NW-tt device, 5g system, tsctsf device, and message conversion method

Abstract

A network-side time-sensitive networking translator (NW-TT) device (30) in a 5 Generation (5G) system (100) acquires the data type of a packet data unit (PDU) session (60) from a time sensitive communication time synchronization function (TSCTSF) device (10). The NW-TT device (30) converts the content of a message body of a precision time protocol (PTP) message according to a combination of the data type acquired from the TSCTSF device (10) and the data type of PTP data received from the network side.

Description

NW-TT device, 5G system, TSCTSF device and message conversion method

[0001] The present disclosure relates to a time synchronization protocol conversion technology in a 5G system.

[0002] Digital factories and Industry 4.0 require mobile communications that are real-time and have predictable latency. Also, a function that allows networks and devices with different profiles to coexist using the PnP method is desirable. PnP stands for Plug and Play. Therefore, time sharing is necessary. 3GPP (registered trademark) aims to expand the application of 5G systems from mobile broadband services to industrial networks. 3GPP stands for 3rd Generation Partnership Project. 5G stands for 5 Generation. Local 5G URLLC enables seamless communication for mobile devices on industrial networks. URLLC stands for Ultra-Reliable and Low Latency Communications. Therefore, there is growing interest in time synchronization between devices of different profiles connected to 5G systems.

[0003] When wired networks or terminals with different time synchronization profiles are mixed, it is necessary to add a function for interpreting time synchronization messages. Patent Document 1 describes a technology for converting the format of data to be transmitted depending on the type of network at the port of a relay device. Patent Document 2 describes a technology for generating frames related to time synchronization using profile technology. It is conceivable to combine the technologies described in Patent Documents 1 and 2 and configure the relay device to convert into time synchronization messages with different time synchronization profiles. This makes it possible to realize a function for interpreting time synchronization messages in the relay device.

[0004] JP 2017-212728 A JP 2016-184809 A

[0005] Terminals with different time synchronization profiles may be connected through a 5G system. In this case, the 5G system must function as the relay device described above and implement the time synchronization message interpretation function. However, the 5G system is a system composed of multiple devices, and no device has the information necessary to implement the time synchronization message interpretation function. The present disclosure aims to enable the implementation of the time synchronization message interpretation function in a 5G system.

[0006] The NW-TT device according to the present disclosure is a NW-TT (Network-side Time-sensitive networking Translator) device in a 5G (5 Generation) system, and includes: an information acquisition unit that acquires a data type of a PDU (Packet Data Unit) session from a TSCTSF (Time Sensitive Communication Time Synchronization Function) device; and a Precision Time Protocol (PTP) message received from the network side according to a combination of the data type acquired by the information acquisition unit and the data type of the PTP message. The NW-TT device includes: an information acquisition unit that acquires a data type of a PDU (Packet Data Unit) session from a TSCTSF (Time Sensitive Communication Time Synchronization Function) device; and a conversion unit that converts the PTP message according to a combination of the data type acquired by the information acquisition unit and the data type of the PTP message received from the network side.

[0007] In the present disclosure, the NW-TT device acquires the data type of the PDU session from the TSCTSF device. This allows the NW-TT device to identify the data type to which PTP data received from the network side is to be converted. As a result, the NW-TT device can realize the translation function of the time synchronization message.

[0008] 1 is a configuration diagram of a 5G system 100 according to the first embodiment. A configuration diagram of a TSCTSF device 10 according to the first embodiment. A configuration diagram of a NW-TT device 30 according to the first embodiment. An explanatory diagram of an operation overview of the 5G system 100 according to the first embodiment. A flowchart showing the overall operation of the NW-TT device 30 according to the first embodiment. A flowchart of type determination processing according to the first embodiment. An explanatory diagram of a data type combination according to the first embodiment. A flowchart of protocol conversion processing according to the first embodiment. An explanatory diagram of conversion between an IEEE 1588-2019 one-step sync message and an IEEE 802.1AS one-step sync message according to the first embodiment. An explanatory diagram of conversion between an IEEE 1588-2019 two-step sync message and an IEEE 802.1AS two-step sync message according to the first embodiment. 1 is an explanatory diagram of conversion between a one-step Sync message of IEEE 1588-2019 and a two-step Sync message of IEEE 802.1AS according to the first embodiment. FIG. 2 is an explanatory diagram of conversion between a two-step Sync message of IEEE 1588-2019 and a one-step Sync message of IEEE 802.1AS according to the first embodiment. FIG. 3 is an explanatory diagram of conversion of an Announce message according to the first embodiment. FIG. 4 is an explanatory diagram of conversion of a Pdelay_Req message according to the first embodiment. FIG. 5 is an explanatory diagram of processing for a Delay_Req message according to the first embodiment. FIG. 6 is a flowchart of transmission information conversion processing according to the first embodiment. FIG. 7 is an explanatory diagram of conversion processing for combination (A) according to the first embodiment. FIG. 8 is an explanatory diagram of conversion processing for combination (B) according to the first embodiment. FIG. 9 is an explanatory diagram of conversion processing for combination (C) according to the first embodiment. FIG. 10 is an explanatory diagram of conversion processing for combination (D) according to the first embodiment.

[0009] Embodiment 1. *** Description of Configuration *** The configuration of a 5G system 100 according to embodiment 1 will be described with reference to Figure 1. The 5G system 100 includes a TSCTSF device 10, a UPF device 20, an NW-TT device 30, and a plurality of sets of UEs 40 and DS-TT devices 50. Here, the NW-TT device 30 is mounted on the UPF device 20, but is not limited to this. 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 pair of a UE 40 and a 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 a 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 a PDU session 60 established between the UE 40 and the UPF device 20 in a pair 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 a 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 a PDU session 60 established between the UE 40 and the UPF device 20 in a pair including the DS-TT device 50. Then, this message is transmitted from the NW-TT device 30 to a terminal connected to the network side.

[0011] In the first embodiment, the NW-TT device 30 realizes the translation function of the time synchronization message.

[0012] The configuration of the TSCTSF device 10 according to the first embodiment will be described with reference to Fig. 2. The TSCTSF device 10 is a computer. The TSCTSF device 10 includes hardware such as a processor 11, a memory 12, a storage 13, and a communication interface 14. The processor 11 is connected to other hardware via signal lines and controls the other hardware.

[0013] The TSCTSF device 10 includes a type transmission unit 111 as a functional component. The functions of the functional components of the TSCTSF device 10 are realized by software. A program that realizes the functions of the functional components of the TSCTSF device 10 is stored in the storage 13. This program is read into the memory 12 by the processor 11 and executed by the processor 11. In this way, the functions of the functional components of the TSCTSF device 10 are realized.

[0014] The configuration of the NW-TT device 30 according to the first embodiment will be described with reference to Fig. 3. The NW-TT device 30 is a computer. The NW-TT device 30 includes the following hardware: a processor 31, a memory 32, a storage 33, a first communication interface 34, a second communication interface 35, and a third communication interface 36. The processor 31 is connected to other hardware via signal lines and controls this other hardware.

[0015] The NW-TT device 30 comprises, as functional components, a time synchronization unit 311, an information acquisition unit 312, a type determination unit 313, and a conversion unit 314. The conversion unit 314 comprises a protocol conversion unit 315 and a transmission processing unit 316. The functions of each functional component of the NW-TT device 30 are realized by software. The storage 33 stores a program that realizes the function of each functional component of the NW-TT device 30. This program is read into the memory 32 by the processor 31 and executed by the processor 31. In this way, the function of each functional component of the NW-TT device 30 is realized.

[0016] The processors 11 and 31 are ICs that perform processing. IC stands for Integrated Circuit. Specific examples of the processors 11 and 31 include a CPU, a DSP, and a GPU. CPU stands for Central Processing Unit. DSP stands for Digital Signal Processor. GPU stands for Graphics Processing Unit.

[0017] The memories 12 and 32 are storage devices that temporarily store data. Specific examples of the memories 12 and 32 include SRAM and DRAM. SRAM stands for Static Random Access Memory. DRAM stands for Dynamic Random Access Memory.

[0018] The storages 13 and 33 are storage devices that store data. Specific examples of the storages 13 and 33 are HDDs. HDD stands for Hard Disk Drive. The storages 13 and 33 may also be portable recording media such as an SD (registered trademark) memory card, CompactFlash (registered trademark), NAND flash, a flexible disk, an optical disk, a compact disk, a Blu-ray (registered trademark) disk, or a DVD. SD stands for Secure Digital. DVD stands for Digital Versatile Disk.

[0019] The communication interface 14 is an interface for communicating with the NW-TT device 30. The first communication interface 34 is an interface for communicating with a device connected to the network side. The second communication interface 35 is an interface for communicating with a device connected to the 5G system 100 side. In other words, the second communication interface 35 is an interface for communicating via a PDU session 60. The third communication interface 36 is an interface for communicating with the TSCTSF device 10. The communication interface 14, the first communication interface 34, the second communication interface 35, and the third communication interface 36 are, as specific examples, ports for communication.

[0020] ***Description of Operation*** The operation of the 5G system 100 according to the first embodiment will be described with reference to Figures 4 to 20. The operation procedure of the 5G system 100 according to the first embodiment corresponds to the message conversion method according to the first embodiment. Furthermore, the program that realizes the operation of the 5G system 100 according to the first embodiment corresponds to the message conversion program according to the first embodiment.

[0021] In the first embodiment, it is assumed that the time synchronization message is a PTP message. PTP is an abbreviation for Precision Time Protocol. In the first embodiment, it is assumed that there are three types of data types for PTP messages: IP packets of IEEE 1588-2019, Ethernet frames of IEEE 1588-2019, and Ethernet frames of IEEE 802.1AS. In the following description, IP packets of IEEE 1588-2019 are referred to as IP1588. Ethernet frames of 1588-2019 are referred to as Ethernet1588. Ethernet frames of IEEE 802.1AS are referred to as Ethernet1AS.

[0022] An overview of the operation of the 5G system 100 according to the first embodiment will be described with reference to FIG. 4. There are two cases for protocol conversion: (1) and (2) below. (1) The NW-TT device 30 receives a PTP message from the network side, performs protocol conversion, and transmits the message to the 5G system 100 side. (2) The NW-TT device 30 receives a PTP message from the 5G system 100 side, performs protocol conversion, and transmits the message to the network side. Protocol conversion requires the data type of the sender and the data type of the destination. The data type of the sender is the data type of the transmitted PTP message. In case (1), the NW-TT device 30 can identify the data type of the sender, but cannot identify the data type of the 5G system 100 side, which is the destination. In case (2), the NW-TT device 30 can identify the data types of the sender and the destination. Therefore, in the first embodiment, in the case of (1), the NW-TT device 30 acquires information on the data type on the 5G system 100 side, which is the destination, from the TSCTSF device 10.

[0023] The TSCTSF device 10 is a device that manages time synchronization and deterministic communication services. Generally, in a 5G system 100, the TSCTSF device 10 constantly transmits TSC-related information to the NW-TT device 30. TSC stands for Time Sensitive Communication. In the first embodiment, the TSCTSF device 10 transmits, in addition to the TSC-related information, information on the PDU session 60 established between each UE 40 and the UPF device 20 to the NW-TT device 30. The NW-TT device 30 receives a PTP message from the network side. The NW-TT device 30 acquires the data type of the PDU session 60 to which the destination terminal is connected from the information on the PDU session 60 transmitted from the TSCTSF device 10. This allows the NW-TT device 30 to identify the data types of the source and destination even in case (1). The NW-TT device 30 converts the PTP message according to the combination of the data type of the sender and the data type of the destination, and then transmits the converted PTP message to the destination.

[0024] 5, the overall operation of the NW-TT device 30 according to the first embodiment will be described. (Step S1: Time Synchronization Processing) Upon receiving a PTP message, the time synchronization unit 311 executes processing related to time synchronization based on the PTP message.

[0025] (Step S2: Type Determination Process) The type determination unit 313 identifies the combination of the data type of the transmission source and the data type of the transmission destination. At this time, when a PTP message is received from the network side, the information acquisition unit 312 acquires the data type of the PDU session 60 to which the transmission destination terminal is connected from the information of the PDU session 60 transmitted from the TSCTSF device 10. Then, the type determination unit 313 identifies the combination using the data type acquired by the information acquisition unit 312.

[0026] If the data type of the sender and the data type of the destination are the same, the type determination unit 313 skips the processes of steps S3 and S4 and proceeds to step S5. On the other hand, if the data type of the sender and the data type of the destination are different, the type determination unit 313 proceeds to step S3. In steps S3 and S4, the conversion unit 314 converts the PTP message according to the combination identified in step S2.

[0027] (Step S3: Protocol conversion process) The protocol conversion unit 315 converts the content of the message body of the PTP message according to the combination identified in step S2. Specifically, the protocol conversion unit 315 converts the content of the message body of the PTP message to 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 316 converts the configuration of the transmission information indicating the destination and source of the PTP message. Specifically, the transmission processing unit 316 converts the configuration of the transmission information of the PTP message to 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 316 transmits the PTP message to the destination.

[0030] The operation of the type determination process (step S2 in FIG. 5) according to the first embodiment will be described with reference to FIG. 6. When a PTP message is received from the 5G system 100, even an existing NW-TT device can identify the combination of the data type of the sender and the data type of the destination. Therefore, here, a case where a PTP message is received from the network side will be described.

[0031] (Step S21: Message Extraction Process) The type determination unit 313 extracts the message body of the PTP message, and identifies the data type of the sender from the structure of the message body.

[0032] (Step S22: Information Acquisition Processing) The information acquisition unit 312 acquires the data type of the PDU session 60 to which the destination terminal is connected from the information of the PDU session 60 transmitted from the TSCTSF device 10. This identifies the data type of the destination.

[0033] (Step S23: Combination Identification Process) The type determination unit 313 identifies the combination of the data type of the sender identified in step S21 and the data type of the destination identified in step S22. If the data type of the sender and the data type of the destination are the same, the type determination unit 313 proceeds to step S5 in Fig. 5. On the other hand, if the data type of the sender and the data type of the destination are different, the type determination unit 313 proceeds to step S3 in Fig. 5.

[0034] There are six cases where the data type of the sender and the data type of the destination are different, as shown in Figure 7, (A) to (F). (A) The sender is IP1588 and the destination is Ethernet1588. (B) The sender is Ethernet1588 and the destination is IP1588. (C) The sender is Ethernet1588 and the destination is Ethernet1AS. (D) The sender is Ethernet1AS and the destination is Ethernet1588. (E) The sender is IP1588 and the destination is Ethernet1AS. (F) The sender is Ethernet1AS and the destination is IP1588.

[0035] The protocol conversion process (step S3 in FIG. 5) according to the first embodiment will be described with reference to FIG. 8. (Step S31: Conversion Determination Process) The protocol conversion unit 315 determines whether the combination identified in step S2 is a combination that requires message body conversion. If the combination requires message body conversion, the protocol conversion unit 315 proceeds to step S32. On the other hand, if the combination does not require message body conversion, the protocol conversion unit 315 outputs the message body of the received PTP message as is.

[0036] In the first embodiment, of the six types (A) to (F), the combinations (A) and (B) in which both the source and destination use the IEEE 1588-2019 protocol are combinations in which message body conversion is not required. The other combinations (C) to (F) are combinations in which the source and destination use different protocols and require message body conversion.

[0037] (Step S32: Message Type Determination Process) The protocol conversion unit 315 determines the message type of the PTP message. In the first embodiment, the message types of the PTP message include a Sync message, a Follow_Up message, an Announce message, a Pdelay_Req message, a Pdelay_Resp message, and a DelayReq message.

[0038] First, the protocol conversion unit 315 determines whether the message type of the sender or destination is a Sync message or a Follow_Up message. If the message type is a Sync message or a Follow_Up message, the protocol conversion unit 315 proceeds to step S33. If the message type is neither a Sync message nor a Follow_Up message, the protocol conversion unit 315 determines whether the message type is an Announce message. If the message type is an Announce message, the protocol conversion unit 315 proceeds to step S34. If the message type is not an Announce message, the protocol conversion unit 315 determines whether the message type is either a Pdelay_Req message or a Pdelay_Resp message. If the message type is either a Pdelay_Req message or a Pdelay_Resp, the protocol conversion unit 315 proceeds to step S35. If the message type is neither a Pdelay_Req message nor a Pdelay_Resp, the protocol conversion unit 315 determines whether the message type is a DelayReq message. If the message type is a DelayReq message, the protocol conversion unit 315 proceeds to step S36. If the message type is not a DelayReq message, the protocol conversion unit 315 terminates the process as an error.

[0039] (Step S33: First Conversion Process) The protocol conversion unit 315 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 using only the Sync message. In contrast, in two-step synchronization, synchronization is performed using the Sync message and the Follow_Up message. There are four patterns of conversion here, (a) to (d). (a) Conversion between the one-step Sync message of IEEE 1588-2019 and the one-step Sync message of IEEE 802.1AS. (b) Conversion between the two-step Sync message of IEEE 1588-2019 and the two-step Sync message of IEEE 802.1AS. (c) Conversion between IEEE 1588-2019 one-step Sync messages and IEEE 802.1AS two-step Sync messages. (d) Conversion between IEEE 1588-2019 two-step Sync messages and IEEE 802.1AS one-step Sync messages.

[0040] Referring to FIG. 9, (a) conversion between an IEEE 1588-2019 one-step sync message and an IEEE 802.1AS one-step sync message will be described. When the source message type is an IEEE 1588-2019 sync message, the protocol conversion unit 315 adds a Follow_Up information TLV. TLV stands for Type Length Value. Here, the protocol conversion unit 315 assumes that the clock deviation between the NW-TT device 30 and the time synchronization master device is 0. Then, as shown in FIG. 9, the protocol conversion unit 315 adds the Follow_Up information TLV. On the other hand, if the message type of the sender is a Sync message in IEEE802.1AS, the protocol conversion unit 315 changes the frame length and deletes the Follow_Up information TLV.

[0041] 10, (b) the conversion between the IEEE 1588-2019 two-step Sync message and the IEEE 802.1AS two-step Sync message will be described. If the source message type is an IEEE 1588-2019 Sync message, the protocol conversion unit 315 adds a Follow_Up information TLV to the Follow_Up message. Also, if the source message type is an IEEE 1588-2019 Sync message, the protocol conversion unit 315 sets all of the fields containing "originTimestamp" to 0. On the other hand, if the message type of the sender is a Sync message in IEEE 802.1AS, the protocol conversion unit 315 changes the frame length and deletes the Follow_Up information TLV in the Follow_Up message.

[0042] Referring to Figure 11, (c) the conversion between the 1-step Sync message of IEEE1588-2019 and the 2-step Sync message of IEEE802.1AS will be described. When the message type of the sender is a Sync message in IEEE1588-2019, the protocol conversion unit 315 generates a Follow_Up message in IEEE802.1AS. At this time, the protocol conversion unit 315 sets the value of the originTimestamp field of the Sync message to the PreciseOriginTimestamp field of the Follow_Up message. In addition, the protocol conversion unit 315 sets the Follow_Up information TLV. Furthermore, if the message type of the sender is a Sync message in IEEE 1588-2019, protocol conversion unit 315 sets all of the fields in originTimestamp to 0. On the other hand, if the message type of the sender is a Sync message in IEEE 802.1AS, protocol conversion unit 315 sets the value of the PreciseOriginTimestamp field of the Follow_Up message in IEEE 802.1AS to the reserved field of the Sync message.

[0043] Referring to FIG. 12, (d) conversion between an IEEE 1588-2019 two-step Sync message and an IEEE 802.1AS one-step Sync message will be described. If the source message type is an IEEE 1588-2019 Sync message, the protocol conversion unit 315 adds a Follow_Up information TLV. Furthermore, the protocol conversion unit 315 sets the value of the Precise origin timestamp field of the Follow_Up message to the origin timestamp field of the Sync message. On the other hand, if the source message type is an IEEE 802.1AS Sync message, the protocol conversion unit 315 generates a Follow_Up message. At this time, the protocol conversion unit 315 sets the value of the originTimestamp field of the Sync message to the PreciseoriginTimestamp field of the Follow_Up message. The protocol conversion unit 315 also sets all of the values ​​in the originTimestamp field of the Sync message to 0.

[0044] (Step S34: Second Conversion Process) The protocol conversion unit 315 adds or deletes a TLV field to or from the Announce message.

[0045] The case of an Announce message will be specifically described with reference to Fig. 13. If the message type of the sender is an Announce message in IEEE 1588-2019, the protocol conversion unit 315 adds a PATH TRACE TLV. Furthermore, the protocol conversion unit 315 sets all fields containing originTimestamp to 0. On the other hand, if the message type of the sender is an Announce message in IEEE 802.1AS, the protocol conversion unit 315 changes the frame length and deletes the PATH TRACE TLV.

[0046] Here, the protocol conversion unit 315 configures PATH TRACE TLV information from the MAC address of the time-synchronized master device in the Announce message, the MAC address of the NW-TT device 30, and the stepRemoved information in the Announce message. Because the MAC addresses of the devices between the master device and the NW-TT device 30 are unknown, the protocol conversion unit 315 sets them to specific values ​​(for example, all 0s). As a specific example, the PATH TRACE TLV information is configured as shown in FIG. 13. Here, the stepRemoved information in the Announce message is set to N.

[0047] (Step S35: Third Conversion Process) The protocol conversion unit 315 converts the items of the Pdelay_Req message.

[0048] This will be described in detail with reference to Fig. 14. When the message type of the sender is a Pdelay_Req message in IEEE1588-2019, the protocol conversion unit 315 sets all fields corresponding to originTimestamp to 0. Note that no conversion is required for a Pdelay_Resp message.

[0049] (Step S36: Fourth Conversion Process) The protocol conversion unit 315 transmits a Delay_Resp message to the sender.

[0050] A specific description will be given with reference to FIG. 15. IEEE 1588-2019 includes a Delay_Req message and a Delay_Resp message. However, these messages do not exist in IEEE 802.1AS. Therefore, when a Delay_Req message is received, the protocol conversion unit 315 does not send a Delay_Req message to the destination, but sends a Delay_Resp message to the source. At this time, the protocol conversion unit 315 sets the delay value with the grandmaster calculated by the 5G system from the timestamp value acquired by the 5G system 100 in the receiveTimestamp field of the Delay_Resp message.

[0051] Note that the protocol conversion between IEEE 1588-2019 and IEEE 802.1AS has been described here. However, protocol conversion between other protocols is also possible according to the above-described concepts. The above-described concepts are the four concepts (S) to (V). (S) The protocol conversion unit 315 converts a message with TLVs into a message without TLVs. In this case, the protocol conversion unit 315 deletes the TLVs. (T) The protocol conversion unit 315 converts a message without TLVs into a message with TLVs. In this case, the protocol conversion unit 315 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 315 switches the timestamp between one-step synchronization messages and two-step synchronization messages. Specifically, the protocol conversion unit 315 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) When a message that does not exist in the destination's data type and that requests a reply is received, a reply message is sent to the destination. Specifically, when a Delay_Req message and a Delay_Resp message do not exist in the destination's data type, and a Delay_Req message is received, a Delay_Resp message is sent to the sender.

[0052] The transmission information conversion process (step S4 in FIG. 5) according to the first embodiment will be described with reference to FIG. 16. (Step S41: Combination Determination Process) The transmission processing unit 316 determines which combination in FIG. 7 the combination identified in step S2 corresponds to. If the combination is (A), the transmission processing unit 316 proceeds to step S42. If the combination is (B), the transmission processing unit 316 proceeds to step S43. If the combination is (C), the transmission processing unit 316 proceeds to step S44. If the combination is (D), the transmission processing unit 316 proceeds to step S45. If the combination is (E), the transmission processing unit 316 proceeds to step S46. If the combination is (F), the transmission processing unit 316 proceeds to step S47.

[0053] (Step S42: A Conversion Process) As shown in FIG. 17, the transmission processing unit 316 converts the IP header and UDP header into a DA, SA, and EtherType. DA stands for Destination MAC Address. SA stands for Source MAC Address. MAC stands for Media Access Control. Specifically, the transmission processing unit 316 prepares in advance a DA, SA, and EtherType in which the information shown in FIG. 17 is set. The transmission processing unit 316 then replaces the IP header and UDP header with the prepared DA, SA, and EtherType.

[0054] (Step S43: Conversion Process B) The transmission processing unit 316 converts the DA, SA, and EtherType into an IP header and a UDP header, as shown in Fig. 18. Specifically, the transmission processing unit 316 prepares in advance the IP header and UDP header shown in Fig. 18. Then, the transmission processing unit 316 replaces the DA, SA, and EtherType with the prepared IP header and UDP header.

[0055] (Step S44: C Conversion Process) As shown in FIG. 19, the transmission processing unit 316 replaces the DA for Ethernet1588 with the DA for Ethernet1AS.

[0056] (Step S45: D Conversion Process) The transmission processing unit 316 replaces the DA for Ethernet1AS with a DA for Ethernet1588, as shown in FIG.

[0057] (Step S46: E Conversion Process) The E conversion process can be realized by combining the A conversion process and the C conversion process. Therefore, the transmission processing unit 316 performs the process of step S42 and then the process of step S44. That is, after converting IP1588 to Ethernet1588, it converts Ethernet1588 to Ethernet1AS.

[0058] (Step S47: F Conversion Process) The F conversion process can be realized by combining the D conversion process and the B conversion process. Therefore, the transmission processing unit 316 performs the process of step S45 and then the process of step S43. That is, after converting Ethernet1AS to Ethernet1588, it converts Ethernet1588 to IP1588.

[0059] ***Effects of First Embodiment*** As described above, in the 5G system 100 according to the first embodiment, the TSCTSF device 10 transmits the data type of the PDU session 60 to the NW-TT device 30. This allows the NW-TT device 30 to identify the data type to which the PTP data received from the network side is converted. As a result, the NW-TT device 30 can realize the interpretation function of the time synchronization message.

[0060] The NW-TT device 30 according to the first embodiment converts the contents of the message body of a PTP message to match the data type of the destination by a method according to the combination of the data type of the source and the data type of the destination, thereby enabling protocol conversion of time synchronization messages.

[0061] The NW-TT device 30 according to the first embodiment converts the configuration of the transmission information of the PTP message to match the data type of the destination by a method according to the combination of the data type of the source and the data type of the destination, thereby realizing the conversion of the transmission information of the time synchronization message.

[0062] In the 5G system 100 according to the first embodiment, when the NW-TT device 30 receives a Delay_Req message in IEEE1588-2019 when the destination protocol is IEEE802.1AS, it transmits a Delay_Resp message to the sender. This makes it possible to appropriately respond to the Delay_Req message received from the sender.

[0063] ***Other Configurations*** <Modification 1> In the first embodiment, each functional component is realized by software. However, in Modification 1, each functional component may be realized by hardware. The differences between Modification 1 and the first embodiment will be described below.

[0064] When each functional component is realized by hardware, the TSCTSF device 10 includes an electronic circuit instead of the processor 11, the memory 12, and the storage 13. The electronic circuit is a dedicated circuit that realizes the functions of each functional component, the memory 12, and the storage 13.

[0065] When each functional component is realized by hardware, the NW-TT device 30 includes an electronic circuit instead of the processor 31, memory 32, and storage 33. The electronic circuit is a dedicated circuit that realizes the functions of each functional component, the memory 32, and the storage 33.

[0066] Possible electronic circuits include a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, a logic IC, a GA, an ASIC, and an FPGA. GA stands for Gate Array. ASIC stands for Application Specific Integrated Circuit. FPGA stands for Field-Programmable Gate Array. Each functional component may be realized by a single electronic circuit, or each functional component may be distributed across multiple electronic circuits.

[0067] <Modification 2> As a modification 2, some of the functional components may be realized by hardware, and other functional components may be realized by software.

[0068] The processors 11 and 31, the memories 12 and 32, the storages 13 and 33, and the electronic circuits are collectively referred to as a processing circuit. In other words, the functions of the functional components are realized by the processing circuit.

[0069] Furthermore, the term "unit" in the above description may be read as a "circuit," "step," "procedure," "process," or "processing circuit."

[0070] The embodiments and modifications of the present disclosure have been described above. Some of these embodiments and modifications may be combined and implemented. Furthermore, one or more of them may be implemented partially. Note that the present disclosure is not limited to the above embodiments and modifications, and various modifications are possible as needed.

[0071] 100 5G system, 10 TSCTSF device, 11 processor, 12 memory, 13 storage, 14 communication interface, 111 type transmission unit, 20 UPF device, 30 NW-TT device, 31 processor, 32 memory, 33 storage, 34 first communication interface, 35 second communication interface, 36 third communication interface, 311 time synchronization unit, 312 information acquisition unit, 313 type determination unit, 314 conversion unit, 315 protocol conversion unit, 316 transmission processing unit, 40 UE, 50 DS-TT device, 60 PDU session.

Claims

1. A network-side time-sensitive networking translator (NW-TT) device in a 5G (5 Generation) system, An information acquisition unit that acquires a data type of a PDU (Packet Data Unit) session from a TSCTSF (Time Sensitive Communication Time Synchronization Function) device; a conversion unit that converts a Precision Time Protocol (PTP) message according to a combination of the data type acquired by the information acquisition unit and a data type of a PTP message received from a network side; A network-transfer-transfer (NW-TT) device comprising:

2. The conversion unit is a protocol conversion unit that converts the contents of the message body of the PTP message according to a combination of a data type of the PDU session for a destination of the PTP message and a data type of the PTP message. The NW-TT device according to claim 1 .

3. The protocol conversion unit converts the content of the message body of the PTP message into content that matches the data type of the PDU session for the destination of the PTP message. The NW-TT device according to claim 2.

4. The protocol conversion unit converts the content of the message body according to the message type of the PTP message. The NW-TT device according to claim 2.

5. The protocol conversion unit transmits a reply message to the destination when the protocol conversion unit receives a message that does not exist in the data type of the destination and that requests a reply. The NW-TT device according to claim 2.

6. The conversion unit further a transmission processing unit that converts a configuration of transmission information indicating a destination and a source of the PTP message according to the combination. The NW-TT device according to claim 1 .

7. A 5G (5 Generation) system including a TSCTSF (Time Sensitive Communication Time Synchronization Function) device and a NW-TT (Network-side Time-sensitive networking Translator) device, The TSCTSF device transmits a data type of a PDU (Packet Data Unit) session to the NW-TT device; The NW-TT device converts the contents of the message body of the Precision Time Protocol (PTP) message according to a combination of the data type transmitted from the TSCTSF device and the data type of the PTP message received from the network side. 5G system.

8. A TSCTSF (Time Sensitive Communication Time Synchronization Function) device in a 5G (5 Generation) system, A type sending unit that sends the data type of a PDU (Packet Data Unit) session to a NW-TT (Network-side Time-sensitive networking Translator) device that converts the contents of the message body of a PTP (Precision Time Protocol) message received from the network side. A TSCTSF device comprising:

9. A message conversion method in a 5G (5 Generation) system, A Time Sensitive Communication Time Synchronization Function (TSCTSF) device transmits a data type of a Packet Data Unit (PDU) session to a Network-side Time-sensitive networking Translator (NW-TT) device; A message conversion method in which the NW-TT device converts the contents of a message body of a Precision Time Protocol (PTP) message according to a combination of a data type transmitted from the TSCTSF device and a data type of a PTP message received from a network side.