Patent Description:
To meet the demand for wireless data traffic having increased since deployment of <NUM> th generation (<NUM>) communication systems, efforts have been made to develop an improved <NUM>th generation (<NUM>) or pre-<NUM> communication system.

In the <NUM> system, Hybrid frequency-shift keying (FSK) and quadrature amplitude modulation (QAM) Modulation (FQAM) and sliding window superposition coding (SWSC) as an advanced coding modulation (ACM), and filter bank multi carrier (FBMC), non-orthogonal multiple access (NOMA), and sparse code multiple access (SCMA) as an advanced access technology have been developed.

In a <NUM> wireless communication system, clock synchronization between nodes in the system is required for normal use of the system.

Examples of prior-art include:.

Accordingly, an aspect of the disclosure is to provide a method for transmitting and receiving clock information between a gateway (e.g., user-plane function (UPF)) and a terminal (e.g., user equipment) (UE)) has been proposed to allow a clock synchronization function, which to date has only been supported by wired networks, to also be supported on wireless communication networks. According to this method, a gateway, a terminal, and a base station (e.g., gNB), which are nodes in a wireless communication network, are all synchronized using a common clock (e.g., 5GS clock) while the base station is not synchronized with a clock (e.g., time-sensitive networking (TSN)) on a wired network.

Meanwhile, a representative of time-sensitive communication (TSC) traffic is periodic traffic, which has a traffic pattern including period, a burst size, and a burst arrival time. However, there already exists a standard to centrally collect and manage traffic patterns. Resources can be efficiently managed if a base station (gNB) of a wireless communication network utilizes a TSC traffic pattern (time-sensitive communication assistance information (TSCAI)) by utilizing this standard. For example, the base station allocates resources for a burst size to perform transmission at a burst arrival time for each pre-configured time period.

In the disclosure, the expressions "exceeding" (or "larger than" or "greater than") or "less than" (or "below" or "smaller than") may be used to determine whether a certain condition is satisfied or fulfilled. However, this is only a description for expressing an example, and does not exclude the cases of "equal to or greater than" or "equal to or less than". In relation to described conditions, "equal to or greater than", "less than or equal to", and "equal to or greater than and less than" may be replaced by "exceeding", "less than", and "exceeding and less than or equal to", respectively.

<FIG> illustrates a wireless communication system according to an embodiment of the disclosure.

Referring to <FIG>, a wireless communication system includes a radio access network (RAN) <NUM> and a core network (CN) <NUM>.

The radio access network <NUM>, which is a network that is directly connected to a user device, for example, a terminal <NUM>, is an infrastructure that provides wireless connection to the terminal <NUM>. The radio access network <NUM> may include a group of a plurality of base stations including a base station <NUM>, and the plurality of base stations may perform communication via an interface configured therebetween. At least a part of the interfaces between the plurality of base stations may be wired or wireless. The base station <NUM> may have a structure having a central unit (CU) and a distributed unit (DU) separated from each other. In this case, one CU may control a plurality of DUs. The base station <NUM> may be referred to as a "access point (AP)", a "next-generation node (gNB)", a "<NUM>th generation node", a "wireless point", or a "transmission/reception point (TRP)", rather than a base station, or using some other terms having a technical meaning equivalent thereto. The terminal <NUM> accesses the wireless or radio access network <NUM> and communicates with the base station <NUM> via a wireless channel. The terminal <NUM> may be referred to as a "user equipment (UE)", a "mobile station", a "subscriber station", a "remote terminal", and a "wireless terminal", or a "user device", rather than a terminal, or other terms having a technical meaning equivalent thereto.

A core network <NUM>, which is the network that manages the entire system, controls the radio access network <NUM> and processes data and control signals for the terminal <NUM>, transmitted and received via the radio access network <NUM>. The core network <NUM> performs various functions including control of a user plane and a control plane, processing of mobility, management of subscriber information, charging, interworking with other types of systems (e.g., long-term evolution (LTE) system), and the like. To perform the various functions described above, the core network <NUM> may include a plurality of functionally separated entities having different network functions (NFs). For example, the core network <NUM> may include an access and mobility management function (AMF) <NUM>, an session management function (SMF) <NUM>, a user-plane function (UPF) <NUM>, a policy and charging function (PCF) <NUM>, a network repository function (NRF) <NUM>, a unified data management (UDM) <NUM>, a network exposure function (NEF) <NUM>, and a unified data repository (UDR) <NUM>. The core network <NUM> may interwork with an application function (AF) <NUM>, a central network controller (CNC) <NUM>, and a time-sensitive networking (TSN) system. The core network <NUM> may be referred to as a <NUM>th generation (<NUM>) core (5GC), which is a core network of a <NUM> system.

The terminal <NUM> is connected to the radio access network <NUM> and accesses the AMF <NUM>, which performs a mobility management function of the core network <NUM>. The AMF <NUM> is a function or a device that is responsible for both access to the radio access network <NUM> and the mobility management of the terminal <NUM>. The SMF <NUM> is an NF that manages a session. The AMF <NUM> is connected to the SMF <NUM>, and the AMF <NUM> routes session-related messages of the terminal <NUM> to the SMF <NUM>. The SMF <NUM> is connected to the UPF <NUM> to allocate a user plane resource to be provided to the terminal <NUM> and establishes a tunnel for transmitting data between the base station <NUM> and the UPF <NUM>. The SMF <NUM>, as a main entity managing a PDU session, may be responsible for QoS setting/update for QoS flows in the PDU session. The PCF <NUM> controls information associated with a policy and charging of a session used by the terminal <NUM>. The NRF <NUM> stores information on NFs installed in the wireless communication operator network and performs a function of informing the stored information. The NRF <NUM> may be connected to all NFs. Each NF is registered with the NRF <NUM> when starting to run in the operator network, so as to inform the NRF <NUM> that the NF is running in the network. The UDM <NUM>, as an NF that performs a role similar to a home subscriber server (HSS) of a <NUM> network, stores subscription information of the terminal <NUM> or context information used by the terminal <NUM> in the network.

The NEF <NUM> serves to connect a <NUM>rd-party server to an NF in the <NUM> wireless communication system. In addition, the NEF <NUM> serves to provide data to the UDR <NUM> and to update or obtain data. The UDR <NUM> serves to store subscription information of the terminal <NUM>, store policy information, store data exposed to the outside, or store information necessary for a <NUM>rd-party application. Further, the UDR <NUM> also serves to provide stored data to other NFs.

The UDM <NUM>, PCF <NUM>, SMF <NUM>, AMF <NUM>, NRF <NUM>, NEF <NUM>, and UDR <NUM> may be connected to a service-based interface. Services or application programing interfaces (APIs) provided by NFs are used by other NFs and thus may exchange control messages with each other. The NFs define services they provide, which are defined in standard as Nudm, Npcf, Nsmf, Namf, Nnrf, Nnef, Nudr, etc. For example, when the AMF <NUM> delivers a session-related message to the SMF <NUM>, a service or API called Nsmf_PDUSession_CreateSMContext may be used. The AF may be configured in various manners. Although the AF is not explicitly shown in <FIG>, the AF may be associated with 5GC <NUM>. The AF may be a 3rd-party entity outside the operator network or an entity inside the operator network. For example, TSN AF may be an entity within 5GC, which is an operator network, since 5GC corresponds to an essential function for supporting TSN.

<FIG> shows a configuration of a base station in a wireless communication system according to an embodiment of the disclosure. The configuration illustrated in <FIG> may be understood as a configuration of the base station <NUM>. Terms such as ". device" used below refer to a unit for processing at least one function or operation, which may be implemented by hardware, software, or a combination of hardware and software.

Referring to <FIG>, the base station <NUM> includes a wireless communication unit <NUM>, a backhaul communication unit <NUM>, a storage unit <NUM>, and a controller <NUM>.

The wireless communication unit <NUM> performs functions for transmitting and receiving a signal via a wireless channel. For example, the wireless communication unit <NUM> performs a function of conversion between a baseband signal and a bitstream according to the physical layer standard of the system. For example, the wireless communication unit <NUM> generates complex symbols during data transmission by encoding and modulating a transmission bitstream. In addition, the wireless communication unit <NUM> restores, when receiving data, a reception bitstream through demodulation and decoding of the baseband signal.

In addition, the wireless communication unit <NUM> up-converts a baseband signal into an RF (radio-frequency) band signal and then transmits the signal via an antenna, and down-converts an RF-band signal received via the antenna into a baseband signal. To this end, the wireless communication unit <NUM> may include a transmission filter, a reception filter, an amplifier, a mixer, an oscillator, a DAC (digital-to-analog convertor), and an ADC (analog-to-digital converter). In addition, the wireless communication unit <NUM> may include a plurality of transmission/reception paths. Furthermore, the wireless communication unit <NUM> may include at least one antenna array configured by a plurality of antenna elements.

With regard to hardware, the wireless communication unit <NUM> may be configured by a digital unit and an analog unit, and the analog unit may be configured by a plurality of sub-units according to operating power, operating frequency, and the like. The digital unit may be implemented as at least one processor (e.g., DSP (digital signal processor)).

The wireless communication unit <NUM> transmits and receives a signal as described above. Accordingly, all or part of the wireless communication unit <NUM> may be referred to as a "transmitter", a "receiver", or a "transceiver". In addition, transmission and reception performed via a wireless channel are used in the following description as a meaning of including a process performed as described above by the wireless communication unit <NUM>.

A backhaul communication unit <NUM> provides an interface for performing communication with other nodes in a network. That is, the backhaul communication unit <NUM> converts a bitstream transmitted from a base station to another node, for example, another access node, another base station, an upper node, a core network, or the like into a physical signal, and converts a physical signal received from another node into a bitstream.

The storage unit <NUM> stores data, such as a basic program, applications, and configuration information, for the operation of a base station. The storage unit <NUM> may configured as volatile memory, nonvolatile memory, or a combination of volatile memory and nonvolatile memory. Further, the storage unit <NUM> provides the stored data at the request of the controller <NUM>.

The controller <NUM> controls the overall operations of a base station. For example, the controller <NUM> transmits and receives a signal via the wireless communication unit <NUM> or the backhaul communication unit <NUM>. In addition, the controller <NUM> records and reads data in the storage unit <NUM>. The controller <NUM> may perform the functions of a protocol stack required by a communication standard. According to another embodiment, the protocol stack may be included in the wireless communication unit <NUM>. To this end, the controller <NUM> may include at least one processor. According to various embodiments, the controller <NUM> may control the base station to perform operations according to various embodiments described below.

<FIG> shows a configuration of a terminal in a wireless communication system according to an embodiment of the disclosure. The configuration illustrated in <FIG> may be understood as a configuration of the terminal <NUM>. Terms such as ". device" used below refer to a unit that processes at least one function or operation, which may be implemented by hardware, software, or a combination of hardware and software.

Referring to <FIG>, the terminal <NUM> includes a communication unit <NUM>, a storage unit <NUM>, and a controller <NUM>.

The communication unit <NUM> performs functions for transmitting and receiving a signal via a wireless channel. For example, the communication unit <NUM> performs a function of conversion between a baseband signal and a bitstream according to the physical-layer standard of a system. For example, the communication unit <NUM> generates complex symbols during data transmission by encoding and modulating a transmission bitstream. In addition, the communication unit <NUM> restores, when receiving data, a reception bitstream through demodulation and decoding of the baseband signal. In addition, the communication unit <NUM> up-converts a baseband signal into an RF-band signal and then transmits the signal via an antenna, and down-converts an RF-band signal received via the antenna into a baseband signal. For example, the communication unit <NUM> may include a transmission filter, a reception filter, an amplifier, a mixer, an oscillator, a DAC, and an ADC.

In addition, the communication unit <NUM> may include a plurality of transmission/ reception paths. Furthermore, the communication unit <NUM> may include at least one antenna array configured as a plurality of antenna elements. With regard to hardware, the communication unit <NUM> may be configured as a digital circuit and an analog circuit (e.g. RFIC (radio frequency integrated circuit)). In this regard, the digital circuit and the analog circuit may be implemented as a single package. In addition, the communication unit <NUM> may include a plurality of RF chains. Furthermore, the communication unit <NUM> may perform beamforming.

The communication unit <NUM> transmits and receives a signal as described above. Accordingly, all or part of the communication unit <NUM> may be referred to as a "transmitter", a "receiver", or a "transceiver". In addition, transmission and reception performed via a wireless channel are used in the following description as a meaning of including a process performed as described above by the communication unit <NUM>.

The storage unit <NUM> stores data, such as a basic program, applications, and configuration information, for the operation of a terminal. The storage unit <NUM> may be configured as volatile memory, nonvolatile memory, or a combination of volatile memory and nonvolatile memory. Further, the storage unit <NUM> provides the stored data at the request of the controller <NUM>.

The controller <NUM> controls the overall operations of a terminal. For example, the controller <NUM> transmits and receives a signal via the communication unit <NUM>. In addition, the controller <NUM> records and reads data in the storage unit <NUM>. In addition, the controller <NUM> may perform the functions of a protocol stack required by a communication standard. To this end, the controller <NUM> may include at least one processor or microprocessor or may be a part of the processor. Further, a part of the communication unit <NUM> and the controller <NUM> may be referred to as a CP (communication processor). According to various embodiments, the controller <NUM> may control the terminal to perform operations according to various embodiments described below.

<FIG> shows a configuration of a core network object in a wireless communication system according to an embodiment of the disclosure. The configuration shown in <FIG> may be understood as a configuration of a device having at least one function among the AMF <NUM>, SMF <NUM>, UPF <NUM>, PCF <NUM>, NRF <NUM>, UDM <NUM>, AF <NUM>, NEF <NUM>, and UDR <NUM> of <FIG>. Terms such as ". device" used below refer to a unit that processes at least one function or operation, which may be implemented by hardware or software, or a combination of hardware and software.

Referring to <FIG>, the core network object <NUM> includes a communication unit <NUM>, a storage unit <NUM>, and a controller <NUM>.

The communication unit <NUM> provides an interface for performing communication with other devices in a network. That is, the communication unit <NUM> converts a bitstream transmitted from the core network object to another device into a physical signal, and converts a physical signal received from another device into a bitstream. That is, the communication unit <NUM> may transmit and receive signals. Accordingly, the communication unit <NUM> may be referred to as a modem, a transmitter, a receiver, or a transceiver. At this time, the communication unit <NUM> allows the core network object to communicate with other devices or systems via a backhaul connection (e.g., wired backhaul or wireless backhaul) or via a network.

The storage unit <NUM> stores data, such as a basic program, applications, and configuration information, for the operation of the core network object. The storage unit <NUM> may be configured as volatile memory, nonvolatile memory, or a combination of volatile memory and nonvolatile memory. Further, the storage unit <NUM> provides the stored data at the request of the controller <NUM>.

The controller <NUM> controls the overall operations of the core network object. For example, the controller <NUM> transmits and receives a signal via the communication unit <NUM>. In addition, the controller <NUM> records and reads data in the storage unit <NUM>. To this end, the controller <NUM> may include at least one processor. According to various embodiments, the controller <NUM> may control the core network object to perform operations according to various embodiments described below.

According to an embodiment, a method performed by a network entity of a core network in a wireless communication system, the method comprises obtaining a burst arrival time associated with a <NUM>th generation (<NUM>) clock; and transmitting time-sensitive communication assistant information (TSCAI) including information on the burst arrival time to a node of an access network. The burst arrival time associated with the <NUM> clock is mapped from a TSN clock to the <NUM> clock, based on an offset between <NUM>th generation system (5GS) time and a time-sensitive networking (TSN) time.

In some embodiments, the method further comprises receiving information on the offset from a user-plane function (UPF).

In some embodiments, if a change to the offset from a previous offset between a TSN time and a 5GS time is greater than a threshold value, the information is transmitted from the UPF to the network entity.

In some embodiments, the TSCAI is transmitted based on a protocol data unit (PDU) session modification procedure.

In some embodiments, the burst arrival time is determined based on a core network (CN) packet delay budget (PDB) if the burst arrival time is associated with a downlink, and the burst arrival time is determined based on a UE residence time if the burst arrival time is associated with an uplink.

In some embodiments, the method further comprises receiving information from an application function (AF); and determining the TSCAI, based on the received information.

In some embodiments, the network entity is a session management function (SMF), and a mapping of the burst arrival time associated with the <NUM> clock is performed by an application function (AF).

According to an embodiment, a method performed by a base station in a wireless communication system, the method comprises receiving time-sensitive communication assistant information (TSCAI) including information on a burst arrival time associated with a <NUM>th generation (<NUM>) clock from a network entity of a core network. Information on the burst arrival time is determined based on an offset between a <NUM>th generation system (5GS) time and a time-sensitive networking (TSN) time.

According to an embodiment, a method performed by a user-plane function (UPF) in a wireless communication system, the method comprises transmitting information on an offset between a <NUM>th generation system (5GS) time and a time-sensitive networking (TSN) time to a network entity of a core network.

In some embodiments, the transmitting of the information on the offset comprises determining whether a change to the offset from a previous offset between a TSN time and a 5GS time is greater than a threshold value; and transmitting information on the offset to the network entity based on the change being greater than the threshold value.

According to an embodiment, a method performed by an application function (AF) in a wireless communication system, the method comprises transmitting information to a network entity of a core network. The information is used for determination of time-sensitive communication assistant information (TSCAI). The TSCAI includes information on a burst arrival time associated with a <NUM>th generation (<NUM>) clock.

In some embodiments, the method further comprises mapping a burst arrival time from a TSN clock to a <NUM> clock, based on an offset between a <NUM>th generation system (5GS) time and a time-sensitive networking (TSN) time; and obtaining a burst arrival time associated with the <NUM> clock, based on the mapping.

According to an embodiment, an apparatus of a network entity of a core network in a wireless communication system, the apparatus comprises at least one transceiver; and at least one processor coupled to the at least one transceiver. The at least one processor is configured to: obtain a burst arrival time associated with a <NUM>th generation (<NUM>) clock; and control the at least one transceiver to transmit time-sensitive communication assistant information (TSCAI) including information on the burst arrival time to a node of an access network. The burst arrival time associated with the <NUM> clock is mapped to the <NUM> clock from a time-sensitive networking (TSN) clock, based on an offset between a <NUM>th generation system (5GS) time and a TSN time.

In some embodiments, the at least one processor is further configured to control the at least one transceiver to receive information on the offset from a user-plane function (UPF).

In some embodiments, the at least one processor is configured to: control the at least one transceiver to receive information from an application function (AF); and determine the TSCAI, based on the received information.

According to an embodiment, an apparatus operated by a base station in a wireless communication system, the apparatus comprises at least one transceiver; and at least one processor coupled to the at least one transceiver. The at least one processor is configured to: control the at least one transceiver to receive time-sensitive communication assistant information (TSCAI) including information on a burst arrival time associated with a <NUM>th generation (<NUM>) clock from a network entity of a core network. Information on the burst arrival time is determined based on an offset between a <NUM>th generation system (5GS) time and a time-sensitive networking (TSN) time.

According to an embodiment, an apparatus operated by a user-plane function (UPF) in a wireless communication system, the apparatus comprises at least one transceiver; and at least one processor coupled to the at least one transceiver. The at least one processor is configured to control the at least one transceiver to transmit information on an offset between a <NUM>th generation system (5GS) time and a time-sensitive networking (TSN) time to a network entity of a core network.

In some embodiments, in order to transmit the information on the offset, the at least one processor is configured to: determine whether a change to the offset from a previous offset between a TSN time and a 5GS time is greater than a threshold value, and control the at least one transceiver to transmit information on the offset to the network entity if the change is greater than the threshold value.

According to an embodiment, an apparatus operated by an application function (AF) in a wireless communication system, the apparatus comprises at least one transceiver; and at least one processor coupled to the at least one transceiver. The at least one processor is configured to control the at least one transceiver to transmit information to a network entity of a core network. The information is used for determination of time-sensitive communication assistant information (TSCAI). The TSCAI includes information on a burst arrival time associated with a <NUM>th generation (<NUM>) clock.

In some embodiments, the processor is further configured to: map a burst arrival time from a TSN clock to a <NUM> clock, based on an offset between a <NUM>th generation system (5GS) time and a time-sensitive networking (TSN) time; and obtain a burst arrival time associated with the <NUM> clock, based on the mapping.

According to an embodiment, a method for obtaining clock synchronization information in a base station configured to operate based on a reference clock of a wireless communication system, the method comprises: obtaining a burst arrival time of time-sensitive communication assistance information (TSCAI) based on a time-sensitive networking (TSN) clock; obtaining offset information indicating a difference between the TSN clock and a reference clock of the wireless communication system; and adjusting a burst arrival time, based on an offset to obtain an adjusted burst arrival time based on the reference clock of the wireless communication system. In some embodiments, the operation "adjustment" from a previous one to a current one comprises an mapping from the previous one to the current one.

In some embodiments, the obtaining of the offset information comprises: obtaining the offset information using a radio resource control (RRC) message coming from a terminal; or obtaining the offset information using an N2 request message coming from an access and mobility management function (AMF).

In some embodiments, the obtaining of the offset information indicating a difference between the TSN clock and the reference clock of the wireless communication system, comprises: obtaining offset difference information indicating a difference between a previous offset and a current offset. The obtaining of the adjusted burst arrival time comprises: adjusting again the adjusted burst arrival time, based on the offset difference information to obtain an adjusted burst arrival time based on the reference clock of the wireless communication system.

According to an embodiment, a method for obtaining clock synchronization information in a base station configured to operate based on a reference clock of a wireless communication system in the wireless communication system, the method comprises: obtaining an adjusted burst arrival time obtained by adjusting a burst arrival time of time-sensitive communication assistance information (TSCAI) based on a time-sensitive networking (TSN) clock, based on a reference clock of the wireless communication system.

In some embodiments, the obtaining of the adjusted burst arrival time comprises a previously adjusted burst arrival time and a newly calculated and adjusted burst arrival time, which are received from an external device.

In some embodiments, the obtaining of the adjusted burst arrival time comprises: obtaining the adjusted burst arrival time using a radio resource control (RRC) message coming from a terminal; or obtaining the adjusted burst arrival time using an N2 request message coming from an access and mobility management function (AMF).

In some embodiments, the obtaining of the adjusted burst arrival time comprises: obtaining a previously adjusted burst arrival time and offset difference information indicating a difference between a previous offset and a current offset; and obtaining the adjusted burst arrival time, based on the offset difference information and the previously adjusted burst arrival time.

In some embodiments, the adjusted burst arrival time is calculated by a terminal, a session management function (SMF), a policy and charging function (PCF), or an application function (AF).

In some embodiments, a base station allocates resources to perform transmission of the adjusted burst arrival time for a pre-configured time period.

In some embodiments, the reference clock comprises a <NUM> clock.

In some embodiments, time expressed by the <NUM> clock includes 5GS reference time.

<FIG> illustrates clock synchronization of a wireless network that does not support TSN (time-sensitive networking) of a wired network, which is referred for explanation of the disclosure, and problem with a TSCAI reference clock, which is to be solved by the disclosure according to an embodiment of the disclosure.

<FIG> illustrates an example of time-sensitive communication assistance information (TSCAI) delivered between TSN support nodes according to an embodiment of the disclosure.

Referring to <FIG>, in order to support TSN in a wired network, TSN nodes <NUM> and <NUM> support a protocol that delivers a clock of TSN GM (Grand Master) <NUM> via an Ethernet frame. In order to extend this to a wireless network, a UPF (user-plane function) <NUM>, which is a gateway, and a UE (user equipment) <NUM>, which is a terminal, have a TSN translator function so as to support the above-mentioned protocol. A method for supporting the transmission of TSN clock even between the UPF <NUM> and the UE <NUM> has been proposed. In this method, the terminal (UE) <NUM>, the base station (gNB) <NUM>, and the gateway (UPF) <NUM> in a <NUM> system are synchronized using a <NUM> system clock, and the UPF <NUM> and the UE <NUM> deliver the value of a TSN clock to a 5GS clock through time-stamping using this synchronization. That is, in the case in which this method is used, the UPF <NUM> and the UE <NUM> are both aware of the TSN clock and the 5GS clock at the same time, but the base station is only aware of the 5GS clock.

Meanwhile, in order to effectively deliver TSC traffic between TSN support nodes, the TSN nodes <NUM> and <NUM> deliver traffic pattern information to a CNC (central network controller) <NUM>, and the CNC <NUM> shares traffic pattern information with other TSN nodes <NUM> and <NUM>, thereby assisting the scheduling of all nodes. The <NUM> system is regarded as one TSN node, and receives a traffic pattern, which comes from an external TSN node to the <NUM> system via the UE <NUM> and the UPF <NUM>, from the CNC <NUM> via the AF <NUM>. Similarly, with respect to the traffic coming into the <NUM> system, a pattern of traffic going out to the external TSN node via the UE <NUM> and the UPF <NUM> is shared to the CNC <NUM> via the AF <NUM>. When the TSCAI (TSC assistance information), which is traffic characteristics information including period, a burst size, and a burst arrival time, as shown in <FIG>, is delivered to the gNB <NUM>, the gNB <NUM> may reflect the information to use the same for scheduling, and thus may efficiently utilize resources. For example, the gNB <NUM> allocates resources a burst size to perform transmission at a burst arrival time for each pre-configured time period. In fact, since information coming from the CNC <NUM> is a pattern of traffic arriving at the UPF <NUM> in the case of a downlink (DL), the maximum UPF residence time and CN PDB (packet delay budget) need to be corrected in order to change with reference to an input terminal of the gNB <NUM>. Similarly, since information coming from the CNC <NUM> is a pattern of traffic arriving at the UE <NUM> in the case of uplink (UL), the UE residence time needs to be corrected in order to change with reference to the input end of the gNB <NUM>. The TSN reference time refers to the time used as a reference for expressing a time on a TSN clock. As an example, the TSN reference time may include a time epoch associated with TSN.

In the case of utilizing a clock synchronization method using the wireless communication network proposed above, the gateway (UPF) <NUM> and the terminal (UE) <NUM> of the wireless communication network are aware of the clock (TSC clock) of the wired network while the base station (gNB) <NUM> is not. Therefore, the base station (gNB) <NUM> may not be aware of the exact reference clock of TSCAI. In particular, since a burst arrival time is indicated based on the TSN clock, the gNB <NUM>, which is aware only of the 5GS clock, may not utilize the information.

<FIG> describes information that needs to be additionally delivered to the gNB <NUM> in order to solve the problem raised in <FIG> according to an embodiment of the disclosure.

<FIG> illustrates an example of a burst arrival time, adjusted based on TSCAI. A 5GS reference time refers to the time used as a reference for expressing the time of a <NUM> clock. As an example, the 5GS reference time may include a time epoch, associated with 5GS according to an embodiment of the disclosure.

In a first solution, the problem may be solved by delivering an offset, which is the difference between the 5GS clock and the TSN clock, to the gNB <NUM>. In one embodiment, the UPF <NUM> or UE <NUM> calculates an offset=T_5GS-T_TSN (the difference between the 5GS clock and the TSN clock) and delivers the calculated offset to the gNB <NUM>, and the gNB <NUM> converts a burst arrival time based on the TSN clock into a time based on the 5GS clock (mapping), so that the converted time can be used for scheduling.

In a second solution, the problem may be solved by delivering a burst arrival time converted based on a 5GS clock, to the gNB <NUM>. The problem may be solved by converting a burst arrival time based on the TSN clock into a time based on the 5GS clock at any node in an information transfer process to the UE <NUM>, the UPF <NUM>, or the gNB <NUM>. The gNB <NUM> may also convert a burst arrival time based the TSN clock into a time based on the 5GS clock (mapping). In this case, the difference between the first solution and the second solution lies in the entity that manages the burst arrival time based on the TSN clock of the corresponding domain. The gNB <NUM> manages a list of burst arrival times for each TSN domain in the first solution, and another network function other than the gNB <NUM> manages the list in the second solution. A TSN domain, which refers to nodes using an identical TSN GM as a reference, may have a plurality of TSN domains existing in a wired network. The current standard of wired network supports up to <NUM>, and the current 5GS standard supports up to <NUM> at the same time.

<FIG> illustrates an embodiment of the flow of information delivered in order to solve a problem with a TSCAI reference clock using a wireless communication network according to an embodiment of the disclosure, and <FIG> illustrates an embodiment of the flow of information delivered in order to solve a problem with a TSCAI reference clock using a wireless communication network according to an embodiment of the disclosure. A method for delivering an offset or a burst arrival time converted based on the 5GS clock to the gNB <NUM> includes a method in which the UE <NUM> starts information flow, and a method in which the UPF <NUM> starts information flow.

Referring to <FIG>, the UE <NUM> may start an information flow in the following cases.

<NUM> With respect to the gNB <NUM> via a RRC (a newly defined RRC (radio resource control)) (operation <NUM>): the UE <NUM> or gNB <NUM> may change from a burst arrival time based on the TSN clock to a time based on the <NUM> GS clock.

<NUM> With respect to the SMF <NUM> via NAS (PDU (protocol data unit) session modification) (operation <NUM>): the UE <NUM>, SMF <NUM>, or gNB <NUM> may change from a burst arrival time based on the TSN clock to a time based on the 5GS clock.

<NUM> With respect to the SMF <NUM> via an NAS (PDU session modification)-(notification)-PCF <NUM> path (operation <NUM>): the UE <NUM>, PCF <NUM>, SMF <NUM>, or gNB <NUM> may change from a burst arrival time based on the TSN clock to a time based on the 5GS clock.

<NUM> With respect to the SMF <NUM> via an NAS (PDU session modification)-(notification)-PCF <NUM>-(notification)-AF <NUM> path (operation <NUM>): the UE <NUM>, AF <NUM>, PCF <NUM>, SMF <NUM>, or gNB <NUM> may change from a burst arrival time based on the TSN clock to a time based on the 5GS clock.

<NUM> With respect to the AF <NUM> via a non-3GPP method (operation <NUM>): the UE <NUM>, AF <NUM>, PCF <NUM>, SMF <NUM>, or gNB <NUM> may change from a burst arrival time based on the TSN clock to a time based on the 5GS clock.

<NUM> With respect to the UPF <NUM> via piggyback of a synchronization procedure or a new interface (operation <NUM>): adjustment for changing a burst arrival time based on the TSN clock to a time based on the 5GS clock according to a follow-up flow after the UPF <NUM> may be performed in various NFs (network functions).

Referring to <FIG>, the UPF <NUM> may start an information flow in the following cases.

<NUM> To the AF <NUM> via a non-3GPP method including an AF <NUM>-UPF <NUM> combination (operation <NUM>): adjustment for changing a burst arrival time based on the TSN clock to a time based on the 5GS clock may be performed by the AF <NUM>, PCF <NUM>, SMF <NUM>, or gNB <NUM>.

<NUM> To the SMF <NUM> via an N4 interface (N4 report/notification) (operation <NUM>): adjustment for changing a burst arrival time based on the TSN clock to a time based on the 5GS clock may be performed by the SMF <NUM> or gNB <NUM>.

<NUM> To the PCF <NUM> via a UPF <NUM>-N4-SMF <NUM>-(notification)-PCF <NUM> (operation <NUM>): adjustment for changing a burst arrival time based on the TSN clock to a time based on the 5GS clock may be performed by the PCF <NUM>, SMF <NUM>, or gNB <NUM>.

<NUM> To the AF <NUM> via a UPF <NUM>-(N4)-SMF <NUM>-(notification)-PCF <NUM>-(notification)-AF <NUM> path (operation <NUM>): adjustment for changing a burst arrival time based on the TSN clock to a time based on the 5GS clock may be performed by the AF <NUM>, PCF <NUM>, SMF <NUM>, or gNB <NUM>.

<NUM> To the UE <NUM> via piggyback of a synchronization procedure or a new interface: adjustment for changing a burst arrival time based on the TSN clock to a time based on the 5GS clock according to a follow-up flow from the UE <NUM> may be performed by various NFs.

Table <NUM> shows the corresponding embodiments reflecting synthetic review in terms of information to be additionally delivered in a wireless network, the flow of information delivery, and adjustment of TSCAI in order to solve the problem with a TSCAI reference clock utilizing a wireless communication network. Table <NUM> collectively shows the contents described above with reference to <FIG> and <FIG> and <FIG> and <FIG> and includes drawing numbers of the corresponding embodiments.

Hereinafter, embodiments of each entity performing operations and each flow of information for application of an offset for delivering an offset or adjusting a time will be described with reference to <FIG>. Meanwhile, the signaling shown in <FIG> is only examples for embodiments, and signaling (e.g., notification, request, and response) between specific entities is not to be interpreted as limiting the embodiments described in connection with the corresponding drawings.

Hereinafter, the offset between the 5GS clock and the TSN clock mentioned in the disclosure may include at least one of a time offset, which is a time difference, or a frequency offset, which is a speed difference. The time offset is determined based on a time of a 5GS clock (e.g., 5GS_time)/a time of TSN clock (e.g., TSN_time). For example, the time offset may be determined based on the difference between a time of a TSN clock and a time of a 5GS clock. According to one embodiment, a UPF (NW-TT) may calculate and update a time offset value. The UPF may update a core network entity (e.g., SMF and AF) on the time offset. The time offset may be used to convert a burst arrival time based on the TSN clock into a time based on the 5GS clock (mapping). A network entity (e.g., SMF, AF, PCF, and AMF) associated with the core network (5GC) may map a burst arrival time based on the TSN clock to a time based on the 5GS clock, based on a time offset. The base station (e.g., gNB) may obtain a burst arrival time associated with the 5GS clock via TSCAI.

The frequency offset may be determined based on the frequency of the 5GS clock (e.g., frequency_5GS)/a frequency of TSN clock (e.g., frequency_TSN). For example, the frequency offset may be determined based on the ratio of the frequency of the TSN clock to the frequency of the 5GS clock. According to one embodiment, the UPF (NW-TT) may calculate and update a frequency offset value. The UPF may update a core network entity (e.g., SMF and AF) on the frequency offset. The frequency offset may be used to map period based on the TSN clock to the period based on the 5GS clock. A network entity (e.g., SMF, AF, PCF, and AMF) associated with a core network (5GC) may map a period based on the TSN clock to period based on the 5GS clock, based on a frequency offset. The base station (e.g., gNB) may obtain a period associated with the 5GS clock via TSCAI. The operations and related descriptions of each entity with respect to the time offset may be modified and applied in a manner the same as or similar to that applied for the frequency offset.

<FIG> is a signal flow diagram showing an initial flow in a method the gNB <NUM> uses an offset and illustrates adjustment performed by the AF <NUM> according to an embodiment of the disclosure, <FIG> is a signal flow diagram showing an initial flow in a method the gNB <NUM> uses an offset and illustrates adjustment performed by the PCF <NUM> according to an embodiment of the disclosure, and <FIG> is a signal flow diagram showing an initial flow in a method in which the gNB <NUM> uses an offset and illustrates adjustment performed by the SMF <NUM> according to an embodiment of the disclosure. The signaling illustrated in <FIG>, <FIG>, and <FIG>, which corresponds to an initial flow in a method in which the gNB <NUM> uses an offset, is only examples for the embodiments in which the AF <NUM>, PCF <NUM>, and SMF <NUM> perform adjustment, and signaling (e.g., notification, request, and response) shown between specific entities is not to be interpreted as limiting the operations of the embodiments to be described in drawings. In this case, a separate stream ID is not required, and TSCAI including a burst arrival time for each domain is delivered to the gNB <NUM>. The UE <NUM> manages a TSN domain-specific offset for UL traffic, manages TSCAI received from the TSN domain-specific CNC <NUM>, and is aware of the maximum UE residence time. The UPF <NUM> manages a domain-specific offset for DL traffic, and the AF <NUM> manages domain-specific TSCAI for DL traffic and is aware of the maximum UPF residence time and CN PDB. The AF <NUM> may also be responsible for exchanging information with the CNC <NUM> with respect to UL and DL traffic, and thus is also aware of domain-specific TSCAI for UL and DL traffic, the maximum UE residence time, the maximum UPF residence time, and CN PDB.

Referring to <FIG>, information may be delivered along the following flow to obtain a burst arrival time by the gNB <NUM>. A TSN system may deliver TSCAI information via CNC <NUM> and CNC management messages (operation <NUM>), and the CNC <NUM> may deliver TSCAI information to the AF <NUM> via TSN bridge management messages (operation <NUM>). The AF <NUM> may perform adjustment for a burst arrival time by applying a UL residence time in the case of UL or a UPF residence time and CN PDB in the case of DL (operation <NUM>). The initial value of a domain-specific default offset may be applied, apart from this. The AF <NUM> is aware of this value. Next, the AF <NUM> may deliver TSCAI information and a default offset to the PCF <NUM> via an NR request/ response message (operation <NUM>), the PCF <NUM> may deliver the TSCAI information and the default offset to the SMF <NUM> via N7 PDU session modification Req. (operation <NUM>), the SMF <NUM> may deliver the default offset to the UPF <NUM> via N4 PDU session modification Req. (operations <NUM> and <NUM>), the SMF <NUM> may deliver the TSCAI information and the default offset to the AMF <NUM> via N11 Req. message (operation <NUM>), and the AMF <NUM> may deliver the TSCAI information and the default offset to the gNB <NUM> via N2 session Req. message (operation <NUM>). The gNB <NUM> may modify a resource to be used for transmitting data to the terminal <NUM>, based on the received TSCAI information and default offset (operation <NUM>). Further, the gNB <NUM> may deliver an N2 session Res. message to the AMF <NUM> (operation <NUM>), and the AMF <NUM> may transmit an N11 Res. message to the SMF <NUM> (operation <NUM>). The SMF <NUM> having received the N11 Res. message may inform the UE <NUM> the default offset by delivering an N1 PDU session modification Req. message to the UE <NUM> (operation <NUM>), and the UE <NUM> may deliver an N1 PDU session modify Res. message in response to the received message to the SMF <NUM> (operation <NUM>). Thereafter, the SMF <NUM> may deliver an N7 notification message to the PCF <NUM> (operation <NUM>), and the PCF <NUM> may deliver an N5 notification message to the AF <NUM> (operation <NUM>).

Referring to <FIG>, when the PCF <NUM> performs adjustment (operation <NUM>), the PCF <NUM> uses a domain-specific default offset, which is delivered from the AF <NUM>, and the PCF <NUM> is aware of the maximum UE residence time, the maximum UPF residence time and CN PDB. Other operations for obtaining a burst arrival time by the gNB <NUM> are similar to those in <FIG>. That is operations <NUM> to <NUM> shown in <FIG> may be similar to operations <NUM> to <NUM> shown in <FIG>.

Referring to <FIG>, when the SMF <NUM> performs adjustment (operation <NUM>), the SMF <NUM> uses a default offset for each domain, which is delivered via the AF <NUM> and the PCF <NUM>. In this case, the SMF <NUM> is aware of the maximum UE residence time, the maximum UPF residence time and CN PDB. Other operations for obtaining a burst arrival time by the gNB <NUM> are similar to those in <FIG>. Operations <NUM> to <NUM> shown in <FIG> may be similar to operations <NUM> to <NUM> shown in <FIG>.

<FIG> is a signal flow diagram showing the flow of UE <NUM>->gNB <NUM> in a method in which the gNB <NUM> uses an offset according to an embodiment of the disclosure, <FIG> is a signal flow diagram showing the flow of UE <NUM>->SMF <NUM> in the method in which the gNB <NUM> uses an offset according to an embodiment of the disclosure, <FIG> is a signal flow diagram showing the flow of UE <NUM>->SMF <NUM>->PCF <NUM> in a method in which the gNB <NUM> uses an offset according to an embodiment of the disclosure, <FIG> is a signal flow diagram showing the flow of UE <NUM>->SMF <NUM>->PCF <NUM>->AF <NUM> in a method in which the gNB <NUM> uses an offset according to an embodiment of the disclosure, <FIG> is a signal flow diagram showing the flow of AF <NUM> in a method in which the gNB <NUM> uses an offset according to an embodiment of the disclosure, and <FIG> is a signal flow diagram showing the flow of UE <NUM>->UPF <NUM> in a method in which the gNB <NUM> uses an offset according to an embodiment of the disclosure. The signaling illustrated in <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, and <FIG>, which shows a method in which the gNB <NUM> uses an offset, is only examples for explaining the flow of UE <NUM>->gNB <NUM>, UE <NUM>->SMF <NUM>, UE <NUM>->SMF <NUM>->PCF <NUM>, UE <NUM>->SMF <NUM>->PCF <NUM>->AF <NUM>, AF <NUM>, and UE <NUM>->UPF <NUM> in the embodiments, and signaling between specific entities is not to be interpreted as limiting the operations of the embodiments to be described in connection with drawings.

The UE <NUM> calculates an offset (Example <NUM>: time offset=5GS-TSN (difference between the 5GS clock and the TSN clock), Example <NUM>: frequency offset) (operations <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and <NUM>) during a process of transmitting and receiving a sync frame to or from the UPF <NUM> for TSN clock synchronization with the UPF <NUM>. At this time, if a difference (or change) between an old offset, which is an offset previously used for adjustment, and a newly calculated (measured) new offset, exceeds a certain threshold value, information delivery is triggered. This threshold value is a difference in accuracy between the 5GS clock and the TSN clock or is determined according to the size of the corresponding stream period or the latency request. For example, if the difference in accuracy between the 5GS clock and the TSN clock is too large (i.e. frequent), a threshold value may be large in order to prevent the signaling occurrence. In addition, if the corresponding stream period is large or the latency request is large, a threshold value thereof may be large. With regard to the condition in which information is transmitted by the UE <NUM>, the UE <NUM> may transmit information at regular intervals or may transmit the information when the signaling load does not exceed a certain level. In this case, since the gNB <NUM> is aware of a burst arrival time(s) of a stream associated with each domain, when the domain and the offset difference (difference between the old offset and the new offset) is delivered to the gNB <NUM>, the gNB <NUM> may adjust the burst arrival times of all streams associated with the corresponding domain using offset difference without consideration of a separate stream ID. This process may be implemented such that each domain is synchronized with the 5GS clock and thus has a separate clock having as much difference as the offset. The operation through the comparison of the offset difference and the threshold value may be equally applied to the second solution, as shown in <FIG>, as well as <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, and <FIG>.

Referring to <FIG>, the figure shows the flow of UE <NUM>->gNB <NUM> in a method in which the gNB <NUM> uses an offset. The UE <NUM> delivers only domain and offset difference (a difference between an old offset and a new offset) information to the gNB <NUM> using the RRC (operation <NUM>). The gNB <NUM> adjusts the burst arrival times of all streams corresponding to the corresponding domain using an offset (operation <NUM>). At this time, the UE <NUM> may send the domain and offset to the AF <NUM> (operation <NUM>) so that a domain-specific offset managed by the AF <NUM> may be updated, and the AF <NUM> may send a notification (ACK) to the UE <NUM> (operation <NUM>). The gNB <NUM> may send acknowledgment of an RRC response to the UE <NUM> (operation <NUM>).

Referring to <FIG>, the figure shows the flow of UE <NUM>->SMF <NUM> in the method in which the gNB <NUM> uses an offset. The UE <NUM> sends a request to the SMF <NUM> using a PDU session modification message, and the domain and offset difference information is delivered to the gNB <NUM> via an N2 message (operation <NUM>). The SMF <NUM> shares the domain and offset difference with the PCF <NUM> and the AF <NUM> via a notification process (operations <NUM> to <NUM>). In addition, the SMF <NUM> may also share the domain and offset difference with to the UPF <NUM> via the N4 message (operations <NUM> and <NUM>). N11 request, N2 request, update offset, resource modification, N2 response, N11 response, and N1 PDU session modification response occur at operations <NUM> to <NUM>, as shown in <FIG>.

Referring to <FIG>, the figure shows the flow of UE <NUM>->SMF <NUM>->PCF <NUM> in a method in which the gNB <NUM> uses an offset. The SMF <NUM> immediately performs a PDU session modification request in <FIG>, but the PCF <NUM> performs a determination on a PDU session modification request by a terminal in <FIG>. Operations <NUM> to <NUM> are shown in <FIG>.

Referring to <FIG>, the figure shows the flow of UE <NUM>-> SMF <NUM>->PCF <NUM>->AF <NUM> in a method in which the gNB <NUM> uses an offset. The SMF <NUM> immediately performs the PDU session modification request in <FIG>, the PCF <NUM> performs determination on a PDU session modification request by a terminal in <FIG>, but the AF <NUM> makes determination on a PDU session modification request by a terminal in <FIG>. Operations <NUM> to <NUM> are shown in <FIG>.

Referring to <FIG>, the figure shows the flow of UE <NUM>->AF <NUM> in a method in which the gNB <NUM> uses an offset. Information is delivered using the message sent by the UE <NUM> to the SMF <NUM> in <FIG>, but direct communication of an application stage between the UE <NUM> and the AF <NUM> is used in <FIG>. Other processes are as shown in <FIG>. Operations <NUM> to <NUM> are shown in <FIG>.

Referring to <FIG>, the figure shows the flow of UE <NUM>->UPF <NUM> in a method in which the gNB <NUM> uses an offset. Whenever the UE <NUM> receives a TSN synchronization frame, the UE <NUM> sends an offset to UPF <NUM> to achieve a TSN synchronization therebetween. Although another method may be employed, the mapping may be achieved by a process in which the offset is logically delivered. At this time, when a criterion in which information delivery needs to be triggered is satisfied, the UE <NUM> delivers the offset to the UPF <NUM> by adding a separate indicator indicating that this offset needs to be delivered up to the gNB <NUM> (operation <NUM>). Upon receiving the offset having this indicator, the UPF <NUM> starts a process of delivering the corresponding domain and offset difference to the gNB <NUM>. Reference may be made to <FIG>, <FIG>, <FIG>, or <FIG> in connection with the process. Operations <NUM> to <NUM> are shown in <FIG>.

<FIG> is a signal flow diagram showing the flow of UPF <NUM>->AF <NUM> in a method in which the gNB <NUM> uses an offset according to an embodiment of the disclosure. Operations <NUM> to <NUM> are shown in <FIG>. <FIG> is a signal flow diagram showing the flow of UPF <NUM>->SMF <NUM> in a method in which the gNB <NUM> uses an offset according to an embodiment of the disclosure. Operations <NUM> to <NUM> are shown in <FIG>. <FIG> is a signal flow diagram showing the flow of UPF <NUM>->SMF <NUM>->AF <NUM> in a method in which the gNB <NUM> uses an offset according to an embodiment of the disclosure. Operations <NUM> to <NUM> are shown in <FIG>. <FIG> is a signal flow diagram showing the flow of UPF <NUM>->SMF <NUM>->PCF <NUM> in a method in which the gNB <NUM> uses an offset according to an embodiment of the disclosure. Operations <NUM> to <NUM> are shown in <FIG>. <FIG> is a signal flow diagram showing the flow of UPF <NUM>->UE <NUM> in a method in which the gNB <NUM> uses an offset according to an embodiment of the disclosure. Operations <NUM> to <NUM> are shown in <FIG>. The signaling in <FIG>, <FIG>, <FIG>, <FIG>, and <FIG>, which shows a method in which the gNB <NUM> uses an offset, is only examples for explaining the flow of UPF <NUM>->AF <NUM>, UPF <NUM>->SMF <NUM>, UPF30->SMF <NUM>->AF <NUM>, UPF <NUM>->SMF <NUM>->PCF <NUM>, and UPF <NUM>->UE <NUM>, and signaling between specific entities is not to be interpreted as limiting the operations of the embodiments to be described in connection with the drawings.

The UPF <NUM> calculates an offset (Example <NUM>: time offset=5GS-TSN (difference between the 5GS clock and the TSN clock), Example <NUM>: frequency offset) (operations <NUM>, <NUM>, <NUM>, <NUM>, and <NUM>), during a process of transmitting and receiving a sync frame to or from the UE <NUM> for TSN clock synchronization. At this time, if a difference (or change) between an old offset, which is an offset previously used for adjustment, and a newly calculated (measured) new offset exceeds a certain threshold value, information delivery is triggered. This threshold value is a difference in accuracy between the 5GS clock and the TSN clock, or is determined according to the size of the corresponding stream period or a latency request. For example, if the difference in accuracy between the 5GS clock and the TSN clock is too large (i.e. frequent), a threshold value may be large in order to prevent the signaling occurrence. In addition, if the corresponding stream period is large or the latency request is large, a threshold value thereof may be large. With regard to the condition in which information is transmitted by the UPF <NUM>, the UPF <NUM> may transmit information at regular intervals or may transmit the information when the signaling load does not exceed a certain level. In this case, since the gNB <NUM> manages a domain-specific stream, no ID for identifying a stream needs to be delivered separately. The gNB <NUM>, which has received the domain and offset difference information, selects all burst arrival time(s) associated with the corresponding domain and performs adjustment by the offset_difference. This process may be implemented such that each domain is synchronized with the 5GS clock and thus has a separate clock having as much difference as the offset. The operation through the comparison of the threshold value and the difference between a previous offset and a current offset may be equally applied to the second solution, as shown in <FIG>, as well as <FIG>, <FIG>, <FIG>, <FIG>, and <FIG>.

Referring to <FIG>, the figure shows the flow of UPF <NUM>->AF <NUM> in a method in which the gNB <NUM> uses an offset. Operation (<NUM>) in which the UPF <NUM> is directly connected to the AF <NUM> via an application process does not exist in the prior art, and thus needs to be separately defined. At this time, the UPF <NUM> needs to deliver information including the domain and offset difference to the AF <NUM>. When the information delivery request triggered by the AF <NUM> is delivered to the SMF <NUM> via the PCF <NUM> (operations <NUM> and <NUM>), the SMF <NUM> delivers this information to the gNB <NUM> via an N2 message (operations <NUM> and <NUM>).

Referring to <FIG>, the figure shows the flow of UPF <NUM>->SMF <NUM> in a method in which the gNB <NUM> uses an offset. If the UPF <NUM> delivers domain-specific offset difference using an N4 Report message or the like (operation <NUM> and <NUM>), the SMF <NUM> uses a PDU session modification procedure based on the difference in order to deliver domain and offset difference information to the gNB <NUM> using an N2 message. During this process, the SMF <NUM> and the PCF <NUM> deliver the domain and offset difference to the PCF <NUM> and the AF <NUM>, respectively, using a notification message (operations <NUM>, <NUM>, <NUM>, and <NUM>).

Referring to <FIG>, the figure shows the flow of UPF <NUM>->SMF <NUM>->PCF <NUM> in a method in which the gNB <NUM> uses an offset. The SMF <NUM> determines PDU session modification in <FIG> but the PCF <NUM> determines whether to modify PDU session in <FIG>.

Referring to <FIG>, the figure shows the flow of UPF <NUM>->SMF <NUM>->PCF <NUM>->AF <NUM> in a method in which the gNB <NUM> uses an offset. The SMF <NUM> determines PDU session modification in <FIG>, the PCF <NUM> determines whether to modify PDU session in <FIG>, and the AF <NUM> determines PDU session modification in <FIG>.

Referring to <FIG>, the figure shows the flow of UPF <NUM>->UE <NUM> in a method in which the gNB <NUM> uses an offset. Whenever the UPF <NUM> receives a TSN synchronization frame from an external TSN node, the UPF <NUM> sends an offset to the UE <NUM> to achieve TSN synchronization with the UE <NUM>. Although another method may be employed, the mapping may be achieved by a process in which the offset is logically delivered. At this time, when a criterion in which information delivery needs to be triggered is satisfied, the UPF <NUM> delivers the offset to the UE <NUM> by adding a separate indicator indicating that this offset needs to be delivered up to the gNB <NUM>. Upon receiving the offset having this indicator, the UE <NUM> starts a process of delivering the corresponding domain and offset difference to the gNB <NUM>. Reference may be made to <FIG>, <FIG>, <FIG>, <FIG>, or <FIG> in connection with this process.

<FIG> is a signal flow diagram showing an initial flow in a method in which the gNB <NUM> uses an adjusted burst arrival time and illustrates adjustment performed by the AF <NUM> according to an embodiment of the disclosure. Operations <NUM> to <NUM> are shown in <FIG>. <FIG> is a signal flow diagram showing an initial flow in a method in which the gNB <NUM> uses an adjusted burst arrival time and illustrates adjustment performed by the PCF <NUM> according to an embodiment of the disclosure. Operations <NUM> to <NUM> are shown in <FIG>. <FIG> is a signal flow diagram showing an initial flow in a method in which the gNB <NUM> uses an adjusted burst arrival time and illustrates adjustment performed by the SMF <NUM> according to an embodiment of the disclosure. Operations <NUM> to <NUM> are shown in <FIG>. The signaling in <FIG>, <FIG>, and <FIG>, which corresponds to an initial flow in a method in which the gNB <NUM> uses an adjusted burst arrival time, is only examples for explaining embodiments performed by AF <NUM>, PCF <NUM>, and SMF <NUM>, respectively, and signaling between specific entities is not to be interpreted as limiting the operation of the embodiments to be described in connection with drawings. In this case, a separate stream ID is not required, and TSCAI including a domain-specific burst arrival time is delivered to the gNB <NUM>. The UE <NUM> manages TSN domain-specific offset for UL traffic, manages TSCAI received from the CNC <NUM> for each TSN domain, and is aware of the maximum UE residence time. The UPF <NUM> manages a domain-specific offset for DL traffic, and the AF <NUM> manages domain-specific TSCAI for DL traffic, and is aware of the maximum UPF residence time and CN PDB. The AF <NUM> is also responsible for exchanging information with CNC <NUM> with respect to UL and DL traffic, and thus is aware of domain-specific TSCAI for UL and DL traffic, and is aware of the maximum UE residence time, maximum UPF residence time, and CN PDB. In <FIG>, <FIG>, and <FIG>, if the gNB <NUM> receives domain and offset as an input, the gNB <NUM> receives an adjusted burst arrival time as an input in <FIG>, <FIG>, and <FIG>.

Referring to <FIG>, the figure corresponds to an initial flow in a method in which the gNB <NUM> uses an adjusted burst arrival time and shows adjustment performed by the AF <NUM> (operation <NUM>). A burst arrival time included in the flow after the adjustment is performed by the AF <NUM> means an adjusted burst arrival time.

Referring to <FIG>, the figure corresponds to an initial flow in a method in which the gNB <NUM> uses an adjusted burst arrival time and shows adjustment performed by the PCF <NUM> (operation <NUM>). From the AF <NUM> to the PCF <NUM>, a burst arrival time that has not been adjusted is delivered. A burst arrival time included in the flow after adjustment is performed by the PCF <NUM> is an adjusted burst arrival time.

Referring to <FIG>, the figure corresponds to an initial flow in a method in which the gNB <NUM> uses an adjusted burst arrival time, and the SMF <NUM> performs adjustment therein (operation <NUM>). A burst arrival time that has not been adjusted is delivered from the AF <NUM> to the SMF <NUM>, and a burst arrival time included in the flow after adjustment is performed by the SMF <NUM> is an adjusted burst arrival time.

As described in <FIG>, the main entity that performs a mapping operation and delivers TSCAI may be the same or different. According to one embodiment (e.g., <FIG>), an SMF may perform a mapping operation and transmit TSCAI, based on the mapping result. For example, the SMF may determine the delivery of TSCAI. That is, the SMF may trigger the transmission of TSCAI. The SMF may generate TSCAI. The SMF may transmit the generated TSCAI to <NUM>-AN, that is, to a base station. Further, according to one embodiment (e.g., <FIG>), a node other than the SMF (e.g., AF) may determine the delivery of TSCAI. That is, another node may trigger the delivery of TSCAI. At this time, the SMF of 5GC may transmit the TSCAI via another node to the <NUM>-AN, that is, the base station. This is because the SMF, as a main entity that manages the PDU session, may be responsible for configuration/update on QoS flow in the PDU session. Since TSCAI is delivered through a QoS update procedure, the SMF may finally transmit TSCAI to the <NUM>-AN, that is, to the base station.

<FIG> is a signal flow diagram showing the flow of UE <NUM>->gNB <NUM> utilized in a method in which the gNB <NUM> uses an adjusted burst arrival time and illustrates adjustment performed by the UE (operation <NUM>) according to an embodiment of the disclosure. Operations <NUM> to <NUM> are shown in <FIG>. <FIG> is a signal flow diagram showing the flow of UE <NUM>->gNB <NUM> utilized in a method in which the gNB <NUM> uses an adjusted burst arrival time and illustrates adjustment performed by the gNB <NUM> (operation <NUM>) according to an embodiment of the disclosure. Operations <NUM> to <NUM> are shown in <FIG>. The signaling shown in <FIG> and <FIG>, which utilizes the flow of UE <NUM>->gNB <NUM> in a method in which an adjusted burst arrival time is used, is only an example for explaining the embodiment of adjustment performed by the UE <NUM> (operation <NUM>) or the gNB <NUM> (operation <NUM>), and signaling between specific entities is not to be interpreted as limiting operations of the embodiments to be described in connection with the drawings. The criterion for triggering information delivery by the UE <NUM> is the same as in <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, and <FIG>. In this case, since a domain-specific stream is not managed by the gNB <NUM>, an old burst arrival time is used as an ID for identifying streams.

<FIG>, which shows the flow of UE <NUM>->gNB <NUM>, utilized in a method in which the gNB <NUM> uses an adjusted burst arrival time, illustrates the case of adjustment performed by the UE <NUM>. In the case of satisfying information delivery condition, the UE <NUM> selects all streams associated with the corresponding domain and performs adjustment by using offset difference (operation <NUM>). When a burst arrival time that has not been adjusted is indicated as an old burst arrival time and a burst arrival time that has been adjusted is indicated as a new burst arrival time, the UE <NUM> delivers both of these pieces information to the gNB <NUM> (operation <NUM>). The gNB <NUM> replaces the old burst arrival time with the new burst arrival time.

<FIG>, which shows the flow of UE <NUM>->gNB <NUM>, utilized in a method in which the gNB <NUM> uses an adjusted burst arrival time, illustrates the case of adjustment performed by the gNB <NUM>. In the case of satisfying information delivery condition, the UE <NUM> selects all streams associated with the corresponding domain, and delivers the streams along with offset difference to the gNB <NUM> by specifying the streams as old burst arrival times (operation <NUM>). The gNB <NUM> applies the offset difference to an old burst arrival time to adjust the old burst arrival time to the new burst arrival time (operation <NUM>).

<FIG> is a signal flow diagram showing the flow of UE <NUM>->SMF <NUM> utilized in a method in which the gNB <NUM> uses an adjusted burst arrival time and illustrates adjustment performed by the UE <NUM> (operation <NUM>) according to an embodiment of the disclosure. Operations <NUM> to <NUM> are shown in <FIG>. <FIG> is a signal flow diagram showing the flow of UE <NUM>->SMF <NUM> utilized in a method in which the gNB <NUM> uses an adjusted burst arrival time and illustrates adjustment performed by the SMF <NUM> (operation <NUM>) according to an embodiment of the disclosure. Operations <NUM> to <NUM> are shown in <FIG>. <FIG> is a signal flow diagram showing the flow of UE <NUM>->SMF <NUM> utilized in a method in which the gNB <NUM> uses an adjusted burst arrival time and illustrates adjustment performed by the gNB <NUM> (operation <NUM>) according to an embodiment of the disclosure. Operations <NUM> to <NUM> are shown in <FIG>. The signaling shown in <FIG>, <FIG>, and <FIG>, which utilizes the flow of UE <NUM>->SMF <NUM> in a method in which the gNB <NUM> uses an adjusted burst arrival time, is only examples for explaining the embodiments of the adjustments performed by the UE <NUM>, SMF <NUM>, and gNB <NUM> (operations <NUM>, <NUM>, and <NUM>), respectively, and signaling between specific entities is not to be interpreted as limiting the operations of the embodiments to be described in connection with the drawings.

The criterion for triggering information delivery by the UE <NUM> is identical to that in the other flowcharts described above. The UE <NUM> selects all the domain-specific streams and uses a stream ID instead as an old burst arrival time in <FIG>, and the SMF <NUM> selects all of the domain-specific streams and uses a stream ID instead as an old burst arrival time in <FIG> and <FIG>.

<FIG> is a signal flow diagram showing the flow of UE <NUM>->SMF <NUM>->PCF <NUM> utilized in a method in which the gNB <NUM> uses an adjusted burst arrival time and illustrates adjustment performed by the UE <NUM> according to an embodiment of the disclosure. Operations <NUM> to <NUM> are shown in <FIG>. <FIG> is a signal flow diagram showing the flow of UE <NUM>->SMF <NUM>->PCF <NUM> utilized in a method in which the gNB <NUM> uses an adjusted burst arrival time and illustrates adjustment performed by the PCF <NUM> according to an embodiment of the disclosure. Operations <NUM> to <NUM> are shown in <FIG>. <FIG> is a signal flow diagram showing the flow of UE <NUM>->SMF <NUM>->PCF <NUM> utilized in a method in which the gNB <NUM> uses an adjusted burst arrival time and illustrates adjustment performed by the SMF <NUM> according to an embodiment of the disclosure. Operations <NUM> to <NUM> are shown in <FIG>. <FIG> is a signal flow diagram showing the flow of UE <NUM>->SMF <NUM>->PCF <NUM> utilized in a method in which the gNB <NUM> uses an adjusted burst arrival time and illustrates adjustment performed by the gNB <NUM> according to an embodiment of the disclosure. Operations <NUM> to <NUM> are shown in <FIG>. The signaling shown in <FIG>, <FIG>, <FIG>, and <FIG>, which utilizes the flow of UE <NUM>->SMF <NUM>->PCF <NUM> in a method in which the gNB <NUM> uses an adjusted burst arrival time, is only examples for explaining the embodiments of the adjustments performed by the UE <NUM>, PCF <NUM>, SMF <NUM>, and gNB <NUM>, respectively, and signaling between specific entities is not to be interpreted as limiting the operations of the embodiments to be described in connection with the drawings. The SMF <NUM> determines PDU session modification in <FIG>, <FIG>, and <FIG>, but the PCF <NUM> determines PDU session modification in <FIG>, <FIG>, <FIG>, and <FIG>. The UE <NUM> selects all of the domain-specific streams and uses a stream ID instead as an old burst arrival time in <FIG>, and the PCF <NUM> selects all the domain-specific streams and uses a stream ID instead as an old burst arrival time in <FIG>, <FIG>, and <FIG>.

<FIG> is a signal flow diagram showing the flow of UE <NUM>->SMF <NUM>->PCF <NUM>->AF <NUM> utilized in a method in which the gNB <NUM> uses an adjusted burst arrival time and illustrates adjustment performed by the UE <NUM> according to an embodiment of the disclosure. Operations <NUM> to <NUM> are shown in <FIG>. <FIG> is a signal flow diagram showing the flow of UE <NUM>->SMF <NUM>->PCF <NUM>->AF <NUM> utilized in a method in which the gNB <NUM> uses an adjusted burst arrival time and illustrates adjustment performed by the AF <NUM> according to an embodiment of the disclosure. Operations <NUM> to <NUM> are shown in <FIG>. <FIG> is a signal flow diagram showing the flow of UE <NUM>->SMF <NUM>->PCF <NUM>->AF <NUM> utilized in a method in which the gNB <NUM> uses an adjusted burst arrival time and illustrates adjustment performed by the PCF <NUM>. Operations <NUM> to <NUM> are shown in <FIG>. <FIG> is a signal flow diagram showing the flow of UE <NUM>->SMF <NUM>->PCF <NUM>->AF <NUM> utilized in a method in which the gNB <NUM> uses an adjusted burst arrival time and illustrates adjustment performed by the SMF <NUM> according to an embodiment of the disclosure. Operations <NUM> to <NUM> are shown in <FIG>. <FIG> is a signal flow diagram showing the flow of UE <NUM>->SMF <NUM>->PCF <NUM>->AF <NUM> utilized in a method in which the gNB <NUM> uses an adjusted burst arrival time and illustrates adjustment performed by the gNB <NUM> according to an embodiment of the disclosure. Operations <NUM> to <NUM> are shown in <FIG>.

The signaling shown in <FIG>, <FIG>, <FIG>, <FIG>, and <FIG>, which utilizes the flow of UE <NUM>->SMF <NUM>->PCF <NUM>->AF <NUM> in a method in which the gNB <NUM> uses an adjusted burst arrival time, is only examples for explaining the embodiments of the adjustments performed by the UE <NUM>, AF <NUM>, PCF <NUM>, SMF <NUM>, and gNB <NUM>, respectively, and signaling between specific entities is not interpreted as limiting the operations of the embodiments to be described in connection with the drawings. The SMF <NUM> determines PDU session modification in <FIG>, <FIG>, and <FIG>, the PCF <NUM> determines PDU session modification in <FIG>, <FIG>, <FIG>, and <FIG>, but the AF <NUM> determines PDU session modification in <FIG>, <FIG>, <FIG>, <FIG>, and <FIG>. The UE <NUM> selects all of the domain-specific streams and uses a stream ID instead as an old burst arrival time in <FIG>, and the AF <NUM> selects all of the domain-specific streams and uses a stream ID instead as an old burst arrival time in <FIG>, <FIG>, <FIG>, and <FIG>.

<FIG> is a signal flow diagram showing the flow of UE <NUM>->AF <NUM> utilized in a method in which the gNB <NUM> uses an adjusted burst arrival time and illustrates showing adjustment performed by the UE <NUM> according to an embodiment of the disclosure. Operations <NUM> to <NUM> are shown in <FIG>. <FIG> is a signal flow diagram showing the flow of UE <NUM>->AF <NUM> utilized in a method in which the gNB <NUM> uses an adjusted burst arrival time and illustrates adjustment performed by the AF <NUM> according to an embodiment of the disclosure. Operations <NUM> to <NUM> are shown in <FIG>. <FIG> is a signal flow diagram showing the flow of UE <NUM>->AF <NUM> utilized in a method in which the gNB <NUM> uses an adjusted burst arrival time and illustrates adjustment performed by a PCF <NUM> according to an embodiment of the disclosure. Operations <NUM> to <NUM> are shown in <FIG>. <FIG> is a signal flow diagram showing the flow of UE <NUM>->AF <NUM> utilized in a method in which the gNB <NUM> uses an adjusted burst arrival time and illustrates adjustment performed by an SMF <NUM> according to an embodiment of the disclosure. Operations <NUM> to <NUM> are shown in <FIG>. <FIG> is a signal flow diagram showing the flow of UE <NUM>->AF <NUM> utilized in a method in which the gNB <NUM> uses an adjusted burst arrival time and illustrates adjustment performed by the gNB <NUM> according to an embodiment of the disclosure. Operations <NUM> to <NUM> are shown in <FIG>.

The signaling shown in <FIG>, <FIG>, <FIG>, <FIG>, and <FIG>, which utilizes the flow of UE <NUM>->AF <NUM> in a method in which the gNB <NUM> uses an adjusted burst arrival time, is only examples for explaining the embodiments of the adjustments performed by the UE <NUM>, AF <NUM>, PCF <NUM>, SMF <NUM>, and gNB <NUM>, respectively, and signaling between specific entities is not interpreted as limiting the operations of the embodiments to be described in connection with the drawings. While the UE <NUM> delivers information to the AF <NUM> using an application-level message in <FIG>, <FIG>, <FIG>, <FIG>, and <FIG>, information delivered by the UE <NUM> to the SMF <NUM> via an NAS message is delivered to the AF <NUM> via the PCF <NUM> using a notification function in <FIG>, <FIG>, <FIG>, <FIG>, and <FIG>.

<FIG> is a signal flow diagram showing the flow of UE <NUM>->UPF <NUM>, utilized in a method in which the gNB <NUM> uses an adjusted burst arrival time according to an embodiment of the disclosure. Operations <NUM> to <NUM> are shown in <FIG>. The signaling in <FIG> is only an example for explaining an embodiment utilizing the flow of UE <NUM>->UPF <NUM> in a method in which an adjusted burst arrival time is used, and signaling between specific entities is not to be interpreted as limiting the operation of the embodiments to be described in connection with the drawings. Adjustment represents the case in which the flow of UPF <NUM>->AF <NUM> among various subsequent flows from the UPF <NUM> is combined, and the adjustment is performed by the PCF <NUM> (operation <NUM>). Reference may be made to <FIG> in connection with other processes of delivering information from the UPF <NUM>.

<FIG> is a signal flow diagram showing the flow of UPF <NUM>->AF <NUM> utilized in a method in which the gNB <NUM> uses an adjusted burst arrival time and illustrates adjustment performed by the AF <NUM> according to an embodiment of the disclosure. Operations <NUM> to <NUM> are shown in <FIG>. <FIG> is a signal flow diagram showing the flow of UPF <NUM>->AF <NUM> utilized in a method in which the gNB <NUM> uses an adjusted burst arrival time and illustrates adjustment performed by the PCF <NUM> according to an embodiment of the disclosure. Operations <NUM> to <NUM> are shown in <FIG>. <FIG> is a signal flow diagram showing the flow of UPF <NUM>->AF <NUM> utilized in a method in which the gNB <NUM> uses an adjusted burst arrival time and illustrates adjustment performed by an SMF <NUM> according to an embodiment of the disclosure. Operations <NUM> to <NUM> are shown in <FIG>. <FIG> is a signal flow diagram showing the flow of UPF <NUM>->AF <NUM> utilized in a method in which the gNB <NUM> uses an adjusted burst arrival time and illustrates adjustment performed by the gNB <NUM> according to an embodiment of the disclosure. Operations <NUM> to <NUM> are shown in <FIG>.

The signaling shown in <FIG>, <FIG>, <FIG>, and <FIG>, which utilizes the flow of UPF <NUM>->AF <NUM> in a method in which the gNB <NUM> uses an adjusted burst arrival time, is only examples for explaining the embodiments of the adjustments performed by the AF <NUM>, PCF <NUM>, SMF <NUM>, and gNB <NUM>, respectively, and signaling between specific entities is not to be interpreted as limiting the operations of the embodiments to be described in connection with the drawings. The criterion for triggering information delivery is the same as in <FIG>. After adjustment is performed, an old burst arrival time is used as a stream ID.

<FIG> is a signal flow diagram showing the flow of UPF <NUM>->SMF <NUM> utilized in a method in which the gNB <NUM> uses an adjusted burst arrival time and illustrates adjustment performed by the SMF <NUM> according to an embodiment of the disclosure. Operations <NUM> to <NUM> are shown in <FIG>. <FIG> is a signal flow diagram showing the flow of UPF <NUM>->SMF <NUM> utilized in a method in which the gNB <NUM> uses an adjusted burst arrival time and illustrates adjustment performed by the gNB <NUM> according to an embodiment of the disclosure. Operations <NUM> to <NUM> are shown in <FIG>.

The signaling shown in <FIG>, and <FIG>, which utilizes the flow of UPF <NUM>->SMF <NUM> in a method in which the gNB <NUM> uses an adjusted burst arrival time, is only an example for explaining the embodiment of the adjustment performed by the SMF <NUM> or gNB <NUM>, and signaling between specific entities is not to be interpreted as limiting the operation of the embodiment to be described in connection with the drawings. The criterion for triggering information delivery is the same as in <FIG>. After adjustment is performed, an old burst arrival time is used as a stream ID.

<FIG> is a signal flow diagram showing the flow of UPF <NUM>->SMF <NUM>->PCF <NUM> utilized in a method in which the gNB <NUM> uses an adjusted burst arrival time and illustrates adjustment performed by the PCF <NUM> according to an embodiment of the disclosure. Operations <NUM> to <NUM> are shown in <FIG>. <FIG> is a signal flow diagram showing the flow of UPF <NUM>->SMF <NUM>->PCF <NUM> utilized in a method in which the gNB <NUM> uses an adjusted burst arrival time and illustrates adjustment performed by the SMF according to an embodiment of the disclosure. Operations <NUM> to <NUM> are shown in <FIG>. <FIG> is a signal flow diagram showing the flow of UPF <NUM>->SMF <NUM>->PCF <NUM> utilized in a method in which the gNB <NUM> uses an adjusted burst arrival time and illustrates adjustment performed by the gNB <NUM> according to an embodiment of the disclosure. Operations <NUM> to <NUM> are shown in <FIG>.

The signaling shown in <FIG>, <FIG>, and <FIG>, which utilizes the flow of UPF <NUM>->SMF <NUM>->PCF <NUM> in a method in which the gNB <NUM> uses an adjusted burst arrival time, is only an example for explaining the embodiment of the adjustment performed by the PCF <NUM>, SMF <NUM> or gNB <NUM>, and signaling between specific entities is not to be interpreted as limiting the operation of the embodiment to be described in connection with the drawings. The criterion for triggering information delivery is the same as in <FIG>. After adjustment is performed, the old burst arrival time is used as a stream ID.

<FIG> is a signal flow diagram showing the flow of UPF <NUM>->SMF <NUM>->PCF <NUM>->AF <NUM> utilized in a method in which the gNB <NUM> uses an adjusted burst arrival time and illustrates adjustment performed by the AF <NUM> according to an embodiment of the disclosure. Operations <NUM> to <NUM> are shown in <FIG>. <FIG> is a signal flow diagram showing the flow of UPF <NUM>->SMF <NUM>->PCF <NUM>->AF <NUM> utilized in a method in which the gNB <NUM> uses an adjusted burst arrival time and illustrates adjustment performed by the PCF <NUM> according to an embodiment of the disclosure. Operations <NUM> to <NUM> are shown in <FIG>. <FIG> is a signal flow diagram showing the flow of UPF <NUM>->SMF <NUM>->PCF <NUM>->AF <NUM> utilized in a method in which the gNB <NUM> uses an adjusted burst arrival time and illustrates adjustment performed by the SMF <NUM> according to an embodiment of the disclosure. Operations <NUM> to <NUM> are shown in <FIG>. <FIG> is a signal flow diagram showing the flow of UPF <NUM>->SMF <NUM>->PCF <NUM>->AF <NUM> utilized in a method in which the gNB <NUM> uses an adjusted burst arrival time and illustrates adjustment performed by the gNB <NUM> according to an embodiment of the disclosure. Operations <NUM> to <NUM> are shown in <FIG>.

The signaling shown in <FIG>, <FIG>, <FIG>, and <FIG>, which utilizes the flow of UPF <NUM>->SMF <NUM>->PCF <NUM>->AF <NUM> in a method in which the gNB <NUM> uses an adjusted burst arrival time, is only an example for explaining the embodiment of the adjustment performed by the AF <NUM>, PCF <NUM>, SMF <NUM> or gNB <NUM>, and signaling between specific entities is not to be interpreted as limiting the operation of the embodiment to be described in connection with the drawings. The criterion for triggering information delivery is the same as in <FIG>. After adjustment is performed, the old burst arrival time is used as a stream ID.

<FIG> is a signal flow diagram showing the flow of UPF <NUM>->UE <NUM>, utilized in a method in which the gNB <NUM> uses an adjusted burst arrival time, represents the case in which the flow of UE <NUM>->gNB <NUM> among the subsequent flows from the UE <NUM> is combined, and in this case, adjustment is performed by the gNB <NUM> (operation <NUM>) according to an embodiment of the disclosure. Operations <NUM> to <NUM> are shown in <FIG>.

The signaling in <FIG> is only an example for explaining an embodiment utilizing the flow of UPF <NUM>->UE <NUM> in a method in which the gNB <NUM> uses an adjusted burst arrival time, and signaling between specific entities is not to be interpreted as limiting the operation of the embodiments to be described in connection with the drawings. Reference may be made to <FIG> in connection with other processes of delivering information from the UE <NUM>.

As described through <FIG>, depending on which entity (e.g., AF, SMF, etc.) performs a mapping operation, the path via which the UPF transmits and updates the difference between the <NUM> clock and the TSN clock (e.g., time offset and frequency offset) is different. For example, as shown in <FIG>, the UPF may transmit information on the difference (hereinafter, difference information) between the <NUM> clock and the TSN clock to the SMF. The SMF may deliver difference information to the AF. The AF may perform a mapping operation, based on the difference information and may obtain a burst arrival time or period mapped based on the <NUM> clock. The AF may deliver information on the mapped burst arrival time or mapped period to the SMF, and the SMF may deliver information (e.g., burst arrival time and period) in respect to the <NUM> clock to a base station (e.g., the gNB <NUM>) through a PDU session procedure. For example, as shown in <FIG>, the UPF may transmit information on the difference between the <NUM> clock and the TSN clock (hereinafter, difference information) to the SMF. The SMF may deliver the difference information to the AF. The AF may deliver the difference information to the PCF. The PCF may perform a mapping operation, based on the difference information and may obtain a burst arrival time or period mapped based on the <NUM> clock. The PCF may deliver information on the mapped burst arrival time or mapped period to the SMF, and the SMF may deliver information in respect to the TSN clock to a base station (e.g., the gNB <NUM>) through a PDU session procedure. For example, as shown in <FIG>, the UPF may transmit information on the difference between the <NUM> clock and the TSN clock (hereinafter, difference information) to the SMF. The SMF performs a mapping operation, based on the difference information, and may obtain a burst arrival time or period mapped based on a <NUM> clock. The SMF may deliver information on the mapped burst arrival time or mapped period to the SMF, and the SMF may deliver information in respect to the TSN clock to a base station (e.g., the gNB <NUM>) through a PDU session procedure. For example, as shown in <FIG>, the UPF may transmit information on the difference between the <NUM> clock and the TSN clock (hereinafter, difference information) to the SMF. The SMF may deliver the difference information to a base station. The base station may obtain a burst arrival time or period mapped based on the <NUM> clock. For example, as shown in <FIG>, the UPF may transmit information on the difference between the <NUM> clock and the TSN clock (hereinafter, difference information) to a terminal. The terminal may deliver difference information to a base station. The base station may obtain a burst arrival time or period mapped based on the <NUM> clock.

Since the base station (e.g., gNB) is not aware of the TSN clock, the description has been made on signaling between entities in a core network for delivering an offset, which is the difference between the <NUM> clock and the TSN clock, to a base station or for delivering information (e.g., burst arrival time associated with a <NUM> clock reference) in which an offset is reflected. At this time, the offset, which is the difference between the 5GS clock and the TSN clock, may be indicated in a distinguished manner according to the absolute time difference and the speed difference. In one embodiment, the UPF <NUM> or UE <NUM> may calculate a time offset=T_5GS-T_TSN (the difference between the 5GS clock and the TSN clock) and may calculate the offset to a frequency offset=frequency_SGS/frequency_TSN. In this case, the time offset may be used to map a burst arrival time based on the TSN clock to a time based on the 5GS clock. The frequency offset may be used to map period based on the TSN clock to period based on the 5GS clock.

When an offset is delivered from the UPF <NUM> or UE <NUM> to SMF/PCF/AF, etc., one of the UPF <NUM> or UE <NUM> may perform delivery, or both may support the delivery. In some embodiments, the UPF <NUM> and UE <NUM> may deliver an offset to at least one of SMF, PCF, or AF. In other embodiments, the UPF <NUM> may deliver an offset to at least one of SMF, PCF, or AF. When one of the UPF <NUM> and UE <NUM> performs the delivery, either of the UPF or the UE may support the delivery. However, resources may be saved when the UPF performs the delivery since the UE uses air resources when delivering. In other embodiments, the UE <NUM> may deliver an offset to at least one of the SMF, PCF, or AF. In the case in which the UPF is not aware of the TSN clock and only the UE is aware of the TSN clock due to a special case, such as when TSC traffic is transmitted from one UE to another UE, the UE may deliver an offset.

When TSCAI is derived, it is necessary to reflect the difference between the 5GS clock and the TSN clock and correct a CN PDB (packet delay budget) or UE residence time. These two processes may be performed in one network entity (NE) or in another NE. The NE may be an entity of 5GC (e.g., the core network <NUM> of <FIG>). In one embodiment, the AF reflects the difference between the 5GS clock and the TSN clock, and the SMF may correct a CN PDB (packet delay budget) or UE residence time. The AF may map period based on the TSN clock to period based on the 5GS clock using a frequency offset, and the SMF may be responsible for mapping of a burst arrival time based on the TSN clock to a time based on the 5GS clock using a time offset and for mapping of a burst arrival time to which CN PDB, UE residence time, etc. are reflected. In addition, in one embodiment, the AF reflects the difference between the 5GS clock and the TSN clock, and the AMF may correct the CN PDB or UE residence time. In addition, in one embodiment, the AF may reflect the difference between the 5GS clock and the TSN clock, and the AF may correct the CN PDB or UE residence time. In addition, in one embodiment, the AF reflects the difference between the 5GS clock and the TSN clock, and the PCF may correct the CN PDB or UE residence time. In addition, in one embodiment, the SMF reflects the difference between the 5GS clock and the TSN clock, and the SMF may correct the CN PDB or UE residence time. In addition, in one embodiment, the SMF reflects the difference between the 5GS clock and the TSN clock, and the AMF may correct the CN PDB or UE residence time. In addition, in one embodiment, the SMF reflects the difference between the 5GS clock and the TSN clock, and the AF may correct the CN PDB or UE residence time. In addition, in one embodiment, the SMF reflects the difference between the 5GS clock and the TSN clock, and the PCF may correct the CN PDB or UE residence time.

In the disclosure, the description has been made on roles/signaling of each entity with respect to a main entity that maps a time offset and a frequency offset. However, various embodiments are not limited thereto. In some embodiments, an entity responsible for mapping a time offset and an entity responsible for mapping a frequency offset may be configured independently of each other. That is, functional separation between the AF and the SMF may be performed in order to obtain information in TSCAI associated with the TSN clock. According to one embodiment, the AF performs time conversion using a time offset (e.g., mapping associated with a burst arrival time of TSCAI), and the SMF performs frequency conversion using a frequency offset (e.g., mapping associated with a burst arrival time of TSCAI). The AF performs time conversion of TSCAI, and the SMF may reflect only CN PDB, UE residence time, and the like inside 5GS. In addition, according to one embodiment, the AF maps only period (mapping period information from the TSN clock to the <NUM> clock) by reflecting only a frequency offset (e.g., frequency ratio), and the SMF may include CN PDB, UE residence time, etc. so as to be responsible for mapping of a burst arrival time.

In the disclosure, the gNB has been described for the sake of illustration as a base station of an access network (AN), but the embodiments herein are not limited thereto. That is, the embodiments may be applied in the same or a similar manner for a base station using a <NUM> core network, rather than the gNB. For example, in the case in which a base station (e.g., eNB) associated with LTE RAT (radio access technology) is connected to a 5GC (<NUM> core) instead of an EPC, the base station may obtain TSSAI according to the first solution or second solution which have been described in connection with <FIG>.

Claim 1:
A method performed by a session management function, SMF, in a wireless communication system, the method comprising:
mapping a burst arrival time from a time-sensitive networking, TSN, clock to a 5th generation, <NUM>, clock, based on an offset between a 5th generation system, 5GS, time and a time-sensitive networking, TSN, time; and
transmitting, to a node of an access network, time-sensitive communication assistant information, TSCAI, including information on the burst arrival time mapped to the <NUM> clock.