Transmission device and transmission method, reception device and reception method, program, and transmission / reception device

Abstract

To achieve multipath redundant communication for achieving low delay and high reliability.SOLUTION: A transmission device that transmits a packet through a mobile wireless communication network includes a frequency setting unit that sets use frequencies, which are frequencies used by wireless communication interfaces for communication with a base station of the mobile wireless communication network, in a plurality of wireless communication interfaces so that the use frequencies are different from each other, and a packet sending unit that duplicates the same packet to generate at least two packets, adds an additional header to each of the packets, and sends the packets to the plurality of wireless communication interfaces provided corresponding to the additional headers.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a transmitting device and a transmitting method, a receiving device and a receiving method, a program, and a transmitting / receiving device, and more particularly to a transmitting device and a transmitting method, a receiving device and a receiving method, a program, and a transmitting / receiving device that enable multipath redundant communication that is application-independent, achieves low latency, and high reliability. [Background technology]

[0002] Intelligent Transport Systems (ITS), which are built as an integrated system that exchanges information between vehicles, between vehicles and people, and between vehicles and road facilities, have long been studied alongside the spread of automobiles. ITS is a system that utilizes cutting-edge information and communication technology with the aim of improving road traffic safety, transport efficiency, and comfort, and in recent years, there has been active global research into the advancement of ITS and the realization of an autonomous driving society.

[0003] Against this background, expectations are rising for the further development of ITS through connected car services and autonomous driving technology that utilize V2X (Vehicle-to-Everything) communications, which connects cars with everything. V2X refers to communications between vehicles and everything, and includes communication between vehicles (V2V) and between vehicles and networks (V2N).

[0004] V2V is direct vehicle-to-vehicle communication that does not involve a mobile wireless communication network such as a mobile communication carrier's base station or backbone communication network, making it easy to achieve low transmission latency in vehicle-to-vehicle communication, but it has a short communication distance because it uses only wireless terminal devices with low antenna gain. On the other hand, V2N2V (Vehicle-to-Network-to-Vehicle), which is achieved by vehicle-to-vehicle wireless communication via a mobile wireless communication network, makes it easy to achieve a wide communication distance because it communicates via a base station with high antenna gain. In addition, technology has been proposed that allows switching between V2V communication and V2N2V communication (see, for example, Patent Document 1).

[0005] For example, in ITS, which realizes autonomous driving, stable reliability and low latency are required for V2N / V2N2V communications for autonomous vehicles that use mobile wireless communication networks.However, in V2N / V2N2V communications, when onboard terminals move within and outside the area coverage of base stations, communication latency spikes and packet loss can occur when handovers occur between cells or base stations.

[0006] One example of a technique proposed to suppress such degradation in communication quality due to handover is multipath redundant communication technology, which transmits the same packet over multiple paths, selects the packet that arrives first at the receiving end, and, if a packet is lost, recovers the lost packet using packets obtained from the remaining paths.

[0007] Multipath TCP (MPTCP), an extension of TCP, has been proposed as a communication protocol compatible with multipath redundant communication technology. Multipath QUIC, an extension of the QUIC protocol used as the lower layer of HTTP / 3, has also been proposed.

[0008] Furthermore, as a method for configuring a multipath redundant communication line using a mobile wireless communication network, a method using the mobile wireless communication networks of multiple different mobile network operators (MNOs) has been proposed (see, for example, Non-Patent Document 1). This makes it possible, for example, even if a handover occurs in wireless communication related to one MNO, to continue communication without a handover in wireless communication related to the other MNO. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Japanese Patent Publication No. 2023-141501 [Non-patent literature]

[0010] [Non-Patent Document 1] J. Nakazato et al., “Enhancing Real-Time Streaming Quality through a Multipath Redundant Communication Framework”, in Proc. The International Federation for Information Processing (IFIP) Networking 2024, Thessaloniki, Greece, June 2024. Summary of the Invention [Problem to be solved by the invention]

[0011] However, because MPTCP is a TCP-based protocol, it cannot be used for communication with applications that use UDP, for example. Furthermore, Multipath QUIC can only be used for communication with applications that were created with this protocol in mind. In other words, conventional multipath redundant communication protocols have the problem that their suitability depends on the application.

[0012] Furthermore, when actually providing a service related to multipath redundant communication to a customer, if the mobile wireless communication networks of multiple different MNOs are used as in the technology of Non-Patent Document 1, a problem may arise as to which MNO will be the main provider of the service. Furthermore, since one MNO cannot guarantee the communication quality of another MNO, a problem may arise regarding the guarantee of communication quality for the entire service related to multipath redundant communication.

[0013] In this regard, it is possible to configure a multipath redundant communication line with the same MNO. However, for example, multipath redundant communication in which two UEs (User Equipment) contracted with the same MNO transmit the same packets has the following problems.

[0014] For example, if an in-vehicle terminal is connected using two UEs in this way, there is a high possibility that the two UEs will be connected to the same base station, and there is a high possibility that handovers will occur simultaneously on two wireless communication paths. In this case, it becomes difficult to suppress deterioration in communication quality due to handovers using multipath redundant communication.

[0015] An object of one aspect of the present invention is to provide a technology that enables realization of multipath redundant communication that is application independent and achieves low latency and high reliability. [Means for solving the problem]

[0016] A transmitting device according to one embodiment of the present invention is a transmitting device that transmits packets via a mobile wireless communication network, and includes a frequency setting unit that sets the utilization frequencies, which are the frequencies that the wireless communication interfaces use to communicate with base stations of the mobile wireless communication network, to multiple wireless communication interfaces so that each frequency is different, and a packet sending unit that copies the same packet to generate at least two packets, adds an additional header to each packet, and sends the packets to each of the multiple wireless communication interfaces that are provided corresponding to the additional header.

[0017] A transmission method according to one embodiment of the present invention is a transmission method of a transmitting device that transmits packets via a mobile wireless communication network, and includes the steps of setting a usage frequency, which is a frequency that the wireless communication interface uses to communicate with a base station of the mobile wireless communication network, to a plurality of wireless communication interfaces so that each frequency is a different frequency, and duplicating the same packet to generate at least two packets, adding an additional header to each packet, and sending the packets to each of the plurality of wireless communication interfaces that are provided corresponding to the additional header.

[0018] A receiving device according to one embodiment of the present invention is a receiving device that receives packets via a mobile wireless communication network, and an additional header is added to the packets.The receiving device is equipped with a first output unit that uses a buffer that holds packets received within a predetermined period of time to select received packets one by one for each sequence number stored in the additional header and output them in the order of the sequence numbers, a second output unit that selects received packets one by one for each sequence number stored in the additional header and outputs them in the order they were received, and a setting reception unit that receives settings for operating either the first output unit or the second output unit.

[0019] A receiving method according to one embodiment of the present invention is a receiving method for a receiving device that receives packets via a mobile wireless communication network, wherein an additional header is added to the packets, and includes a setting reception step for receiving a setting for executing either a first output process or a second output process, wherein if a setting for executing the first output process is received in the setting reception step, a first output process is executed in which, using a buffer that holds packets received within a predetermined time, received packets are selected one by one for each sequence number stored in the additional header and output in the order of the sequence numbers, and if a setting for executing the second output process is received in the setting reception step, a second output process is executed in which received packets are selected one by one for each sequence number stored in the additional header and output in the order received.

[0020] Each aspect of the present invention may be realized by a computer. In this case, a program that causes a computer to execute each step of the above method, and a computer-readable recording medium on which the program is recorded, also fall within the scope of the present invention. [Effects of the Invention]

[0021] According to one aspect of the present invention, it is possible to provide a technology that enables realization of multipath redundant communication that achieves low latency and high reliability. [Brief explanation of the drawings]

[0022] [Figure 1] FIG. 1 is a diagram illustrating an example of a vehicle communication system. [Figure 2] FIG. 1 is a diagram illustrating an example of UE connections in a mobile radio communication network that employs Dual Connectivity. [Figure 3] 1 is a sequence chart illustrating an example of handover in a mobile wireless communication network that employs Dual Connectivity. [Figure 4] 1 is a diagram illustrating an example of the configuration of a transmission system according to a first embodiment of the present invention. [Figure 5] FIG. 5 is a block diagram showing an example of the configuration of the transmitting device shown in FIG. [Figure 6] FIG. 1 is a diagram illustrating, in table form, a list of radio wave frequencies that are allocated to a specific MNO and that can be used for wireless communication. [Figure 7] FIG. 10 is another diagram illustrating, in table form, a list of radio wave frequencies that are allocated to a specific MNO and that can be used for wireless communication. [Figure 8] FIG. 5 is a block diagram showing an example of the configuration of the receiving device shown in FIG. [Figure 9] 10A and 10B are diagrams illustrating the operation of a second output unit. [Figure 10] 10A and 10B are diagrams illustrating the operation of a first output unit. [Figure 11] 10 is a flowchart illustrating an example of the flow of a packet transmission process. [Figure 12] 10 is a flowchart illustrating an example of the flow of a packet reception process. [Figure 13] FIG. 10 is a diagram illustrating an example of the configuration of a transmission system according to a second embodiment of the present invention. [Figure 14] FIG. 14 is a block diagram showing an example of the configuration of the receiving device shown in FIG. [Figure 15] FIG. 10 is a diagram illustrating an example of the configuration of a transmission system according to a third embodiment of the present invention. [Figure 16] FIG. 10 is a block diagram showing an example of the configuration of a transmission / reception device according to a fourth embodiment of the present invention. [Figure 17] FIG. 10 is a diagram illustrating another example of the configuration of a transmission system according to the present invention. [Figure 18] FIG. 1 is a diagram illustrating an example of the configuration of a computer that executes instructions of a program, which is software that realizes each function. DETAILED DESCRIPTION OF THE INVENTION

[0023] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings. First, a vehicle communication system will be described.

[0024] (Vehicle communication system) 1 is a diagram showing an example of a vehicle communication system 10. In the figure, a vehicle 41 is equipped with an on-board communication device 50, which performs communication via a mobile wireless communication network such as a base station or a backbone communication network of a predetermined mobile network operator (MNO). In this example, base stations 21-1, 21-2, and 21-3 of the predetermined MNO are shown, and each base station is connected to a core network 22 of the predetermined MNO.

[0025] The in-vehicle communication device 50 has a wireless communication interface for communicating with each base station of a predetermined MNO. For example, the wireless communication interface may be UE (User Equipment).

[0026] In mobile communications, a base station communicates with UEs (User Equipment), which are terminal devices located within a cell that is a predetermined wireless communication area. In the example of Fig. 1, a cell 30-1 corresponding to base station 21-1, a cell 30-2 corresponding to base station 21-2, and a cell 30-3 corresponding to base station 21-3 are shown. In practice, one base station can communicate with several hundred UEs simultaneously.

[0027] Furthermore, the UE can be located in multiple cells at the same time, and in this example, the in-vehicle communication device 50 is located in both cell 30-1 and cell 30-3. In this case, the wireless communication network interface of the in-vehicle communication device 50 can communicate with the base station 21-1 as a Master Node (MN) and the base station 21-3 as a Secondary Node (SN).

[0028] The MN may be a base station for LTE communication, and the SN may be a base station for NR (5G) communication. The above-mentioned predetermined MNO is assumed to employ Dual Connectivity, a technology that enables communication via simultaneous connection with two base stations in the mobile wireless communication network in the vehicle communication system 10.

[0029] (Dual Connectivity) 2 is a diagram showing an example of UE connections in a mobile wireless communication network that employs Dual Connectivity. In the diagram, base station 21-1 is shown as MN, base station 21-3 is shown as SN, and core network 22 is shown as CN. In addition, the wireless communication interface of in-vehicle communication device 50 is shown as UE 51.

[0030] As described above, for example, MN is a base station for LTE communication, and SN is a base station for NR (5G) communication. In this case, the core network 22 is a core network that supports both LTE and 5G.

[0031] As shown in Fig. 2, UE 51 is wirelessly connected to both MN and SN, and MN and SN are connected to each other via an X2 interface or the like. U-Plane communication is performed between CN and SN, and C-Plane communication is mainly performed between CN and MN. The configuration shown in Fig. 2 is called SN terminated Split bearer.

[0032] For example, when a UE moves from a wireless communication area corresponding to one cell to a wireless communication area corresponding to another cell, a handover occurs. In the example of Figure 1, when a vehicle 41 moves from left to right in the figure and leaves cell 30-1, a handover occurs in which the MN changes from base station 21-1 to base station 21-2.

[0033] (Handover) 3 is a sequence chart illustrating an example of handover in a mobile wireless communication network that employs Dual Connectivity. Here, it is assumed that as vehicle 41 moves, the MN in the wireless communication of wireless communication interface (UE) 51 changes from base station 21-1 to base station 21-2. In this case, base station 21-1 is referred to as Source MN, and base station 21-2 is referred to as Target MN. It is assumed that base station 21-3, which is SN, continues to be connected to UE 51.

[0034] When the vehicle 41 moves and the strength of the radio wave received from the base station 21-1 decreases, the UE transmits a Messaging Report (Event A3) to the Source MN in step S21, which is received by the Source MN in step S41. This results in a handover request from the UE to the Source MN.

[0035] In step S42, the Source MN decides to execute the handover requested by the UE (HO decision in the figure). In step S43, the Source MN transmits an HO request to the Target MN, which receives it in step S61. In step S44, the Source MN executes Suspend DRB to suspend the DRB related to communication with the UE.

[0036] In step S62, the Target MN transmits an SN Addition Request to the SN, which is received by the SN in step S81. In step S82, the SN transmits an SN Addition Request Ack to the Target MN, which is received by the Target MN in step S63. This results in the reservation of resources in base station 21-3 as the SN corresponding to the Target MN. Furthermore, in step S64, the Target MN performs call admission control in communication with the UE (Admission Control in the figure).

[0037] In step S65, the Target MN transmits an HO request Ack to the Source MN, which is received by the Source MN in step S45.

[0038] In step S46, the Source MN sends an RRC Connection Reconfiguration (HO Command) to the UE, which is received by the UE in step S22.

[0039] In step S47, the Source MN sends an SN Release Request to the SN, which is received by the SN in step S83. In step S84, the SN executes Suspend DRB to suspend the DRB related to communication with the UE. As a result, the SN suspends U-Plane communication with the UE.

[0040] In step S85, the SN sends an SN Release Request Ack to the Source MN, which is received by the Source MN in step S48. In step S49, the Source MN sends a PDCP Serial Number to the Target MN, which is received by the Target MN in step S66.

[0041] In step S23, the UE executes "Detach Source MN" to release the connection with the Source MN. After the process of step S23 is completed, the MN Random Access Procedure is executed between the UE and the Target MN. Then, the MN Random Access Procedure is executed between the UE and the SN.

[0042] In step S24, the UE sends an RRC Reconfiguration Complete to the Target MN, which is received by the Target MN in step S67.

[0043] In step S68, the Target MN sends SN Reconfiguration Complete to the SN, which is received by the SN in step S86. In step S87, the SN executes Resume DRB to resume the DRB related to communication with the UE. This allows the SN to resume U-Plane communication with the UE.

[0044] In this way, when a handover occurs, U-Plane communication with the UE is stopped from the time Suspend DRB is executed in step S84 until Resume DRB is executed in step S87.

[0045] Such a communication interruption causes a delay spike associated with handover. That is, even in a mobile wireless communication network that employs Dual Connectivity, the occurrence of a delay spike associated with handover cannot be avoided because U-Plane communication in the SN is interrupted when an MN handover occurs.

[0046] If a radio link failure occurs during handover from base station 21-1 to base station 21-2, the handover fails, but the UE must reconnect via RRC, which again causes a stop of U-Plane communication in the SN. This also results in a delay spike associated with the handover.

[0047] To avoid such delay spikes due to handover, a method of transmitting the same information (packets) using two UEs can be considered. In this way, even if a handover occurs in one UE, the other UE can continue communication, thereby avoiding the occurrence of delay spikes due to handover. For example, it seems that delay spikes due to handover can be avoided by using multipath redundant communication, in which two UEs (User Equipment) contracted with the same MNO transmit the same packets.

[0048] However, for example, if the in-vehicle communication device 50 is configured using two UEs in this way, there is a high possibility that the two UEs will actually be connected to the same base station, and there is a high possibility that handovers will occur simultaneously on two wireless communication paths. In this case, it becomes difficult to avoid the occurrence of delay spikes associated with handovers due to multipath redundant communication.

[0049] In this regard, for example, multipath redundant communication, in which two UEs (User Equipment) contracted with different MNOs transmit the same packets, can be considered to reduce the possibility of simultaneous handovers occurring on two wireless communication paths. However, when using mobile wireless communication networks of different MNOs, it can be problematic to determine which MNO will be the entity providing the service. Furthermore, since one MNO cannot guarantee the communication quality of the other MNO, problems can arise regarding the guarantee of communication quality for the entire service related to multipath redundant communication.

[0050] (First embodiment) A first embodiment of the present invention will be described below.

[0051] (Example of transmission system configuration) Fig. 4 is a diagram illustrating an example of the configuration of a transmission system according to a first embodiment of the present invention. The transmission system 100 shown in the figure includes a transmitting device 120 that transmits packets via a mobile wireless communication network connected by multiple wireless communication interfaces, and a receiving device 220 that is connected to an external network such as the Internet 200 and receives the packets transmitted from the transmitting device 120 via the mobile wireless communication network. A packet 111 transmitted from a packet transceiver 101 is received by a packet transceiver 241 via the mobile wireless communication network and the Internet 200. The transmission system 100 of Fig. 4 is applied to, for example, vehicle-to-network (V2N) communications between a vehicle and a network.

[0052] In the example of Figure 4, base station 161-1 and base station 161-2 are shown as base stations of the mobile wireless communication network, and core network 180 is shown as the core network of the mobile wireless communication network. Core network 180 may be a core network (EPC) that supports LTE, or a core network (5GC) that supports 5G. Alternatively, core network 180 may be a core network that supports both LTE and 5G. Note that the mobile wireless communication network in Figure 4 is operated by a single MNO.

[0053] The packet transceiver 101 generates and outputs packets to be transmitted. The packet transceiver 101 may be, for example, a sensor device that packetizes a detection signal from a sensor. Alternatively, the packet transceiver 101 may be a personal computer, a smartphone, or the like. The packet 111 output from the packet transceiver 101 is supplied to the transmitting device 120.

[0054] The transmitting device 120 copies the packet 111 supplied from the packet transceiver 101 to generate two packets 111. The transmitting device 120 adds an additional header to each of the two packets 111. In the example of FIG. 4, an additional header PHA is added to one packet 111, and an additional header PHB is added to the other packet 111. The additional header PHA and the additional header PHB are each a network layer header. As an example, the additional header PHA and the additional header PHB each include an IP address.

[0055] Also, as an example, the additional headers PHA and PHB each include a sequence number. The sequence number is a number that indicates the transmission order of the packets. For example, when packets are output from the packet transceiver 101 in the order of packet 111-1, packet 111-2, packet 111-3, ..., packet 111-N, the additional headers PHA and PHB added to packet 111-1 store the sequence number 1. The additional headers PHA and PHB added to packet 111-2 store the sequence number 2, the additional headers PHA and PHB added to packet 111-3 store the sequence number 3, and the additional headers PHA and PHB added to packet 111-N store the sequence number N, etc.

[0056] In this way, a sequence number indicating the transmission order of the packet is stored in the additional header, and packets having additional headers storing the same sequence number are generated in the same number as the wireless communication interfaces (e.g., modem 141-1, modem 141-2, etc.) described below.

[0057] Additionally, a timestamp for delay measurement may be stored in the additional header.

[0058] The transmitting device 120 is connected to modems 141-1 and 141-2. The modems 141-1 and 141-2 have wireless communication interfaces for wireless communication with base stations of a mobile wireless communication network. Each of the modems 141-1 and 141-2 may be configured by, for example, a mobile router, a smartphone, or the like. However, unlike general mobile routers, smartphones, and the like, each of the modems 141-1 and 141-2 has a frequency (usage frequency described later) used for wireless communication with a base station of the mobile wireless communication network controlled by the transmitting device 120. Each of the modems 141-1 and 141-2 may be a UE.

[0059] Packet 111 to which an additional header has been added by transmitting device 120 is supplied to modem 141-1 and modem 141-2. Modem 141-1 performs wireless communication with base station 161-1 using a first frequency used. Modem 141-2 performs wireless communication with base station 161-2 using a second frequency used. In this way, the packets transmitted from modem 141-1 and modem 141-2 are sent to core network 180 of the mobile wireless communication network via base station 161-1 and base station 161-2, respectively.

[0060] The core network 180 is connected to the Internet 200 via a network function unit such as a network exposure function (NEF) (not shown). In the example of Fig. 4, a router 201 of the Internet 200 is connected to the core network 180. A packet 111 with an additional header PHA added and a packet 111 with an additional header PHB added are each sent from the core network 180 to the router 201. These packets are then routed within the Internet 200 to reach the router 202.

[0061] A receiving device 220 is connected to the router 202, and the packet 111 with the additional header PHA added and the packet 111 with the additional header PHB added are each sent to the receiving device 220. The receiving device 220 refers to the information stored in the additional header PHA and the additional header PHB, and selects one of the packets 111 having the same sequence number.

[0062] In principle, the receiving device 220 selects the packet 111 that is received first from the packet 111 with the additional header PHA added and the packet 111 with the additional header PHB added. Naturally, if there is only one packet 111 with the same sequence number due to packet loss within the mobile wireless communication network or the Internet 200, the packet 111 selected by the receiving device 220 will be the packet 111 that has not been lost.

[0063] The receiving device 220 removes the additional header from the selected packet 111 and supplies the packet to the packet transceiver 241. In this way, the packet transceiver 241 receives the packet 111 transmitted from the packet transceiver 101. Furthermore, as will be described later, the receiving device 220 reorders the received packet as necessary, removes the additional header, and supplies the packet to the packet transceiver 241.

[0064] In this way, in the transmission system 100 according to this embodiment, the packet 111 is transmitted via a wireless communication path via the modem 141-1 and the base station 161-1, and a wireless communication path via the modem 141-2 and the base station 161-2, thereby performing multipath redundant communication. This makes it extremely unlikely that handovers will occur simultaneously on two paths, and makes it possible to avoid delay spikes that accompany handovers.

[0065] 4, the transmitting device 120 and the receiving device 220 are connected via a VPN (Virtual Private Network) before communication between the packet transceiver 101 and the packet transceiver 241 is started. Separate IP addresses are assigned to the communication port connected to the modem 141-1 of the transmitting device 120 and the communication port connected to the modem 141-2 of the transmitting device 120. A VPN connection is established using these IP addresses and an IP address assigned to the communication port connected to the router 202 of the receiving device 220.

[0066] 4, a first virtual private line 151-1 is established between modem 141-1 (more precisely, a communication port of transmitting device 120) and a communication port connected to router 202 of receiving device 220. A second virtual private line 151-2 is established between modem 141-2 (more precisely, a communication port of transmitting device 120) and a communication port connected to router 202 of receiving device 220.

[0067] If the modems 141-1 and 141-2 have different IP addresses, the modems 141-1 and 141-2 may be the terminations of the first virtual private line 151-1 and the second virtual private line 151-2 relating to the VPN connection.

[0068] In the example of Figure 4, packet 111 with additional header PHA added is transmitted using the first virtual private line 151-1, and packet 111 with additional header PHB added is transmitted using the second virtual private line 151-2.

[0069] Here, an example has been described in which a virtual private line network consisting of virtual private lines 151-1 and 151-2 is configured between one transmitting device 120 and one receiving device 220. However, for example, a virtual private line network may be configured between a plurality of transmitting devices 120 and one receiving device 220. In other words, a star-shaped virtual private line network may be configured between the transmitting device 120 and the receiving device 220.

[0070] In this way, in the transmission system 100 according to this embodiment, the two paths are configured by the mobile radio communication network of the same MNO, which makes it possible to guarantee the communication quality of the entire service related to the multipath redundant communication.

[0071] (Example of transmitter configuration) Fig. 5 is a block diagram showing an example of the configuration of transmission device 120 shown in Fig. 4. As shown in the figure, transmission device 120 includes frequency setting unit 121 and packet sending unit 122. Note that modems 141-1 and 141-2 may be configured as an integrated unit in transmission device 120.

[0072] The frequency setting unit 121 sets the frequencies used by the multiple wireless communication interfaces for communication with base stations of the mobile wireless communication network to different frequencies for each of the multiple wireless communication interfaces.

[0073] The packet sending unit 122 copies the same packet to generate at least two packets, adds an additional header to each packet, and sends the packets to a plurality of wireless communication interfaces provided corresponding to the additional headers.

[0074] (Frequency setting section) In the example of FIG. 5, the frequency setting unit 121 includes a modem control unit 131 and a usage frequency information storage unit 132.

[0075] Each of the above-mentioned multiple wireless communication interfaces communicates with multiple base stations in the mobile wireless communication network of the same mobile communication operator, and the frequency setting unit 121 limits the candidate utilization frequencies selectable by each wireless communication interface, thereby making the utilization frequency of one wireless communication interface different from the utilization frequencies of other wireless communication interfaces. Note that the utilization frequency may be, for example, the center frequency of one component carrier.

[0076] (Modem control unit) The modem control unit 131 controls the modems 141-1 and 141-2, each having a wireless communication interface, by referring to information stored in the frequency usage information storage unit 132. As an example, the modem control unit 131 issues an AT command to limit the candidate frequencies that are the targets of a cell search or an SSB search when the modems 141-1 and 141-2 are started up.

[0077] (Used frequency information storage unit) The utilization frequency information storage unit 132 stores information related to frequencies that can be used by a UE for communication with a base station of a mobile wireless communication network in a specific MNO. Details of the information stored in the utilization frequency information storage unit 132 will be described later.

[0078] (Packet sending part) In the example of FIG. 5, the packet sending unit 122 includes a packet replicating unit 133, an additional header control unit 134, and a sending unit 135.

[0079] (Packet duplication unit) The packet replicating unit 133, for example, replicates the packet 111 supplied from the packet transceiver 101 to generate two packets 111. The packet 111 is a network layer packet. As an example, the packet 111 may be an IP packet.

[0080] (Additional header control section) The additional header control unit 134 controls, for example, the processes related to the generation and addition of additional headers for each of the two packets 111. For example, the additional header control unit 134 adds an additional header PHA to one packet 111 and an additional header PHB to the other packet 111. The additional headers are generated corresponding to the respective wireless communication interfaces related to the transmission of the packets. In this case, modems 141-1 and 141-2 are provided as wireless communication interfaces, so two types of additional headers (additional header PHA and additional header PHB) are generated.

[0081] The additional headers PHA and PHB are each a network layer header, and as an example, each of the additional headers PHA and PHB includes an IP address. Also, as an example, each of the additional headers PHA and PHB includes a sequence number. The sequence number indicates the order in which the packets are transmitted, and as described above, may be a number added to each packet supplied from the packet transceiver 101 in the order in which they are supplied. Furthermore, a timestamp for measuring delay may be stored in the additional header.

[0082] Although the example in which the additional header control unit 134 is provided in the transmitting device 120 has been described above, the additional header control unit 134 may be provided in each of the modem 141-1 and the modem 141-2. In this case, one of the two packets 111 generated through processing by the packet duplication unit 133 is supplied to the communication port to which the modem 141-1 is connected, and the other is supplied to the communication port to which the modem 141-2 is connected. Then, the modem 141-1 may add the additional header PHA to the packet 111, and the modem 141-2 may add the additional header PHB to the packet 111.

[0083] Alternatively, for example, modem 141-1 may store predetermined header information (first header information) in the additional header added by additional header control unit 134 of transmitting device 120, thereby transmitting packet 111 with additional header PHA added, and modem 141-2 may store different header information (second header information) in the additional header added by additional header control unit 134 of transmitting device 120, thereby transmitting packet 111 with additional header PHB added.

[0084] In this case, the additional header control unit 134 of the transmitting device 120 adds an additional header storing the same sequence number to each of the two packets 111 generated by the packet replicating unit 133 .

[0085] In this way, the network layer packet is duplicated and a network layer header is added (encapsulated), so that the transmission system 100 can be used whether the communication between the packet transceiver 101 and the packet transceiver 241 uses TCP or UDP.

[0086] (Transmission section) The sending unit 135 supplies the packet with the additional header added to a wireless communication interface corresponding to the added additional header. For example, the sending unit 135 supplies the packet 111 with the additional header PHA added to the modem 141-1, and supplies the packet 111 with the additional header PHB added to the modem 141-2.

[0087] (Information stored in the usage frequency information storage unit 132) Next, examples of information stored in the utilization frequency information storage unit 132 will be described with reference to FIGS.

[0088] The Third Generation Partnership Project (3GPP) specifies the frequency bands for high-frequency signals used in Time Division Duplex (TDD) and Frequency Division Duplex (FDD). Furthermore, from these frequency bands, a frequency band is allocated to each of multiple MNOs, and communication services provided by each MNO are provided using the allocated frequency band.

[0089] The allocated frequency bands are distinguished by the symbols used by 3GPP to represent the frequency bands (herein referred to as "3GPP bands"). For example, for 5G smartphones for use in Japan, "n1," "n3," "n28," "n41," "n77," "n78," "n79," and "n257" are allocated for 5G communications. Furthermore, "B1," "B3," "B8," "B18," "B19," "B21," "B26," "B28," "B41," and "B42" are allocated for LTE communications.

[0090] Fig. 6 is a diagram illustrating, in table format, a list of radio wave frequencies that are allocated to a specific MNO (e.g., MNO#1) and that can be used for wireless communication. The table in Fig. 6 shows radio wave frequencies that can be used in LTE communication, and all columns labeled "RAT (Radio Access Technology)" state LTE.

[0091] In the table of FIG. 6, the column marked "Duplex" contains information indicating the duplexing method, and FDD and TDD are listed. In the table of FIG. 6, the column marked "Frequency band" contains frequency bands such as the 2.1 GHz band, the 1.7 GHz band, the 900 MHz band, and so on. In the table of FIG. 6, the column marked "3GPP band" contains symbols representing the frequency bands used in 3GPP. That is, the 2.1 GHz band is listed as "B1," the 1.7 GHz band as "B3," the 900 MHz band as "B8," and so on.

[0092] In addition, the column labeled "Cell Search Target Information" in the table of Figure 6 contains information used by the UE when performing a cell search. The column labeled "Cell Search Target Information" is divided into a column labeled "Center Frequency" and a column labeled "EARFCN (E-UTRAN Absolute radio-frequency channel number)," each of which contains the center frequency and the absolute radio frequency channel number (ARFCN).

[0093] The center frequencies listed here are the center frequencies of the component carriers for the downlink (DL), but the center frequencies of the component carriers for the uplink (UL) are uniquely determined corresponding to the center frequencies for the DL. In the table of Figure 6, the column labeled "Bandwidth" lists the bandwidths corresponding to each EARFCN.

[0094] Fig. 7 is a diagram showing another example of information stored in the utilization frequency information storage unit 132. Fig. 7 is a diagram showing an example of a list of radio wave frequencies that are allocated to a specific MNO (e.g., MNO #1) and can be used for wireless communication, in tabular form. The table in Fig. 7 shows radio wave frequencies that can be used in 5G communication (NR), and all columns marked "RAT" are marked with "NR."

[0095] In the table of FIG. 7, the column marked "Duplex" contains information indicating the duplexing method, and FDD and TDD are listed. In the table of FIG. 7, the column marked "Frequency band" contains frequency bands such as the 1.7 GHz band, the 700 MHz band, the 3.4 GHz band, etc. In the table of FIG. 7, the column marked "3GPP band" contains symbols that identify the frequency bands used in 3GPP. That is, the 1.7 GHz band is listed as "n3," the 700 MHz band as "n28," the 3.4 GHz band as "n77," etc.

[0096] In the table of Figure 7, the column labeled "SSB Frequency Information" indicates information for searching for an SSB (Synchronization Signal Block) when a UE connects to a base station, and is divided into "Frequency," "GSCN," and "SSB-ARFCN." The column labeled "GSCN" contains a symbol that identifies the frequency of the synchronization raster position to be searched next when searching for an SSB, and the column labeled "Frequency" contains the frequency corresponding to that GSCN. The column labeled "SSB-ARFCN" contains the absolute radio frequency channel number (ARFCN) that identifies that frequency.

[0097] In the table of Fig. 7, the column marked "DL Radio License Information" is divided into a column for "Bandwidth," a column for "Center Frequency," and a column for "NR-ARFCN." The "NR-ARFCN" column lists an absolute radio frequency channel number, the "Center Frequency" column lists the frequency identified by the absolute radio frequency channel number, and the "Bandwidth" column lists the bandwidth of the component carrier having the center frequency.

[0098] 6 and 7 is stored in the utilization frequency information storage unit 132. Here, an example has been described in which information on radio wave frequencies that are allocated to one MNO (MNO#1) and that can be used for wireless communication is stored in the utilization frequency information storage unit 132. However, for example, if the user of the transmitting device 120 has contracts with multiple MNOs, information on frequencies allocated to multiple MNOs (MNO#1, MNO#2, . . .) may be stored in the utilization frequency information storage unit 132.

[0099] (Setting of frequency to be used) As described above, the modem control unit 131 issues an AT command, for example, to set the utilization frequencies, which are the frequencies used for communication with base stations of a mobile wireless communication network, to the modems 141-1 and 141-2. Note that if the utilization frequencies of the modems 141-1 and 141-2 are different, it is highly likely that the base station to which the modems 141-1 and 141-2 are connected will be different. Therefore, by making the utilization frequencies of the modems 141-1 and 141-2 different, it is possible to avoid the occurrence of delay spikes associated with handover.

[0100] The modem control unit 131, for example, limits the component carriers that can be searched at the time of startup in each of the modems 141-1 and 141-2, so that the frequency used by the modem 141-1 and the frequency used by the modem 141-2 are different.

[0101] (Selection of frequency for each RAT) The modem control unit 131 may, for example, control the modem 141-1 to select a utilization frequency from among the radio wave frequencies available for LTE communication shown in Fig. 6. The modem control unit 131 may then control the modem 141-2 to select a utilization frequency from among the radio wave frequencies available for 5G communication shown in Fig. 7. That is, the modem control unit 131 may control the modem 141-1 and the modem 141-2 so that the "RAT" (for example, LTE) associated with the utilization frequency of the modem 141-1 and the "RAT" (for example, NR) associated with the utilization frequency of the modem 141-2 are different from each other.

[0102] In this case, the modem control unit 131 sets the startup configuration information of the modem 141-1 so that when the modem 141-1 performs a cell search, only the frequency bands corresponding to the symbols in the "3GPP band" column shown in Fig. 6 can be searched. This limits the frequency bands that are the targets of the cell search when the modem 141-1 is started up.

[0103] Furthermore, the modem control unit 131 sets the startup configuration information of the modem 141-2 so that when the modem 141-2 performs an SSB search, only the frequency bands corresponding to the symbols in the "3GPP band" column shown in Fig. 7 can be searched. This limits the frequency bands that are the targets of the SSB search when the modem 141-2 starts up.

[0104] That is, the modem control unit 131 of the frequency setting unit 121 restricts the candidate utilization frequencies of the individual wireless communication interfaces to utilization frequencies included in frequency bands used by different RATs (Radio Access Technologies).

[0105] In this case, the utilization frequency (center frequency of the component carrier) actually used by modem 141-1 is determined by a search by modem 141-1, and a utilization frequency included in the frequency band used for LTE communication (first RAT) is set in modem 141-1. Also, the utilization frequency actually used by modem 141-2 is determined by a search by modem 141-2, and a utilization frequency included in the frequency band used for 5G communication (second RAT) is set in modem 141-2.

[0106] (Select the frequency to be used in 3GPP band units) Furthermore, the modem control unit 131 may, for example, control the modem 141-1 to select a utilization frequency included in the first "3GPP band" from the available radio wave frequencies shown in Figures 6 and 7. Then, the modem control unit 131 may control the modem 141-2 to select a utilization frequency included in the second "3GPP band" from the available radio wave frequencies shown in Figures 6 and 7. That is, the modem control unit 131 may control the modems 141-1 and 141-2 so that the "3GPP band" related to the utilization frequency of the modem 141-1 and the "3GPP band" related to the utilization frequency of the modem 141-2 are different from each other. In this case, the "RAT" may be the same.

[0107] For example, the first and second "3GPP bands" may be B1 and B3, or B41 and B42, respectively. Also, the first and second "3GPP bands" may be n3 and n28, or n77 and n257, respectively. Furthermore, the first and second "3GPP bands" may be B1 and n28, or n77 and B41, respectively.

[0108] In this case, modem control unit 131 sets the startup configuration information of modem 141-1 so that when modem 141-1 performs a cell search or SSB search, only the frequencies listed in the "center frequency" or "frequency" column corresponding to the first "3GPP band" can be searched. This limits the frequency bands that are the targets for a cell search or SSB search when modem 141-1 starts up.

[0109] Furthermore, the modem control unit 131 sets the startup configuration information of the modem 141-2 so that when the modem 141-2 performs a cell search or an SSB search, only the frequencies listed in the "center frequency" or "frequency" column corresponding to the second "3GPP band" can be searched. This limits the frequency bands that are the targets for the cell search or SSB search when the modem 141-2 starts up.

[0110] That is, the modem control unit 131 of the frequency setting unit 121 restricts the candidate frequencies for use by each wireless communication interface to be 3GPP bands defined by 3GPP and included in different 3GPP bands.

[0111] In this case, the frequency (center frequency of the component carrier) actually used by modem 141-1 is determined by a search by modem 141-1, and a frequency included in the frequency band corresponding to the first "3GPP band" is set for modem 141-1. Also, the frequency actually used by modem 141-2 is determined by a search by modem 141-2, and a frequency included in the frequency band corresponding to the second "3GPP band" is set for modem 141-2.

[0112] (Selection of frequency for each component carrier) Furthermore, the modem control unit 131 may, for example, control the modem 141-1 to select a utilization frequency corresponding to a component carrier having a first center frequency from the available radio wave frequencies shown in Figures 6 and 7. Then, the modem control unit 131 may control the modem 141-2 to select a utilization frequency corresponding to a component carrier having a second center frequency from the available radio wave frequencies shown in Figures 6 and 7. That is, the modem control unit 131 may control the modem 141-1 and the modem 141-2 so that the component carrier associated with the utilization frequency of the modem 141-1 and the component carrier associated with the utilization frequency of the modem 141-2 are different from each other. In this case, the "RAT" may be the same, and the "3GPP band" may be the same.

[0113] In this case, modem control unit 131 sets configuration information and the like at startup of modem 141-1 so that when modem 141-1 performs a cell search or SSB search, only the first frequency listed in the "center frequency" or "frequency" column can be searched. This limits the EARFCNs or SSB-ARFCNs that are targets for a cell search or SSB search when modem 141-1 starts up.

[0114] Furthermore, modem control unit 131 sets configuration information and the like at startup of modem 141-2 so that when modem 141-2 performs a cell search or SSB search, only the second frequency listed in the "center frequency" or "frequency" column can be searched. This limits the EARFCNs or SSB-ARFCNs that are targets for a cell search or SSB search when modem 141-2 starts up.

[0115] Note that component carriers can be individually identified by "EARFCN" in Fig. 6 or "NR-ARFCN" in Fig. 7. Therefore, selection of a utilization frequency in component carrier units can also be said to be selection of a utilization frequency in ARFCN units.

[0116] Here, an example has been described in which modem 141-1 and modem 141-2 are each made to select a utilization frequency corresponding to one component carrier. However, for example, modem 141-1 and modem 141-2 may each be given two, three, etc. component carrier candidates and made to select one from among them.

[0117] That is, the modem control unit 131 of the frequency setting unit 121 restricts the candidate utilization frequencies of the individual wireless communication interfaces to utilization frequencies corresponding to different component carriers.

[0118] (Another example of frequency selection) (Frequency selection based on priority) For example, when a utilization frequency is selected for each RAT, frequency bands corresponding to multiple 3GPP bands are searched. In such a case, for example, information indicating the priority order of the frequency bands to be searched may be stored in the utilization frequency information storage unit 132.

[0119] Similarly, when the frequency to be used is selected in 3GPP band units, the center frequency to be searched for in the cell search or information indicating the priority of the SSB frequency may be stored in the frequency to be used information storage unit 132.

[0120] For example, when the modem control unit 131 sets the startup configuration information of the modems 141-1 and 141-2, the startup configuration information may be set so that a search is performed according to information indicating priority.

[0121] In this way, the frequency setting unit 121 may further set the priority order in which the wireless communication interface should select from among the candidate frequencies used by each wireless communication interface.

[0122] (Exclude certain frequencies from selection) Furthermore, if an MNO adopts Dynamic Spectrum Sharing (DSS), it may avoid selecting the center frequency of a component carrier that is subject to DSS (Dynamic Spectrum Sharing) as a frequency to be used. DSS is a technology for introducing 5G into part or all of the frequency band used by LTE. In cases where an NR system operates in the same band as an existing LTE system, DSS may be adopted to allow the existing LTE system and NR (5G) system to coexist in the same band in order to improve frequency utilization efficiency.

[0123] For example, consider a case where modem 141-1 selects a frequency to be used from among radio wave frequencies available for LTE communication, and modem 141-2 selects a frequency to be used from among radio wave frequencies available for LTE communication. If the frequencies determined as a result of searches by modem 141-1 and modem 141-2 are subject to DSS, there is a possibility that the ranges defined by the minimum and maximum frequencies of the component carriers corresponding to the frequencies to be used will partially overlap, even if the RATs are different. If the frequency ranges of the component carriers partially overlap, there is a high possibility that modem 141-1 and modem 141-2 will be connected to the same base station, making it difficult to avoid the occurrence of delay spikes associated with handover.

[0124] For this reason, for example, the component carriers that are the target of DSS may be set to be excluded from the search targets. For example, the frequency usage information storage unit 132 may store information indicating the center frequencies that are the target of cell search or the SSB frequencies that cannot be searched.

[0125] For example, when the modem control unit 131 sets the startup configuration information of the modems 141-1 and 141-2, the startup configuration information may be set so that certain frequencies in use are excluded from the search targets in accordance with information indicating what cannot be searched.

[0126] In this way, the frequency setting unit 121 may further set utilization frequencies that should be excluded from selection by the wireless communication interface from among the utilization frequency candidates of the individual wireless communication interfaces.

[0127] (Example of receiving device configuration) Fig. 8 is a block diagram showing an example of the configuration of the receiving device 220 shown in Fig. 4. As shown in the figure, the receiving device 220 includes a buffer 221, a first output unit 222, a second output unit 223, and a setting receiving unit 224.

[0128] The buffer 221 holds packets received within a predetermined time period.

[0129] The first output unit 222 uses the buffer 221 to select the received packets one by one for each sequence number stored in the additional header, remove the additional header from the selected packets, and output them in the order of sequence numbers.

[0130] The second output unit 223 selects the received packets one by one for each sequence number stored in the additional header, removes the additional headers from the selected packets, and outputs them in the order they were received. Note that the second output unit 223 selects the received packets one by one for each sequence number and outputs them in the order they were received without using the buffer 221.

[0131] The setting receiving unit 224 receives a setting for operating either the first output unit 222 or the second output unit 223.

[0132] (Operation of the first output unit and the second output unit) 9 and 10 are diagrams illustrating the operations of the first output section 222 and the second output section 223. First, the operation of the second output section 223 will be described with reference to FIG.

[0133] 9, A, B, and C enclosed in rectangles each represent a packet. As described above, packets are duplicated and transmitted in transmitting device 120, so the figure shows two packets A, two packets B, and two packets C. It is assumed that transmitting device 120 transmits packets in the order of packet A, packet B, and packet C.

[0134] As shown in Fig. 9, packets transmitted via two paths are input to second output unit 223. Here, for convenience, input path 223a and input path 223b are shown, and packet A, packet B, and packet C are input from each input path. Also, in Fig. 9, packet B on input path 223a is indicated by a dotted rectangle and an "X" symbol. This indicates that packet B on input path 223a, which should have been received, has been lost somewhere on the path from transmitting device 120 to receiving device 220.

[0135] In practice, it is not necessary to physically separate the input paths, but it is sufficient to distinguish between packets received via the first virtual private line 151-1 and packets received via the second virtual private line 151-2. For example, the input path may be identified by an additional header of a packet transmitted from the transmitting device 120.

[0136] For example, input path 223a indicates the time series of packets (packets with additional header PHA added) received via the first virtual private line 151-1 received by the receiving device 220, and input path 223b indicates the time series of packets (packets with additional header PHB added) received via the second virtual private line 151-2 received by the receiving device 220. The packets displayed on the right side of the figure are the packets received first, and the packets displayed on the left side of the figure are the packets received later.

[0137] In the example of Figure 9, since the packet with the additional header PHA added is received before the packet with the additional header PHB added, each packet is input to the second output unit 223 from input path 223a first, and each packet is input to the second output unit 223 from input path 223b after each packet from input path 223a.

[0138] 9, for convenience, output path 223c is shown, and second output unit 223 outputs packets to output path 223c. When outputting packets to output path 223c, second output unit 223 removes the additional header. Note that the packet displayed on the right in the figure is the packet that was output first, and the packet displayed on the left in the figure is the packet that was output later.

[0139] The second output unit 223 identifies the sequence number of each packet by referring to the additional headers of packet A, packet B, and packet C input from the respective input paths. Since the transmitting device 120 transmits packets in the order of packet A, packet B, and packet C, the sequence number of packet A is assumed to be 1, the sequence number of packet B is assumed to be 2, and the sequence number of packet C is assumed to be 3.

[0140] 9 shows four second output units 223, and the states of the second output units 223 over time are shown in order from top to bottom. For example, in the state of the topmost second output unit 223 in the figure, neither packets from input path 223a nor packets from input path 223b have yet been input to the second output unit 223.

[0141] The second output unit 223 outputs packet A, which was initially input on input path 223a, to output path 223c (the state of the second output unit 223 from the top in the figure). At this time, the second output unit 223 stores in a memory (not shown) or the like that the packet with sequence number 1 has been output.

[0142] Next, packet A is input to the second output unit 223 from input path 223b, but since the packet with sequence number 1 has already been output, the second output unit 223 discards packet A from input path 223b without outputting it.

[0143] Thereafter, packet C is input to second output unit 223 from input path 223a (state of second output unit 223, third from the top in the figure). Second output unit 223 outputs packet C from input path 223a to output path 223c. At this time, second output unit 223 stores in a memory (not shown) or the like that the packet with sequence number 3 has been output.

[0144] Thereafter, packet B is input from input path 223b to second output unit 223. Second output unit 223 outputs packet B from input path 223b to output path 223c (state of second output unit 223 at the bottom in the figure). At this time, second output unit 223 stores in a memory (not shown) or the like that the packet with sequence number 2 has been output.

[0145] Thereafter, packet C is input to the second output unit 223 from input path 223b, but since the packet with sequence number 3 has already been output, the second output unit 223 discards packet C from input path 223b without outputting it.

[0146] In this way, packets are output to output path 223c in the order of packet A on input path 223a, packet C on input path 223a, and packet B on input path 223b. Therefore, the packets transmitted from packet transceiver 101 are supplied to packet transceiver 241 connected to receiving device 220 in the order of packet A, packet C, and packet B. In this case, packet transceiver 241 needs to perform reordering to swap the order of packet C and packet B as necessary.

[0147] Next, the operation of the first output unit 222 will be described with reference to Fig. 10. In the first output unit 222, reordering using the buffer 221 is executed.

[0148] 10, similar to FIG. 9, A, B, and C enclosed in rectangles each represent a packet. Also, as shown in FIG. 10, packets transmitted via two paths are input to first output unit 222. Here, for convenience, input path 222a and input path 222b are shown, and packet A, packet B, and packet C are input from each input path, respectively, but packet B on input path 222a, which should have been received, is assumed to have been lost somewhere along the path from transmitting device 120 to receiving device 220.

[0149] For example, input path 222a shows the time series in which packets with an additional header PHA added are received by the receiving device 220, and input path 222b shows the time series in which packets with an additional header PHB added are received by the receiving device 220. Note that the packets displayed on the right side of the figure are packets received first, and the packets displayed on the left side of the figure are packets received later.

[0150] In the case of Figure 10, as in Figure 9, packets with additional header PHA added are received before packets with additional header PHB added, and each packet is input to the first output unit 222 from input path 222a first, and each packet is input to the first output unit 222 from input path 222b after each packet from input path 222a.

[0151] 10, for convenience, output path 222c is shown, and first output unit 222 outputs packets to output path 222c. When outputting packets to output path 222c, first output unit 222 removes the additional header. Note that the packet displayed on the right in the figure is the packet that was output first, and the packet displayed on the left in the figure is the packet that was output later.

[0152] The first output unit 222 identifies the sequence number of each packet by referring to the additional headers of packet A, packet B, and packet C that are input from the respective input paths. Since the transmitting device 120 transmits packets in the order of packet A, packet B, and packet C, the sequence number of packet A is assumed to be 1, the sequence number of packet B is assumed to be 2, and the sequence number of packet C is assumed to be 3.

[0153] In FIG. 10, two first output units 222 are shown, and the states of the first output units 222 over time are shown in order from top to bottom.

[0154] The first output unit 222 outputs packet A, which was initially input on input path 222a, to output path 222c. At this time, the first output unit 222 stores in a memory (not shown) or the like that the packet with sequence number 1 has already been output.

[0155] Next, packet A is input to the first output unit 222 from input path 222b, but since the packet with sequence number 1 has already been output, the first output unit 222 discards packet A from input path 222b without outputting it.

[0156] Thereafter, packet C is input from input path 222a to first output unit 222. At this time, first output unit 222 holds packet C with sequence number 3 in buffer 221 because the packet with sequence number 2 has not been output (state of first output unit 222 at the top in the figure).

[0157] Thereafter, packet B is input from input path 222b to first output unit 222. First output unit 222 outputs packet B from input path 222b to output path 222c. At this time, first output unit 222 stores in a memory (not shown) or the like that the packet with sequence number 2 has been output.

[0158] Thereafter, the first output unit 222 outputs packet C on the input path 222a, which has been held in the buffer 221, to the output path 222c. At this time, the first output unit 222 stores in a memory (not shown) or the like that the packet with sequence number 3 has been output.

[0159] Thereafter, packet C is input to the first output unit 222 from input path 222b, but since the packet with sequence number 3 has already been output, the first output unit 222 discards packet C from input path 222b without outputting it (state of the first output unit 222 at the bottom of the figure).

[0160] In this way, packets are output to output path 222c in the order of packet A on input path 222a, packet B on input path 222b, and packet C on input path 222a. Therefore, the packets transmitted from packet transceiver 101 are supplied to packet transceiver 241 connected to receiving device 220 in the order of packet A, packet B, and packet C. In this case, reordering is performed in receiving device 220, and there is no need for packet transceiver 241 to perform reordering.

[0161] The time that buffer 221 can hold a packet is predetermined, and if, for example, packet B on input path 222b cannot be received within this time, packet B is considered to be lost, and, for example, it may be stored in a memory (not shown) or the like as a pseudo-information that packet with sequence number 2 has already been output.

[0162] When the receiving device 220 detects the loss of packet B, the receiving device 220 may notify the packet transceiver 241 of the loss of packet B. In this case, the packet transceiver 241 may request the packet transceiver 101 to retransmit packet B.

[0163] Furthermore, when receiving device 220 detects the loss of packet B, receiving device 220 may notify transmitting device 120 of the loss of the packet with sequence number 2 and a retransmission request.

[0164] In this way, the first output unit 222 can perform reordering to change the order of packets using the buffer 221. For example, in an application such as WebRTC (Web Real-Time Communication), performing reordering can improve the quality of communication in the application.

[0165] On the other hand, when reordering is performed, overhead occurs due to the received packets being held in the buffer 221, which may cause delays in receiving packets. For example, in intelligent transport systems (ITS) that realize autonomous driving, the tolerable delay time is extremely short. In such delay-sensitive applications, low latency takes priority over reordering.

[0166] For this reason, the receiving device 220 according to this embodiment is provided with a setting receiving unit 224 that receives settings for operating either the first output unit 222 that performs reordering or the second output unit 223 that does not perform reordering. This makes it possible to select whether or not to perform reordering depending on the type of application executed between the packet transceiver 101 and the packet transceiver 241, for example.

[0167] Although an example has been described above in which receiving device 220 includes both first output unit 222 and second output unit 223, receiving device 220 may include only one of first output unit 222 and second output unit 223. In this case, receiving device 220 may not include setting acceptance unit 224.

[0168] That is, the receiving device 220 may be configured as a device having an output unit that selects the received packets one by one for each sequence number stored in the additional header, removes the additional header from the selected packet, and outputs it.

[0169] (Packet transmission process flow) Next, a packet transmission process performed by the transmission device 120 according to this embodiment will be described below. Fig. 11 is a flowchart illustrating an example of the flow of the packet transmission process.

[0170] In step S121, the modem control unit 131 sets, in the modem 141-1 and the modem 141-2, a utilization frequency, which is a frequency to be used for communication with a base station of a mobile wireless communication network, by referring to the information stored in the utilization frequency information storage unit 132. Note that the utilization frequency may be, for example, the center frequency of one component carrier.

[0171] At this time, as described above, the utilization frequency may be selected for each RAT. That is, the modem control unit 131 may set the utilization frequency included in the frequency band used for the first RAT to the modem 141-1, and the utilization frequency included in the frequency band used for the second RAT to the modem 141-2.

[0172] At this time, as described above, the utilization frequency may be selected for each 3GPP band. That is, the modem control unit 131 may set the utilization frequency included in the first 3GPP band to the modem 141-1, and the utilization frequency included in the second 3GPP band to the modem 141-2.

[0173] Furthermore, at this time, as described above, the utilization frequency may be selected for each component carrier. That is, the modem control unit 131 may set the utilization frequency corresponding to the first component carrier to the modem 141-1, and the utilization frequency corresponding to the second component carrier to the modem 141-2.

[0174] In step S122, packet duplication unit 133 duplicates the packet. At this time, packet duplication unit 133 duplicates the packet so that the number of duplicated packets is the same as the number of wireless communication interfaces. For example, if modem 141-1 and modem 141-2 are provided as the wireless communication interfaces, two packets are generated as a result of the processing of step S122.

[0175] In step S123, the additional header control unit 134 adds an additional header to each of the multiple packets generated as a result of the processing in step S122. For example, if two packets are generated as a result of the processing in step S122, an additional header PHA and an additional header PHB are added to each packet.

[0176] In step S124, the sending unit 135 sends the packets to which the additional headers have been added in the process of step S23 to the multiple wireless communication interfaces corresponding to the additional headers. For example, the packet to which the additional header PHA has been added is sent to modem 141-1, and the packet to which the additional header PHB has been added is sent to modem 141-2.

[0177] As described above, the modem 141-1 may add the additional header PHA to the packet 111, the modem 141-2 may add the additional header PHB to the packet 111, and the processing corresponding to step S123 may be executed by the modem 141-1 and the modem 141-2.

[0178] Alternatively, for example, modem 141-1 may store predetermined header information (first header information) in the additional header added by additional header control unit 134 of transmitting device 120, thereby transmitting packet 111 with additional header PHA added, and modem 141-2 may store different header information (second header information) in the additional header added by additional header control unit 134 of transmitting device 120, thereby transmitting packet 111 with additional header PHB added.

[0179] In this case, in step S123, the additional header control unit 134 adds additional headers containing the same sequence number to each of the two packets 111 generated in the process of step S122.

[0180] In this way, the packet transmission process is carried out.

[0181] (Packet reception processing flow) Next, a packet reception process performed by the reception device 220 according to this embodiment will be described below. Fig. 12 is a flowchart illustrating an example of the flow of the packet reception process.

[0182] In step S141, the setting receiving unit 224 receives a setting for operating either the first output unit 222 or the second output unit 223.

[0183] In step S142, it is determined whether or not a setting has been accepted to operate the first output unit 222. If it is determined in step S142 that a setting has been accepted to operate the first output unit 222, the process proceeds to step S143.

[0184] In step S143, the first output unit 222 performs reordering on the received packets using the buffer 221 and outputs the packets. As a result, for example, as described above with reference to Fig. 10, additional headers are removed from the packets received by the receiving device 220, and the packets are reordered and output.

[0185] Furthermore, if it is determined in step S142 that the setting to operate the second output unit 223 has been accepted (the setting to operate the first output unit 222 has not been accepted), the process proceeds to step S144.

[0186] In step S144, the second output unit 223 outputs the received packets in the order in which they were received. As a result, for example, as described above with reference to Fig. 9, additional headers are removed from the packets received by the receiving device 220, and the packets are output in the order in which they were received without being reordered.

[0187] In this way, the packet reception process is executed.

[0188] (Effects of the first embodiment) According to the transmission system 100 of this embodiment, a network layer packet is duplicated and a network layer header is added. Therefore, unlike MPTCP, for example, the transmission system 100 can be used whether the communication between the packet transceiver 101 and the packet transceiver 241 uses TCP or UDP. Therefore, it is possible to realize multipath redundant communication, the suitability of which does not depend on the application.

[0189] Furthermore, according to the transmission system 100 of this embodiment, it is possible to configure a multipath redundant communication line by the same MNO and to prevent handovers from occurring simultaneously on two wireless communication paths. As a result, it is possible to guarantee the communication quality of the entire service related to the multipath redundant communication while suppressing degradation of communication quality due to handover.

[0190] Therefore, according to this embodiment, it is possible to realize multipath redundant communication that is application independent and achieves low latency and high reliability.

[0191] Second Embodiment Next, a second embodiment of the present invention will be described.

[0192] (Example of transmission system configuration) 13 is a diagram illustrating an example of the configuration of a transmission system according to a second embodiment of the present invention. Note that components having the same functions as those described in the first embodiment are given the same reference numerals, and their description will be omitted as appropriate.

[0193] The transmission system 100 shown in Fig. 13 is applied to, for example, V2N2V (Vehicle-to-Network-to-Vehicle) realized by vehicle-to-vehicle wireless communication via a mobile wireless communication network. The transmission system 100 shown in the figure includes a transmitting device 120 that transmits packets via a mobile wireless communication network connected by multiple wireless communication interfaces, and a receiving device 220a that receives packets transmitted from the transmitting device via the mobile wireless communication network connected by multiple wireless communication interfaces. A packet 111 transmitted from a packet transceiver 101 is received by a packet transceiver 241 via the mobile wireless communication network.

[0194] Note that, unlike the case of Fig. 4, the example of Fig. 13 does not go through the Internet 200. Also, unlike the case of Fig. 4, the example of Fig. 13 shows base stations 162-1 and 162-2 as base stations of the mobile wireless communication network. Note that the mobile wireless communication network of Fig. 13 is operated by a single MNO, as in the case of Fig. 4.

[0195] 13, unlike the example in FIG. 4, packet transceiver 241 is connected to receiving device 220a, which is connected to modem 142-1 and modem 142-2. Modem 142-1 and modem 142-2 have wireless communication interfaces for wireless communication with base stations of a mobile wireless communication network. Each of modem 142-1 and modem 142-2 may be configured by, for example, a mobile router, a smartphone, or the like. However, unlike general mobile routers, smartphones, and the like, each of modem 142-1 and modem 142-2 has a frequency used for wireless communication with a base station of a mobile wireless communication network controlled by receiving device 220a. Each of modem 142-1 and modem 142-2 may be a UE.

[0196] Modem 142-1 uses a third utilization frequency to perform wireless communication with base station 162-1. Modem 142-2 uses a fourth utilization frequency to perform wireless communication with base station 161-2. Note that the third utilization frequency and the fourth utilization frequency are different from each other, but for example, the third utilization frequency may be the same as the first frequency set in modem 141-1 or the second frequency set in modem 141-2, and the fourth utilization frequency may be the same as the first frequency or the second frequency.

[0197] That is, packets transmitted from modem 141-1 and modem 141-2 reach modem 142-1 and modem 142-2 via base station 161-1 and base station 161-2, core network 180, and base station 162-1 and base station 162-2, respectively.

[0198] In this way, in the transmission system 100 according to this embodiment, the packet 111 is transmitted via a wireless communication path that passes through the modem 141-1, base station 161-1, base station 162-1, and modem 142-1, and a wireless communication path that passes through the modem 141-2, base station 161-2, base station 162-2, and modem 142-2, thereby performing multipath redundant communication. This makes it extremely unlikely that handovers will occur simultaneously on two paths, and makes it possible to avoid delay spikes that accompany handovers.

[0199] 13, before communication between the packet transceiver 101 and the packet transceiver 241 begins, the transmitting device 120 and the receiving device 220a are VPN-connected. Separate IP addresses are assigned to the communication port connected to the modem 141-1 of the transmitting device 120 and the communication port connected to the modem 141-2 of the transmitting device 120. Separate IP addresses are assigned to the communication port connected to the modem 142-1 of the receiving device 220a and the communication port connected to the modem 142-2 of the receiving device 220a. These IP addresses are used to establish the VPN connection.

[0200] 13, a first virtual private line 152-1 is established between modem 141-1 (more precisely, the communication port of transmitting device 120) and modem 142-1 (more precisely, the communication port of receiving device 220a). Also, a second virtual private line 152-2 is established between modem 141-2 (more precisely, the communication port of transmitting device 120) and modem 142-2 (more precisely, the communication port of receiving device 220a). That is, a point-to-point type virtual private line network is established between transmitting device 120 and receiving device 220a.

[0201] If modems 141-1 and 141-2 have different IP addresses, modems 141-1 and 141-2 may be configured to be the termination points of first virtual private line 152-1 and second virtual private line 152-2 related to the VPN connection. Similarly, if modems 142-1 and 142-2 have different IP addresses, modems 142-1 and 142-2 may be configured to be the termination points of first virtual private line 152-1 and second virtual private line 152-2 related to the VPN connection.

[0202] The packet 111 with the additional header PHA added is transmitted using the first virtual private line 152-1, and the packet 111 with the additional header PHB added is transmitted using the second virtual private line 152-2.

[0203] In this way, in the transmission system 100 according to this embodiment, the two routes are configured by the mobile wireless communication network of the same MNO. Therefore, for example, it is possible to guarantee the communication quality of the entire service related to the multipath redundant communication that realizes V2N2V.

[0204] (Example of receiving device configuration) Fig. 14 is a block diagram showing an example of the configuration of receiving device 220a shown in Fig. 13. As shown in the figure, receiving device 220a, like receiving device 220 in Fig. 8, includes buffer 221, first output unit 222, second output unit 223, and setting acceptance unit 224. Note that modem 142-1 and modem 142-2 may be configured as an integrated unit of receiving device 220a.

[0205] 8, receiving device 220a includes a frequency setting unit 225 having a modem control unit 231 and a utilization frequency information storage unit 232. The functions of modem control unit 231 and utilization frequency information storage unit 232 may be similar to those of modem control unit 131 and utilization frequency information storage unit 132 described above with reference to FIG.

[0206] That is, in receiving device 220a, modem control unit 231 sets utilization frequencies, which are frequencies used for communication with base stations of a mobile wireless communication network, in modems 142-1 and 142-2, which have wireless communication interfaces, by referring to information stored in utilization frequency information storage unit 232. That is, utilization frequencies, which are frequencies used by the wireless communication interfaces for communication with base stations of a mobile wireless communication network, are set in a plurality of wireless communication interfaces so that they are different from one another.

[0207] The method of setting the utilization frequency is the same as that described in the first embodiment. That is, each of the multiple wireless communication interfaces communicates with multiple base stations in the mobile wireless communication network of the same mobile communication operator, and the frequency setting unit limits the utilization frequency candidates that can be selected by each wireless communication interface, thereby making the utilization frequency of one wireless communication interface different from the utilization frequencies of the other wireless communication interfaces.

[0208] Here, the modem control unit 231 of the frequency setting unit 225 may limit the candidates for the utilization frequency of each wireless communication interface to utilization frequencies included in frequency bands used by different RATs.

[0209] In addition, the modem control unit 231 of the frequency setting unit 225 may limit the candidates for the utilization frequency of each wireless communication interface to utilization frequencies that are included in the frequency bands of different 3GPP bands defined by 3GPP.

[0210] Furthermore, the modem control unit 231 of the frequency setting unit 225 may limit the candidates for the utilization frequency of each wireless communication interface to utilization frequencies corresponding to different component carriers.

[0211] Furthermore, the modem control unit 231 of the frequency setting unit 225 may further set a priority order in which the wireless communication interface should select from among the candidate frequencies to be used by each wireless communication interface.

[0212] Furthermore, the modem control unit 231 of the frequency setting unit 225 may further set utilization frequencies that should be excluded from selection by the wireless communication interface from among the utilization frequency candidates of the individual wireless communication interfaces.

[0213] Modem 142-1 and modem 142-2 are connected to base station 162-1 and base station 162-2, respectively, by wireless communication using the third and fourth utilization frequencies set for them.

[0214] (Effects of the second embodiment) As described above, in this embodiment, the receiving device 220a connected to the packet transceiver 241 is connected to two different base stations, similar to the transmitting device 120. By doing so, for example, even when the packet transceiver 241 is mounted on a vehicle, the possibility of simultaneous handover occurring on two wireless communication paths can be reduced. That is, according to this embodiment, in V2N2V communication, multipath redundant communication that is application-independent and achieves low latency and high reliability can be realized.

[0215] (Third embodiment) Next, a third embodiment of the present invention will be described.

[0216] (Example of transmission system configuration) 15 is a diagram illustrating an example of the configuration of a transmission system according to a third embodiment of the present invention. Note that components having the same functions as those described in the first and second embodiments are denoted by the same reference numerals, and their description will be omitted as appropriate.

[0217] The transmission system 100 shown in the figure includes a transmitting device 120 that transmits packets via a mobile wireless communication network connected by multiple wireless communication interfaces, and a receiving device 220a that receives the packets transmitted from the transmitting device via the mobile wireless communication network connected by multiple wireless communication interfaces. A packet 111 transmitted from a packet transceiver 101 is received by a packet transceiver 241 via the mobile wireless communication network. The transmission system 100 shown in Figure 15 is applied to, for example, V2N2V (Vehicle-to-Network-to-Vehicle) realized by wireless communication between vehicles via a mobile wireless communication network.

[0218] In the transmission system 100 shown in Fig. 15, before communication between the packet transceiver 101 and the packet transceiver 241 begins, a VPN connection is established between the transmitting device 120 and the receiving device 220a. Different IP addresses are assigned to the communication port connected to the modem 141-1 of the transmitting device 120 and the communication port connected to the modem 141-2 of the transmitting device 120. Different IP addresses are also assigned to the communication port connected to the modem 142-1 of the receiving device 220a and the communication port connected to the modem 142-2 of the receiving device 220a. The VPN connection is established using these IP addresses.

[0219] In the example of Fig. 15, the configuration of the virtual private line network is different from that of Fig. 13. That is, as shown in Fig. 15, a first virtual private line 153-1 is configured between modem 141-1 (more precisely, the communication port of transmitting device 120) and modem 142-1 (more precisely, the communication port of receiving device 220a). Also, a second virtual private line 153-2 is configured between modem 141-2 (more precisely, the communication port of transmitting device 120) and modem 142-2 (more precisely, the communication port of receiving device 220a).

[0220] 15, a third virtual private line 153-3 is established between modem 141-1 (more precisely, the communication port of transmitting device 120) and modem 142-2 (more precisely, the communication port of receiving device 220a). Also, a fourth virtual private line 153-4 is established between modem 141-2 (more precisely, the communication port of transmitting device 120) and modem 142-1 (more precisely, the communication port of receiving device 220a).

[0221] If modems 141-1 and 141-2 have different IP addresses, modem 141-1 may be the termination of first virtual private line 153-1 and third virtual private line 153-3 related to the VPN connection, and modem 141-2 may be the termination of second virtual private line 153-2 and fourth virtual private line 153-4 related to the VPN connection. Similarly, if modems 142-1 and 142-2 have different IP addresses, modem 142-1 may be the termination of first virtual private line 153-1 and fourth virtual private line 153-4 related to the VPN connection, and modem 142-2 may be the termination of second virtual private line 153-2 and third virtual private line 153-3 related to the VPN connection.

[0222] In this way, in the case of FIG. 15, a full-mesh virtual private line network is configured between the transmitting device 120 and the receiving device 220a.

[0223] In the case of FIG. 15, the transmitting device 120 replicates the packet 111 supplied from the packet transceiver 101 to generate four packets 111. The transmitting device 120 adds an additional header to each of the four packets 111. In the example of FIG. 15, an additional header PHA, an additional header PHB, an additional header PHC, and an additional header PHD are added to each of the four packets 111. The additional headers PHA to PHD are each network layer headers. As an example, the additional headers PHA and PHB each include an IP address. Also, as an example, the additional headers PHA to PHD each include a sequence number.

[0224] In addition, when the additional header control unit 134 is provided in each of the modem 141-1 and the modem 141-2, the modem 141-1 may add the additional headers PHA and PHC to the packet 111, and the modem 141-2 may add the additional headers PHB and PHD to the packet 111.

[0225] Alternatively, the modem 141-1 may store the first header information and the third header information in the additional header added by the additional header control unit 134 of the transmitting device 120, thereby transmitting the packet 111 to which the additional headers PHA and PHC have been added, and the modem 141-2 may store the second header information and the fourth header information, thereby transmitting the packet 111 to which the additional headers PHB and PHD have been added.

[0226] In this case, the additional header control unit 134 of the transmitting device 120 adds an additional header storing the same sequence number to each of the four packets 111 generated by the packet replicating unit 133 .

[0227] 15, the packet 111 to which the additional header has been added by the transmitting device 120 is supplied to the modems 141-1 and 141-2. The packet 111 to which the additional header PHA has been added is transmitted using the first virtual private line 153-1, and the packet 111 to which the additional header PHB has been added is transmitted using the second virtual private line 153-2. As a result, the packet 111 to which the additional header PHA has been added is received by the receiving device 220a via the modem 142-1, and the packet 111 to which the additional header PHB has been added is received by the receiving device 220a via the modem 142-2.

[0228] 15, the packet 111 to which the additional header PHC has been added by the transmitting device 120 is supplied to the modems 141-1 and 141-2. The packet 111 to which the additional header PHC has been added is transmitted using the third virtual private line 153-3, and the packet 111 to which the additional header PHD has been added is transmitted using the fourth virtual private line 153-4. As a result, the packet 111 to which the additional header PHC has been added is received by the receiving device 220a via the modem 142-2, and the packet 111 to which the additional header PHD has been added is received by the receiving device 220a via the modem 142-1.

[0229] In this way, according to this embodiment, communication is carried out via four different paths, which can increase redundancy in multipath redundant communication.

[0230] (Fourth embodiment) Next, a fourth embodiment of the present invention will be described. In this embodiment, a transmitting / receiving device 320 is used instead of the transmitting device 120 and the receiving device 220 or the receiving device 220a.

[0231] (Example of configuration of transmitting and receiving device) 16 is a block diagram showing an example of the configuration of a transmission / reception device according to the fourth embodiment of the present invention. Note that components having the same functions as those described in the first, second, and third embodiments are denoted by the same reference numerals, and their description will be omitted as appropriate.

[0232] As shown in the figure, the transmitting / receiving device 320 includes a frequency setting unit 341 having a modem control unit 331 and a frequency information storage unit 332. The transmitting / receiving device 320 also includes a packet duplication unit 333, an additional header control unit 334, and a packet sending unit 342 having a sending unit 335.

[0233] The functions of the modem control unit 331 and the utilization frequency information storage unit 332 may be similar to those of the modem control unit 131 and the utilization frequency information storage unit 132 in Fig. 5. The functions of the packet duplication unit 333, the additional header control unit 334, and the transmission unit 335 may be similar to those of the packet duplication unit 133, the additional header control unit 134, and the transmission unit 135 in Fig. 5.

[0234] 16, the transmission / reception device 320 further includes a buffer 321, a first output unit 322, a second output unit 323, and a setting reception unit 324. The functions of the buffer 321, the first output unit 322, the second output unit 323, and the setting reception unit 324 may be similar to those of the buffer 221, the first output unit 222, the second output unit 223, and the setting reception unit 224 in FIG.

[0235] The transmitting / receiving device 320 may include only one of the first output unit 322 and the second output unit 323. In this case, the transmitting / receiving device 320 does not need to include the setting receiving unit 324.

[0236] Furthermore, for example, when the transmitting / receiving device 320 is directly connected to a router or the like, the transmitting / receiving device 320 may not be provided with the frequency setting unit 341.

[0237] In this way, the transmitting / receiving device 320 used in this embodiment has a configuration that integrates the transmitting device 120 and the receiving device 220 in Fig. 4. By replacing the transmitting device 120 and the receiving device 220 in Fig. 4 with the transmitting / receiving device 320, packets can be transmitted and received between the packet transceiver 101 and the packet transceiver 241.

[0238] Fig. 17 is a diagram illustrating an example of a transmission system 100 using a transmission / reception device 320. Fig. 17 illustrates another example of the transmission system 100 of Fig. 4, in which the transmission device 120 and the reception device 220 of Fig. 4 are replaced with the transmission / reception device 320.

[0239] 17, the transmitting / receiving device 320-1 duplicates the packet 111 supplied from the packet transceiver 101 to generate two packets 111. The transmitting device 320-1 adds an additional header to each of the two packets 111.

[0240] Packet 111 to which an additional header has been added by transmitting / receiving device 320-1 is supplied to modem 141-1 and modem 141-2. Modem 141-1 performs wireless communication with base station 161-1 using a first frequency used. Modem 141-2 performs wireless communication with base station 161-2 using a second frequency used. In this way, the packets transmitted from modem 141-1 and modem 141-2 are sent to core network 180 of the mobile wireless communication network via base station 161-1 and base station 161-2, respectively.

[0241] The core network 180 is connected to the Internet 200, and a router 201 of the Internet 200 is connected to the core network 180. Two packets 111 with additional headers added are sent from the core network 180 to the router 201. These packets are then routed through the Internet 200 and reach the router 202.

[0242] The router 202 is connected to the transmitting / receiving device 320-2, and the two packets 111 with the additional headers are sent to the transmitting / receiving device 320-2. The transmitting / receiving device 320-2 refers to the information stored in the additional headers and selects one of the packets 111 having the same sequence number.

[0243] The transmitting / receiving device 320-2 removes the additional header from the selected packet 111 and supplies the packet to the packet transceiver 241. As a result, the packet transceiver 241 receives the packet 111 transmitted from the packet transceiver 101. Furthermore, the transmitting / receiving device 320-2 reorders the received packet as necessary, removes the additional header, and supplies the packet to the packet transceiver 241.

[0244] Furthermore, the transmitting / receiving device 320-2 duplicates the packet 111 supplied from the packet transceiver 241 to generate two packets 111. The transmitting device 320-2 adds an additional header to each of the two packets 111.

[0245] The packets 111 to which the additional header has been added by the transmitting / receiving device 320-2 are supplied to the router 202. The two packets are received by the modems 141-1 and 141-2 via the first virtual private line 151-1 and the second virtual private line 151-2, and reach the transmitting / receiving device 320-1. The transmitting / receiving device 320-1 refers to the information stored in the additional header and selects one of the packets 111 having the same sequence number.

[0246] The transmitting / receiving device 320-1 removes the additional header from the selected packet 111 and supplies the packet to the packet transceiver 101. As a result, the packet transceiver 101 receives the packet 111 transmitted from the packet transceiver 241. The transmitting / receiving device 320-1 also reorders the received packet as necessary, removes the additional header, and supplies the packet to the packet transceiver 101.

[0247] The transmitting / receiving device 320 can also be applied to the transmission system 100 shown in Fig. 13 or the transmission system 100 shown in Fig. 15. That is, by replacing the transmitting device 120 and the receiving device 220a in Fig. 13 or 15 with the transmitting / receiving device 320, packets can be transmitted and received between the packet transceiver 101 and the packet transceiver 241.

[0248] Furthermore, the transceiver 320 may be configured to be integrated with a wireless communication interface such as a modem.

[0249] (Other embodiments) In the above, an example has been described in which the transmitting device 120, the receiving device 220a, and the transceiver device 320 are each connected to two different base stations using two modems. However, the transmitting device 120, the receiving device 220a, and the transceiver device 320 may each be connected to three or more different base stations using three or more modems. Alternatively, the transmitting device 120, the receiving device 220a, and the transceiver device 320 may each be connected to multiple different base stations using multiple modems, and may further be connected to redundant lines of a wireless network other than a mobile wireless network, such as optical wireless, WiFi, or DSRC (Dedicated Short Range Communication).

[0250] (Software implementation example) The above-described transmitting device 120, receiving device 220, receiving device 220a, and transmitting / receiving device 320 are each a program for causing a computer to function, and can be realized by a program for causing a computer to function as the transmitting device 120, receiving device 220, receiving device 220a, and transmitting / receiving device 320. In this case, the transmitting device 120, receiving device 220, receiving device 220a, and transmitting / receiving device 320 are each provided with a computer having at least one control device (e.g., a processor) and at least one storage device (e.g., a memory) as hardware for executing the above-mentioned programs. An example of such a computer is shown in FIG. 18.

[0251] The computer 500 includes at least one processor 501 and at least one memory 502. The memory 502 stores a program 520 for causing the computer 500 to operate as the transmitting device 120, the receiving device 220, the receiving device 220a, and the transceiver device 320. In the computer 500, the processor 501 reads and executes the program 520 from the memory 502, thereby realizing the functions of the transmitting device 120, the receiving device 220, the receiving device 220a, and the transceiver device 320.

[0252] The processor 501 may be, for example, a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), a DSP (Digital Signal Processor), an MPU (Micro Processing Unit), an FPU (Floating point number Processing Unit), a PPU (Physics Processing Unit), a microcontroller, or a combination thereof.

[0253] The memory 502 may be, for example, a flash memory, a hard disk drive (HDD), a solid state drive (SSD), or a combination of these.

[0254] The computer 500 may further include a RAM (Random Access Memory) for expanding the program 520 during execution and for temporarily storing various data. The computer 500 may also include a communication interface for transmitting and receiving data to and from other devices. The computer 500 may also include an input / output interface for connecting input / output devices such as a keyboard, a mouse, a display, and a printer.

[0255] Furthermore, the program 520 can be recorded on a non-transitory tangible recording medium 530 that can be read by the computer 500. For example, a tape, a disk, a card, a semiconductor memory, or a programmable logic circuit can be used as such a recording medium 530. The computer 500 can acquire the program 520 via such a recording medium 530.

[0256] The program 520 can also be transmitted via a transmission medium. Examples of such a transmission medium include a communication network and broadcast waves. The computer 500 can also acquire the program 520 via such a transmission medium.

[0257] In addition, some or all of the functions of the transmitting device 120, the receiving device 220, the receiving device 220a, and the transmitting / receiving device 320 can be realized by logic circuits. For example, an integrated circuit in which a logic circuit functioning as each of the above control blocks is formed is also included in the scope of the present invention. In addition, the functions of each of the above control blocks can also be realized by, for example, a quantum computer.

[0258] Furthermore, in each of the above-described embodiments, examples of applying the present invention to a 5G communication system have been described, but the present invention can also be applied to communication systems from 6G onwards.

[0259] According to each aspect of the present invention described above, the above-mentioned effects can be achieved, thereby contributing to the achievement of Goal 9 of the Sustainable Development Goals (SDGs), "Build resilient infrastructure, promote inclusive and sustainable industrialization, and build resilient infrastructure."

[0260] The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention.

[0261] 〔summary〕 A transmitting device according to aspect 1 of the present invention is a transmitting device that transmits packets via a mobile wireless communication network, and includes a frequency setting unit that sets a usage frequency, which is a frequency that the wireless communication interface uses to communicate with a base station of the mobile wireless communication network, to a plurality of wireless communication interfaces so that each frequency is different, and a packet sending unit that copies the same packet to generate at least two packets, adds an additional header to each packet, and sends the packets to each of the plurality of wireless communication interfaces that are provided corresponding to the additional header.

[0262] A transmitting device according to aspect 2 of the present invention is, in the above-mentioned aspect 1, such that each of the plurality of wireless communication interfaces communicates with a plurality of base stations of the mobile wireless communication network of the same mobile communication operator, and the frequency setting unit limits the candidate utilization frequencies that can be selected by each wireless communication interface, thereby making the utilization frequency of one wireless communication interface different from the utilization frequencies of other wireless communication interfaces.

[0263] In a transmitting device according to aspect 3 of the present invention, in the above aspect 2, the frequency setting unit restricts the candidate utilization frequencies of each wireless communication interface to utilization frequencies included in frequency bands used for different RATs (Radio Access Technologies).

[0264] In a transmitting device according to aspect 4 of the present invention, in the above-mentioned aspect 2 or 3, the frequency setting unit restricts the candidate utilization frequencies of each wireless communication interface to utilization frequencies that are 3GPP bands defined by 3GPP and that are included in frequency bands of different 3GPP bands.

[0265] A transmitting device according to a fifth aspect of the present invention is based on any one of the second to fourth aspects, wherein the frequency setting unit restricts the candidates for the utilization frequency of each wireless communication interface to utilization frequencies corresponding to different component carriers.

[0266] A transmitting device according to a sixth aspect of the present invention is any one of the third to fifth aspects above, wherein the frequency setting unit further sets a priority order in which the wireless communication interface should select from among the candidate frequencies to be used by each wireless communication interface.

[0267] A transmitting device according to aspect 7 of the present invention is any one of aspects 3 to 6 above, wherein the frequency setting unit further sets utilization frequencies to be excluded from selection by the wireless communication interface from among the utilization frequency candidates of each wireless communication interface.

[0268] In a transmitting device according to aspect 8 of the present invention, in any of aspects 1 to 7 above, the packet sending unit stores a sequence number indicating the transmission order of the packet in the additional header, and generates packets having the additional header storing the same sequence number in the same number as the types of the additional header.

[0269] A transmitting device according to a ninth aspect of the present invention is configured as an integrated device with the plurality of wireless communication interfaces in any one of the first to eighth aspects.

[0270] A transmission method according to aspect 10 of the present invention is a transmission method of a transmitting device that transmits packets via a mobile wireless communication network, and includes the steps of setting a usage frequency, which is a frequency that the wireless communication interface uses to communicate with a base station of the mobile wireless communication network, to a plurality of wireless communication interfaces so that each frequency is a different frequency, and duplicating the same packet to generate at least two packets, adding an additional header to each packet, and sending the packets to each of the plurality of wireless communication interfaces that are provided corresponding to the additional header.

[0271] A program according to an eleventh aspect of the present invention causes a computer to function as a transmitting device for transmitting packets via a mobile wireless communication network, comprising: a frequency setting unit that sets, in a plurality of wireless communication interfaces, frequencies that the wireless communication interfaces use to communicate with base stations of the mobile wireless communication network so that each frequency is a different frequency; and a packet sending unit that copies the same packet to generate at least two packets, adds a different additional header to each packet, and sends the packets to the plurality of wireless communication interfaces that are provided corresponding to the additional headers.

[0272] A receiving device according to aspect 12 of the present invention is a receiving device that receives packets via a mobile wireless communication network, wherein an additional header storing a sequence number is added to the packets, and the receiving device is equipped with an output unit that selects the received packets one by one for each sequence number stored in the additional header, removes the additional header from the selected packets, and outputs the selected packets.

[0273] A receiving device according to aspect 13 of the present invention is, in the above-mentioned aspect 12, wherein the output unit has a first output unit that uses a buffer that holds packets received within a predetermined period of time to output packets from which the additional header has been removed in the order of the sequence numbers, and a second output unit that outputs packets from which the additional header has been removed in the order in which they were received, and further includes a setting receiving unit that receives settings for operating either the first output unit or the second output unit.

[0274] A receiving device according to aspect 14 of the present invention, in accordance with aspect 12 above, further includes a frequency setting unit that sets the utilization frequencies, which are the frequencies used by the wireless communication interfaces for communication with base stations of the mobile wireless communication network, to the multiple wireless communication interfaces so that each of the utilization frequencies is a different frequency.

[0275] A receiving device according to aspect 15 of the present invention is, in aspect 14 above, such that each of the multiple wireless communication interfaces communicates with multiple base stations of the mobile wireless communication network of the same mobile communication operator, and the frequency setting unit limits the candidate utilization frequencies that can be selected by each wireless communication interface, thereby making the utilization frequency of one wireless communication interface different from the utilization frequencies of other wireless communication interfaces.

[0276] In a receiving device according to aspect 16 of the present invention, in the above aspect 15, the frequency setting unit restricts the candidate utilization frequencies of each wireless communication interface to utilization frequencies included in frequency bands used for different RATs (Radio Access Technologies).

[0277] In a receiving device according to aspect 17 of the present invention, in the above-mentioned aspect 15 or 16, the frequency setting unit limits the candidate utilization frequencies of each wireless communication interface to utilization frequencies that are 3GPP bands defined by 3GPP and that are included in frequency bands of different 3GPP bands.

[0278] A receiving device according to aspect 18 of the present invention is any one of aspects 15 to 17 above, wherein the frequency setting unit restricts the candidate utilization frequencies of each wireless communication interface to utilization frequencies corresponding to different component carriers.

[0279] A receiving device according to aspect 19 of the present invention is any one of aspects 15 to 18 above, wherein the frequency setting unit further sets a priority order in which the wireless communication interface should select from among the candidate frequencies to be used by each wireless communication interface.

[0280] In a receiving device according to aspect 20 of the present invention, in any of aspects 15 to 19 above, the frequency setting unit further sets utilization frequencies that should be excluded from selection by the wireless communication interface from among the candidate utilization frequencies of each wireless communication interface.

[0281] A receiving device according to aspect 21 of the present invention is one in which, in any of aspects 14 to 20 above, there are up to as many packets having the additional header storing the same sequence number as the number of wireless communication interfaces, and the packets are received via different wireless communication paths corresponding to each of the multiple wireless communication interfaces.

[0282] A receiving device according to a twenty-second aspect of the present invention is configured in any one of the fourteenth to twenty-first aspects by being integrated with the plurality of wireless communication interfaces.

[0283] A receiving method according to a twenty-third aspect of the present invention is a receiving method for a receiving device that receives packets via a mobile wireless communication network, comprising: An additional header storing a sequence number is added to the packet, and the method includes the steps of selecting received packets one by one for each sequence number stored in the additional header, removing the additional header from the selected packet, and outputting the selected packet.

[0284] A program according to aspect 24 of the present invention causes a computer to function as a receiving device that receives packets via a mobile wireless communication network, wherein an additional header storing a sequence number is added to the packets, and the receiving device has an output unit that selects the received packets one by one for each sequence number stored in the additional header, removes the additional header from the selected packets, and outputs the selected packets.

[0285] A transmitting / receiving device according to a twenty-fifth aspect of the present invention is configured by integrating the transmitting device according to the first aspect above and the receiving device according to the fourteenth aspect above.

[0286] A transmitting / receiving device according to a twenty-sixth aspect of the present invention is configured by integrating the transmitting device according to the ninth aspect and the receiving device according to the twenty-second aspect.

[0287] A transmission system according to aspect 27 of the present invention is a transmission system having a transmitting device that transmits packets via a mobile wireless communication network connected by a plurality of wireless communication interfaces, and a receiving device that receives packets transmitted from the transmitting device via the mobile wireless communication network connected by a plurality of wireless communication interfaces, wherein the transmitting device comprises a frequency setting unit that sets the utilization frequencies used by the wireless communication interfaces for communication with base stations of the mobile wireless communication network to different frequencies, and a packet sending unit that copies the same packet to generate at least two packets, adds an additional header to each packet, and sends the packets to each of the plurality of wireless communication interfaces provided corresponding to the additional headers, and the receiving device comprises the frequency setting unit and an output unit that selects received packets one by one for each sequence number stored in the additional header, removes the additional header from the selected packet, and outputs the selected packet, wherein the plurality of wireless communication interfaces connected to the transmitting device are each assigned a different network layer address, and the plurality of wireless communication interfaces connected to the receiving device are each assigned a different network layer address, and a virtual private network is formed between the wireless communication interface connected to the transmitting device and the wireless communication interface connected to the receiving device.

[0288] A transmission system according to aspect 28 of the present invention is the same as that of aspect 27 above, in which a point-to-point virtual private network is configured between the communication port of the transmitting device and the communication port of the receiving device.

[0289] A transmission system according to a twenty-ninth aspect of the present invention is the same as the twenty-seventh aspect, in which a full-mesh virtual private line network is configured between the communication port of the transmitting device and the communication port of the receiving device.

[0290] A transmission system according to a thirtieth aspect of the present invention is the same as that of the twenty-seventh aspect, in which a star-type virtual private network is configured between a communication port of the transmitting device and a communication port of the receiving device. [Explanation of symbols]

[0291] 100 Transmission Systems 101 Packet Transceiver 111 packets 120 Transmitting device 121 Frequency setting unit 122 Packet sending unit 131 Modem control unit 132 Usage frequency information storage unit 133 Packet Replication Unit 134 Additional Header Control Section 135 Transmission Department 141-1, 141-2 modems 142-1, 142-2 modems 151-1, 151-2 Virtual Private Line 152-1, 152-2 Virtual Private Line 153-1~153-4 Virtual Private Line 161-1, 161-2 base station 162-1, 162-2 base station 180 Core Network 200 Internet 201 Router 202 Router 220 Receiving Device 221 buffer 222 First output section 223 Second Output Section 224 Settings Reception Section 241 Packet Transceiver 320 Transmitting and Receiving Device

Claims

1. A transmitting device for transmitting packets via a mobile wireless communication network, comprising: a frequency setting unit that sets frequencies to be used by the wireless communication interfaces for communication with base stations of the mobile wireless communication network to different frequencies for the wireless communication interfaces; a packet sending unit that copies the same packet to generate at least two packets, adds an additional header to each packet, and sends the packets to the plurality of wireless communication interfaces that are provided corresponding to the additional headers; A transmitting device comprising:

2. each of the plurality of wireless communication interfaces communicates with a plurality of base stations of a mobile wireless communication network of the same mobile communication operator; The frequency setting unit limits, for each wireless communication interface, the candidate frequencies that can be selected by the wireless communication interface, thereby making the frequency used by one wireless communication interface different from the frequencies used by other wireless communication interfaces. The transmitting device according to claim 1 .

3. The frequency setting unit The candidate utilization frequencies of each wireless communication interface are restricted to utilization frequencies included in frequency bands used by different RATs (Radio Access Technologies). The transmitting device according to claim 2 .

4. The frequency setting unit The candidate frequencies for use of each wireless communication interface are restricted to be 3GPP bands defined by 3GPP, and are limited to use frequencies included in frequency bands of different 3GPP bands. The transmitting device according to claim 2 .

5. The frequency setting unit The candidate utilization frequencies for each wireless communication interface are restricted to utilization frequencies corresponding to different component carriers. The transmitting device according to claim 2 .

6. The frequency setting unit Further, a priority order for the wireless communication interface to select from among the candidate frequencies for use by each wireless communication interface is set. The transmitting device according to claim 2 .

7. The frequency setting unit Further, among the candidate utilization frequencies of each wireless communication interface, utilization frequencies to be excluded from selection by the wireless communication interface are set. The transmitting device according to claim 2 .

8. The packet sending unit A sequence number indicating the transmission order of the packet is stored in the additional header, and packets each having the additional header storing the same sequence number are generated in the same number as the number of wireless communication interfaces. The transmitting device according to claim 1 .

9. Integrated with the plurality of wireless communication interfaces The transmitting device according to claim 1 .

10. A transmission method for a transmitting device that transmits packets via a mobile wireless communication network, comprising: setting, for the plurality of wireless communication interfaces, frequencies used by the wireless communication interfaces for communication with base stations of the mobile wireless communication network so that the frequencies are different from each other; and generating at least two packets by duplicating the same packet, adding an additional header to each packet, and transmitting the packets to the plurality of wireless communication interfaces provided corresponding to the additional headers. Sending method.

11. Computer, A transmitting device for transmitting packets via a mobile wireless communication network, comprising: a frequency setting unit that sets frequencies to be used by the wireless communication interfaces for communication with base stations of the mobile wireless communication network to different frequencies for the wireless communication interfaces; and a packet sending unit that copies the same packet to generate at least two packets, adds an additional header to each packet, and sends the packets to the plurality of wireless communication interfaces that are provided corresponding to the additional headers. program.

12. A receiving device for receiving packets via a mobile wireless communication network, An additional header containing a sequence number is added to the packet; Selecting one received packet for each sequence number stored in the additional header; an output unit that removes the additional header from the selected packet and outputs the packet; A receiving device comprising:

13. the output unit includes a first output unit that uses a buffer that holds packets received within a predetermined time to output the packets from which the additional headers have been removed in order of the sequence numbers; a second output unit that outputs the packets from which the additional header has been removed in the order in which they have been received; The output device further includes a setting receiving unit that receives a setting for operating either the first output unit or the second output unit.

13. The receiving device according to claim 12.

14. The wireless communication device further includes a frequency setting unit that sets, to the wireless communication interfaces, frequencies that the wireless communication interfaces use for communication with base stations of the mobile wireless communication network so that the frequencies are different from each other.

13. The receiving device according to claim 12.

15. each of the plurality of wireless communication interfaces communicates with a plurality of base stations of a mobile wireless communication network of the same mobile communication operator; The frequency setting unit limits, for each wireless communication interface, the candidate frequencies that can be selected by the wireless communication interface, thereby making the frequency used by one wireless communication interface different from the frequencies used by other wireless communication interfaces.

15. The receiving device according to claim 14.

16. The frequency setting unit The candidate utilization frequencies of each wireless communication interface are restricted to utilization frequencies included in frequency bands used by different RATs (Radio Access Technologies).

16. The receiving device according to claim 15.

17. The frequency setting unit The candidate frequencies for use of each wireless communication interface are restricted to be 3GPP bands defined by 3GPP, and are limited to use frequencies included in frequency bands of different 3GPP bands.

16. The receiving device according to claim 15.

18. The frequency setting unit The candidate utilization frequencies for each wireless communication interface are restricted to utilization frequencies corresponding to different component carriers.

16. The receiving device according to claim 15.

19. The frequency setting unit Further, a priority order for the wireless communication interface to select from among the candidate frequencies for use by each wireless communication interface is set.

16. The receiving device according to claim 15.

20. The frequency setting unit Further, among the candidate utilization frequencies of each wireless communication interface, utilization frequencies to be excluded from selection by the wireless communication interface are set.

16. The receiving device according to claim 15.

21. the number of packets having the additional header storing the same sequence number is at most the same as the number of wireless communication interfaces; The packet is received via a different wireless communication path corresponding to each of the plurality of wireless communication interfaces.

15. The receiving device according to claim 14.

22. Integrated with the plurality of wireless communication interfaces 15. The receiving device according to claim 14.

23. A receiving method for a receiving device that receives packets via a mobile wireless communication network, comprising: An additional header containing a sequence number is added to the packet; Selecting one received packet for each sequence number stored in the additional header; removing the additional header from the selected packet and outputting the packet. Receiving method.

24. Computer, A receiving device for receiving packets via a mobile wireless communication network, An additional header containing a sequence number is added to the packet; Selecting one received packet for each sequence number stored in the additional header; an output unit that removes the additional header from the selected packet and outputs the packet; and functioning as a receiving device comprising: program.

25. The transmitting device according to claim 1 and the receiving device according to claim 14 are integrated into one device. Transmitting and receiving equipment.

26. The transmitting device according to claim 9 and the receiving device according to claim 22 are integrally configured. Transmitting and receiving equipment.

27. A transmission system including a transmitting device that transmits packets via a mobile wireless communication network connected by a plurality of wireless communication interfaces, and a receiving device that receives packets transmitted from the transmitting device via the mobile wireless communication network connected by a plurality of wireless communication interfaces, The transmitting device a frequency setting unit that sets frequencies to be used by the wireless communication interfaces for communication with base stations of the mobile wireless communication network to different frequencies for the wireless communication interfaces; a packet sending unit that copies the same packet to generate at least two packets, adds an additional header to each packet, and sends the packets to the plurality of wireless communication interfaces that are provided corresponding to the additional headers; The receiving device the frequency setting unit; Selecting one received packet for each sequence number stored in the additional header; an output unit that removes the additional header from the selected packet and outputs the packet; Equipped with a plurality of wireless communication interfaces connected to the transmitting device are assigned different network layer addresses, The plurality of wireless communication interfaces connected to the receiving device are assigned different network layer addresses, A virtual private network is configured between a wireless communication interface connected to the transmitting device and a wireless communication interface connected to the receiving device. Transmission system.

28. A point-to-point virtual private line network is configured between the communication port of the transmitting device and the communication port of the receiving device.

28. The transmission system of claim 27.

29. A full-mesh virtual private line network is configured between the communication port of the transmitting device and the communication port of the receiving device.

28. The transmission system of claim 27.

30. a star-type virtual private line network is configured between the communication port of the transmitting device and the communication port of the receiving device; 28. The transmission system of claim 27.

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