_UL' may refer to the PHY frame time when the base station 110 receives uplink Ethernet from the wireless section. At this time, the PHY frame may be synchronized with the GPS time of the base station 110. In various embodiments, base station 110 may be connected to a GPS system. Therefore, T_TX may mean GPS time when base station 110 transmits a GTP-U payload with UPF 130c. As described above, residence time correction may be performed at the terminal 120, the base station 110, and the UPF 130c. To solve the problem of uplink and downlink radio section delay asymmetry, uplink and downlink radio section delays may be delivered. For example, the uplink radio section delay may be delivered through GTP-U, and the downlink radio section delay may be delivered through SDAP and MAC. In various embodiments, the master 1110 may transmit a delay measurement request to the slave 1130. The delay measurement request transmitted by the master base station 1110 can be corrected in UPF 130c and TSN SW 1120.

FIG. 12 is a diagram illustrating a synchronization method in the downlink in a wireless communication system according to various embodiments of the present disclosure.

Referring to FIG. 12, each entity within a wireless communication network can perform dwell time correction on a delay measurement response Ethernet frame similar to the uplink case. In various embodiments, the UPF 130c may transmit the residence time of the downlink Ethernet within the UPF 130c to the base station 110 by including it in the GTP-U header. Base station 110 can record the received time T_RX in GTP-U, include T_RX in SDAP and transmit it to terminal 120. Terminal 110 can obtain the time T_DL at which the frame was received in the downlink based on the MAC/RLC/PHY frame time, and then calculate the residence time R_RAN of the wireless section as shown in Equation 6.

Referring to <Equation 6>, R_RAN is the residence time of the wireless section, T_DL is the frame time when the terminal 120 receives the downlink Ethernet, and T_RX is the time when the base station 110 receives the GTP-U payload from UPF 130c. It can mean. In various embodiments, at the time when the terminal 120 transmits the delay measurement response Ethernet frame to the outside, reflecting the residence time within the terminal 120, the modified residence time R_3GPP' in the wireless communication network can be calculated as <Equation 7> there is.

Referring to <Equation 7>, R_3GPP' may mean the residence time within the modified wireless communication network, R_UE may represent the residence time within the terminal 120, R_RAN may represent the residence time of the wireless access network, and R_UPF may represent the residence time within the UPF 130c. In various embodiments, the terminal 120 may add the calculated R_3GPP' to the correction field. In various embodiments, the slave 1230 may synchronize with the master 1210 based on the master timestamp received from the master 1210, a correction value, and a delay time (d).

In various embodiments, T_DL may mean PHY frame time when the terminal 120 receives Ethernet from a wireless section. At this time, the PHY frame may be synchronized with the GPS time of the base station 110. T_DL' may refer to the PHY frame time when the base station 110 transmits downlink Ethernet to the wireless section. At this time, the PHY frame may be synchronized with the GPS time of the base station 110. T_RX may mean the base station time at which base station 110 receives the GTP-U payload from UPF 130c. As described above, residence time correction may be performed at the terminal 120, the base station 110, and the UPF 130c. To solve the problem of uplink and downlink radio section delay asymmetry, uplink and downlink radio section delays may be delivered. For example, the uplink radio section delay may be delivered through GTP-U, and the downlink radio section delay may be delivered through SDAP and MAC. In various embodiments, the slave 1230 may transmit a delay measurement response to the master 1210. TSN SW 1220 can record a timestamp (T3) of the time at which the delay measurement response passes.

The time synchronization procedure in a network supporting 802.1AS has the same basic principle as the time synchronization procedure in IEEE 1588 described above, but there are differences in the procedure. For example, a procedure for measuring the periodic link delay time between two adjacent TSN systems (e.g. end-stations or bridges) and a correction field including residence time on the bridge. The update procedure may be included in the different procedures described above. In various embodiments, an end-station may refer to a node that can perform a master or slave role. Hereinafter, Figures 13 and 14 explain specific operating methods for the above-described procedures.

FIG. 13 illustrates a method of measuring delay time between adjacent TSN systems in a wireless communication system according to various embodiments of the present disclosure.

Referring to FIG. 13, a peer delay initiator 1302 requests delay time measurement, and a peer delay responder 1304 receives a request for delay time measurement. In various embodiments, a peer delay initiator may refer to a node that requests delay time measurement, and a peer delay responder may refer to a node that receives a request for delay time measurement. Additionally, peer delay initiator and peer delay responder may refer to different TSN systems. For example, peer delay initiator and peer delay responder may mean bridge and bridge, bridge and master, and bridge and slave, respectively.

In step 1301, the peer delay initiator 1302 may transmit a Pdelay_Req Ethernet frame requesting delay time measurement to the peer delay responder 1304 at time (t ₁ ) 1312. The peer delay responder 1304 may receive the Pdelay_Req Ethernet frame at time (t ₂ ) 1314 and store the time (t ₂ ) 1314 at which the frame was received. In various embodiments, time (t _ir ) 1320 may mean the difference between time (t ₁ ) 1312 and time (t ₂ ) 1314.

In step 1303, the peer delay responder 1304 may transmit a Pdelay_Resp Ethernet frame containing information about the stored time (t ₂ ) 1314 to the peer delay initiator 1302 at time (t ₃ ) 1316. Thereafter, the peer delay responder 1304 may store the time (t ₃ ) 1316 at which the Pdelay_Resp Ethernet frame was transmitted.

In step 1305, the peer delay responder 1304 may transmit a Pdelay_Resp_Follow_Up Ethernet frame containing information about the stored time (t ₃ ) 1316 to the peer delay initiator 1302. Peer delay initiator 1302 may receive the Pdelay_Resp Ethernet frame at time (t ₄ ). Afterwards, the peer delay initiator 1302 may receive a Pdelay_Resp_Follow_Up Ethernet frame. The peer delay initiator 1302 determines time (t ₂ ) 1314 and time (t ₃₎ by checking the Pdelay_Resp Ethernet frame and the Pdelay_Resp_Follow_Up Ethernet frame.

) You can see 1316. The peer delay initiator 1302 can determine the delay time (D) between adjacent TSN systems using the above-described time (t ₁ ) 1312, time (t ₂ ) 1314, time (t ₃ ) 1316, and time (t ₄ ) 1318. there is. The delay time (D) between adjacent TSN systems can be defined as <Equation 8> below.

Referring to <Equation 8>, D is the delay time between adjacent TSN systems, t ₁ is the time when the peer delay initiator 1302 requests delay time measurement from the peer delay responder 1304, and t ₂ is the peer delay time of the peer delay responder 1304. The time at which the Pdelay_Req Ethernet frame is received from the initiator 1302, t ₃ is the time at which the peer delay responder 1304 transmits the Pdelay_Resp Ethernet frame to the peer delay initiator 1302, t ₄ is the time at which the peer delay initiator 1302 transmits the Pdelay_Resp Ethernet frame from the peer delay responder 1304. This may mean the time at which the frame was received. In various embodiments, time (t _ri ) 1322 may mean the difference between time (t ₃ ) 1316 and time (t ₄ ) 1318. In various embodiments, the delay time between adjacent TSN systems described above may be determined as the average of time (t _ir ) 1320 and time (t _ri ) 1322, where the average of time (t _ir ) 1320 and time (t _ri ) 1322 can be expressed as mean path delay (meanPathDelay). In various embodiments, when the initiator time awareness system 1310 transmits a signal to the responder time awareness system 1308, a delay of time t _ir 1320 may occur. Additionally, when the responder time recognition system 1308 transmits a signal to the initiator time recognition system 1310, a delay of time (t _ri ) 1322 may occur. In various embodiments, time (t _ir ) 1320 may be determined by the difference between the average path delay and the delay asymmetry value (meanPathDelay - delayAsymmetry). Additionally, time (t _ri ) 1322 can be determined by the sum of the average path delay and delay asymmetry (meanPathDelay + delayAsymmetry). In various embodiments, peer delay responder 1304 may store a timestamp 1306 known by peer delay initiator 1302. For example, timestamps 1306 known by peer delay initiator 1302 may include t ₁ , t ₁ , t ₂ , t ₄ , and t ₁ , t ₂ , t ₃ , and t ₄ . In various embodiments, the delay time between adjacent TSN systems described above may be periodically calculated according to a predetermined period. At this time, along with calculating the periodic delay time, the neighborRateRatio between TSN systems can also be calculated. For example, neighborRateRatio is the ratio of the local clock frequency i of the peer delay initiator 1302 and the local clock frequency r of the peer delay responder 1304 ((local clock frequency i)/(local clock frequency r)). It can be decided through In various embodiments, the local clock frequency may mean the unique oscillation frequency or reciprocal of the period of the corresponding TSN system.

FIG. 14 illustrates a method of time synchronization between TSN systems in a wireless communication system according to various embodiments of the present disclosure.

Referring to FIG. 14, a time-aware system may refer to a TSN system. In step 1401, the master port 1402-1 of the time recognition system i-1 1402 may transmit a Sync frame to the slave port 1408 of the time recognition system i 1404 at time (t _{s, i-1} ) 1412. . Slave port 1408 can receive the Sync frame described above at time (t _r,i ) 1416. At this time, the difference between time (t _{s, i-1} ) 1412 and time (t _r,i ) 1416 means the propagation delay i-1 1414 between the TSN system i-1 1402 and the TSN system i 1404. You can.

In step 1403, the master port 1402-1 of the time recognition system i-1 1402 may transmit a Follow_Up frame to the slave port 1408 of the time recognition system i 1404. At this time, the Follow_Up frame may include preciseOriginTimestamp, correctionField _{i -1} , and rateRatio _{i -1} parameters. Here, preciseOriginTimestamp may mean the time when the Grandmaster in the TSN domain transmitted the Sync frame. correctionField _ii may mean a value reflecting the difference between preciseOriginTimestamp and the time when the TSN system i-1 1402 transmitted the Sync frame. rateRatio _{i - 1} represents the ratio of the clock frequency of the grand master and the clock frequency of the TSN system i-1 1402, and can be calculated as (Grandmaster Clock Frequency)/(Local Clock Frequency i-1). In various embodiments, the grand master may refer to a master node that first transmits a Sync frame for time synchronization in a TSN system.

In step 1405, the master port 1410 of the time recognition system i 1404 may transmit a Sync frame to the slave port 1406-1 of the time recognition system i+1 1406 at time (t _s,i ) 1420. Slave port 1406-1 can receive the Sync frame described above at time (t _{r, i+1} ) 1424. At this time, the difference between time (t _s,i ) 1420 and time (t _{r, i+1} ) 1424 may mean the propagation delay i 1422 of the TSN system i 1404 and the TSN system i+1 1406.

In step 1407, the master port 1410 of the time recognition system i may transmit a Follow_Up frame to the slave port 1406-1 of the time recognition system i+1 1406. At this time, the Follow_Up frame may include preciseOriginTimestamp, correctionField _i , and rateRatio _i parameters. Here, correctionField _i and rateRatio _i may be values calculated by the time recognition system i 1404. correctionField _i can be calculated as correctionField _i = correctionField _i-1 + LinkDelay _{i -1} + ResidenceTime _i . Here, LinkDelay _{i -1} refers to the delay time (D) between TSN systems described in FIG. 13, and may refer to a value periodically calculated according to a predetermined period and stored as an average value. Additionally, LinkDelay _{i - 1} may mean propagation delay i-1. In various embodiments, the residence time i 1418 represents the time of residence in the TSN system i 1404, the time (t _r,i ) 1416 at which the TSN system i 1404 receives the Sync frame, and the time when the TSN system i 1404 receives the Sync frame. This may mean the difference in time (t _s,i ) 1420 when the Sync frame is transmitted to system i+1 1406. In addition, rateRatio _i represents the ratio of the local clock frequencies of TSN system i 1404 and TSN system i+1 1406, rateRatio _i = rateRatio _{i - 1} x (Local Clock Frequency _{i -1} )/(Local Clock Frequency _i ) can be calculated together. Here, (Local Clock Frequency _{i -1} )/(Local Clock Frequency _i ) may mean a value that is calculated as neighborRateRatio and continuously updated when measuring the periodic delay time of FIG. 13. Generally, when building an Ethernet LAN, the link delay value is several hundred ns, the rateRatio is close to 1, but the dwell time is allowed up to 10 ms, so the TSN system is capable of accurately conveying the dwell time value. is the most important thing. In various embodiments, rateRatio may be a value having a difference of 200 bpm or less based on 1.

FIG. 15 illustrates a time synchronization method of a TSN bridge model in a wireless communication system according to various embodiments of the present disclosure.

Referring to FIG. 15, terminal 120 can periodically measure delay time on a link shared with an adjacent TSN system. That is, the terminal 120 can periodically measure the link 1 delay (D_Link1), and the UPF 130c can periodically measure the link 2 delay (D_Link2) and store them as average values. In Figure 15, when the 5G system including the terminal 120, the base station 110, and the UPF 130c transmits a Sync frame and a Follow_Up frame to the adjacent bridge 2 1520, R_5GS, which is the link delay and the time spent in the 5G system, is updated in the correction field. You can. At this time, the radio delay between the terminal 120 and the base station 110 in the 5G system and the backhaul (BH) delay between the base station 110 and the UPF 130c can be assumed to be fixed and symmetrical values by applying a predetermined delay QoS class. . In various embodiments, the above-described R_5GS may be calculated through the sum of the residence time, radio delay, and backhaul delay at the terminal 120, base station 110, and UPF 130c within the 5G system section. For example, the 5G system can confirm that the value of the correction field has become T3-T1 by updating the Link 1 delay and R_5GS in the Sync frame in the correction field. In various embodiments, the master 1510 may transmit a Sync frame to the terminal 120 included in the 5G system at time T1. Afterwards, the master 1510 can transmit a Follow_Up frame. At this time, Link 1 delay (D_Link1) may mean the difference between the time T1 when the master 1510 transmitted the Sync frame and the time T2 when the terminal 120 received the Sync frame. And, the time stamp can be set to T1 and the correction field can be set to 0. UPF 130c can transmit a Sync frame to Bridge 2 1520 at time T3. Bridge 2 1520 can receive Sync frames from T4. Afterwards, UPF 130c can also transmit Follow_Up frames. At this time, the difference between T2 and T3 may mean R_5GS. Additionally, the difference between T3 and T4 may mean Link 2 delay (D_Link2). Here, the time stamp can be set to T1 and the correction field can be set to T3-T1. Bridge 2 1520 can transmit a Sync frame to slave 1530 on T5. Slave 1530 can receive Sync frame from T6. At this time, the difference between T4 and T5 may mean the residence time of bridge 2 1520, R_Bridge2. Afterwards, Bridge 2 1520 can also transmit a Follow_Up frame. At this time, the difference between T5 and T6 may mean Link 3 delay (D_Link3). Here, the time stamp can be set to T1 and the correction field can be set to (T3-T1)+(T5-T3). Figure 16, described later, shows the time synchronization process using uplink in a network supporting IEEE 802.1AS and a 3GPP network.

Referring to FIG. 16, UE 120 and UPF 130c can perform periodic link delay measurements with neighboring TSN systems. Additionally, R_3GPP, which is the residence time within the 3GPP network, can be determined by UPF 130c in a method similar to the method described in FIG. 11 described above. In various embodiments, the backhaul delay time may be assumed to be known in advance by the UPF 130c through a management system or a separate measurement method. In Figure 16, R_UE may mean the stay time in UE 120, R_UPF may mean the stay time in UPF 130c, and R_TSN may mean the stay time in TSN SW 1620. BH may refer to a backhaul in which the delay is symmetrical. Wireless (Air) may refer to a 3GPP wireless environment in which delay is not symmetrical. In Figure 16, the master 1610 may transmit a Sync frame and a Follow_Up frame to the terminal 120 at time T1. Here, the time stamp can be set to T1 and the correction field can be set to 0. UPF 130c can transmit the Sync frame and Follow_Up frame transmitted through the terminal 120 and the base station 110 to TSN SW 1620. At this time, the time stamp is T1, and the correction field can be determined by the sum of link delay (D_Link) and R_3GPP, which is the residence time in the 3GPP network. Afterwards, TSN SW 1620 can transmit a Sync frame and a Follow_Up frame to the slave 1630. Where the timestamp is T1 and the correction field is the sum of link 1 delay (D_Link1), time of stay in 3GPP network (R_3GPP), link 2 delay (D_Link2), and time of stay in TSN SW 1620 (R_TSN). It can be set to . In FIG. 16, T_UL may mean the PHY frame time when the terminal 120 wirelessly transmits uplink Ethernet. At this time, the PHY frame may be synchronized with the base station GPS time. T_UL' may refer to the PHY frame time when the base station 110 receives uplink Ethernet from wireless. At this time, the PHY frame may be synchronized with the base station GPS time. T_TX may mean the GPS time at which base station 110 transmits the GTP-U payload with UPF 130c. Figure 17, described later, shows the time synchronization process using downlink in a network supporting IEEE 802.1AS and a 3GPP network.

Figure 17 illustrates a time synchronization method in the downlink in a wireless communication system according to various embodiments of the present disclosure.

Referring to FIG. 17, UE 120 and UPF 130c can perform periodic link delay measurements with neighboring TSN systems. In addition, R_3GPP, which is the residence time within the 3GPP network, can be determined by the terminal 120 in a method similar to the method described in FIG. 12 described above. The difference between the methods described in FIGS. 12 and 17 is that the value that UPF 130c transmits to base station 110 is R_CN including the delay time of the backhaul rather than R_UPF, and base station 110 can transmit this R_CN to terminal 120 instead of R_UPF. . In various embodiments, the backhaul delay time may be assumed to be known in advance by the UPF 130c through a management system or a separate measurement method. In Figure 17, R_UE may mean the stay time in UE 120, R_UPF may mean the stay time in UPF 130c, and R_TSN may mean the stay time in TSN SW 1720. BH may refer to a backhaul in which the delay is symmetrical. Wireless (Air) may refer to a 3GPP wireless environment in which the delay is not symmetrical. In Figure 17, the master 1730 can transmit a Sync frame and a Follow_Up frame to TSN SW 1720 at time T3. Here, the time stamp can be set to T3 and the correction field can be set to 0. TSN SW 1720 can transmit the transmitted Syn frame and Follow_Up frame with UPF 130c. At this time, the time stamp can be determined by T3, and the correction field can be determined by the sum of Link 3 delay (D_Link3) and the residence time (R_TSN) of TSN SW 1720. Afterwards, the Sync frame and Follow_Up frame may be transmitted to the slave 1710 through the base station 110 and the terminal 120. Slave 1710 can receive Sync frame and Follow_Up frame at time T4. At this time, the time stamp is T3, and the correction field is set to the sum of Link 3 delay (D_Link3), residence time in TSN SW 1720 (R_TSN), Link 2 delay (D_Link2), and residence time in 3GPP system (R_3GPP). You can.

Methods according to embodiments described in the claims or specification of the present disclosure may be implemented in the form of hardware, software, or a combination of hardware and software.

When implemented as software, a computer-readable storage medium that stores one or more programs (software modules) may be provided. One or more programs stored in a computer-readable storage medium are configured to be executable by one or more processors in an electronic device (configured for execution). One or more programs include instructions that cause the electronic device to execute methods according to embodiments described in the claims or specification of the present disclosure.

These programs (software modules, software) may include random access memory, non-volatile memory, including flash memory, read only memory (ROM), and electrically erasable programmable ROM. (electrically erasable programmable read only memory, EEPROM), magnetic disc storage device, compact disc-ROM (CD-ROM), digital versatile discs (DVDs), or other types of disk storage. It can be stored in an optical storage device or magnetic cassette. Alternatively, it may be stored in a memory consisting of a combination of some or all of these. Additionally, multiple configuration memories may be included.

In addition, the program may be distributed through a communication network such as the Internet, an intranet, a local area network (LAN), a wide area network (WAN), or a storage area network (SAN), or a combination thereof. It may be stored on an attachable storage device that is accessible. This storage device can be connected to a device performing an embodiment of the present disclosure through an external port. Additionally, a separate storage device on a communication network may be connected to the device performing an embodiment of the present disclosure.

In the specific embodiments of the present disclosure described above, elements included in the disclosure are expressed in singular or plural numbers depending on the specific embodiment presented. However, singular or plural expressions are selected to suit the presented situation for convenience of explanation, and the present disclosure is not limited to singular or plural components, and even components expressed in plural may be composed of singular or singular. Even expressed components may be composed of plural elements.

Meanwhile, in the detailed description of the present disclosure, specific embodiments have been described, but of course, various modifications are possible without departing from the scope of the present disclosure. Therefore, the scope of the present disclosure should not be limited to the described embodiments, but should be determined not only by the scope of the patent claims described later, but also by the scope of this patent claim and equivalents.

Claims (28)

In the method performed by the user plane function (UPF) device of the 5th generation system (5GS),
Receiving a message for synchronization from a time sensitive network (TSN) node;
generating an updated message including information for determining time spent within 5GS and information regarding link delay from a node of the TSN;
Including transmitting the updated message to a user equipment (UE) in the 5GS,
The updated message is one in which information about the link delay is added to a correction field of the message for synchronization.
In claim 1,
The message for synchronization includes a sync frame or a follow up frame.
In claim 1,
The dwell time is added by the UE to a correction field of the updated message.
In claim 1,
The residence time is the difference between the time when the message for synchronization is received and the time when the message is transmitted to the slave node by the UE that has received the updated message.
In a method performed by UE (user equipment) of 5GS (5th generation system),
For synchronization, including information for determining residence time spent within the 5GS from a user plane function (UPF) device within the 5GS, and link delay information from a node of a time sensitive network (TSN) in a correction field. receiving a message;
identifying the residence time; and
Transmitting an updated message to a slave node associated with the TSN, wherein the updated message has information about the residence time added to the correction field of the message for synchronization.
In claim 5,
The message for synchronization includes a sync frame or a follow up frame.
In claim 5,
The link delay is added to a correction field of the message for synchronization.
In claim 5,
The residence time is the difference between the time when the UPF device receives a message for synchronization from the TSN node and the time when the UE transmits the updated message.
In the UPF (user plane function) device in the 5th generation system (5GS), the UPF device,
Transmitter and receiver; and
Comprising at least one processor coupled to the transceiver,
The at least one processor,
Receive messages for synchronization from TSN (time sensitive network) nodes and
generate an updated message containing information for determining dwell time spent within 5GS, and information regarding link delay from a node of the TSN;
Configured to transmit the updated message to a user equipment (UE) in the 5GS,
The updated message is a UPF device in which information about the link delay is added to a correction field of the message for synchronization.
In claim 9,
The message for synchronization is a UPF device including a sync frame or a follow up frame.
In claim 9,
The dwell time is added by the UE to a correction field of the updated message.
In claim 9,
The residence time is the difference between the time when the message for synchronization is received and the time when the message is transmitted to the slave node by the UE that has received the updated message.
In a UE (user equipment) in 5GS (5th generation system), the UE,
Transmitter and receiver; and
Comprising at least one processor coupled to the transceiver,
The at least one processor,
For synchronization, including information for determining residence time spent within the 5GS from a user plane function (UPF) device within the 5GS, and link delay information from a node of a time sensitive network (TSN) in a correction field. receive a message,
identify said residence time;
Configured to transmit an updated message to a slave node associated with the TSN,
The updated message is one in which information about the stay time is added to the correction field of the message for synchronization.
In claim 13,
The message for synchronization is a UE including a sync frame or a follow up frame.
In claim 13,
The link delay is added to the correction field of the message for synchronization.
In claim 13,
The residence time is the difference between the time when the UPF device received a message for synchronization from the TSN node and the time when the UE transmitted the updated message. delete delete delete delete delete delete delete delete delete delete delete delete

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