KR20210038302A - Apparatus and method for supporting tsc - Google Patents

Abstract

The present disclosure relates to a device and method for supporting time sensitive communication (TSC). The method for supporting TSC by a user plane function (UPF) comprises: a step of receiving a sync frame for time synchronization between time sensitive network (TSN) nodes from a first user terminal, wherein the sync frame is transmitted from a first TSN node corresponding to a grand master to the first user terminal; a step of measuring a residence time taken until the sync frame is received in the UPF from the first user terminal; a step of updating a field of the sync frame based on the measured residence time and a reception time of the sync frame; and a step of transmitting the updated sync frame to a second TSN node or a second user terminal. Accordingly, it is possible to effectively support a service in a wireless communication system.

Description

Apparatus and method to support TSC {APPARATUS AND METHOD FOR SUPPORTING TSC}

The present disclosure relates to an apparatus and method for supporting TSC. Specifically, it relates to an apparatus and method for providing time synchronization (Time Synchronization) between terminals by interworking with a time sensitive network (TSN) and a 5G system (5GS) that is a wireless communication system.

Efforts are being made to develop an improved 5G communication system or a pre-5G communication system in order to meet the increasing demand for wireless data traffic after the commercialization of 4G communication systems. For this reason, the 5G communication system or the pre-5G communication system is called a communication system after a 4G network (Beyond 4G Network) or a system after an LTE system (Post LTE). In order to achieve a high data rate, the 5G communication system is being considered for implementation in the ultra-high frequency (mmWave) band (eg, the 60 giga (80 GHz) band). In order to mitigate the path loss of radio waves in the ultra-high frequency band and increase the transmission distance of radio waves, 5G communication systems include beamforming, massive MIMO, and Full Dimensional MIMO (FD-MIMO). ), array antenna, analog beam-forming, and large scale antenna technologies are being discussed. In addition, in order to improve the network of the system, in 5G communication system, evolved small cell, advanced small cell, cloud radio access network (cloud RAN), ultra-dense network , Device to Device communication (D2D), wireless backhaul, moving network, cooperative communication, CoMP (Coordinated Multi-Points), and interference cancellation And other technologies are being developed. In addition, in 5G systems, advanced coding modulation (ACM) methods such as Hybrid FSK and QAM Modulation (FQAM) and SWSC (Sliding Window Superposition Coding), advanced access technologies such as Filter Bank Multi Carrier (FBMC), NOMA (non-orthogonal multiple access), and sparse code multiple access (SCMA) have been developed.

Meanwhile, the Internet is evolving from a human-centered connection network in which humans create and consume information, to an Internet of Things (IoT) network that exchanges and processes information between distributed components such as objects. IoE (Internet of Everything) technology, which combines IoT technology with big data processing technology through connection with cloud servers, etc., is also emerging. In order to implement IoT, technological elements such as sensing technology, wired/wireless communication and network infrastructure, service interface technology, and security technology are required. , M2M), and MTC (Machine Type Communication) technologies are being studied. In the IoT environment, intelligent IT (Internet Technology) services that create new value in human life by collecting and analyzing data generated from connected objects can be provided. IoT is the field of smart home, smart building, smart city, smart car or connected car, smart grid, healthcare, smart home appliance, advanced medical service, etc. through the convergence and combination of existing IT (information technology) technology and various industries. Can be applied to.

Accordingly, various attempts have been made to apply a 5G communication system to an IoT network. For example, technologies such as sensor network, machine to machine (M2M), and machine type communication (MTC) are implemented by techniques such as beamforming, MIMO, and array antenna, which are 5G communication technologies. . The application of a cloud radio access network (cloud RAN) as the big data processing technology described above can be said as an example of the convergence of 3eG technology and IoT technology.

As described above and with the development of a wireless communication system, various services can be provided. In particular, a method for providing time synchronization between terminals by interworking a Time Sensitive Network (TSN) and a wireless communication system is required.

The disclosed embodiment is to provide an apparatus and method capable of effectively supporting a service in a wireless communication system.

In a method for supporting Time Sensitive Communication (TSC) by a User Plane Function (UPF) according to an embodiment of the present disclosure, a sync frame for time synchronization between Time Sensitive Network Nodes (TSN) is provided by a first user. Receiving from a terminal, the sync frame being transmitted from a first Time Sensitive Network Node (TSN) corresponding to a grand master to the first user terminal; Measuring a residence time taken until the sync frame is received by the UPF from the first user terminal; Updating a field of the sync frame based on the measured residence time and a reception time of the sync frame; And transmitting the updated sync frame to a second TSN node or a second user terminal.

1 is a diagram for explaining a principle of Time Synchronization of a TSN over Ethernet according to an embodiment of the present disclosure.
2 is a diagram illustrating a scenario for supporting TSN Time Synchronization of a 5G network according to an embodiment of the present disclosure.
3 is a diagram illustrating a method of supporting TSN Time Synchronization in a 5G network according to an embodiment of the present disclosure.
4 is a diagram for describing a management function of a TSN according to an embodiment of the present disclosure.
5 is a diagram illustrating a structure in which a 5G network interworks with TSN Management according to an embodiment of the present disclosure.
6 is a diagram illustrating a method of using TSC Assistance Information according to an embodiment of the present disclosure.
7 is a diagram illustrating a Time Synchronization scenario between UEs when there is a GM of TSN on the UE side according to an embodiment of the present disclosure.
FIG. 8 is a diagram illustrating a scenario in which a 5G network interworkes with TSN Management for TSC support between UEs according to an embodiment of the present disclosure.
9 is a diagram illustrating a scenario in which a 5G network uses TSCAI to support TSC between UEs according to an embodiment of the present disclosure.
10 is a flowchart illustrating a Time Synchronization scenario between UEs when there is a GM of TSN on the UE side according to an embodiment of the present disclosure.
11 is a flowchart illustrating a process of supporting time synchronization between UEs according to an embodiment of the present disclosure.
12 is a flowchart illustrating a process of supporting time synchronization by multicast transmission of a Sync Frame according to an embodiment of the present disclosure.
13 is a flowchart illustrating a process of performing BMCA by SMF managing information when there is a GM of TSN on the UE side according to an embodiment of the present disclosure.
14 is a flowchart illustrating a process in which the UPF manages information and performs BMCA when there is a GM of TSN on the UE side according to an embodiment of the present disclosure.
15 is a diagram illustrating a process of performing BMCA by comprehensively managing information by TSN AF when there is a GM of TSN on the UE side according to an embodiment of the present disclosure.
16 is a flowchart illustrating a process in which a PCF manages information and performs BMCA when there is a GM of TSN on the UE side according to an embodiment of the present disclosure.
17 is a flowchart illustrating a process of applying TSCAI to a 3GPP network by comprehensively managing information by SMF to support TSC from a UE to another UE according to an embodiment of the present disclosure.
18 is a flowchart illustrating a process of applying TSCAI to a 3GPP network by comprehensively managing information by a UPF to support TSC from a UE to another UE according to an embodiment of the present disclosure.
19A is a flowchart illustrating a process of applying TSCAI to a 3GPP network by comprehensively managing information by an AF in order to support TSC from a UE to another UE according to an embodiment of the present disclosure.
19B is a flowchart illustrating a process in which TSN AF manages schedule information for a new PCF session according to an embodiment of the present disclosure.
20A is a flowchart illustrating a process of applying TSCAI to a 3GPP network by comprehensively managing information by a PCF to support TSC from a UE to another UE according to an embodiment of the present disclosure.
20B is a flowchart illustrating a process in which the PCF manages schedule information for a new PCF session according to an embodiment of the present disclosure.
21 is a block diagram illustrating an internal configuration of a terminal according to an embodiment of the present disclosure.
22 is a block diagram illustrating an internal configuration of a network entity according to an embodiment of the present disclosure.

With reference to the accompanying drawings will be described in detail the operating principle of the present invention. In the following description of the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, a detailed description thereof will be omitted. In addition, terms to be described later are terms defined in consideration of functions in the present invention, which may vary according to the intention or custom of users or operators. Therefore, the definition should be made based on the contents throughout the present specification.

A term for identifying an access node used in the following description, a term for network entities, a term for messages, a term for an interface between network objects, a term for various identification information And the like are illustrated for convenience of description. Accordingly, the present invention is not limited to the terms described below, and other terms referring to objects having an equivalent technical meaning may be used.

For convenience of explanation, the present invention uses terms and names defined in the 5GS and NR standards, which are the latest standards defined by the 3GPP (The 3rd Generation Partnership Project) organization among currently existing communication standards. However, the present invention is not limited by the terms and names, and may be equally applied to wireless communication networks according to other standards. In particular, the present invention can be applied to 3GPP 5GS/NR (5th generation mobile communication standard).

Time synchronization of related nodes is required to support scenarios such as factory automation. In particular, in situations requiring precise work, the accuracy of time synchronization must be high. When using Ethernet for industrial purposes, TSN (Time Sensitive Networking) technology, a method that supports time synchronization between Ethernet-connected notes, has been studied and has been commercially used.

1 is a diagram for explaining the principle of Time Synchronization of TSN over Ethernet according to an embodiment of the present disclosure.

In the manufacturing site, various networks can be used according to the configuration requirements of the equipment and systems required for each plant. When networks with different standards are used, there may be difficulties in flexible system management. According to an embodiment of the present disclosure, an apparatus and method for synchronizing time between TSN nodes when TSN nodes operate according to different time standards are provided.

Nodes (hereinafter, TSN Node) of TSN (Time Synchronization in Ethernet) may set a standard GM (Grand Master). When the TSN Node0 is set to GM, the TSN Node0 can insert the current time of the GM into the Timestamp field, fill in the Correction field with 0 to create a Sync Frame, and transmit the generated Sync Frame to the next node. The next node, TSN Node1, receives the Sync Frame that has undergone Link Delay 1, updates the Correction field by considering up to Residence Time1, which is the time spent in TSN Node1, and transmits the Sync Frame to the next node, TSN Node2. The TSN Node2 may receive the Sync Frame that has undergone Link Delay 2, update the Correction field in consideration of the Residence Time2, which is the time spent in the TSN Node2, and transmit the Sync Frame to the next node (not shown). Each node periodically measures the delay time for the link with the previous node and calculates and manages the average. In addition, it may have a method of calculating the residence time in its own node.

2 is a diagram illustrating a scenario for supporting TSN Time Synchronization of a 5G network according to an embodiment of the present disclosure.

Specifically, FIG. 2 shows a factory automation scenario supporting mobility of a user equipment (UE) to which a 5G network is applied. In this case, the 5G network may support TSN. Referring to FIG. 2, Actuator A may include a UE-side component. For example, Actuator A may include a UE and a TSN Node connected to the UE. In addition, the 3GPP network may include some configurations of a base station and a core network. For example, the 3GPP network may include a UE, gNB, and UPF, but is not limited thereto. Referring to FIG. 2, a 3GPP network may be connected to a factory network, and the factory network may include a TSN Ethernet switch and a control unit B connected through a wired network, but is not limited thereto, and other components within the factory network Of course, it can be included.

3 is a diagram illustrating a method of supporting TSN Time Synchronization in a 5G network according to an embodiment of the present disclosure.

FIG. 3 is a diagram illustrating a method for a 5G network to support TSN in the same situation as in FIG. 2. In this disclosure, the 5G Network refers to including UE, gNB, and UPF. Specifically, a 5G network including UE, gNB, and UPF is modeled as a TSN Bridge (TSN node) of FIG. 1. That is, the 5G network UPF-gNB-UE can operate as one TSN node, and this TSN node can support TSN by updating the Sync Frame by correcting Link Delay and Residence Time. For this, it is assumed that the UPF, gNB, and UE in the 5G network are synchronized to a common 5G GM. For example, the gNB is connected to the GPS, the UPF is connected to the gNB through an Ethernet-based TSN to synchronize with the gNB, and the UE may be synchronized with the gNB through a process of exchanging PHY frames. The UPF is connected to the TSN node of the wired network, and the UE can also be connected to the TSN node of the wired network. Referring to FIG. 3, since there is a GM of the TSN in the TSN node connected to the UPF, the UPF receives a Sync Frame from the TSN node connected to the UPF. UPF records the Ingress Time of the received Sync Frame at the time based on 5G GM. The UPF can periodically calculate and manage the Link Delay with the TSN node connected to the UPF. UPF can deliver a Sync Frame including Ingress Time and Link Delay to the UE. The UE can calculate the residence time, which is the residence time in the 5G network, as the time based on the 5G GM at the moment when this Sync Frame is transmitted to the TSN node connected to the UE. For example, the UE may calculate the Residence Time and Link Delay based on the 5G GM reference time at the moment of transmitting the Ingress Time recorded at the 5G GM reference time and the Sync Frame to the TSN Node. In addition, the UE may transmit the Sync Frame to the TSN node connected to the UE by updating the Correction field using the Residence Time and Link Delay.

4 is a diagram for explaining the management function of TSN.

There are two types of TSN nodes: Bridge and End-Station. Among the TSN nodes, the Bridge sends its port configuration and its scheduling capability to the CNC (Centralized Network Configuration) server, and the End-Station among the TSN nodes transmits/receives TSC (Time Sensitive Communication) Stream 1 information to the CNC server. can send. The CNC server informs the schedule information of each TSN node for each stream, and the TSN nodes reflect this to ensure that the corresponding stream is delivered while experiencing a certain delay. For example, when Stream 1 is transmitted from the Talkers Node (End-Station), if the transmission period of Stream 1 is 10 ms, the Listeners Node (End-Station) receives Stream 1 within 10 ms from the time when Stream 1 is transmitted. Should be. Referring to FIG. 3, each bridge node reports a predetermined delay time and a link delay to the CNC server. For example, it is possible to report to the CNC server that the delay time in Bridges 1, 2, 3, 4 is 1 ms or less and the link delay is 1 ms or less. In this case, when the expected arrival time from Bridge 1 is 1ms, the expected arrival time from Bridge 2 is 3ms, the expected arrival time from Bridge 3 is 5ms, and the expected arrival time from Bridge 4 is 7ms, the CNC server 1 to Bridge 4 may report each delay time information to the CNC server. At this time, since the total delay time in Bridge 1 to Bridge 4 is 16ms, the CNC server transmits scheduling information to each TSN node (Bridge Node) so that Stream 1 can be transmitted with a predetermined delay time within 10ms. I can. In this case, it is expected to arrive at the Listener Node in 9ms, so it satisfies the requirement to transmit within 10ms.

5 is a diagram illustrating a structure in which a 5G network interworks with TSN Management according to an embodiment of the present disclosure.

The logical function block called Network-side TSN Translator (NW-TT) is responsible for the connection between the UPF and the external TSN, and the logical function block called DS-TT (Device-Side TSN Translator) is responsible for the connection between the UE and the external TSN. can do. They deliver information as a port in one logical TSN Bridge called 5G Network to TSN AF, and TSN AF can take charge of management interworking with external TSN. When external TSN is managed through the CNC server, TSN AF is also linked with the CNC server.

6 is a diagram illustrating a method of using TSC Assistance Information (TSCAI) according to an embodiment of the present disclosure.

As described above in FIG. 4, the CNC server may inform the schedule information of each TSN node for each stream. The 5G network can receive schedule information of TSN nodes through TSN AF. The 5G network can know the period of the corresponding stream and the expected arrival time to the 5G network through the schedule information of the TSN nodes. This is written based on the TSN GM, so the SMF converts it to the 5G GM standard. In addition, in the case of downlink traffic, correction as much as the CN-PDB (Core Network Packet Delay Budget), which is the maximum delay time for the packet arrival at the gNB in the UPF, may be performed. To this end, the SMF delivers information that is TSCAI to the gNB. TSCAI includes UL/DL, Periodicity, Burst Arrival Time information, among which Burst Arrival Time is a value reflecting CN-PDB correction and time translation based on 5G GM in the stream schedule information received from the CNC server as mentioned above. to be.

7 is a diagram illustrating a Time Synchronization scenario between UEs when there is a GM of TSN on the UE side according to an embodiment of the present disclosure.

Conventionally, as shown in FIG. 2, a scenario in which a TSN GM is located at an external TSN node connected to the UPF, and a TSN GM and a UE or a TSN node connected to the TSN GM and the UE supports time synchronization was considered. In this case, time synchronization between the UE and the UE or the external TSN nodes connected to the UE and the UE, or between the external TSN nodes connected to the UEs is all indirectly performed through synchronization with the TSN GM connected to the UPF. Was assumed. However, it may also be possible when the TSN GM is connected to the UE or the TSN node connected to the UE. For example, this is the case where a controller mounted on a moving vehicle controls a robot or electronic device having a position movement function. Because real-time monitoring and control of the user is important, the laptop or tablet that the user can carry becomes the GM of TSN, and the operation of the surrounding mobile devices can be precisely controlled based on the laptop or tablet. In this case, time synchronization may be supported between UEs belonging to the same base station as well as UEs belonging to different base stations.

FIG. 8 is a diagram illustrating a scenario in which a 5G network interworkes with TSN Management to support TSC between UEs according to an embodiment of the present disclosure.

In FIG. 2, as shown in FIG. 5, TSN AF collects information of NW-TT/UPF and DS-TT/UE, and TSN AF exchanges information with the CNC, so that the 5G network interoperates with the TSN Manager. In this case, the establishment/modification process for one PDU session including NW-TT/UPF and DS-TT/UE is used. However, in a situation as shown in FIG. 7 in which time synchronization between UEs is required because the TSN GM is located on the UE side, a plurality of PDU sessions configured by connection between UPF-UEs may be required. For example, in one 5G network, information of NW-TT/UPF and DS-TT/UE for one PDU session is collected in TSN AF, so in order to collect information on two UEs, as shown in FIG. PDU Session is required. In FIG. 8, a case of two UEs has been described, but the number of UEs is not limited thereto, and may be a plurality of UEs.

9 is a diagram illustrating a scenario in which a 5G network uses TSCAI to support TSC between UEs according to an embodiment of the present disclosure.

As shown in FIG. 8, TSN AF may collect TSN-related information in two PDU sessions. Referring to FIG. 9, the collected PDU Session information may be interlocked with the CNC through TSN AF. To this end, the PDU Session information is transmitted through a path such as UE-SMF-PCF-AF or UPF-SMF-PCF-AF. Since the schedule information received from the CNC is based on the TSN GM, the Burst Arrival Time of TSCAI reflected in the gNB1 on the ingress UE1 side should be changed from the TSN GM standard to the 5G GM standard. The Burst Arrival Time of TSCAI delivered to gNB2 on the UE2 side must be changed from TSN GM standard to 5G GM standard, and additionally, uplink PDB1 and Downlink CN-PDB2, which are 5GS internal delay times, must be corrected. It is clear that the SMF carries two TSCAIs, but there are many choices as to when the information received from the CNC is split into two.

10 is a flowchart illustrating a Time Synchronization scenario between UEs when there is a TSN GM on the UE side according to an embodiment of the present disclosure.

As shown in FIG. 7, when there is a GM of TSN on the UE side, the UE may support time synchronization by transmitting a Sync Frame to the CN. When DS-TT1 or UE1 receives a Sync Frame from TSN Node0, which is an external TSN node, the reception time is recorded based on 5G GM. Hereinafter, for convenience of description, the operation of UE1 is described, but DS-TT1 may perform the operation. When UE1 transmits the Sync Frame to UPF, it can transmit the recorded value based on 5G GM. For example, UE1 may transmit reception time information by adding a separate Ingress Timestamp field to the Sync Frame. In addition, UE1 may periodically measure a delay time Link Delay1 for Link1, which is a link with a neighboring external TSN node TSN Node0, and calculate and manage an average time based on the measured delay time. When UE1 transmits a Sync Frame to UPF, it may also transmit Link Delay1. For example, UE1 may add the Link Delay1 value to the Correction field of the Sync Frame and transmit it. When Link Delay1 is added to the Correction field, Link Dealy1 must be converted based on TSN GM, so it can be calculated by applying rateRatio1. rateRatio1 is a value obtained by dividing “TSN GM Clock Frequency” by “UE1's Local Clock Frequency”, which can be obtained by multiplying the rateRatio0 contained in the rateRatio field transmitted from the Sync Frame and the neighborRateRatio managed by UE1. rateRatio0 is the value obtained by dividing “TSN GM Clock Frequency” by “TSN Node0 Local Clock Frequency”, and the neighborRateRatio managed by UE1 is the value obtained by dividing “TSN Node0 Local Clock Frequency” by “UE1 Local Clock Frequency”. UE1 transmits the Sync Frame to UPF and also transmits rateRatio1. For example, the value of the rateRatio field of the Sync Frame is updated to rateRatio1 and transmitted. UE1 can synchronize with TSN GM by setting the Sync Frame reception time to “The Correction field value including Link Delay 1 converted based on TSN GM + TSN GM”.

The NW-TT or UPF calculates the Residence Time, which is the time spent in the 5G network, after receiving the Sync Frame transmitted from DS-TT1 or UE1, and before delivering it to the TSN Node4, which is an external TSN node, and updates the Correction field. Hereinafter, for convenience of explanation, the operation of the UPF is described, but the NW-TT of the UPF may perform the corresponding operation. The UPF calculates the Residence Time by subtracting the Ingress Timestamp value received from UE1 at the egress time at which the Sync Frame is transmitted to the outside. UPF converts the 5G GM standard to the TSN GM standard by applying rateRatio1 to the residence time value before adding the residence time value to the correction field. UPF removes the separately added Ingress Timestamp field before transmitting the Sync Frame to the outside. UPF can synchronize with TSN GM by setting the transmission time of Sync Frame as “TSN GM + Correction field value”.

At this time, since the residence time at one TSN node cannot exceed 10ms, UE-DS-TT ResiTime1, which is the UL UE-DS-TT residence time for DS-TT1 or UE1, and the UL Packet Delay Budget (PDB) of PDU Session1. The QoS requirement that the sum of phosphorus and PDB1 is less than 10ms should be applied.

11 is a flowchart illustrating a process of supporting time synchronization between UEs according to an embodiment of the present disclosure.

Referring to FIG. 11, when there is a TSN GM on the UE side as shown in FIG. 7, Time Synchronization may be supported by transmitting a Sync Frame from the UE to another UE. Hereinafter, for convenience of description, the operation of UE1 or UE2 is described, but DS-TT1 of UE1 or DS-TT2 of UE2 may each perform the corresponding operation. When UE1 receives a Sync Frame from TSN Node0, which is an external TSN node, it records the reception time based on 5G GM. When UE1 transmits the Sync Frame to UPF, it delivers the recorded value based on 5G GM. For example, by adding a separate Ingress Timestamp field to the Sync Frame, reception time information can be sent. In addition, UE1 may periodically measure a delay time Link Delay1 for Link1, a link with TSN Node0, a neighboring external TSN node, calculate an average time based on the measured delay time, and manage the average time. When UE1 transmits the Sync Frame to UPF, this Link Delay1 is also transmitted. For example, UE1 may add the Link Delay1 value to the Correction field of the Sync Frame and transmit it. When Link Delay1 is added to the Correction field, Link Dealy1 must be converted based on TSN GM, so it can be calculated by applying rateRatio1. rateRatio1 is the value obtained by dividing “5G Clock Frequency” by “UE1's Local Clock Frequency”. UE1 transmits the Sync Frame to UPF and also transmits rateRatio1. For example, the value of the rateRatio field of the Sync Frame is updated to rateRatio1 and transmitted. UE1 can synchronize with TSN GM by setting the Sync Frame reception time to “The Correction field value including Link Delay 1 converted based on TSN GM + TSN GM”.

UPF processes this Sync Frame through UPF internal local switching between PDU Session1 and PDU Session2 and transmits it to UE2. At this time, there is no change in the contents of the Sync Frame.

After receiving the Sync Frame from the UPF, UE2 calculates the Residence Time, which is the time spent in the 5G network, before transmitting the Sync Frame to the TSN Node3, which is an external TSN node, and updates the Correction field. UE2 calculates the Residence Time by subtracting the Ingress Timestamp value received from UE1 at the time of transmitting the Sync Frame to the outside. Before adding this value to the Correction field, UE2 converts from 5G GM standard to TSN GM standard by applying rateRatio1 to this value. UE2 removes the separately added Ingress Timestamp field before transmitting the Sync Frame to the outside. UE2 can synchronize with TSN GM by setting the sync frame transmission time to “TSN GM + Correction field value”.

At this time, since the residence time at one TSN node cannot exceed 10ms, the sum of the UL UE-DS-TT Residence Time UE-DS-TT ResiTime1 and the UL PDB PDB1 and the DL UE-DS-TT Residence Time UE -The QoS requirement that the sum of both the DS-TT ResiTime2 and the DL PDB2 PDB2 is less than 10ms should be applied. Actually, PDB1 is applied as QoS for PDU Session1, and PDB2 is applied as QoS for PDU Session2, so for transmitting a Sync Frame between UEs, QoS considering both PDU Sessions is applied at the same time. For example, a QoS requirement that the sum of PDB1 (UL PDB) and PDB2 (DL PDB) is less than 10ms is converted into two QoS requirements that PDB1 must be less than 5ms and PDB2 must be less than 5ms, and are converted into two PDU Session1 and PDU Session2. Each can be applied to.

12 is a flowchart illustrating a process of supporting time synchronization by multicast transmission of a Sync Frame according to an embodiment of the present disclosure.

Specifically, referring to FIG. 12, when there is a GM of TSN on the UE side, time synchronization may be supported by multicast transmission of a Sync Frame from the UE to the CN or from the UE to another UE. In this case, the procedures described above in FIGS. 10 and 11 may be applied at the same time. Hereinafter, for convenience of description, the operation of UE1 or UE2 is described, but DS-TT1 of UE1 or DS-TT2 of UE2 may each perform the corresponding operation.

When UE1 receives a Sync Frame from TSN Node0, which is an external TSN node, it records the reception time based on 5G GM. When UE1 transmits the Sync Frame to UPF, it delivers the recorded value based on 5G GM. For example, UE1 may transmit reception time information by adding a separate Ingress Timestamp field to the Sync Frame. In addition, UE1 may periodically measure a delay time Link Delay1 for Link1, which is a link with a neighboring external TSN node TSN Node0, and calculate and manage an average time based on the measured delay time. When UE1 transmits a Sync Frame to UPF, it may also transmit Link Delay1. For example, UE1 may add the Link Delay1 value to the Correction field of the Sync Frame and transmit it. When Link Delay1 is added to the Correction field, Link Dealy1 must be converted based on TSN GM, so it can be calculated by applying rateRatio1. rateRatio1 is the value obtained by dividing “5G Clock Frequency” by “UE1's Local Clock Frequency”. UE1 may transmit the Sync Frame to UPF and also transmit rateRatio1. For example, UE1 updates and transmits the value of the rateRatio field of the Sync Frame to rateRatio1. UE1 can synchronize with TSN GM by setting the Sync Frame reception time to “The Correction field value including Link Delay 1 converted based on TSN GM + TSN GM”.

UPF applies Multicast so that one Sync Frame is directed to an external TSN node directly from UPF through NW-TT, and the other Sync Frame is directed to DS-TT2 or UE2.

After receiving the Sync Frame to the external TSN Node, the UPF calculates the Residence Time, which is the time spent in the 5G network, before delivering it to the external TSN node, TSN Node4, and updates the Correction field. UPF calculates the Residence Time by subtracting the Ingress Timestamp value received from UE1 at the time of transmitting the Sync Frame to the outside. UPF converts from 5G GM standard to TSN GM standard by applying rateRatio1 to this value before adding the Residence Time value to the Correction field. UPF may remove the separately added Ingress Timestamp field before transmitting the Sync Frame to the outside. UPF can synchronize with TSN GM by setting the transmission time of Sync Frame as “TSN GM + Correction field value”.

At this time, since the residence time at one TSN node cannot exceed 10ms, the QoS requirement for Uplink Flow that the sum of UE-DS-TT ResiTime1, UL UE-DS-TT Residence Time, and PDB1, UL PDB, is less than 10ms. Can be applied.

After receiving another Sync Frame from the UPF, UE2 calculates the residence time, which is the time spent in the 5G network, before transmitting it to the external TSN node, TSN Node3, and updates the Correction field. UE2 calculates the Residence Time by subtracting the Ingress Timestamp value received from UE1 at the time of transmitting the Sync Frame to the outside. Before adding the Residence Time value to the Correction field, UE2 applies rateRatio1 to the Residence Time value and converts it from the 5G GM standard to the TSN GM standard. UE2 may remove the separately added Ingress Timestamp field before transmitting the Sync Frame to the outside. UE2 can synchronize with TSN GM by setting the transmission time of the Sync Frame as “TSN GM + Correction field value”.

At this time, since the residence time at one TSN node cannot exceed 10ms, the sum of the UL UE-DS-TT Residence Time UE-DS-TT ResiTime1 and the UL PDB PDB1 and the DL UE-DS-TT Residence Time UE -The QoS requirement that the sum of both the DS-TT ResiTime2 and the DL PDB, PDB2 is less than 10ms can be applied.

Since PDB1 is actually applied as QoS for PDU Session1 and PDB2 is applied as QoS for PDU Session2, QoS considering two PDU sessions at the same time is applied to transfer Sync Frame between UEs. For example, the QoS requirement that the sum of PDB1 and PDB2, which is a DL PDB, is less than 10ms, is converted into two QoS requirements that PDB1 must be less than 5ms and PDB2 must be less than 5ms. Can be applied.

Compared to the requirement that the previously calculated PDB1 is less than 10ms, the newly calculated requirement is more stringent, and therefore the requirements calculated later must be satisfied in order to be satisfied at the same time.

13 is a flowchart illustrating a process of performing BMCA by SMF managing information when there is a GM of TSN on the UE side according to an embodiment of the present disclosure.

Specifically, referring to FIG. 13, when there is a GM of TSN on the UE side, BMCA may be performed by SMF comprehensively managing information. As described above in FIG. 9, interworking between the 5G Network and TSN Management may be performed by considering the 5G Network as one TSN Bridge through TSN AF. Meanwhile, information management for PDU Session1 related to UE1 and PDU Session2 related to UE2 may be divided and managed within the 5G network. For example, in order to create a tree through which a Sync Frame is transmitted, when BMCA (Best Master Clock Algorithm) is performed for each TSN Clock Domain, a process of synthesizing information of PDU Session1 and PDU Session2 may be required. BMCA is an algorithm to determine which TSN Node is to be determined as the Grand Master, and the Port that receives the Announcement Message from the Node close to the Grand Master displays its status as S (Slave) status. Since only one port is in the S state within one bridge, when several ports are candidates for the S state, only one port among the candidates is determined as S state by synthesizing information inside the bridge. 5G Logical Bridge also participates in BMCA as one bridge, and UE or DS-TT and UPF or NW-TT participate in BMCA as one port of 5G Logical Bridge. TSN GM can be set for each Work Clock Domain. When the TSN is in the S (Slave) state, it may mean that the priority to be designated as the Grand Master is lower than when the TSN is in the M (Master) state.] Hereinafter, for convenience of explanation, DS-TT1 or UE1, DS-TT2 Or UE2, and NW-TT or UPF will be described as corresponding to each of the DS-TT1 / UE1, DS-TT2 / UE2, and NW-TT / UPF.

When receiving the Announcement Frame from TSN Node0, which is an external TSN node, DS-TT1/UE1 sets its port to a provisional S (Slave) state, and transmits the corresponding Announcement Frame to UPF. UPF broadcasts the Announcement Frame to other ports inside the logical TSN Bridge of the 5G network. That is, UE1 may head to an external TSN node through NW-TT for one announcement frame, and the UPF may go to DS-TT2/UE2 by local switching the other announcement frame in the UPF.

Upon receiving the Announcement Frame, the NW-TT sets its Port to M (Master) and transmits this Announcement Frame to TSN Node4, an external TSN node. Likewise, DS-TT2/UE2, receiving the Announcement Frame transmitted through UPF from DS-TT1/UE1, temporarily sets its port to M (Master) state and transmits the Announcement Frame to TSN Node3, which is an external TSN node.

After passing through the process of delivering such Announcement Frames, DS-TT1/UE1, DS-TT2/UE2, and NW-TT/UPF update the information of the corresponding port to the SMF through the PDU Session Modification procedure. What makes data communication possible through the UPF by the UE is called one PDU Session, and the process of changing the information of this PDU Session is the PDU Session Modification procedure. In fact, in PDU Session Modification, DS-TT1/UE1 and NW-TT/UPF deliver information about PDU Session1, and DS-TT2/UE2 and NW-TT/UPF deliver information about PDU Session2, but SMF is PDU. Session1 and PDU Session2 can be managed knowing that they belong to the same TSN Management. SMF can be classified into information that must be managed comprehensively by utilizing the fact that PDU Session1 and PDU Session2 have the same TSN Logical Bridge ID and TSN Working Clock Domain ID. SMF determines the final port configuration information to be actually reflected based on the aggregated port information, and then converts this information to DS-TT1/UE1, DS using the PDU Session Modification procedure and N4 Update procedure for PDU Session1 and PDU Session2. -Transfer to TT2/UE2 and NW-TT/UPF. The final confirmed port configuration information is also reflected in the PCF and TSN AF through the notification procedure.

14 is a flowchart illustrating a process in which the UPF manages information and performs BMCA when there is a GM of TSN on the UE side according to an embodiment of the present disclosure.

Specifically, referring to FIG. 14, as described above with reference to FIG. 9, the interworking between the 5G network and TSN Management may be performed by considering the 5G network as one TSN bridge through TSN AF. Meanwhile, information management for PDU Session1 related to UE1 and PDU Session2 related to UE2 may be divided and managed within the 5G network. For example, in order to generate a tree through which a Synch Frame is transmitted, when BMCA (Best Master Clock Algorithm) is performed for each TSN Clock Domain, a process of synthesizing information of PDU Session1 and PDU Session2 may be required. When receiving the Announcement Frame from TSN Node0, which is an external TSN node, DS-TT1/UE1 sets its port to a provisional S (Slave) state, and transmits the corresponding Announcement Frame to UPF. UPF can broadcast the announcement frame to other ports inside the logical TSN bridge of the 5G network. In this example, one Announcement Frame may be directed to an external TSN node via NW-TT, and the other Announcement Frame may be directed to DS-TT2/UE2 by Local Switching in the UPF.

Upon receiving the Announcement Frame, the NW-TT temporarily sets its port to the M (Master) state and transmits the Announcement Frame to TSN Node4, an external TSN node. Likewise, DS-TT2/UE2, which received the Announcement Frame transmitted through UPF from DS-TT1/UE1, temporarily sets its port to the M (Master) state and transmits this Announcement Frame to TSN Node2, an external TSN node.

After going through the process of delivering Announcement Frames as described above, DS-TT1/UE1 and DS-TT2/UE2 update the information of the corresponding port to SMF (Session Management Function) through the PDU Session Modification procedure, and the SMF updates this information. Delivered to UPF through N4 update. In fact, in PDU Session Modification, DS-TT1/UE1 and NW-TT/UPF deliver information about PDU Session1, and DS-TT2/UE2 and NW-TT/UPF deliver information about PDU Session2, but UPF is a PDU. Session1 and PDU Session2 can be managed knowing that they belong to the same TSN Management. UPF can distinguish that information to be managed comprehensively by utilizing the fact that PDU Session1 and PDU Session2 have the same TSN Logical Bridge ID and TSN Working Clock Domain ID. UPF determines the final port configuration information to be actually reflected based on the aggregated port information, and then converts this information to DS-TT1/UE1, DS using the N4 Update procedure and PDU Session Modification procedure for PDU Session1 and PDU Session2. -Pass it to TT2/UE2. In addition, the UPF can also update the configuration of NW-TT or UPF according to the final Port Configuration information. The determined final Port Configuration information may be reflected in the PCF (Policy Control Function) and TSN AF through the notification procedure.

15 is a diagram illustrating a process of performing BMCA by managing information by TSN AF when there is a GM of TSN on the UE side according to an embodiment of the present disclosure.

As described above in FIG. 9, the 5G Network and TSN Management can be interworked through TSN AF, considering the 5G Network as one TSN Bridge. Meanwhile, in the 5G Network, PDU Session1 related to UE1 and PDU Session2 related to UE2. Management of information on can be divided. For example, in order to generate a tree through which a Synch Frame is transmitted, when BMCA (Best Master Clock Algorithm) is performed for each TSN Clock Domain, a process of synthesizing information of PDU Session1 and PDU Session2 may be required. When receiving the Announcement Frame from TSN Node0, which is an external TSN node, DS-TT1/UE1 sets its port to a provisional S (Slave) state, and transmits the corresponding Announcement Frame to UPF. UPF broadcasts the Announcement Frame to other ports inside the logical TSN Bridge of the 5G network. That is, one Announcement Frame may be directed to an external TSN node via NW-TT, and the other Announcement Frame may be directed to DS-TT2/UE2 by Local Switching in the UPF.

Upon receiving the Announcement Frame, the NW-TT temporarily sets its Port to the M (Master) state and transmits this Announcement Frame to TSN Node4, an external TSN node. Likewise, DS-TT2/UE2, which received the Announcement Frame transmitted through UPF from DS-TT1/UE1, temporarily sets its port to M (Master) state and transmits this Announcement Frame to TSN Node3, an external TSN node.

After passing through the process of delivering such Announcement Frames, DS-TT1/UE1, DS-TT2/UE2, and NW-TT/UPF update the information of the corresponding port to TSN AF through the PDU Session Modification procedure. In fact, in PDU Session Modification, DS-TT1/UE1 and NW-TT/UPF deliver information about PDU Session1, and DS-TT2/UE2 and NW-TT/UPF deliver information about PDU Session2, but TSN AF It knows that PDU Session1 and PDU Session2 belong to the same TSN Management and can be managed. TSN AF can be classified as information to be managed by utilizing the fact that PDU Session1 and PDU Session2 have the same TSN Logical Bridge ID and TSN Working Clock Domain ID. TSN AF determines the final port configuration information to be actually reflected based on the aggregated port information, and then converts this information to DS-TT1/UE1, using the PDU Session Modification procedure and N4 Update procedure for PDU Session1 and PDU Session2. Delivered to DS-TT2/UE2 and NW-TT/UPF. The final confirmed port configuration information is also reflected in the PCF through the notification procedure.

16 is a flowchart illustrating a process in which a PCF manages information and performs BMCA when there is a GM of TSN on the UE side according to an embodiment of the present disclosure.

Specifically, referring to FIG. 16, as described above with reference to FIG. 9, the interworking between the 5G network and TSN Management may be performed by considering the 5G network as one TSN bridge through TSN AF. Meanwhile, information management for PDU Session1 related to UE1 and PDU Session2 related to UE2 may be divided and managed within the 5G network. For example, in order to generate a tree through which a Synch Frame is transmitted, when BMCA (Best Master Clock Algorithm) is performed for each TSN Clock Domain, a process of synthesizing information of PDU Session1 and PDU Session2 may be required. When receiving the Announcement Frame from TSN Node0, which is an external TSN node, DS-TT1/UE1 sets its port to a provisional S (Slave) state, and transmits the corresponding Announcement Frame to UPF. UPF broadcasts the Announcement Frame to other ports inside the logical TSN Bridge of the 5G network. In this example, one Announcement Frame may be directed to an external TSN node via NW-TT, and the other Announcement Frame may be locally switched in the UPF to be directed to DS-TT2/UE2.

Upon receiving the Announcement Frame, the NW-TT temporarily sets its Port to the M (Master) state and transmits this Announcement Frame to TSN Node4, an external TSN node. Likewise, DS-TT2/UE2, receiving the Announcement Frame transmitted through UPF from DS-TT1/UE1, temporarily sets its port to M (Master) state and transmits the Announcement Frame to TSN Node3, which is an external TSN node.

After going through the process of delivering such Announcement Frames, DS-TT1/UE1, DS-TT2/UE2, and NW-TT/UPF update the information of the corresponding port to the PCF through the PDU Session Modification procedure. In fact, in PDU Session Modification, DS-TT1/UE1 and NW-TT/UPF deliver information about PDU Session1, and DS-TT2/UE2 and NW-TT/UPF deliver information about PDU Session2, but PCF does this. Knowing and managing both of them belong to the same TSN Management. PCF is classified as information that must be managed comprehensively by taking advantage of the fact that PDU Session1 and PDU Session2 have the same TSN Logical Bridge ID and TSN Working Clock Domain ID. PCF determines the final port configuration information to be actually reflected based on the aggregated port information, and then converts this information to DS-TT1/UE1, DS using the PDU Session Modification procedure and N4 Update procedure for PDU Session1 and PDU Session2. -Transfer to TT2/UE2 and NW-TT/UPF. The final confirmed port configuration information is also reflected in TSN AF through the notification procedure.

17 is a flowchart illustrating a process of applying TSCAI to a 3GPP network by comprehensively managing information by an SMF to support TSC from a UE to another UE according to an embodiment of the present disclosure.

The CNC can obtain configuration information for each port of the 5G network through TSN AF. Since the configuration information for each port also includes information on the surrounding ports for each port, the CNC server can know the port through which the stream between the Talker and the listener, which is an end-station, will pass. In addition, since the configuration information for each port includes the scheduling capability of each TSN node or TSN bridge, the CNC can determine and inform the schedule information of the stream for each port between the talker and the listener. The CNC delivers the schedule information of the stream for each port to the 5G network through TSN AF. Stream Schedule information is delivered from TSN AF through PCF to SMF. When the Stream Schedule information is transmitted from TSN AF through PCF, it is transmitted as for the PDU Session for one of DS-TT1/UE1 and DS-TT2/UE2. For example, the Stream Schedule information may be delivered to the corresponding PCF and SMF by selecting PDU Session1 corresponding to DS-TT1/UE1.

SMF converts BAT1 (Burst Arrival Time1) of TSCAI corresponding to DS-TT1/UE1 from TSN GM standard to 5G GM reference information, and delivers it to gNB through PDU Session Modification process. At the same time, SMF calculates BAT2 (Burst Arrival Time2) of TSCAI corresponding to DS-TT2/UE2. BAT2 is calculated as the sum of BAT1 by the Uplink PDB of PDU Session1, Local Switching Delay of UPF, and Downlink CN-PDB of PDU Session2. The SMF delivers BAT2 to the gNB through the process of updating only RAN parameters during the PDU Session Modification procedure for PDU Session2. In addition, the SMF may inform the PCF and TSN AF that the corresponding scheduling information has been delivered to the gNB through a notification on PDU Session2.

18 is a flowchart illustrating a process of applying TSCAI to a 3GPP network by comprehensively managing information by a UPF to support TSC from a UE to another UE according to an embodiment of the present disclosure.

The CNC knows the configuration of each port of the 5G network through TSN AF. Since this information also includes information on the surrounding ports for each port, the CNC can know the port through which the stream between the talker and the listener will pass. In addition, since the configuration information for each port also includes the scheduling capability of each TSN node or TSN bridge, the CNC can determine and inform the schedule information of the stream for each port between the talker and the listener. The CNC passes this information to the 5G Network via TSN AF. This Stream Schedule information is transferred from TSN AF to SMF through PCF.

When the Stream Schedule information is transmitted from TSN AF through PCF, it is transmitted as for the PDU Session for one of DS-TT1/UE1 and DS-TT2/UE2. For example, a PDU Session corresponding to DS-TT1/UE1 is selected, and Stream Schedule information may be delivered to the corresponding PCF and SMF. The SMF updates this information back to the UPF to N4. UPF maps DS-TT1/UE1 and DS-TT2/UE2 in Port-in information and Port-out information, and delivers this information to SMF through N4 Report. In this case, the UPF may deliver the N4 Report for DS-TT1/UE1 and the N4 Report for DS-TT2/UE2 to the SMF, respectively.

SMF converts BAT1 (Burst Arrival Time1) of TSCAI corresponding to DS-TT1/UE1 from TSN GM standard to 5G GM reference information, and delivers it to gNB through PDU Session Modification process. At the same time, SMF also calculates BAT2 (Burst Arrival Time2) of TSCAI corresponding to DS-TT2/UE2. BAT2 is calculated as the sum of BAT1 by the Uplink PDB of PDU Session1, Local Switching Delay of UPF, and Downlink CN-PDB of PDU Session2. The SMF delivers BAT2 to the gNB through the process of updating only RAN parameters during the PDU Session Modification procedure for PDU Session2. In addition, it is possible to notify the PCF and TSN AF that the corresponding scheduling information has been delivered to the gNB through a notification on PDU Session2.

19A is a flowchart illustrating a process of applying TSCAI to a 3GPP network by comprehensively managing information by TSN AF in order to support TSC from a UE to another UE according to an embodiment of the present disclosure.

The CNC knows the configuration of each port of the 5G network through TSN AF. Since this information also includes information of the surrounding ports for each port, the CNC can know the port through which the stream between the talker and the listener will pass. In addition, since the configuration information for each port also includes the scheduling capability of each TSN node or TSN bridge, the CNC can determine and inform the schedule information of the stream for each port between the talker and the listener. The CNC passes this information to the 5G Network via TSN AF. This Stream Schedule information is transferred from TSN AF to SMF through PCF. TSN AF finds DS-TT1/UE1 and DS-TT2/UE2 corresponding to Port-in and Port-out, and delivers information to the corresponding PCF and SMF for each of the corresponding PDU Session1 and PDU Session2. In this case, the PCF may be different for each PDU session or may be the same. The SMF may be the same or different for each PDU session.

Upon receiving the information on PDU Sesion1, the SMF converts BAT1 (Burst Arrival Time1) of TSCAI corresponding to DS-TT1/UE1 from TSN GM standard to 5G GM reference information, and delivers it to the gNB through the PDU Session Modification process. The SMF receiving information about PDU Session2 also calculates BAT2 (Burst Arrival Time2) of TSCAI corresponding to DS-TT2/UE2. BAT2 is calculated as the sum of BAT1 by the Uplink PDB of PDU Session1, Local Switching Delay of UPF, and Downlink CN-PDB of PDU Session2. The SMF delivers BAT2 to the gNB through a process of updating only RAN parameters in the PDU Session Modification procedure corresponding to PDU Session2.

19B is a flowchart illustrating a process in which TSN AF manages schedule information for a new PCF session according to an embodiment of the present disclosure.

Referring to FIG. 19B, TSN AF may generate schedule information for PDU Session2 by adding DS-TT-UE Residence Time and UL PDB to Schedule information for PDU Session1 and transmit the generated Schedule information to SMF. Also, the UPF switching delay may be further included in the schedule information.

The SMF may change the received schedule information based on 5GS Clock, and add CN PDB to the changed value. Referring to FIG. 19B, it is indicated by translate(schedule2). In this case, TSN AF may change the DS-TT-UE Residence Time and UL PDB from 5GS GM Clock standard to TSN GM Clock standard.

20A is a flowchart illustrating a process of applying TSCAI to a 3GPP network by comprehensively managing information by a PCF to support TSC from a UE to another UE according to an embodiment of the present disclosure.

The CNC knows the configuration of each port of the 5G network through TSN AF. Since this information also includes information of the surrounding ports for each port, the CNC can know the port through which the stream between the talker and the listener will pass. In addition, since the configuration information for each port also includes the scheduling capability of each TSN node or TSN bridge, the CNC can determine and inform the schedule information of the stream for each port between the talker and the listener. The CNC passes this information to the 5G Network via TSN AF. This Stream Schedule information is transferred from TSN AF to SMF through PCF. When transmitted through the PCF in TSN AF, it is transmitted for one of the PDU sessions among DS-TT1/UE1 and DS-TT2/UE2. For example, when a PDU session corresponding to DS-TT1/UE1 is determined, it is transmitted to the corresponding PCF. The PCF finds DS-TT1/UE1 and DS-TT2/UE2 corresponding to Port-in and Port-out, and delivers information to the corresponding SMF for each of the corresponding PDU Session1 and PDU Session2. At this time, if the PCF cannot directly provide information to the SMF for PDU Session2, that is, if the SMF for PDU Session1 and the SMF for PDU Session2 are different, and the PCF connected to each SMF is different, find the PCF bound to the SMF. Through this PCF, information is delivered to the SMF.

Upon receiving the information on PDU Session1, the SMF converts TSCAI's BAT1 (Burst Arrival Time1) corresponding to DS-TT1/UE1 from TSN GM standard to 5G GM standard information, and delivers it to the gNB through the PDU Session Modification process. Upon receiving the information on PDU Session 2, the SMF also calculates BAT2 (Burst Arrival Time2) of TSCAI corresponding to DS-TT2/UE2. BAT2 is calculated as the sum of BAT1 by the Uplink PDB of PDU Session1, Local Switching Delay of UPF, and Downlink CN-PDB of PDU Session2. The SMF delivers BAT2 to the gNB through the process of updating only RAN parameters during the PDU Session Modification procedure for PDU Session2.

20B is a flowchart illustrating a process in which the PCF manages schedule information for a new PCF session according to an embodiment of the present disclosure.

Referring to FIG. 20B, the PCF may generate Schedule information for PDU Session2 by adding DS-TT-UE Residence Time and UL PDB to Schedule information for PDU Session1, and may transmit the generated Schedule information to SMF.

The SMF may change the received schedule information based on 5GS Clock, and add CN PDB to the changed value. Referring to FIG. 20B, it is indicated by translate(schedule2). In this case, the PCF may change the DS-TT-UE Residence Time and UL PDB from the 5GS GM Clock standard to the TSN GM Clock standard.

The above-described procedures of FIGS. 10 to 20B can be applied even when time synchronization is performed from one UE to a plurality of UEs when the TSN GM is located on the UE side. For example, in order to perform time synchronization for a plurality of UEs, the process of FIGS. 10 to 20B described above may be applied by increasing the number of PDU sessions by the number of UEs.

17 to 20B may be applied even when the TSN GM is on the UPF side rather than the UE side. Regardless of whether the GM is located in the UE or UPF, information transfer between UEs is required based on Stream information for TSC communication. That is, it is necessary to transfer the TSCAI between UE1 corresponding to Port-in and UE2 corresponding to Port-out.

17 to 20B, the UPF Local Switching delay may be calculated as 0 depending on the case. In addition, TSCAI's BAT1 is translate(Arrival Time at UE1) = translate(schedule) = TSN GM Clock based schedule information converted to 5GS GM Clock standard, plus UE-DS-TT Residence of UE1/DS-TT1. It is calculated as a value.

17 to 20B, the residence time in the UPF may be separately considered and calculated. That is, the value excluding the UL UPF Residence Time in the UL PDB for PDU Session 1 is used as the UL PDB, the value excluding the DL UPF Residence Time in the DL CN-PDB for PDU Session 2 is used as the DL CN-PDB, and UE- The to-UE UPF Residence Time is used instead of the UPF Local Switching delay so that the corresponding values can be calculated in the same manner as described above. At this time, when the SMF does not know the UPF Residence Time in FIGS. 19B and 20B, in this case, when TSN AF calculates Schedule2, the DL UPF Residence Time for PDU Session 2 is additionally subtracted from Schedule2 in advance, and SMF is the DL UPF Residence Time. BAT2 of TSCAI is calculated using the existing DL CN-PDB that is not omitted. UPF Residence Time refers to the time from the time the packet enters the UPF to the time the packet exits from the UPF.

The processes of FIGS. 9 to 20B apply the PDU Session Modification procedure, information of UPF is transmitted to TSN AF through the path of UPF-SMF-PCF-TSN AF, and information of TSN AF is transmitted to TSN AF-PCF-SMF-UPF. It is delivered to the UPF through the path of. However, when the UPF can be directly connected to another NF (Network Function) and Control Plane, the UPF and TSN AF communicate directly, so that the processes of FIGS. 9 to 20B can be applied.

21 is a diagram illustrating a configuration of a terminal according to an embodiment of the present disclosure.

As illustrated in FIG. 21, the terminal of the present disclosure may include a transceiver 2110, a memory 2120, and a processor 2130. According to the above-described communication method of the terminal, the processor 2130, the transceiver 2110, and the memory 2120 of the terminal may operate. However, the components of the terminal are not limited to the above-described example. For example, the terminal may include more or fewer components than the above-described components. In addition, the processor 2130, the transceiver 2110, and the memory 2120 may be implemented in the form of a single chip.

The transceiver 2110 refers to a receiver of a terminal and a transmitter of a terminal and may transmit and receive signals with a base station or network entities. Signals transmitted and received with the base station may include control information and data. To this end, the transceiver 2110 may include an RF transmitter that up-converts and amplifies a frequency of a transmitted signal, and an RF receiver that amplifies a received signal with low noise and down-converts a frequency. However, this is only an embodiment of the transmission/reception unit 2110, and components of the transmission/reception unit 2110 are not limited to the RF transmitter and the RF receiver.

In addition, the transmission/reception unit 2110 may receive a signal through a wireless channel, output it to the processor 2130, and transmit a signal output from the processor 2130 through a wireless channel.

The memory 2120 may store programs and data necessary for the operation of the terminal. Also, the memory 2120 may store control information or data included in a signal acquired from the terminal. The memory 2120 may be formed of a storage medium such as a ROM, a RAM, a hard disk, a CD-ROM, and a DVD, or a combination of storage media.

The processor 2130 may control a series of processes so that the terminal can operate according to the above-described embodiment of the present disclosure. The processor 2130 may include at least one or more processors. For example, the processor 2130 may include a communication processor (CP) that controls communication and an application processor (AP) that controls an upper layer such as an application program.

22 is a diagram illustrating a configuration of a network entity according to an embodiment of the present disclosure.

As illustrated in FIG. 22, a network entity of the present disclosure may include a transceiver 2210, a memory 2220, and a processor 2230. According to the above-described communication method of the network entity, the processor 2230, the transceiver 2210, and the memory 2220 of the network entity may operate. However, the constituent elements of the network entity are not limited to the above-described example. For example, the network entity may include more or fewer components than the above-described components. In addition, the processor 2230, the transceiver 2210, and the memory 2220 may be implemented in the form of a single chip. Network entities, such as AMF (Access and Mobility Management Function), SMF Session Management Function), PCF (Policy and Charging Function), NEF (Network Exposure Function), UDM (Unified Data Management), UPF (User Plane Function), etc. It may include a network function (NF). It may also include a base station.

The transmission/reception unit 2210 is collectively referred to as a reception unit of a network entity and a transmission unit of a network entity, and may transmit and receive signals with a terminal or other network entity. In this case, the transmitted/received signal may include control information and data. To this end, the transceiver 2210 may include an RF transmitter that up-converts and amplifies a frequency of a transmitted signal, and an RF receiver that amplifies a received signal with low noise and down-converts a frequency. However, this is only an embodiment of the transmission/reception unit 2210, and components of the transmission/reception unit 2210 are not limited to the RF transmitter and the RF receiver. The transceiving unit 2210 may include a wired/wireless transceiving unit, and may include various configurations for transmitting and receiving signals.

In addition, the transmission/reception unit 2210 may receive a signal through a communication channel (eg, a wireless channel), output it to the processor 2230, and transmit a signal output from the processor 2230 through a communication channel.

The memory 2220 may store programs and data necessary for the operation of the network entity. Also, the memory 2220 may store control information or data included in a signal obtained from a network entity. The memory 2220 may be composed of a storage medium such as a ROM, a RAM, a hard disk, a CD-ROM, and a DVD, or a combination of storage media.

The processor 2230 may control a series of processes so that the network entity can operate according to the above-described embodiment of the present disclosure. The processor 2230 may include at least one or more processors. The methods according to the embodiments described in the claims or the specification of the present disclosure may be implemented in the form of hardware, software, or a combination of hardware and software.

When implemented in software, a computer-readable storage medium storing 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 (device). The 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) 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 forms of It may be stored in an optical storage device or a magnetic cassette. Alternatively, it may be stored in a memory composed of a combination of some or all of them. In addition, a plurality of configuration memories may be included.

In addition, the program is a communication network such as the Internet (Internet), Intranet (Intranet), LAN (local area network), WAN (wide area network), or SAN (storage area network), or a communication network composed of a combination thereof. It may be stored in an accessible storage device. Such a storage device may access a device performing an embodiment of the present disclosure through an external port. In addition, a separate storage device on the communication network may access a device performing an embodiment of the present disclosure.

In the above-described specific embodiments of the present disclosure, components included in the disclosure are expressed in the singular or plural according to the presented specific embodiments. However, the singular or plural expression is selected appropriately for the situation presented for convenience of description, and the present disclosure is not limited to the singular or plural constituent elements, and even constituent elements expressed in plural are composed of the singular or in the singular. Even the expressed constituent elements may be composed of pluralities.

Meanwhile, although specific embodiments have been described in the detailed description of the present disclosure, various modifications may be made without departing from the scope of the present disclosure. Therefore, the scope of the present disclosure is limited to the described embodiments and should not be defined, and should be determined by the scope of the claims and equivalents as well as the scope of the claims to be described later.

Claims (15)

In the method for supporting Time Sensitive Communication (TSC) by User Plane Function (UPF),
A sync frame for time synchronization between TSN nodes (Time Sensitive Network Node) is received from a first user terminal, and the sync frame is received from a first TSN node (Time Sensitive Network Node) corresponding to the grand master. It is transmitted to the first user terminal, the step;
Measuring a residence time taken until the sync frame is received by the UPF from the first user terminal;
Updating a field of the sync frame based on the measured residence time and a reception time of the sync frame; And
And transmitting the updated sync frame to a second TSN node or a second user terminal. The method of claim 1,
The sync frame,
The reception time of the sync frame is stored in a field of the sync frame based on the clock of the first TSN node,
The step of measuring the residence time,
The method of claim 1, wherein the residence time is calculated based on a difference between a time point at which the sync frame is received and a time point at which the sync frame is transmitted to the second TSN node or the second user terminal. The method of claim 2,
Updating the field of the sync frame,
Converting the calculated difference from a clock reference of a base station to a clock reference of the first TSN node; And
And updating a field of the sync frame based on a reception time of the sync frame stored as a clock reference of the first TSN node and the measured residence time. The method of claim 3,
The clock of the second TSN node,
Based on the field of the updated sync frame, synchronized to the clock of the first TSN node. The method of claim 1,
Transmitting to the second TSN node or the second user terminal,
And transmitting the updated sync frame to the second TSN node and the second user terminal through a multicast method. The method of claim 1,
The updated sync frame,
When the updated sync frame is transmitted to the second user terminal, it is transmitted to a third TSN node connected to the second user terminal to synchronize the clock of the third TSN node with the clock of the first TSN node. Which is used, the method. The method of claim 1,
The residence time is,
To satisfy the QoS (Quality of Service) condition for the first TSN node. In UPF (User Plane Function) supporting TSC (Time Sensitive Communication),
A transmission/reception unit; And
Including at least one processor connected to the transmitting and receiving unit,
The at least one or more processors,
A sync frame for time synchronization between TSN nodes (Time Sensitive Network Node) is received from a first user terminal, and the sync frame is received from a first TSN node (Time Sensitive Network Node) corresponding to the grand master. Transmitted to the first user terminal,
A residence time taken until the sync frame is received by the UPF from the first user terminal is measured, and
Update a field of the sync frame based on the measured residence time and the reception time of the sync frame,
UPF for transmitting the updated sync frame to a second TSN node or a second user terminal. The method of claim 8,
The sync frame,
The reception time of the sync frame is stored in a field of the sync frame based on the clock of the first TSN node,
The at least one or more processors,
And calculating the residence time based on a difference between a time point at which the sync frame is received and a time point at which the sync frame is transmitted to the second TSN node or the second user terminal. The method of claim 9,
The at least one or more processors,
Converting the calculated difference from a clock reference of the base station to a clock reference of the first TSN node,
Updating a field of the sync frame based on a reception time of the sync frame stored as a clock reference of the first TSN node and the measured residence time. The method of claim 10,
The clock of the second TSN node,
The UPF, which is synchronized with the clock of the first TSN node, based on the field of the updated sync frame. The method of claim 8,
The at least one or more processors,
And transmitting the updated sync frame to the second TSN node and the second user terminal through a multicast method. The method of claim 8,
The updated sync frame,
When the updated sync frame is transmitted to the second user terminal, it is transmitted to a third TSN node connected to the second user terminal to synchronize the clock of the third TSN node with the clock of the first TSN node. UPF, which is used. The method of claim 8,
The residence time is,
To satisfy the QoS (Quality of Service) condition for the first TSN node, UPF. A computer-readable recording medium storing a program for executing the method of claim 1 on a computer.

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