DS-TT device, 5G system, UE, and message conversion method

Abstract

A user equipment (UE) (40) in a 5 Generation System (5GS) (100) establishes a packet data unit (PDU) session (60) together with a user plane function (UPF) device (20), the session being such that information pertaining to both internet protocol (IP) PDU and Ethernet PDU can be stored. A device-side time-sensitive networking translator (DS-TT) device (50) converts the content in the message body of a precision time protocol (PTP) message, which is received via the PDU session (60), in accordance with a combination of the data type of the PTP message and the data type of the transmission destination of the PTP message.

Description

Technical Field

[0001] The present disclosure relates to a technology for converting time synchronization protocols in a 5G system.

Background Art

[0002] In digital factories and Industry 4.0, mobile communications with real-time performance and predictable delay amounts are required. In addition, a function in which networks with different profiles and terminals with different profiles coexist in a PnP manner is desired. PnP is an abbreviation for Plug aNd Play. Therefore, sharing of time is necessary. 3GPP (registered trademark) aims to expand the application target of the 5G system from mobile broadband services to industrial networks. 3GPP is an abbreviation for 3rd Generation Partnership Project. 5G is an abbreviation for 5 Generation. With local 5G URLLC, mobile bodies in industrial networks can communicate seamlessly. URLLC is an abbreviation for Ultra-Reliable and Low Latency Communications. Therefore, interest in time synchronization between devices with different profiles connected to the 5G system is increasing.

[0003] When a wired network or terminal having different time synchronization profiles coexists, it is necessary to add a translation function for time synchronization messages. Patent Document 1 describes a technique for converting the data format to be transmitted according to the type of network of the port of the relay device. Patent Document 2 describes a technique for generating a frame related to time synchronization using profile technology. It is conceivable to combine the techniques described in Patent Documents 1 and 2 and configure the relay device to convert time synchronization messages of different time synchronization profiles. Thereby, a translation function for time synchronization messages can be realized in the relay device.

Prior Art Documents

Patent Documents

[0004] [Patent Document 1] Japanese Unexamined Patent Application Publication No. 2017-212728 [Patent Document 2] Japanese Unexamined Patent Application Publication No. 2016-184809 [Summary of the Invention] [Problems to be Solved by the Invention]

[0005] Terminals with different time synchronization profiles may be connected through a 5G system. In this case, the 5G system needs to function as the relay device described above and realize the translation function of time synchronization messages. However, the 5G system is a system composed of multiple devices, and there is no device having the information necessary to realize the translation function of time synchronization messages. The present disclosure aims to enable the realization of the translation function of time synchronization messages in a 5G system. [Means for Solving the Problems]

[0006] The DS-TT device according to the present disclosure is a DS-TT (Device-Side Time-sensitive networking Translator) device in a 5GS (5 Generation System), a protocol conversion unit that converts the content of the message body of a PTP (Precision Time Protocol) message according to a combination of the data type of the PTP message received via a PDU (Packet Data Unit) session established between a UE (User Equipment) and a UPF (User Plane Function) device and the data type of the destination of the PTP message, the PDU session being capable of storing information of both an IP (Internet Protocol) PDU and an Ethernet PDU and includes. [Advantages of the Invention]

[0007] In the present disclosure, the DS-TT device uses the data type of the PTP message received via the PDU session established between the UE and the UPF device and capable of storing information of both the IP PDU and the Ethernet PDU to identify the data type of the PTP message received from the 5G system side. Thereby, the DS-TT device can realize the translation function of the time synchronization message.

Brief Description of the Drawings

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Mode for Carrying Out the Invention

[0009] Embodiment 1. ***Explanation of Configuration*** Referring to FIG. 1, the configuration of the 5G system 100 according to Embodiment 1 will be described. The 5G system 100 includes a TSCTSF device 10, a UPF device 20, a NW-TT device 30, and a plurality of sets of a UE 40 and a DS-TT device 50. Here, although the NW-TT device 30 is mounted on the UPF device 20, it is not limited thereto. TSCTSF is an abbreviation for Time Sensitive Communication Time Synchronization Function. UPF is an abbreviation for User Plane Function. NW-TT is an abbreviation for NetWork-side Time-sensitive networking Translator. UE is an abbreviation for User Equipment. DS-TT is an abbreviation for Device-Side Time-sensitive networking Translator. A PDU session 60 is established between the UE 40 and the UPF device 20 in each set of the UE 40 and the DS-TT device 50. PDU is an abbreviation for Packet Data Unit.

[0010] A terminal connected to the network side and a terminal connected to the device side communicate via the 5G system. A message transmitted from a terminal connected to the network side is input to the NW-TT device 30. This message is transmitted to the DS-TT device 50 via the PDU session 60 established between the UE 40 and the UPF device 20 in the set including the DS-TT device 50 to which the destination device is connected. Then, this message is transmitted from the DS-TT device 50 to the terminal connected to the device side. A message transmitted from a terminal connected to the device side is input to the DS-TT device 50. This message is transmitted to the NW-TT device 30 via the PDU session 60 established between the UE 40 and the UPF device 20 in the set including the DS-TT device 50. Then, this message is transmitted from the NW-TT device 30 to the terminal connected to the network side.

[0011] In Embodiment 1, the DS-TT device 50 realizes the translation function of time synchronization messages.

[0012] Referring to FIG. 2, the configuration of the UE 40 according to Embodiment 1 will be described. The UE 40 is a computer. The UE 40 includes hardware such as a processor 41, a memory 42, a storage 43, and a communication interface 44. The processor 41 is connected to other hardware via signal lines and controls these other hardware.

[0013] The UE 40 includes a session establishment unit 411 as a functional component. The functions of the functional components of the UE 40 are realized by software. A program for realizing the functions of the functional components of the UE 40 is stored in the storage 43. This program is read into the memory 42 by the processor 41 and executed by the processor 41. Thereby, the functions of the functional components of the UE 40 are realized.

[0014] Referring to FIG. 3, the configuration of the DS-TT device 50 according to Embodiment 1 will be described. The DS-TT device 50 is a computer. The DS-TT device 50 includes hardware such as a processor 51, a memory 52, a storage 53, a first communication interface 54, and a second communication interface 55. The processor 51 is connected to other hardware via signal lines and controls these other hardware.

[0015] The DS-TT device 50 includes a time synchronization unit 511, an information acquisition unit 512, a type determination unit 513, and a conversion unit 514 as functional components. The conversion unit 514 includes a protocol conversion unit 515 and a transmission processing unit 516. The functions of the respective functional components of the DS-TT device 50 are realized by software. The storage 53 stores a program that implements the functions of each functional component of the DS-TT device 50. This program is read into the memory 52 by the processor 51 and executed by the processor 51. Thereby, the functions of each functional component of the DS-TT device 50 are realized.

[0016] The processors 41 and 51 are ICs that perform processing. IC is an abbreviation for Integrated Circuit. Specific examples of the processors 41 and 51 are CPU, DSP, and GPU. CPU is an abbreviation for Central Processing Unit. DSP is an abbreviation for Digital Signal Processor. GPU is an abbreviation for Graphics Processing Unit.

[0017] The memories 42 and 52 are storage devices that temporarily store data. Specific examples of the memories 42 and 52 are SRAM and DRAM. SRAM is an abbreviation for Static Random Access Memory. DRAM is an abbreviation for Dynamic Random Access Memory.

[0018] The storages 43 and 53 are storage devices that store data. Specific examples of the storages 43 and 53 are HDD. HDD is an abbreviation for Hard Disk Drive. Also, the storages 43 and 53 may be portable recording media such as SD (registered trademark) memory cards, CompactFlash (registered trademark), NAND flash, flexible disks, optical disks, compact disks, Blu-ray (registered trademark) disks, and DVDs. SD is an abbreviation for Secure Digital. DVD is an abbreviation for Digital Versatile Disk.

[0019] The communication interface 44 is an interface for communicating with the NW-TT device 30. The first communication interface 54 is an interface for communicating with a device connected to the network side. The second communication interface 55 is an interface for communicating with a device connected to the 5G system 100 side. That is, the second communication interface 55 is an interface for communicating via the PDU session 60. The communication interface 44, the first communication interface 54, and the second communication interface 55 are, as specific examples, ports for communication.

[0020] ***Description of the operation*** With reference to FIGS. 4 to 20, the operation of the 5G system 100 according to Embodiment 1 will be described. The operation procedure of the 5G system 100 according to Embodiment 1 corresponds to the message conversion method according to Embodiment 1. Also, the program for realizing the operation of the 5G system 100 according to Embodiment 1 corresponds to the message conversion program according to Embodiment 1.

[0021] In Embodiment 1, it is assumed that the time synchronization message is a PTP message. PTP is an abbreviation for Precision Time Protocol. In Embodiment 1, as data types of the PTP message, there are three types: IEEE1588-2019 of an IP packet, IEEE1588-2019 of an Ethernet frame, and IEEE802.1AS of an Ethernet frame. In the following description, IEEE1588-2019 of an IP packet is referred to as IP1588. IEEE1588-2019 of an Ethernet frame is referred to as Ethernet1588. IEEE802.1AS of an Ethernet frame is referred to as Ethernet1AS.

[0022] With reference to FIG. 4, the operation overview of the 5G system 100 according to Embodiment 1 will be described. As cases of protocol conversion, there are the following two cases of (1) and (2). (1) The DS-TT device 50 receives a PTP message from the device side, performs protocol conversion, and transmits it to the 5G system 100 side. (2) The DS-TT device 50 receives a PTP message from the 5G system 100 side, performs protocol conversion, and transmits it to the device side. For protocol conversion, the data type of the source and the data type of the destination are required. The data type of the source is the data type of the transmitted PTP message. Regarding the case of (1), the DS-TT device 50 can identify the data types of the source and the destination. Regarding the case of (2), the DS-TT device 50 can identify the data type of the destination. However, there is a possibility that the data of the transmitted PTP message is missing, and the DS-TT device 50 may not be able to identify the data type on the 5G system 100 side that is the source. This is because the PDU session 60 established between the UE 40 and the UPF device 20 is either an IP PDU session or an Ethernet PDU session. The PDU session 60 becomes either an IP PDU session or an Ethernet PDU session depending on the terminal connected to the device side. Therefore, in Embodiment 1, the UE 40 establishes a PDU session 60 including the MAC address of the DS-TT device and the IP address information of the UE with the UPF device 20. As a result, the data of the PTP message received by the DS-TT device 50 will not be missing.

[0023] The UE 40 is a device that establishes a PDU session 60 with the UPF device 20. The session establishment unit 411 of the UE 40 transmits a request for establishing an Unstructured PDU session to the UPF device 20. At this time, the session establishment unit 411 uses a configuration including both the MAC address of the DS-TT device and the IP address information of the UE 40 as the format of the Unstructured PDU session. Thereby, the Unstructured PDU session is established as the PDU session 60. The DS-TT device 50 receives PTP messages from the 5G system 100 side. If the data type of the source of the received PTP message is IP, information is set in the IP field. If the data type of the source of the received PTP message is Ethernet, information is set in the Ethernet field. Therefore, the DS-TT device 50 can receive the data of the PTP message without omission. As a result, the DS-TT device 50 can also perform protocol conversion for the case of (2). The DS-TT device 50 converts the PTP message according to the combination of the data type of the source and the data type of the destination. Then, the NW-TT device 30 transmits the converted PTP message to the destination.

[0024] Referring to FIG. 5, the overall operation of the DS-TT device 50 according to Embodiment 1 will be described. (Step S1: Time synchronization process) When the time synchronization unit 511 receives a PTP message, it executes a process related to time synchronization based on the PTP message.

[0025] (Step S2: Type determination process) The type determination unit 513 identifies the combination of the data type of the source and the data type of the destination. At this time, when a PTP message is received from the 5G system 100, the information acquisition unit 512 acquires data from the IP session or Ethernet session in the PDU session 60. Then, the type determination unit 513 identifies the data type based on the data acquired by the information acquisition unit 512 and identifies the combination.

[0026] When the data type of the source and the data type of the destination are the same, the type determination unit 513 skips the processes of Step S3 and Step S4 and advances the process to Step S5. On the other hand, when the data type of the source and the data type of the destination are different, the type determination unit 513 advances the process to Step S3. In steps S3 and S4, the conversion unit 514 converts the PTP message according to the combination specified in step S2.

[0027] (Step S3: Protocol conversion process) The protocol conversion unit 515 converts the content of the message body of the PTP message according to the combination specified in step S2. Specifically, the protocol conversion unit 515 converts the content of the message body of the PTP message into content that matches the data type of the PDU session 60 for the destination of the PTP message.

[0028] (Step S4: Transmission information conversion process) The transmission processing unit 516 converts the configuration of the transmission information indicating the destination and source of the PTP message. Specifically, the transmission processing unit 516 converts the configuration of the transmission information of the PTP message into content that matches the data type of the PDU session 60 for the destination of the PTP message.

[0029] (Step S5: Transmission process) The transmission processing unit 516 transmits the PTP message to the destination.

[0030] Referring to FIG. 6, the operation of the type determination process (step S2 in FIG. 5) according to Embodiment 1 will be described. In the case where a PTP message is received from the device side, even an existing DS-TT device can identify the combination of the data type of the source and the data type of the destination. Therefore, here, the case where a PTP message is received from the 5G system 100 side will be described.

[0031] (Step S21: IP field determination process) The type determination unit 513 determines whether the IP field of the PDU session 60 is empty. If the type determination unit 513 determines that it is not empty, the process proceeds to step S22. On the other hand, if the type determination unit 513 determines that it is empty, the process proceeds to step S23.

[0032] (Step S22: First Information Extraction Process) The type determination unit 513 extracts information from the IP field of the PDU session 60. Then, the type determination unit 513 identifies the data type of the source from the composition of the extracted information.

[0033] (Step S23: Ethernet Field Determination Process) The type determination unit 513 determines whether the Ethernet field of the PDU session 60 is empty. If the type determination unit 513 determines that it is not empty, it proceeds to step S24. On the other hand, if the type determination unit 513 determines that it is empty, it ends the process as an error.

[0034] (Step S24: Second Information Extraction Process) The type determination unit 513 extracts information from the Ethernet field of the PDU session 60. Then, the type determination unit 513 identifies the data type of the source from the composition of the extracted information.

[0035] (Step S25: Device Side Identification Process) The type determination unit 513 identifies the data type of the device side that is the destination. Regarding the device side, the DS-TT device 50 has information on the data type and can identify the data type.

[0036] (Step S26: Combination Identification Process) The type determination unit 513 identifies the combination of the data type of the source identified in step S22 or step S24 and the data type of the destination identified in step S25. If the data type of the source and the data type of the destination are the same, the type determination unit 513 proceeds to step S5 in FIG. 5. On the other hand, if the data type of the source and the data type of the destination are different, the type determination unit 513 proceeds to step S3 in FIG. 5.

[0037] When the data type of the source and the data type of the destination are different, there are six types shown in (A) to (F) of FIG. 7. (A) The source is IP1588 and the destination is Ethernet1588. (B) The source is Ethernet1588 and the destination is IP1588. (C) The source is Ethernet1588 and the destination is Ethernet1AS. (D) The source is Ethernet1AS and the destination is Ethernet1588. (E) The source is IP1588 and the destination is Ethernet1AS. (F) The source is Ethernet1AS and the destination is IP1588.

[0038] Referring to FIG. 8, the protocol conversion process (step S3 in FIG. 5) according to Embodiment 1 will be described. (Step S31: Conversion determination process) The protocol conversion unit 515 determines whether the combination specified in step S2 is a combination that requires conversion of the message body. If the protocol conversion unit 515 determines that the combination requires conversion of the message body, the process proceeds to step S32. On the other hand, if the protocol conversion unit 515 determines that the combination does not require conversion of the message body, the message body of the received PTP message is output as it is.

[0039] In Embodiment 1, among the six types from (A) to (F), the combinations (A) and (B) in which both the destination and the source use IEEE1588-2019 as the protocol are combinations that do not require conversion of the message body. The other combinations from (C) to (F) use different protocols for the source and the destination, and are combinations that require conversion of the message body.

[0040] (Step S32: Message type determination process) The protocol conversion unit 515 determines what type the message type of the PTP message is. In Embodiment 1, as the message types of PTP messages, there are Sync messages, Follow_Up messages, Announce messages, Pdelay_Req messages, Pdelay_Resp, and DelayReq messages.

[0041] First, the protocol conversion unit 515 determines whether the message type of the source or destination is a Sync message or a Follow_Up message. If the protocol conversion unit 515 determines that it is a Sync message or a Follow_Up message, the process proceeds to step S33. If it is neither a Sync message nor a Follow_Up message, the protocol conversion unit 515 determines whether the message type is an Announce message. If the protocol conversion unit 515 determines that it is an Announce message, the process proceeds to step S34. If it is not an Announce message, the protocol conversion unit 515 determines whether the message type is either a Pdelay_Req message or a Pdelay_Resp. If the protocol conversion unit 515 determines that the message type is either a Pdelay_Req message or a Pdelay_Resp, the process proceeds to step S35. If the message type is neither a Pdelay_Req message nor a Pdelay_Resp, the protocol conversion unit 515 determines whether the message type is a DelayReq message. If the protocol conversion unit 515 determines that it is a DelayReq message, the process proceeds to step S36. If it is not a DelayReq message, the protocol conversion unit 515 ends the process as an error.

[0042] (Step S33: First conversion process) The protocol conversion unit 515 processes the Sync message and the Follow_Up message together. Here, there are one-step synchronization and two-step synchronization in the synchronization process. In one-step synchronization, synchronization is performed only with the Sync message. In contrast, in two-step synchronization, synchronization is performed with the Sync message and the Follow_Up message. There are four patterns from (a) to (d) for the conversion here. (a) Conversion between the one-step Sync message of IEEE1588 - 2019 and the one-step Sync message of IEEE802.1AS. (b) Conversion between the two-step Sync message of IEEE1588 - 2019 and the two-step Sync message of IEEE802.1AS. (c) Conversion between the one-step Sync message of IEEE1588 - 2019 and the two-step Sync message of IEEE802.1AS. (d) Conversion between the two-step Sync message of IEEE1588 - 2019 and the one-step Sync message of IEEE802.1AS.

[0043] Referring to FIG. 9, the conversion between the one-step Sync message of IEEE1588 - 2019 and the one-step Sync message of IEEE802.1AS will be described. When the message type of the source is the Sync message in IEEE1588 - 2019, the protocol conversion unit 515 adds the Follow_Up information TLV. TLV is the abbreviation of Type Length Value. Here, the protocol conversion unit 515 assumes that the clock deviation between the NW-TT device 30 and the master device for time synchronization is 0. Then, as shown in FIG. 9, the protocol conversion unit 515 adds the Follow_Up information TLV. On the other hand, when the message type of the source is the Sync message in IEEE802.1AS, the protocol conversion unit 515 changes the frame length and deletes the Follow_Up information TLV.

[0044] Referring to FIG. 10, the conversion between the two-step Sync message of (b) IEEE 1588-2019 and the two-step Sync message of IEEE 802.1AS will be described. When the message type of the source is the Sync message in IEEE 1588-2019, the protocol conversion unit 515 adds the Follow_Up information TLV to the Follow_Up message. Also, when the message type of the source is the Sync message in IEEE 1588-2019, the protocol conversion unit 515 sets all the fields with originTimestamp to 0. On the other hand, when the message type of the source is the Sync message in IEEE 802.1AS, the protocol conversion unit 515 changes the frame length and deletes the Follow_Up information TLV in the Follow_Up message.

[0045] Referring to FIG. 11, the conversion between the one-step Sync message of (c) IEEE 1588-2019 and the two-step Sync message of IEEE 802.1AS will be described. When the message type of the source is the Sync message in IEEE 1588-2019, the protocol conversion unit 515 generates a Follow_Up message in IEEE 802.1AS. At this time, the protocol conversion unit 515 sets the value of the originTimestamp field of the Sync message to the PreciseoriginTimestamp field of the Follow_Up message. Also, the protocol conversion unit 515 sets the Follow_Up information TLV. Also, when the message type of the source is the Sync message in IEEE 1588-2019, the protocol conversion unit 515 sets all the fields with originTimestamp to 0. On the other hand, when the message type of the source is the Sync message in IEEE802.1AS, the protocol conversion unit 515 sets the value of the PreciseoriginTimestamp field of the Follow_Up message in IEEE802.1AS in the reserved field of the Sync message.

[0046] Referring to FIG. 12, (d) the conversion between the two-step Sync message of IEEE1588-2019 and the one-step Sync message of IEEE802.1AS will be described. When the message type of the source is the Sync message in IEEE1588-2019, the protocol conversion unit 515 adds a Follow_Up information TLV. Also, the protocol conversion unit 515 sets the value of the PreciseoriginTimestamp field of the Follow_Up message in the originTimestamp field of the Sync message of IEEE802.1AS. On the other hand, when the message type of the source is the Sync message in IEEE802.1AS, the protocol conversion unit 515 generates a Follow_Up message in IEEE1588-2019. At this time, the protocol conversion unit 515 sets the value of the originTimestamp field of the Sync message in the PreciseoriginTimestamp field of the Follow_Up message. Also, the protocol conversion unit 515 sets all values of the originTimestamp field of the Sync message to 0.

[0047] (Step S34: Second conversion process) The protocol conversion unit 515 adds or deletes a TLV field to / from the Announce message.

[0048] The case of the Announce message will be specifically described with reference to FIG. 13. When the message type of the source is the Announce message in IEEE 1588-2019, the protocol conversion unit 515 adds a PATH TRACE TLV. Also, the protocol conversion unit 515 sets all the fields with originTimestamp to 0. On the other hand, when the message type of the source is the Announce message in IEEE802.1AS, the protocol conversion unit 515 changes the frame length and deletes the PATH TRACE TLV.

[0049] Here, the protocol conversion unit 515 configures the information of the PATH TRACE TLV from the MAC address of the master device for time synchronization in the Announce message, the MAC address of the NW-TT device 30, and the stepRemoved information of the Announce message. Since the MAC addresses of the devices between the master device and the NW-TT device 30 are unknown, the protocol conversion unit 515 sets them to a specific value (for example, all 0). As a specific example, the information of the PATH TRACE TLV is configured as shown in FIG. 13. Here, the stepRemoved information of the Announce message is set to N.

[0050] (Step S35: Third conversion process) The protocol conversion unit 315 performs item conversion of the Pdelay_Req message.

[0051] A specific description will be given with reference to FIG. 14. When the message type of the source is the Pdelay_Req message in IEEE 1588-2019, the protocol conversion unit 315 sets all the fields with originTimestamp to 0. Note that no conversion is required for the Pdelay_Resp message.

[0052] (Step S36: Fourth conversion process) The protocol conversion unit 515 sends a Delay_Resp message to the source.

[0053] A specific description will be given with reference to FIG. 15. IEEE 1588-2019 has Delay_Req messages and Delay_Resp messages. However, these messages do not exist in IEEE 802.1AS. Therefore, when a Delay_Req message is received, the protocol conversion unit 515 does not transmit the Delay_Req message to the destination, but transmits a Delay_Resp message to the source. At this time, the protocol conversion unit 515 sets the difference of the delay value from the grandmaster calculated by the 5G system in the receiveTimestamp field of the Delay_Resp message to the value of the timestamp acquired in the 5G system 100.

[0054] Here, the protocol conversion between IEEE 1588-2019 and IEEE 802.1AS has been described. However, protocol conversion can also be performed according to the above-described concept between other protocols. The above-described concept consists of four steps from (S) to (V). (S) The protocol conversion unit 515 converts a message with TLV into a message without TLV. In this case, the protocol conversion unit 515 deletes the TLV. (T) The protocol conversion unit 515 converts a message without TLV into a message with TLV. In this case, the protocol conversion unit 515 sets TLVs such as the Follow_Up information TLV described in step S33 and the PATH TRACE TLV described in step S34. (U) The protocol conversion unit 515 exchanges timestamps between one-step synchronization messages and two-step synchronization messages. Specifically, the protocol conversion unit 515 uses the originTimestamp of the Sync message in the case of one-step synchronization and uses the PreciseoriginTimestamp of the Follow_Up message in the case of two-step synchronization. (V) If a message that does not exist in the data type of the destination and requests a reply is received, a reply message is sent to the destination. Specifically, when the Delay_Req message and the Delay_Resp message do not exist in the data type of the destination, if the Delay_Req message is received, a Delay_Resp message is sent to the source.

[0055] Referring to FIG. 16, the transmission information conversion process (step S4 in FIG. 5) according to Embodiment 1 will be described. (Step S41: Combination determination process) The transmission processing unit 516 determines which combination in FIG. 7 the combination specified in step S2 is. In the case of the combination of (A), the transmission processing unit 516 advances the process to step S42. In the case of the combination of (B), the transmission processing unit 516 advances the process to step S43. In the case of the combination of (C), the transmission processing unit 516 advances the process to step S44. In the case of the combination of (D), the transmission processing unit 516 advances the process to step S45. In the case of the combination of (E), the transmission processing unit 516 advances the process to step S46. In the case of the combination of (F), the transmission processing unit 516 advances the process to step S47.

[0056] (Step S42: A conversion process) As shown in FIG. 17, the transmission processing unit 516 converts the IP header and the UDP header into DA, SA, and EtherType. DA is the abbreviation of Destination MAC Address. SA is the abbreviation of Source MAC Address. MAC is the abbreviation of Media Access Control. Specifically, the transmission processing unit 516 prepares DA, SA, and EtherType in which the information shown in FIG. 17 is set in advance. Then, the transmission processing unit 516 replaces the IP header and the UDP header with the prepared DA, SA, and EtherType.

[0057] (Step S43: B conversion process) As shown in FIG. 18, the transmission processing unit 516 converts DA, SA, and EtherType into an IP header and a UDP header. Specifically, the transmission processing unit 516 prepares in advance the IP header and UDP header shown in FIG. 18. Then, the transmission processing unit 516 replaces DA, SA, and EtherType with the prepared IP header and UDP header.

[0058] (Step S44: C conversion process) As shown in FIG. 19, the transmission processing unit 516 replaces the DA for Ethernet 1588 with the DA for Ethernet 1AS.

[0059] (Step S45: D conversion process) As shown in FIG. 20, the transmission processing unit 516 replaces the DA for Ethernet 1AS with the DA for Ethernet 1588.

[0060] (Step S46: E conversion process) The E conversion process can be realized by a combination of the A conversion process and the C conversion process. Therefore, after performing the process of step S42, the transmission processing unit 516 performs the process of step S44. That is, after converting IP1588 to Ethernet 1588, Ethernet 1588 is converted to Ethernet 1AS.

[0061] (Step S47: F conversion process) The F conversion process can be realized by a combination of the D conversion process and the B conversion process. Therefore, after performing the process of step S45, the transmission processing unit 516 performs the process of step S43. That is, after converting Ethernet 1AS to Ethernet 1588, Ethernet 1588 is converted to IP1588.

[0062] ***Effects of Embodiment 1*** As described above, in the 5G system 100 according to Embodiment 1, the UE 40 establishes a PDU session 60 capable of storing information of both IP PDUs and Ethernet PDUs with the UPF device 20. Then, the DS-TT device 50 identifies the data type of the PTP message received from the 5G system 100 side using the data type of the PTP message received via the PDU session 60. Thereby, the DS-TT device 50 can identify the data type of the PTP message received from the 5G system 100 side. As a result, the DS-TT device 50 can realize the translation function of the time synchronization message.

[0063] The DS-TT device 50 according to Embodiment 1 converts the content of the message body of the PTP message according to the data type of the transmission destination by a method according to the combination of the data type of the transmission source and the data type of the transmission destination. Thereby, protocol conversion of the time synchronization message can be realized.

[0064] The DS-TT device 50 according to Embodiment 1 converts the configuration of the transmission information of the PTP message according to the data type of the transmission destination by a method according to the combination of the data type of the transmission source and the data type of the transmission destination. Thereby, conversion of the transmission information of the time synchronization message can be realized.

[0065] In the 5G system 100 according to Embodiment 1, when the protocol of the transmission destination of the DS-TT device 50 is IEEE 802.1AS and the DS-TT device 50 receives a Delay_Req message in IEEE 1588-2019, it transmits a Delay_Resp message to the transmission source. Thereby, it becomes possible to appropriately respond to the Delay_Req message received from the transmission source.

[0066] ***Other configurations*** <Modification Example 1> In Embodiment 1, each functional component is realized by software. However, as Modification Example 1, each functional component may be realized by hardware. The differences from Embodiment 1 will be described for this Modification Example 1.

[0067] When each functional component is implemented in hardware, instead of the processor 41, the memory 42, and the storage 43, the UE40 includes an electronic circuit. The electronic circuit is a dedicated circuit that realizes the functions of each functional component, the memory 42, and the storage 43.

[0068] When each functional component is implemented in hardware, instead of the processor 51, the memory 52, and the storage 53, the DS-TT device 50 includes an electronic circuit. The electronic circuit is a dedicated circuit that realizes the functions of each functional component, the memory 52, and the storage 53.

[0069] As the electronic circuit, a single circuit, a composite circuit, a programmed processor, a parallel-programmed processor, a logic IC, a GA, an ASIC, and an FPGA are assumed. GA is the abbreviation of Gate Array. ASIC is the abbreviation of Application Specific Integrated Circuit. FPGA is the abbreviation of Field-Programmable Gate Array. Each functional component may be realized by one electronic circuit, or may be realized by being distributed among a plurality of electronic circuits.

[0070] <Modification Example 2> As Modification Example 2, some of each functional component may be implemented in hardware, and the other each functional component may be implemented in software.

[0071] The processor 41, 51, the memory 42, 52, the storage 43, 53, and the electronic circuit are referred to as a processing circuit. That is, the functions of each functional component are realized by the processing circuit.

[0072] Also, the "section" in the above description may be read as "circuit", "step", "procedure", "process", or "processing circuit".

[0073] The embodiments and modifications of the present disclosure have been described above. Some of these embodiments and modifications may be implemented in combination. Also, any one or some of them may be partially implemented. Note that the present disclosure is not limited to the above embodiments and modifications, and various changes can be made as necessary.

Description of Reference Numerals

[0074] 100 5G system, 10 TSCTSF device, 20 UPF device, 30 NW-TT device, 40 UE, 41 processor, 42 memory, 43 storage, 44 communication interface, 411 session establishment unit, 50 DS-TT device, 51 processor, 52 memory, 53 storage, 54 first communication interface, 55 second communication interface, 511 time synchronization unit, 512 information acquisition unit, 513 type determination unit, 514 conversion unit, 515 protocol conversion unit, 516 transmission processing unit, 60 PDU session.

Claims

1. A DS-TT (Device-Side Time-sensitive networking Translator) device in a 5GS (5 Generation System), a PDU (Packet Data Unit) session established between a UE (User Equipment) and a UPF (User Plane Function) device, the protocol conversion unit that converts the content of the message body of the PTP (Precision Time Protocol) message according to the combination of the data type of the PTP message received via the PDU session including information of both an IP (Internet Protocol) PDU and an Ethernet PDU and the data type of the destination of the PTP message, A DS-TT device comprising:

2. The protocol conversion unit converts the content of the message body of the PTP message into content adapted to the data type of the destination. The DS-TT device according to Claim 1.

3. The protocol conversion unit converts the content of the message body according to the message type of the PTP message. The DS-TT device according to Claim 1.

4. When the protocol conversion unit receives a message that does not exist in the data type of the destination and requires a reply, it sends a reply message to the source. The DS-TT device according to Claim 2.

5. The DS-TT device further comprises: a transmission processing unit that, according to the combination, converts the configuration of the transmission information indicating the destination and source of the PTP message and then transmits it to the destination. The DS-TT device according to any one of Claims 1 to 4.

6. A 5G (5 Generation) system comprising a UE (User Equipment) and a DS-TT (Device-Side Time-sensitive networking Translator) device, the UE establishes a PDU (Packet Data Unit) session including information of both an IP (Internet Protocol) PDU (Packet Data Unit) and an Ethernet PDU with a UPF (User Plane Function) device. The DS-TT device is a 5G system that converts the content of the message body of the PTP (Precision Time Protocol) message according to the combination of the data type of the PTP message received via the PDU session and the data type of the destination of the PTP message. **Claim 7** A UE (User Equipment) in a 5GS (5 Generation System), A session establishment unit that establishes a PDU session for transmitting the PTP message to a DS-TT (Device-Side Time-sensitive networking Translator) device that converts the content of the message body of the PTP message, the PDU session including information on both an IP (Internet Protocol) PDU (Packet Data Unit) and an Ethernet PDU, between the UE and a UPF (User Plane Function) device The UE comprising. **Claim 8** A message conversion method in a 5G (5 Generation) system, A message conversion method in which a UE (User Equipment) establishes a PDU session including information on both an IP (Internet Protocol) PDU (Packet Data Unit) and an Ethernet PDU with a UPF (User Plane Function) device, and A DS-TT (Device-Side Time-sensitive networking Translator) device converts the content of the message body of the PTP message according to the combination of the data type of the PTP message received via the PDU session and the data type of the destination of the PTP message.

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