CN112690025A

CN112690025A - Wireless communication network in a wireless communication system

Info

Publication number: CN112690025A
Application number: CN201980053894.1A
Authority: CN
Inventors: 文相畯; 李知彻; 朴重信; 白令教
Original assignee: Samsung Electronics Co Ltd
Current assignee: Samsung Electronics Co Ltd
Priority date: 2018-08-13
Filing date: 2019-08-13
Publication date: 2021-04-20
Also published as: KR20200019058A; EP3834517A1; KR102655526B1; EP3834517A4

Abstract

The present disclosure relates to a pre-5 th generation (5G) or 5G communication system to be provided for supporting higher data rates beyond a fourth generation (4G) communication system, such as Long Term Evolution (LTE). According to various embodiments of the present disclosure, a method for operating a base station in a wireless communication system includes receiving information about a dwell time of a terminal and a transmission time of an uplink frame from the terminal, determining a radio access network dwell time based on the transmission time of the uplink frame, and transmitting the radio access network dwell time and the dwell time of the terminal to a User Plane Function (UPF).

Description

Wireless communication network in a wireless communication system

Technical Field

The present disclosure relates to a wireless communication system, and more particularly, to an apparatus and method for synchronization using a wireless communication network in a wireless communication system.

Background

In order to meet the increasing demand for wireless data traffic since the deployment of fourth generation (4G) communication systems, efforts have been made to develop improved fifth generation (5G) or pre-5G (pre-5G) communication systems. Accordingly, a 5G or pre-5G communication system is also referred to as an "beyond 4G network" or a "Long Term Evolution (LTE) system".

To achieve higher data rates, the 5G communication system is considered to be implemented at a higher frequency (millimeter wave) band (e.g., 60GHz band). In order to reduce propagation loss of radio waves and increase transmission distance, beamforming, massive Multiple Input Multiple Output (MIMO), Full-Dimensional MIMO (FD-MIMO), array antenna, analog beamforming, and massive antenna techniques are discussed in the 5G communication system.

Further, in the 5G communication system, development of system network improvement is ongoing based on advanced small cells, cloud Radio Access Networks (RANs), ultra-dense networks, ultra-high density networks, device-to-device (D2D) communication, wireless backhaul, mobile networks, cooperative communication, coordinated multipoint (CoMP), reception side interference cancellation, and the like.

In the 5G system, hybrid Frequency Shift Keying (FSK) and quadrature amplitude modulation (FQAM) and Sliding Window Superposition Coding (SWSC) have been developed as Advanced Coding Modulation (ACM), and filter bank multi-carrier (FBMC), non-orthogonal multiple access (NOMA) and Sparse Code Multiple Access (SCMA) as advanced access technologies.

With the development of mobile communication technology, it has been required to provide clock synchronization technology in a wireless network that has been provided only in a wired network. However, it is difficult to introduce a clock synchronization technique in a wireless network due to the asymmetry of propagation delays of Uplink (UL) and Downlink (DL) in the air link. To overcome such difficulties, a scheme for providing clock synchronization between terminals in a wireless communication network may be required.

BRIEF SUMMARY OF THE PRESENT DISCLOSURE

An aspect of the present disclosure is to provide an apparatus and method for synchronization using a wireless communication network in a wireless communication system.

Another aspect of the present disclosure is to provide an apparatus and method for solving an asymmetry problem of propagation delays of an Uplink (UL) and a Downlink (DL) in an airlink, so that a clock synchronization function supported only in a wired network in a wireless communication system can also be supported in a wireless communication network.

According to one aspect of the present disclosure, a method for operating an apparatus for a User Plane Function (UPF) in a wireless communication system, the method comprising: receiving a synchronization message from a host; and transmitting information determined based on an entry time at which the UPF receives the synchronization message from the host.

According to another aspect of the present disclosure, a method for operating a User Equipment (UE) in a wireless communication system, the method comprising: receiving information determined based on an entry time at which the UPF receives the synchronization message from the host; determining a residence time for the message based on the ingress time and the egress time; and sending information about the dwell time to the slave.

According to another aspect of the present disclosure, a User Equipment (UE) in a wireless communication system, the UE comprising: a transceiver; and at least one processor configured to: receiving information determined based on an entry time at which the UPF receives the synchronization message from the host; determining a residence time for the message based on the ingress time and the egress time; and sending information about the dwell time to the slave.

As described above, apparatuses and methods according to various embodiments of the present disclosure may enable synchronization to be performed using a wireless communication network.

Furthermore, apparatus and methods according to various embodiments of the present disclosure may enable wireless communication networks to be used in applications requiring clock synchronization between nodes, such as factory automation.

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

Before proceeding with the following detailed description, it may be advantageous to set forth definitions of certain words and phrases used throughout this patent document: the terms "include" and "comprise," as well as derivatives thereof, mean inclusion without limitation; the term "or" is inclusive, meaning and/or; the phrases "associated with … …" and "associated with … …," and derivatives thereof, may mean to include, be included within … …, interconnect with … …, contain, be included within … …, connect or connect with … …, couple or couple with … …, be communicable with … …, cooperate with … …, interleave, juxtapose, be proximate to, be joined with or join with … …, have the properties of … …, and the like; and the term "controller" means any device, system, or part thereof that controls at least one operation, such a device may be implemented in hardware, firmware, or software, or in a combination of at least two of the same. It should be noted that the functionality associated with any particular controller may be centralized or distributed, whether locally or remotely.

Further, various functions described below may be implemented or supported by one or more computer programs, each of which is formed from computer readable program code and embodied in a computer readable medium. The terms "application" and "program" refer to one or more computer programs, software components, sets of instructions, procedures, functions, objects, classes, instances, related data, or a portion thereof adapted for implementation in suitable computer readable program code. The phrase "computer readable program code" includes any type of computer code, including source code, object code, and executable code. The phrase "computer readable medium" includes any type of medium capable of being accessed by a computer, such as Read Only Memory (ROM), Random Access Memory (RAM), a hard disk drive, a Compact Disc (CD), a Digital Video Disc (DVD), or any other type of memory. A "non-transitory" computer-readable medium does not include a wired, wireless, optical, or other communication link that transmits transitory electrical or other signals. Non-transitory computer-readable media include media in which data can be permanently stored and media in which data can be stored and subsequently overwritten, such as rewritable optical disks or erasable memory devices.

Definitions for certain words and phrases are provided throughout this patent document. Those of ordinary skill in the art should understand that in many, if not most instances, such definitions apply to prior, as well as future uses of such defined words and phrases.

Drawings

The above and other aspects, features and advantages of certain embodiments of the present disclosure will become more apparent from the following description taken in conjunction with the accompanying drawings, in which:

fig. 1 illustrates a wireless communication system in accordance with various embodiments of the present disclosure;

fig. 2 illustrates a configuration of a base station in a wireless communication system according to various embodiments of the present disclosure;

fig. 3 illustrates a configuration of a terminal in a wireless communication system according to various embodiments of the present disclosure;

fig. 4 illustrates a configuration of a core network entity in a wireless communication system, in accordance with various embodiments of the present disclosure;

fig. 5 illustrates clock synchronization in a wired network that does not support a Time Sensitive Network (TSN) in a wireless communication system, according to various embodiments of the present disclosure;

fig. 6 illustrates clock synchronization in a wired network supporting TSNs in a wireless communication system according to various embodiments of the present disclosure;

fig. 7 illustrates the problem of clock synchronization using a wireless communication network in a wireless communication system according to various embodiments of the present disclosure;

fig. 8 shows a flow diagram of a base station in a wireless communication system, in accordance with various embodiments of the present disclosure;

fig. 9 shows a flow diagram of a terminal in a wireless communication system, in accordance with various embodiments of the present disclosure;

fig. 10 illustrates a protocol of a wireless communication network for addressing the problem of clock synchronization using the wireless communication network in a wireless communication system, in accordance with various embodiments of the present disclosure;

fig. 11 illustrates a synchronization method in an uplink in a wireless communication system according to various embodiments of the present disclosure;

fig. 12 illustrates a synchronization method in a downlink in a wireless communication system according to various embodiments of the present disclosure;

fig. 13 illustrates a method for measuring delay times between neighboring TSN systems in a wireless communication system, in accordance with various embodiments of the present disclosure;

fig. 14 illustrates a clock synchronization method between TSN systems in a wireless communication system, according to various embodiments of the present disclosure;

fig. 15 illustrates a clock synchronization method of a TSN bridge model in a wireless communication system, according to various embodiments of the present disclosure;

fig. 16 illustrates a clock synchronization method in an uplink in a wireless communication system according to various embodiments of the present disclosure; and

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

Detailed Description

Figures 1 through 17, discussed below, and the various embodiments used to describe the principles of the present disclosure in this patent document are by way of illustration only and should not be construed in any way to limit the scope of the disclosure. Those skilled in the art will understand that the principles of the present disclosure may be implemented in any suitably arranged system or device.

The terminology used in the present disclosure is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. Singular expressions may include plural expressions unless they are clearly different in context. Unless otherwise defined, all terms used herein, including technical and scientific terms, have the same meaning as those terms commonly understood by one of ordinary skill in the art to which this disclosure belongs. Such terms as defined in commonly used dictionaries may be interpreted as having a meaning that is equivalent to the contextual meaning in the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein. In certain instances, even terms defined in the present disclosure should not be construed to exclude embodiments of the present disclosure.

Hereinafter, various embodiments of the present disclosure will be described based on a hardware method. However, various embodiments of the present disclosure include techniques that use both hardware and software, and thus, various embodiments of the present disclosure may not preclude a software perspective.

The present disclosure relates to an apparatus and method for synchronization using a wireless communication network in a wireless communication system. In particular, the present disclosure describes a technique for supporting clock synchronization in a wireless communication network by determining a residence time of the wireless communication network based on residence times of various entities in the wireless communication network in a wireless communication system.

For convenience of description, terms related to signals, terms related to channels, terms related to control information, terms related to network entities, terms related to components of equipment, and the like, used in the following description are illustrated. Accordingly, the present disclosure is not limited to the following terms, and other terms having equivalent technical meanings may be used.

Furthermore, the present disclosure describes various embodiments using terminology used in some communication standards (e.g., the third generation partnership project (3GPP)), but this is merely illustrative. The various embodiments of the present disclosure may also be readily modified and applied to other communication systems.

Fig. 1 illustrates a wireless communication system in accordance with 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 RAN 102 is a network directly connected to user equipment, e.g., terminals 120, and is the infrastructure that provides wireless connectivity to the terminals 120. RAN 102 includes a set of multiple base stations, including base station 110, and the multiple base stations may perform communication over an interface formed therebetween. At least some of the interfaces between the plurality of base stations may be provided in a wired or wireless manner. The base station 110 may have a structure divided into a Central Unit (CU) and a Distributed Unit (DU). In this case, one CU can control a plurality of DUs. The base station 110 may be referred to as an "Access Point (AP)", "next generation node b (gnb)", "fifth generation node (5G node)", "wireless point", "transmission/reception point (TRP)" or other terms having equivalent technical meanings. The terminal 120 may be connected to the RAN 102 and may communicate with the base station 110 over a wireless channel. The terminal 120 may be referred to as "User Equipment (UE)", "mobile station", "subscriber station", "remote terminal", "wireless terminal", "user equipment", or other terms with technical equivalents.

The core network 104 is a network that manages the entire system. The core network 104 may control the RAN 102 and may process data and control signals for the terminals 120 that are sent and received by the RAN 102. The core network 104 may perform various functions such as controlling the user plane and control plane, handling mobility, managing subscriber information, charging, interlocking with other types of systems (e.g., Long Term Evolution (LTE) systems), etc. To perform the various functions described above, the core network 104 may include a plurality of functionally separate entities having different Network Functions (NFs). For example, the core network 104 may include 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, a Network Repository Function (NRF)130e, a User Data Management (UDM)130f, a network open function (NEF) 130g, and a Unified Data Repository (UDR)130 h.

The terminal 120 is connected to the RAN 102 and to an AMF 130a that performs mobility management functions of the core network 104. The AMF 130a is a function or device responsible for both the connection of the RAN 102 and the mobility management of the terminal 102. The SMF 130b is an NF for managing sessions. The AMF 130a is connected to the SMF 130b, and the AMF 130a routes the session-related message of the terminal 120 to the SMF 130 b. The SMF 130b allocates user plane resources to be provided to the terminal 120 in conjunction with the UPF130c and establishes a tunnel for transmitting data between the base station 110 and the UPF130 c. PCF 130d controls information related to the policy and charging for the session used by terminal 120. The NRF 130e stores information on NFs installed in the mobile carrier network and performs a function of notifying the stored information. NRF 130e may be connected to all NFs. At the start of driving in the carrier network, each NF is registered in NRF 130e, and NRF 130e is notified that the corresponding NF is being driven in the network. UDM 130f is a NF that plays a role similar to a Home Subscriber Server (HSS) of a 4G network, and stores subscription information of terminal 120 or context used by terminal 120 in the network.

The NEF 130G is used to connect a third party server and NF in the 5G mobile communication system. NEF 130g is also used to provide, update, or retrieve data to UDR 130h or from UDR 130 h. The UDR 130h performs a function of storing subscription information of the terminal 120, storing policy information, storing externally opened data, or storing information required by a third party application. UDR 103h is also used to provide stored data to other NFs.

Fig. 2 illustrates a configuration of a base station in a wireless communication system according to various embodiments of the present disclosure. The configuration shown in fig. 2 can be understood as the configuration of the base station 110. Terms such as "… unit", "… (square)" and the like used herein denote a unit for processing at least one function or operation, and may be implemented by 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 controller 240.

The wireless communication unit 210 performs a function for transmitting and receiving signals through a wireless channel. For example, the wireless communication unit 210 performs conversion between a baseband signal and a bit string according to the physical layer specification of the system. For example, at the time of data transmission, the wireless communication unit 210 generates a complex symbol by encoding and modulating a transmission bit string. In addition, when receiving data, the wireless communication unit 210 demodulates and decodes the baseband signal to recover the received bit string.

Also, the wireless communication unit 210 up-converts a baseband signal into a Radio Frequency (RF) band signal, transmits the RF band signal through an antenna, and down-converts 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 converter (DAC), and an analog-to-digital converter (ADC). In addition, the wireless communication unit 210 may include a plurality of transmission/reception paths. Further, 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 composed of a digital unit and an analog unit, and the analog unit may include a plurality of sub-units according to operating power, operating frequency, and the like. The digital unit may be implemented with at least one processor, such as a Digital Signal Processor (DSP).

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

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

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

The controller 240 controls the overall operation of the base station. For example, the controller 240 transmits and receives signals through the wireless communication unit 210 or the backhaul communication unit 220. In addition, the controller 240 records and reads data in the storage unit 230. The controller 240 may perform the functions of a protocol stack required by a communication standard. According to another implementation example, a protocol stack may be included in the wireless communication unit 210. To this end, the controller 240 may include at least one processor. According to various embodiments, the controller 240 may use wireless communication network control to perform synchronization. For example, the controller 240 may control the base station to perform operations according to various embodiments described below.

Fig. 3 illustrates a configuration of a terminal in a wireless communication system according to various embodiments of the present disclosure. The configuration shown in fig. 3 can be understood as the configuration of the terminal 120. Terms such as "… unit", "… (square)" and the like used herein denote a unit for processing at least one function or operation, and may be implemented by 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 controller 330.

The communication unit 310 performs a function for transmitting and receiving a signal through a wireless channel. For example, the communication unit 310 performs conversion between a baseband signal and a bit string according to the physical layer specification of the system. For example, at the time of data transmission, the communication unit 310 generates a complex symbol by encoding and modulating a transmission bit string. In addition, at the time of data reception, the communication unit 310 demodulates and decodes the baseband signal to restore the received bit string. Further, communication section 310 up-converts a baseband signal into an RF band signal, transmits the RF band signal through an antenna, and down-converts 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, and the like.

In addition, the communication unit 310 may include a plurality of transmission/reception paths. Furthermore, the communication unit 310 may comprise at least one antenna array consisting of a plurality of antenna elements. In terms of hardware, the communication unit 310 may be composed of a digital circuit and an analog circuit (e.g., a Radio Frequency Integrated Circuit (RFIC)). Here, the digital circuit and the analog circuit may be implemented in one package. In addition, the communication unit 310 may include a plurality of RF chains. Further, the communication unit 310 may perform beamforming.

The communication unit 310 transmits and receives signals as described above. Accordingly, all or a portion of the communication unit 310 may be referred to as a "transmitter," receiver, "or" transceiver. In the following description, transmission and reception performed through a wireless channel are used to indicate that the processing described above is performed by the communication unit 310.

The storage unit 320 stores data such as basic programs, application programs, and setting information for terminal operations. The storage unit 320 may include volatile memory, non-volatile memory, or a combination of volatile and non-volatile memory. The storage unit 320 provides stored data according to a request of the controller 330.

The controller 330 controls the overall operation of the terminal. For example, the controller 330 transmits and receives signals through the communication unit 310. In addition, the controller 330 records and reads data in the storage unit 320. The controller 330 may perform the functions of a protocol stack required by the communication standard. To this end, the controller 330 may include at least one processor or microprocessor, or may be part of a processor. In addition, the communication unit 310 and a part of the controller 330 may be referred to as a Communication Processor (CP). According to various embodiments, the controller 330 may use wireless communication network control to perform synchronization. For example, the controller 330 may control the terminal to perform operations according to various embodiments described below.

Fig. 4 illustrates a configuration of a core network entity in a wireless communication system, according to various embodiments of the present disclosure. The configuration 130 shown in fig. 4 may be understood as a configuration of an apparatus having at least one function of 130a, 130b, 130c, 130d, 130e, 130f, 130g, and 130h in fig. 1. Terms such as "… unit", "… (square)" and the like used herein denote a unit for processing at least one function or operation, and may be implemented by hardware, software, or a combination of hardware and software.

Referring to fig. 4 above, the core network entity includes a communication unit 410, a storage unit 420, and a controller 430.

The communication unit 410 provides an interface for performing communication with other devices in the network. That is, the communication unit 410 converts a bit string transmitted from the core network entity to another equipment into a physical signal, and converts a physical signal received from another equipment into a bit string. That is, the communication unit 410 may transmit and receive signals. Thus, 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 enables the core network entity to communicate with other devices or systems via a backhaul connection (e.g., a wired backhaul or a wireless backhaul) or via a network.

The storage unit 420 stores data such as basic programs, application programs, and setting information for the operation of the core network entity. The storage unit 420 may include volatile memory, non-volatile memory, or a combination of volatile and non-volatile memory. The storage unit 420 provides stored data according to a request of the controller 430.

The controller 430 controls the overall operation of the core network entity. For example, the controller 430 transmits and receives signals through the communication unit 410. In addition, the controller 430 records and reads data in the storage unit 420. To this end, the controller 430 may include at least one processor. According to various embodiments, the controller 430 may use wireless communication network control to perform synchronization. For example, the controller 430 may control the core network entities to perform operations according to various embodiments described below.

For convenience of description, terms related to a connection node, terms related to network entities, terms related to a message, terms related to an interface between network entities, terms related to various identification information, and the like used in the following description are illustrated. Accordingly, the present disclosure is not limited to the following terms, and other terms related to objects having equivalent technical meanings may be used.

Hereinafter, for convenience of the following description, the present disclosure uses terms and names defined in a 5G system (5GS) and a New Radio (NR) standard, which are the latest standards defined by 3GPP in existing communication standards. However, the present disclosure is not limited by the above terms and names, and may be equally applied to wireless communication networks conforming to other standards. In particular, the present disclosure is applicable to 3GPP generation 5 mobile communication standards (e.g., 5GS and NR).

Fig. 5 illustrates clock synchronization in a wired network that does not support TSNs in a wireless communication system, according to various embodiments of the present disclosure. Clock synchronization in wired networks may operate based on the IEEE 1588 version (v) 1 specification.

Referring to fig. 5, in various embodiments, a master 510 may refer to a node that provides a reference clock, and a slave 520 may refer to a node that performs clock synchronization to adjust its own clock to match the provided reference time. For example, the master 510 and the slave 520 may include electronics for communication and electronics for factory automation (e.g., factory computer, robotic arm, etc.). If the wired network does not support TSN, the delay time estimation between the master 510 and the slave 520 may not be accurate because the delay time according to direction is asymmetric. As a result, the accuracy of clock synchronization may be reduced. In various embodiments, master 510 may send a delay measurement request ethernet frame to slave 520 with current time (T1)502 recorded in the timestamp field to slave 520. After receiving the ethernet frame, the slave 520 may allow the time (T2)504 at which the ethernet frame was received to be included in the delay measurement response ethernet frame. The slave 520 may transmit a delay measurement response ethernet frame to the host 510, wherein a transmission time (T3)506 of the delay measurement response ethernet frame is recorded in the timestamp field. The host 510 may receive the delay measurement response ethernet frame from the slave 520 at time (T4)508, and may then average the delay times of the delay measurement request ethernet frame and the delay measurement response ethernet frame to estimate the delay time d. At this time, the delay time d may be determined by equation 1.

Equation 1

d＝((T2-T1)+(T4-T3))/2

Referring to equation 1, d denotes an estimated delay time, T1 denotes a time when the master 510 transmits a delay measurement request to the slave 520, T2 denotes a time when the slave 520 receives the delay measurement request from the master 510, T3 denotes a time when the slave 520 transmits a delay measurement response to the master 510, and T4 denotes a time when the master 510 receives 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 may adjust the clock of the slave 520 by adding the estimated delay time d to the timestamp sent by the master 510. Therefore, clock synchronization between the master 510 and the slave 520 can be obtained. In various embodiments, the delay of each of link1 (link 1) and link2 (link 2) is a propagation delay, and thus it is symmetric in the transmit direction. However, the delay through the bridge Network (NW) is not symmetric in the sending direction because it includes queuing delay and processing delay. In various embodiments, each of T1 and T4 may be times relative to the clock of master 510, and each of T2 and T3 may be times relative to the clock of slave 520. As described above, in various embodiments, clock synchronization may be inaccurate because the delay estimate is inaccurate.

Fig. 6 illustrates clock synchronization in a wired network supporting TSNs in a wireless communication system according to various embodiments of the present disclosure. The clock synchronization of wired networks may operate based on the IEEE 1588 version 2 specification.

Referring to fig. 6, when the wired network supports the TSN, the delay time estimation between the master 610 and the slave 620 becomes more accurate than when the TSN does not exist, and thus the accuracy of clock synchronization can be enhanced. In various embodiments, the TSN bridge network may provide a residence time correction function. That is, the host 610 may send the delay measurement request ethernet frame to the slave 620 at time (T1)602, and the TSN bridge network may then calculate the residence time (TB2-TB1) using the time of the delay measurement request ethernet frame entering the TSN bridge network (TB1)604 and the time of the delay measurement request ethernet frame exiting the TSN bridge network (TB2) 606. The TSN bridge network may record the calculated residence time (TB2-TB1) to the correction field of the corresponding ethernet frame. Since the standby delay and the processing delay during the delay through the bridge network are specified in the residence time (TB2-TB1) calculated above, only the propagation delay symmetrical to the transmission direction can be retained when the residence time is corrected in the delay time experienced by the ethernet frame. In various embodiments, slave 620 may receive the delay measurement request at time T2. At time (T3)612, slave 620 may send the delay measurement response ethernet frame to host 610, and the TSN bridge network may then calculate the residence time (TB4-TB3) using time (TB3)614 at which the delay measurement response ethernet frame of slave 620 entered the TSN bridge network and time (TB4)616 at which the delay measurement response ethernet frame exited the TSN bridge network. The TSN bridge network may reflect the calculated residence time in the correction field of the corresponding ethernet frame (TB4-TB 3). When this dwell time (TB4-TB3) is corrected in the delay experienced by the delay measurement response ethernet frame, only the propagation delay symmetrical to the transmission direction can be preserved. At time T4618, the master 610 receives the delay measurement response ethernet frame from the slave 620 and may determine the delay time d estimated by the master as shown in equation 2.

Equation 2

d＝((T2-(T1+(TB2-TB1)))+(T4-(T3+(TB4-TB3)))/2

Referring to equation 2, d denotes an estimated delay time, T1 denotes a time when the master 610 transmits a delay measurement request to the slave 620, T2 denotes a time when the slave 620 receives the delay measurement request from the master 610, T3 denotes a time when the slave 620 transmits a delay measurement response to the master 610, and T4 denotes a time when the master 610 receives the delay measurement response from the slave 620. TB1 denotes the time of the delay measurement request ethernet frame entering the TSN bridge network, TB2 denotes the time of the delay measurement request ethernet frame exiting the TSN bridge network, TB3 denotes the time of the delay measurement response ethernet frame entering the TSN bridge network, and TB4 denotes the time of the delay measurement response ethernet frame exiting the TSN bridge network. In various embodiments, the slave 620 may adjust the clock of the slave 620 by adding the estimated delay time d and the correction field to the timestamp sent by the master 610. Therefore, clock synchronization between the master 610 and the slave 620 can be obtained. As described above, in various embodiments, the TSN may provide dwell time delay correction.

Fig. 7 illustrates a clock synchronization problem 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 Switch (SW))720 that provides TSN functionality, problems may occur in providing clock synchronization. First, the terminal (e.g., UE)120, the base station (e.g., gNB)110, and the UPF130c, which are various entities of the 3GPP NW, may not provide the dwell time correction within the various entities. Second, in an air link between a terminal and a base station, delay times of an Uplink (UL) and a Downlink (DL) may be asymmetric. In various embodiments, master 710 may send a delay measurement request to 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. Slave 730 may send a delay measurement response to master 710 at time (T3) 706. At time (T4)708, master 710 may receive a delay measurement response from slave 730.

Fig. 8 shows a flow diagram of a base station in a wireless communication system, in accordance with various embodiments of the present disclosure. Fig. 8 illustrates a method of operating the base station 110 in uplink.

Referring to fig. 8, in operation 801, a base station may receive information about a dwell time of a terminal and a transmission time of an uplink ethernet frame from the terminal. For example, the terminal may calculate a time during which the uplink ethernet frame stays at the terminal, i.e., a dwell time of the terminal, and the base station may receive information about the dwell time of the terminal and a time at which the terminal transmits the uplink ethernet frame from the terminal. In various embodiments, the time at which the terminal sends the uplink ethernet frame may be included in a Service Data Application Protocol (SDAP) and may be sent to the base station.

In operation 803, the base station may determine a radio access network dwell time using a transmission time of the uplink ethernet frame. For example, the base station may determine the residence time of the radio access network using the time of transmission of the uplink ethernet frame and the time the base station transmits a General Packet Radio Service (GPRS) tunneling protocol user plane (GTP-U) payload to the UPF.

In operation 805, the base station may transmit the determined radio access network residence time and the residence time of the terminal to the UPF. In various embodiments, the base station may enable the determined residence time of the radio access network to be included in a GTP-U header and may send the GTP-U header to the UPF. The UPF may calculate a residence time of the uplink ethernet frame within the modified wireless communication network using the received residence time of the radio access network, the residence time of the terminal, and the residence time of the uplink ethernet frame within the UPF, and may reflect the modified residence time within the wireless communication network in the correction field. Thus, the problem of asymmetry of the air link delay in the uplink can be solved.

Fig. 9 shows a flow diagram of a terminal in a wireless communication system, in accordance with various embodiments of the present disclosure. Fig. 9 illustrates a method of operating the terminal 120 in the downlink.

Referring to fig. 9, the terminal may receive information on a residence time of a UPF and a reception time of a downlink ethernet frame in operation 901. For example, the terminal may receive information from the base station regarding the dwell time of the downlink ethernet frame in the UPF and the time the base station receives the downlink ethernet frame from the UPF. In various embodiments, the residence time of the UPF may be included in a GTP-U header and may be sent to the base station.

In operation 903, the terminal may determine a radio access network residence time using the time of receipt of the downlink ethernet frame. For example, the terminal may determine the residence time of the radio access network using the time the base station receives the GTP-U payload from the UPF and the time the terminal receives the downlink ethernet frame from the base station.

In operation 905, the terminal may determine a wireless communication network residence time based on the residence time of the UPF and the determined radio access network residence time. In various embodiments, the terminal may calculate the modified residence time of the downlink ethernet frame within the 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 radio access network, and may reflect the modified residence time of the wireless communication network in the correction field. Thus, the problem of asymmetry of the air link delay in the downlink can be solved.

Fig. 10 illustrates a protocol of a wireless communication network for addressing clock synchronization issues using the wireless communication network in a wireless communication system according to various embodiments of the present disclosure.

Referring to fig. 10, the ethernet frame enters the wireless communication network through the terminal 120, and then the terminal 120 and the base station 110 may be processed by the SDAP and the Packet Data Convergence Protocol (PDCP). The base station 110 may not read or modify the ethernet frame. In addition, communication between the terminal 120 and the base station 110 may be performed using a Medium Access Control (MAC)/Radio Link Control (RLC)/physical layer (PHY) frame synchronized with a clock of the base station 110. The base station 110 and the UPF130c may communicate with each other using GTP-U and the UPF130c may not directly read or modify ethernet frames. In the UPF130c, the ethernet frame can escape (escape) from the wireless communication network. Even in an ethernet switch (TSN SW)1020 supporting TSN, an ethernet frame can enter from the outside. The incoming ethernet frame may be processed internally and then may be sent out again. Thus, the wireless communication network can be modeled as an ethernet switch supporting one TSN. In various embodiments, dwell time correction may be performed on ethernet frames that have entered the interior of the wireless communication network. In various embodiments, master 1010 may send a delay measurement request to slave 1030. The slave 1030 receiving the delay measurement request may send a delay measurement response to the master 1010.

Fig. 11 illustrates a synchronization method in an 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 UPF130c may perform a dwell time correction for each entity. Each entity may calculate the time that the uplink ethernet stays in each entity as R (dwell time) _ UE, R _ gNB, and R _ UPF. The terminal 120 may cause the time (T) _ UL at which the R _ UE and the uplink ethernet are transmitted to the base station 110 to be included in the SDAP, and may transmit the SDAP to the base station 110. In various embodiments, T _ UL may be determined using MAC/RLC/PHY frame times commonly known by base station 110 and terminal 120. That is, the frame time of the MAC/RLC/PHY when the terminal 120 transmits the uplink ethernet may be recorded as T _ UL. The base station 110 may calculate the residence time R _ RAN of the radio access network by summing the delay time of the uplink air link and the residence time of the base station 110. When the time that the base station 110 sends the GTP-U payload to the UPF130c is T TX, the R _ RAN may be calculated as equation 3.

Equation 3

R_RAN＝T_TX-T_UL

Referring to equation 3, R _ RAN denotes a residence time of a radio access network, T _ TX denotes a time when the base station 110 transmits a GTU-U payload to the UPF130c, and T _ UL denotes a frame time when the terminal 120 transmits uplink ethernet. The base station 110 may cause the R _ RAN value to be included in a GTP-U header and may send the GTP-U header to the UPF130 c. Since the UPF130c is where the ethernet frame escapes the wireless communication network, the UPF130c must reflect the residence time R _3GPP in the wireless communication network in the correction field. The residence time R _3GPP in the wireless communication network can be calculated by equation 4.

Equation 4

R_3GPP＝R_UE+R_RAN+BH+R_UPF

Referring to equation 4, R _3GPP denotes a residence time within the wireless communication network, R _ UE denotes a residence time within the terminal 120, R _ RAN denotes a residence time of the radio access network, BH denotes a backhaul delay time, and R _ UPF denotes a residence time within the UPF130 c. R _3GPP is a value obtained by adding both the residence time within the entity and the delay time in the radio link and the backhaul link. In various embodiments, the delay time of the radio link between the terminal 120 and the base station 110 may be asymmetric in the transmit direction. However, in various embodiments, the backhaul link between the base station 110 and the UPF130c may be comprised of a wired network, and it may be assumed that the link is a link with only propagation delay. Thus, the delay time of the backhaul link may be symmetrical in the transmit direction. In various embodiments, the residence time R _3 GPP' within the modified wireless communication network may be calculated as in equation 5, except for the delay time of the backhaul link, which is symmetric to the transmission direction.

Equation 5

R_3GPP’＝R_UE+R_RAN+R_UPF

Referring to equation 5, R _3 GPP' represents a residence time within the modified wireless communication network, R _ UE represents a residence time of the terminal 120, R _ RAN represents a residence time of the radio access network, and R _ UPF represents a residence time within the UPF130 c. In various embodiments, the UPF130c may update the calculated R _3 GPP' in a correction field before sending the ethernet frame to the outside. In various embodiments, T _ UL represents the PHY frame time when the terminal 120 transmits uplink ethernet to the radio link. At this time, the PHY frame may be synchronized with Global Positioning System (GPS) time of the base station 110. In various embodiments, T _ UL' represents the PHY frame time when the base station 110 receives uplink ethernet from the radio link. At this time, the PHY frame may be synchronized with GPS time of the base station 110. In various embodiments, the base station 110 may be connected to a GPS system. Thus, T _ TX represents GPS time when base station 110 sends a GTP-U payload to UPF130 c. As described above, the dwell time correction may be performed on the terminal 120, the base station 110, and the UPF130 c. To address the asymmetry of uplink and downlink radio link delays, uplink and downlink radio link delays may be delivered. For example, uplink radio link delays may be delivered via GTP-U, and downlink radio link delays may be delivered via SDAP and MAC. In various embodiments, master 1110 may send a latency measurement request to slave 1130. The delay measurement request transmitted by the main base station 1110 may be corrected in the UPF130c and the TSN SW 1120.

Fig. 12 illustrates a synchronization method in a downlink in a wireless communication system according to various embodiments of the present disclosure.

Referring to fig. 12, each entity in the wireless communication network can perform dwell time correction on the delay measurement response ethernet frame even in a similar manner as in the case of the uplink. In various embodiments, the UPF130c may enable the downlink ethernet dwell time within the UPF130c to be included in a GTP-U header and may send the GTP-U to the base station 110. The base station 110 may record the reception time T _ RX in the GTP-U and may cause T _ RX to be included in the SDAP to transmit the SDAP to the terminal 120. The terminal 110 may calculate a residence time R _ RAN of the radio link as shown in equation 6 after obtaining a time T _ DL at which a corresponding frame is received in the downlink based on the MAC/RLC/PHY frame time.

Equation 6

R_RAN＝T_DL-T_RX

Referring to equation 6, R _ RAN represents the dwell time of the radio link, T _ DL represents the frame time when the terminal 120 receives the downlink ethernet, and T _ RX represents the time when the base station 110 receives the GTP-U payload from the UPF130 c. In various embodiments, the residence time R _3 GPP' within the modified wireless communication network may be calculated as shown in equation 7 by reflecting the residence time in the terminal 120 when the terminal 120 transmits the delay measurement response ethernet frame to the outside.

Equation 7

R_3GPP’＝R_UE+R_RAN+R_UPF

Referring to equation 7, R _3 GPP' represents a residence time within the modified wireless communication network, R _ UE represents a residence time within the terminal 120, R _ RAN represents a residence time of the radio access network, and R _ UPF represents a residence time within the UPF130 c. In various embodiments, the terminal 120 may add the calculated R _3 GPP' to the correction field. In various embodiments, the slave 1230 may perform synchronization with the master 1210 based on the master timestamp, the correction value, and the delay time d received from the master 1210.

In various embodiments, T _ DL represents the PHY frame time when the terminal 120 receives ethernet from the radio link. At this time, the PHY frame may be synchronized with GPS time of the base station 110. T _ DL' represents the PHY frame time when the base station 110 transmits downlink ethernet to the radio link. At this time, the PHY frame may be synchronized with GPS time of the base station 110. T RX represents the base station time when base station 110 receives the GTP-U payload from UPF130 c. As described above, the dwell time correction may be performed at the terminal 120, the base station 110, and the UPF130 c. To address the asymmetry of uplink and downlink radio link delays, uplink and downlink radio link delays may be delivered. For example, the uplink radio link delay may be delivered via GTP-U and the downlink radio link delay may be delivered via SDAP and MAC. In various embodiments, the slave 1230 may send a delay measurement response to the master 1210. TSN SW 1220 may record a timestamp T3 that delays the time that the measurement response passed.

The clock synchronization process in a network supporting 802.1AS has the same basic principle AS the above-described clock synchronization process in IEEE 1588, but there is a difference in the process between them. For example, a process for measuring the periodic link delay time between two adjacent TSN systems (e.g., end stations or bridges) and a process for updating a correction field that includes the residence time in a bridge may be included in the different processes described above. In various embodiments, an end station may refer to a node that may act as a master or slave node. Hereinafter, fig. 13 and 14 describe a specific operation method of the above-described process.

Fig. 13 illustrates a method for measuring delay time between neighboring TSN systems in a wireless communication system, according to various embodiments of the present disclosure.

Referring to fig. 13, a peer delay initiator (peer delay initiator)1302 requests a delay time measurement, and a peer delay responder (peer delay responder)1304 receives the request for the delay time measurement. In various embodiments, a peer delay initiator may refer to a node requesting a delay time measurement, and a peer delay responder may refer to a node receiving the request for the delay time measurement. The peer delay initiator and peer delay responder may also refer to different TSN systems. For example, peer delay initiators and peer delay responders may refer to bridges and bridges, bridges and master bridges, and bridges and slave bridges, respectively.

In operation 1301, the peer delay initiator 1302 may be at time (t)_l)1312 sends a Pdelay _ Req ethernet frame to peer delay responder 1304 requesting the delay time measurement from peer delay responder 1304. The peer delay responder 1304 may be at time (t)₂)1314 receive Pdelay _ Req Ethernet frames, and may store the time when the frame was receivedM (t)₂)1314. In various embodiments, time (t)_ir)1320 may refer to time (t)_l)1312 and time (t)₂) 1314.

In operation 1303, the peer delay responder 1304 may be at time (t)₃)1316 will contain the time (t) for storage₂)1314 of the information to the peer delay initiator 1302. Next, peer delay responder 1304 may store the time (t) at which the Pdelay _ Resp Ethernet frame was sent₃)1316。

In operation 1305, the peer delay responder 1304 may transmit a time (t) including information about the storage to the peer delay initiator 1302₃)1316, Pdelay _ Resp _ Follow _ Up ethernet frame. The peer delay initiator 1302 may be at time (t)₄) A Pdelay _ Resp ethernet frame is received. Next, peer delay initiator 1302 may receive the Pdelay _ Resp _ Follow _ Up ethernet frame. Peer-to-peer delay initiator 1302 may know the time (t) by identifying Pdelay _ Resp Ethernet frames and Pdelay _ Resp _ Follow _ Up Ethernet frames₂)1314 and time (t)₃)1316. The peer delay initiator 1302 may use the time (t) described above₁)1312, time (t)₂)1314, time (t)₃)1316 and time (t)₄)1318 to determine the delay time D between adjacent TSN systems. The delay time D between adjacent TSN systems can be defined as the following equation 8.

Equation 8

D＝((t₂-t₁)+(t₄-t₃))/2

Referring to equation 8, D represents a delay time between adjacent TSN systems, t₁Time, t, representing the time at which the peer delay initiator 1302 requests a delay time measurement from the peer delay responder 1304₂Denotes the time, t, at which the peer delay responder 1304 receives the Pdelay _ Req Ethernet frame from the peer delay initiator 1302₃Denotes the time when peer delay responder 1304 sends a Pdelay _ Resp Ethernet frame to peer delay initiator 1302, and t₄Indicating the time at which peer delay initiator 1302 receives a Pdelay _ Resp ethernet frame from peer delay responder 1304. In various embodiments, time: (tri)1322 represents the difference between time (t3)1316 and time (t4) 1318. In various embodiments, the delay time between the aforementioned adjacent TSN systems may be determined as time (t)_ir)1320 and time (t)_ri) Mean value of 1322, where time (t)_ir)1320 and time (t)_ri) The average value of 1322 may be represented by a mean path delay (meanPathDelay). In various embodiments, a delay of time (tir)1320 may occur when initiator time-aware system 1310 sends a signal to responder time-aware system 1308. Additionally, when the responder time aware system 1308 sends a signal to the initiator time aware system 1310, a time (t) may occur_ri) 1322. In various embodiments, time (t)_ir)1320 may be determined by the difference between the average path delay and the delay asymmetry value (means path delay-delayAsymmetry). In addition, time (t)_ri)1322 may be determined by the sum of the average path delay and the delay asymmetry value (meanPathDelay + delayaasymmetry). In various embodiments, peer delay responder 1304 may store a timestamp 1306 that is known by peer delay initiator 1302. For example, the timestamp 1306 known to the peer-to-peer delay initiator 1302 may include t₁And t₁、t₂、t₄And t₁、t₂、t₃、t₄. In various embodiments, the delay time between the above-described adjacent TSN systems may be periodically calculated according to a predetermined period. At this time, neighborRateRatio between TSN systems can be calculated together with the calculation of the periodic delay time. For example, the neighborRateRatio may be determined by radio ((local clock frequency i)/(local clock frequency r)) of the local clock frequency i of the peer-to-peer delay initiator 1302 and the local clock frequency r of the peer-to-peer delay responder 1304. In various embodiments, the local clock frequency may refer to a unique oscillation frequency, an inverse of a period, etc., of the corresponding TSN system.

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

Referring to fig. 14, the time-aware system may be referred to as a TSN system. In operation 1401, the host port 1402-1 of the time aware system i-11402 mayAt time (t)_s，i-1)1412 sends a synchronization (Sync) frame to the slave port 1408 of the time aware system i 1404. The slave port 1408 may be at time (t)_r，i)1416 receive the Sync frame. Here, time (t)_s，i-1)1412 and time (t)_r，i) The difference between 1416 may refer to the propagation delay i-11414 between TSN system i-11402 and TSN system i 1404.

In operation 1403, the master port 1402-1 of the time-aware system i-11402 may send a subsequent (Follow _ Up) frame to the slave port 1408 of the time-aware system i 1404. At this time, the Follow _ Up frame may include preciseOriginTimestamp, corectionFieldi-1, and rateRatio-1 parameters. Here, the presesoriginitinstamp may indicate a time when a master (Grandmaster) in the TSN domain transmits a Sync frame. The corectionfieldi-i may indicate a value reflecting the difference between the preciseOriginTimestamp and the time at which the TSN system i-11402 sent the Sync frame. rateratio-1 indicates the ratio of the master's clock frequency to the TSN system i-11402's clock frequency and can be calculated as (master clock frequency)/(local clock frequency i-1). In various embodiments, the master may instruct the master node to first send a Sync frame for clock synchronization in the TSN system.

In operation 1405, the host port 1410 of the time aware system i1404 may be at time (t)_s，i)1420 transmits the Sync frame to the slave port 1406-1 of the time aware system i + 11406. The slave port 1406-1 may be at time (t)_r，i+1)1424 receive the Sync frame. Time (t)_s，i)1420 and time (t)_r，i+1) The difference between 1424 may refer to the propagation delay i 1422 of TSN system i1404 and TSN system i + 11406.

In operation 1407, the master port 1410 of time aware system i may send a Follow _ Up frame to the slave port 1406-1 of time aware system i + 11406. At this time, the Follow _ Up frame may include a preciseOriginTimestamp, corectionFieldi, and rateRatio parameters. Here, the correctionFieldi and the ratio may be values calculated by the time perception system i 1404. The correctionFieldi can be calculated as correctionFieldi-1+ LinkDelayi-1+ resudenetime. Here, LinkDelayi-1 represents the description in FIG. 13And may represent a value periodically calculated according to a predetermined period and stored as an average value. Further, LinkDelayi-1 may refer to propagation delay i-1. In various embodiments, dwell time i 1418 represents the time of stay in TSN system i 1404. Dwell time i 1418 may indicate the time (t) at which TSN System i1404 receives the Sync frame_r，i) Time (T) at which 1416 and TSN System i1404 transmit a synchronization frame to TSN System i + 11406_s，i) 1420. Furthermore, rateratio denotes a ratio of local clock frequencies of the TSN system i1404 and the TSN system i + 11406, and may be calculated as rateratio-1 x (local clock frequency i-1)/(local clock frequency i). Here, (local clock frequency i-1)/(local clock frequency i) may refer to a value that is calculated as neighborRateRatio and continuously updated when the periodic delay time is measured in fig. 13. Generally, when constructing an ethernet local area network, the link delay value is several hundred ns and the rateRatio is close to 1, but the dwell time is allowed at most 10 ms. Therefore, it is most important that the TSN system accurately communicate the dwell time value. In various embodiments, rateRatio may be a value based on a difference of 1 being less than 200 bpm.

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

Referring to fig. 15, the terminal 120 may perform periodic delay time measurements on a link shared with a neighboring TSN system. That is, the terminal 120 periodically measures the Link1 delay D _ Link1, and the UPF130c periodically measures the Link2 delay D _ Link2 to store the measurement values as an average value. In fig. 15, when the 5G system, including the terminal 120, the base station 110 and the UPF130c, sends Sync frames and Follow Up frames to the neighboring bridge 21520, the link delay and the time to stay in the 5G system, R _5GS, may be updated in the correction field. At this time, the radio delay between the terminal 120 and the base station 110 and the Backhaul (BH) delay between the base station 110 and the UPF130c in the 5G system 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 by the sum of the residence time in the terminal 120, the base station 110, and the UPF130c, and the radio and backhaul delays within the 5G system link. For example, a 5G system may confirm that the value of the correction field is T3-T1 by updating the Link1 delay and R _5GS in the correction field in the Sync frame. In various embodiments, the host 1510 may transmit a Sync frame to the terminal 120 included in the 5G system at time T1. Next, host 1510 may send a Follow _ Up frame. At this time, the Link1 delay D _ Link1 may mean a difference between a time T1 when the host 1510 transmits a Sync frame and a time T2 when the terminal 120 receives the Sync frame. Next, the timestamp may be set to T1, and the correction field may be set to zero. The UPF130c may send a Sync frame to the bridge 21520 at time T3. The bridge 21520 may receive the Sync frame at time T4. Next, the UPF130c may also send a Follow _ Up frame. At this time, the difference between T2 and T3 may be referred to as R _5 GS. Further, the difference between T3 and T4 may refer to Link2 latency (D _ Link 2). Here, the timestamp may be set to T1, and the correction field may be set to T3-T1. The bridge 21520 may send a Sync frame to the slave 1530 at time T5. The slave 1530 may receive the Sync frame at time T6. At this point, the difference between T4 and T5 may refer to the residence time R _ Bridge2 of Bridge 21520. Next, the bridge 21520 may also send Follow _ Up frames. At this time, the difference between T5 and T6 may refer to the Link3 delay (D _ Link 3). Here, the timestamp may be set to T1, and the correction field may be set to (T3-T1) + (T5-T3). Fig. 16 described later shows a clock synchronization process using an uplink in a network supporting IEEE 802.1AS and a 3GPP network.

Referring to fig. 16, the terminal 120 and the UPF130c may perform periodic link delay measurements with neighboring TSN systems. In addition, the UPF130c may master the residence time R _3GPP in the 3GPP network in a manner similar to that described in fig. 11. In various embodiments, it may be assumed that the delay time of the backhaul is known in advance by the UPF130c through a management system or a separate measurement method. In fig. 16, R _ UE may represent a dwell time at the terminal 120, R _ UPF may represent a dwell time at the UPF130c, and R _ TSN may represent a dwell time at the TSN SW 1620. BH may refer to delayed symmetric backhaul. Over-the-air may refer to a 3GPP wireless environment with asymmetric delay. In fig. 16, the host 1610 may transmit a Sync frame and a Follow _ Up frame to the terminal 120 at time T1. Here, the timestamp may be set to T1 and the correction field may be set to zero. The UPF130c may transmit a Sync frame and a Follow _ Up frame transmitted through the terminal 120 and the base station 110 to the TSN SW 1620. At this time, the timestamp may be determined as T1, and the correction field may be determined as a sum of a Link delay (D _ Link) and a residence time R _3GPP in the 3GPP network. Next, the TSN SW 1620 may send a Sync frame and a Follow _ Up frame to the slave 1630. Here, the timestamp is set to T1, and the correction field is set to the sum of the Link1 delay D _ Link1, the dwell time in the 3GPP network R _3GPP, the Link2 delay D _ Link2, and the dwell time in the TSN SW 1620, R _ TSN. In fig. 16, T _ UL may refer to a PHY frame time when the terminal 120 wirelessly transmits uplink ethernet. At this point, 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 the radio. At this point, the PHY frame may be synchronized with the base station GPS time. The T _ TX may refer to the GPS time at which the base station 110 sends the GTP-U payload to the UPF130 c. Fig. 17 described later shows a clock synchronization procedure using a downlink in a network supporting IEEE 802.1AS and a 3GPP network.

Referring to fig. 17, the terminal 120 and the UPF130c may perform periodic link delay measurements with neighboring TSN systems. Further, the residence time R _3GPP in the 3GPP network can be grasped by the terminal 120 in a manner similar to that described in fig. 12. The difference between fig. 12 and 17 is that the value sent by the UPF130c to the base station 110 is R _ CN, including the delay time of the backhaul in addition to R _ UPF, and the base station 110 may deliver R _ CN instead of R _ UPF to the terminal 120. In various embodiments, it may be assumed that the delay time of the backhaul is known in advance by the UPF130c through a management system or a separate measurement method. In fig. 17, R _ UE represents the dwell time at the terminal 120, R _ UPF represents the dwell time at the UPF130c, and R _ TSN represents the dwell time at the TSN SW 1720. BH may refer to delayed symmetric backhaul. Over-the-air may refer to a 3GPP wireless environment with asymmetric delay. In FIG. 17, host 1730 may send a Sync frame and a Follow _ Up frame to TSN SW 1720 at time T3. Here, the timestamp may be set to T3, and the correction field may be set to zero. TSN SW 1720 may send the transmitted Sync frame and Follow _ Up frame to UPF130 c. At this time, the timestamp may be determined as T3, and the correction field may be determined as the sum of the Link3 delay (D _ Link3) and the residence time R _ TSN of TSN SW 1720. Next, the Sync frame and the Follow _ Up frame may be transmitted to the slave 1710 via the base station 110 and the terminal 120. The slave 1710 may receive a Sync frame and a Follow _ Up frame at time T4. At this time, the timestamp is set to T3, and the correction field is set to the sum of the Link3 latency D _ Link3, the dwell time R _ TSN in TSN SW 1720, the Link2 latency D _ Link2, and the dwell time R _3GPP in the 3GPP system.

The method according to the embodiments described in the claims and/or the description of the present disclosure may be implemented in hardware, software, or a combination of hardware and software.

When the method is implemented by software, a computer-readable storage medium for storing one or more programs (software modules) may be provided. One or more programs stored in the computer-readable storage medium may be configured to be executed by one or more processors within the electronic device. The at least one program may include instructions for causing an electronic device to perform methods in accordance with various embodiments of the present disclosure as defined by the appended claims and/or the disclosure herein.

The program (software module or software) may be stored in non-volatile memory, including random access memory and flash memory, Read Only Memory (ROM), Electrically Erasable Programmable Read Only Memory (EEPROM), magnetic disk storage, compact disc read only memory (CD-ROM), Digital Versatile Discs (DVD), or other types of optical storage devices or magnetic tape. Alternatively, any combination of part or all may form a memory storing the program. Further, a plurality of such memories may be included in the electronic device.

Further, the program may be stored in a connectable storage device that is accessible through a communication network such as the internet, an intranet, a Local Area Network (LAN), a Wide Area Network (WAN), and a Storage Area Network (SAN), or a combination thereof. Such storage devices may access the electronic device via an external port. Further, a separate storage device on the communication network may access the portable electronic device.

In the above detailed embodiments of the present disclosure, components included in the present disclosure are expressed in the singular or plural according to the detailed embodiments presented. However, the singular or plural is chosen for convenience in adapting the description to the present case, and the various embodiments of the disclosure are not limited to a single element or a plurality thereof. Further, a plurality of elements expressed in the specification may be configured as a single element, or a single element in the specification may be configured as a plurality of elements. The reception time may be referred to as an entry time. The reception time may be referred to as an entry time. The transmission time is called the exit time.

While the disclosure has been shown and described with reference to certain embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the disclosure. Accordingly, the scope of the present disclosure should not be limited to the embodiments, but should be defined by the appended claims and equivalents thereof.

While the present disclosure has been described with various embodiments, various changes and modifications may be suggested to one skilled in the art. The present disclosure is intended to embrace such alterations and modifications as fall within the scope of the appended claims.

Claims

1. A method for operating an apparatus for User Plane Function (UPF) in a wireless communication system, the method comprising:

receiving a synchronization message from a host; and

transmitting information determined based on an entry time at which the UPF receives the synchronization message from the host.

2. The method of claim 1, wherein the information indicates the entry time.

3. The method of claim 1, wherein the information is determined based on a link delay associated with a Time Sensitive Network (TSN) system of the host.

4. The method of claim 1, wherein transmitting the information determined based on an entry time comprises,

transmitting the information using a field of the synchronization message.

5. The method of claim 1, wherein transmitting the information determined based on an entry time comprises,

sending the information using a field of a subsequent message related to the message.

6. A method for operating a User Equipment (UE) in a wireless communication system, the method comprising:

receiving information determined based on an entry time at which a User Plane Function (UPF) receives a synchronization message from a host;

determining a dwell time for the message based on the ingress and egress times; and

sending information about the dwell time to a slave.

7. The method of claim 6, wherein the information indicates the entry time.

8. The method of claim 6, wherein the information is determined based on a link delay associated with a Time Sensitive Network (TSN) system of the host.

9. The method of claim 6, wherein receiving information determined based on an entry time comprises,

receiving the information using a field of the synchronization message.

10. The method of claim 6, wherein receiving information determined based on an entry time comprises,

receiving the information using a field of a subsequent message related to the message.

11. A User Equipment (UE) in a wireless communication system, the UE comprising:

a transceiver; and

at least one processor configured to:

receiving information determined based on an entry time at which the UPF receives the synchronization message from the host;

sending information about the dwell time to a slave.

12. The UE of claim 11, wherein the information indicates the entry time.

13. The UE of claim 11, wherein the information is determined based on a link delay associated with a Time Sensitive Network (TSN) system of the host.

14. The UE of claim 11, wherein the at least one processor is configured to,

receiving the information using a field of the synchronization message.

15. The UE of claim 11, wherein the at least one processor is configured to,