Communication systems, servers, communication devices, and computer programs

Abstract

A communication system comprising: a first communication device connected to a network via a first communication path passing through a first base station; a second communication device connected to the network via a second communication path passing through a second base station; and a server capable of communicating with each of the first communication device and the second communication device. The second communication device transmits to the server attribute information indicating an attribute of the second communication path including the second base station. The server, on the basis of the attribute information that has been received, generates path configuration information for the first communication device to configure a communication path. The first communication device, on the basis of the path configuration information generated by the server, configures a redundant communication path passing through the second communication device and the second base station.

Description

Technical Field

[0001] The present disclosure relates to a communication system, a server, a communication device, and a computer program. This application claims priority based on Japanese Patent Application No. 2021-118469 filed on July 19, 2021, and incorporates all of its disclosure herein.

Background Art

[0002] Patent Document 1 models a communication network having a redundant configuration in a communication section between a first network device and a second network device, generates a network configuration of a logical layer, and when obtaining failure information indicating that a failure has occurred in the communication network, for the network configuration of the logical layer, from a first logical entity corresponding to a first virtual port set in the first network device to a second logical entity corresponding to a second virtual port set in the second network device, discloses a network management device that searches for a communicable path.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

[0004] A communication system according to one aspect of the present disclosure includes a first communication device connected to a network via a first communication path through a first base station, a second communication device connected to the network via a second base station, and a server capable of communicating with each of the first and second communication devices, wherein the second communication device transmits attribute information indicating the attributes of the second communication path including the second base station to the server, the server generates route setting information for the first communication device to set the communication path based on the received attribute information, and the first communication device sets a redundant communication path via the second communication device and the second base station based on the route setting information generated by the server.

[0005] A server according to one aspect of the present disclosure is a server capable of communicating with a first communication device connected to a network via a first communication path through a first base station, and a second communication device connected to the network via a second communication path through a second base station, and comprises: a receiving unit that receives attribute information indicating the attributes of the second communication path including the second base station transmitted from the second communication device; a generating unit that generates route setting information for the first communication device to set up a communication path based on the attribute information received by the receiving unit; and a transmitting unit that transmits the route setting information generated by the generating unit to the first communication device in order for the first communication device to set up a redundant communication path via the second communication device and the second base station.

[0006] A communication device according to one aspect of the present disclosure is a communication device connected to a network via a first communication path through a first base station, and includes a receiving unit that receives route setting information from a server, which is generated based on attribute information indicating the attributes of the second communication path including the second base station, transmitted from another communication device connected to the network via a second communication path through a second base station, and a route setting unit that sets a redundant communication path via the other communication device and the second base station based on the route setting information received by the receiving unit.

[0007] A computer program according to one aspect of the present disclosure is a computer program for causing a computer to function as a server capable of communicating with a first communication device connected to a network via a first communication path through a first base station, and a second communication device connected to the network via a second communication path through a second base station, wherein the computer is caused to perform the steps of: receiving attribute information indicating the attributes of the second communication path including the second base station, transmitted from the second communication device; generating route setting information for the first communication device to set up a communication path based on the received attribute information; and transmitting the generated route setting information to the first communication device in order for the first communication device to set up a redundant communication path via the second communication device and the second base station.

[0008] This disclosure can be implemented not only as a communication device or server having the characteristic configuration described above, but also as a method of performing characteristic processing in a communication device using steps, as a method of performing characteristic processing in a server using steps, as a computer program that makes a computer function as a communication device, or as a computer program that makes a computer function as a server. Furthermore, this disclosure can be implemented as a semiconductor integrated circuit for part or all of the communication device or server, or as a communication system including a communication device and a server. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 is a schematic diagram illustrating an example of the configuration of a communication system according to an embodiment. [Figure 2] Figure 2 is a block diagram showing an example of the server hardware configuration according to the embodiment. [Figure 3] Figure 3 is a block diagram showing an example of the hardware configuration of a gateway device according to this embodiment. [Figure 4]Figure 4 is a functional block diagram showing an example of the functions of the communication system according to this embodiment. [Figure 5] Figure 5 shows an example of a GW list according to the embodiment. [Figure 6] Figure 6 shows an example of a priority list. [Figure 7] Figure 7 is a sequence diagram showing an example of the operation of the communication system according to the embodiment. [Figure 8] Figure 8 is a flowchart showing an example of the priority list generation process in a gateway device according to the embodiment. [Figure 9] Figure 9 is a diagram illustrating redundant paths in a communication system according to an embodiment. [Figure 10] Figure 10 shows a modified example of the GW list according to the embodiment. [Figure 11] Figure 11 is a flowchart showing a modified example of the priority list generation process in a gateway device according to an embodiment. [Modes for carrying out the invention]

[0010] <Issues this disclosure aims to address> In a wide-area wireless communication network, if one base station fails, communication devices connected to that base station cannot continue communication unless they switch to another communication path (hereinafter referred to as the "redundant communication path"). However, if the redundant communication path passes through the same base station, the communication devices will not be able to communicate even after the path switch. Even if the redundant communication path passes through a base station that is not experiencing failure, if multiple communication devices select a redundant communication path that passes through the same base station, traffic congestion will occur.

[0011] <Effects of this disclosure> According to this disclosure, redundant communication paths can be selected considering base stations.

[0012] <Summary of the embodiments of this disclosure> The embodiments of this disclosure are outlined below.

[0013] (1) The communication system according to this embodiment includes a first communication device connected to the network via a first communication path through a first base station, a second communication device connected to the network via a second communication path through a second base station, and a server capable of communicating with each of the first and second communication devices. The second communication device transmits attribute information indicating the attributes of the second communication path, including the second base station, to the server. Based on the received attribute information, the server generates route setting information for the first communication device to set the communication path. Based on the route setting information generated by the server, the first communication device sets a redundant communication path via the second communication device and the second base station. This allows the first communication device to set a redundant communication path considering the second base station.

[0014] (2) The routing information includes identification information of the second base station, and the first communication device may set the redundant communication route based on the identification information of the second base station included in the routing information. This allows the first communication device to set the redundant communication route using the identification information of the second base station.

[0015] (3) The routing information includes carrier information relating to the telecommunications carrier operating the second base station, and the first communication device may set the redundant communication route based on the carrier information included in the routing information. This allows the first communication device to set the redundant communication route with further consideration to the telecommunications carrier operating the second base station.

[0016] (4) The server generates the path setting information based on the attribute information received from each of the plurality of second communication devices, and the first communication device may set the plurality of redundant communication paths based on the path setting information generated by the server. Thereby, the first communication device can set a plurality of redundant communication paths via each of the plurality of second communication devices.

[0017] (5) The first communication device generates priority information indicating the priority of each of the plurality of redundant communication paths based on the path setting information, and sets the plurality of redundant communication paths based on the generated priority information. Thereby, the first communication device can set an appropriate redundant communication path according to the priority.

[0018] (6) The first communication device determines the priority of each of the plurality of redundant communication paths based on at least one of the determination results of whether the first base station and the second base station are the same and whether the first operator operating the first base station and the second operator operating the second base station are the same. Thereby, the first communication device can determine the priority in consideration of at least one of the base station and the communication operator.

[0019] (7) When the occurrence of a failure in the first communication path is detected, the first communication device transmits the priority information to the server, and the server adds prohibition information indicating a redundant communication path prohibited from being used among the plurality of redundant communication paths to the received priority information, and the first communication device may set the plurality of redundant communication paths based on the priority information to which the prohibition information is added. Thereby, the first communication device can set an appropriate redundant communication path except for the redundant communication path whose use is prohibited.

[0020] (8) The prohibition information may be determined for each of the multiple first communication devices based on the priority information received by the server from each of the multiple first communication devices. This allows the server to mediate redundant communication paths among the multiple first communication devices.

[0021] (9) The server may determine the address of the second communication device, and the first communication device may set the address of the second communication device determined by the server as the gateway address when setting up the redundant communication path. This allows the server to determine the address of the second communication device so as not to overlap with the addresses of other devices, and allows the first communication device to set an appropriate gateway address.

[0022] (10) The server according to this embodiment is a server capable of communicating with a first communication device connected to the network via a first communication path through a first base station, and a second communication device connected to the network via a second communication path through a second base station, and comprises: a receiving unit that receives attribute information indicating the attributes of the second communication path including the second base station transmitted from the second communication device; a generating unit that generates route setting information for the first communication device to set up a communication path based on the attribute information received by the receiving unit; and a transmitting unit that transmits the route setting information generated by the generating unit to the first communication device in order for the first communication device to set up a redundant communication path via the second communication device and the second base station.

[0023] (11) The communication device according to this embodiment is a communication device connected to a network via a first communication path through a first base station, and includes a receiving unit that receives route setting information from a server, which is generated based on attribute information indicating the attributes of the second communication path including the second base station, transmitted from another communication device connected to the network via a second communication path through a second base station, and a route setting unit that sets a redundant communication path via the other communication device and the second base station based on the route setting information received by the receiving unit. As a result, the communication device can set a redundant communication path taking the second base station into consideration.

[0024] (12) The computer program according to this embodiment is a computer program for causing a computer to function as a server capable of communicating with a first communication device connected to the network via a first communication path through a first base station, and a second communication device connected to the network via a second communication path through a second base station, wherein the computer is caused to perform the steps of: receiving attribute information transmitted from the second communication device indicating the attributes of the second communication path including the second base station; generating route setting information for the first communication device to set up the communication path based on the received attribute information; and transmitting the generated route setting information to the first communication device in order for the first communication device to set up a redundant communication path via the second communication device and the second base station.

[0025] <Details of the embodiments of this disclosure> The embodiments of this disclosure will be described in detail below with reference to the drawings. At least some of the embodiments described below may be combined in any way.

[0026] [1. Communication Systems] Figure 1 is a schematic diagram illustrating an example of the configuration of a communication system according to an embodiment.

[0027] The communication system 10 includes a server 100 and gateway devices (hereinafter also referred to as "GW devices") 400A, 400B, and 400C. In the following description, GW devices 400A, 400B, and 400C will be collectively referred to as "GW device 400".

[0028] Base stations 300A and 300B are 5G wireless base stations. In the following explanation, base stations 300A and 300B will be collectively referred to as "base station 300".

[0029] GW devices 400A, 400B, and 400C are, for example, communication terminals for a fifth-generation mobile communication system (5G). GW devices 400A and 400B are connected to network 200 via base station 300A. GW device 400C is connected to network 200 via base station 300B. Note that "connection" here includes not only physical connections but also logical connections.

[0030] Each of the GW devices 400A, 400B, and 400C is connected to multiple sensors 500. These sensors 500 include, for example, cameras, temperature sensors, humidity sensors, motion sensors, pressure sensors, and vibration sensors. The GW devices 400A, 400B, and 400C, along with each sensor 500, are installed within facilities such as factories and commercial buildings. The GW devices 400 and the sensors 500 are connected, for example, by a LAN (Local Area Network). The sensors 500 transmit data obtained through measurement (hereinafter referred to as "sensor data") to the GW device 400. The GW device 400 uploads the sensor data transmitted from the sensors 500 to a database (not shown) connected to the network 200.

[0031] The gateway devices 400A, 400B, and 400C are connected to each other by a wired LAN 450. In this embodiment, if a communication failure occurs in the communication path including the base station 300 connected to the gateway device 400, the gateway device 400 can set up a redundant communication path (hereinafter also referred to as the "redundant path") via another gateway device 400 and communicate through the redundant path.

[0032] Server 100 is connected to network 200. Server 100 communicates with GW device 400 and provides GW device 400 with a service for configuring redundant routes.

[0033] [2. Server Configuration] Figure 2 is a block diagram showing an example of the hardware configuration of a server according to this embodiment. The server 100 includes a processor 101, a non-volatile memory 102, a volatile memory 103, and a communication interface (I / F) 104.

[0034] The volatile memory 103 is a semiconductor memory such as SRAM (Static Random Access Memory) or DRAM (Dynamic Random Access Memory). The non-volatile memory 102 is a flash memory, hard disk, or ROM (Read Only Memory). The non-volatile memory 102 stores the server program 105, which is a computer program, and the data used to execute the server program 105. The server 100 is configured with a computer, and each function of the server 100 is performed by the execution of the server program 105, which is a computer program stored in the computer's storage device, by the processor 101.

[0035] Server program 105 is a computer program that provides services to the GW device 400 for setting up redundant routes.

[0036] The processor 101 is, for example, a CPU (Central Processing Unit). However, the processor 101 is not limited to a CPU. The processor 101 may also be a GPU (Graphics Processing Unit). The processor 101 is configured to execute computer programs. However, the processor 101 may include, for example, an ASIC (Application Specific Integrated Circuit) or a programmable logic device such as a gate array or FPGA (Field Programmable Gate Array).

[0037] Communication I / F 104 is, for example, an Ethernet interface ("Ethernet" is a registered trademark). Communication I / F 104 is connected to network 200. Server 100 can communicate with GW device 400 via communication I / F 104.

[0038] [3. Configuration of the GW device] Figure 3 is a block diagram showing an example of the hardware configuration of the GW device according to this embodiment. The GW device 400 includes a processor 401, a non-volatile memory 402, a volatile memory 403, a first communication I / F 404, and a second communication I / F 405.

[0039] The volatile memory 403 is, for example, a semiconductor memory such as SRAM or DRAM. The non-volatile memory 402 is, for example, flash memory, a hard disk, or ROM. The non-volatile memory 402 stores a configuration program 406, which is a computer program, and data used to execute the configuration program 406. The GW device 400 is configured with a computer, and each function of the GW device 400 is performed by the execution of the configuration program 406, which is a computer program stored in the computer's storage device, by the processor 401.

[0040] Configuration program 406 is a computer program for configuring redundant routes.

[0041] The processor 401 is, for example, a CPU. However, the processor 401 is not limited to a CPU. The processor 401 may also be a GPU. The processor 401 is configured to execute computer programs. However, the processor 401 may include, for example, an ASIC, or a programmable logic device such as a gate array or FPGA.

[0042] The first communication interface 404 is, for example, a wireless communication interface compliant with 5G. The first communication interface 404 includes a wireless antenna and is capable of wireless communication with the base station 300. The first communication interface 404 is configured with an IP address (hereinafter referred to as the "first IP address") used for communication with devices connected to the network 200. The first IP address is either a global IP address or a private IP address.

[0043] The second communication interface 405 is an Ethernet interface. The second communication interface 405 is connected to LAN 450. The gateway device 400 can communicate with the sensor 500 via the second communication interface 405. The gateway device 400 can communicate with other gateway devices 400 via the second communication interface 405. The second communication interface 405 is configured with an IP address (hereinafter referred to as the "second IP address") used for communication with devices connected to LAN 450 (gateway devices 400 and sensor 500). The second IP address is a private IP address. However, if the first IP address is a private IP address, the second IP address must be set to a different IP address from the first IP address.

[0044] At least some of the devices connected to LAN450 belong to the same subnet as GW device 400. In other words, at least some of the above devices are assigned the same IP address for both the secondary IP address and the network portion.

[0045] The GW device 400 functions as a router. The processor 401 can perform address translation processing using NAT (Network Address Translation) or NAPT (Network Address Port Translation). The processor 401 performs address translation processing by referring to the NAT table 630 stored in the non-volatile memory 402, for example. The NAT table 630 registers the first IP address as the internal global address (the address of the LAN-side device as seen from the WAN (Wide Area Network) side). The NAT table 630 also registers the IP addresses of devices belonging to the same subnet as the GW device 400 as the internal local address (the address of the LAN-side device as seen from the LAN side). The processor 401 translates the source IP address of the IP packet received by the second communication interface 405 to the internal global address and sends the translated IP packet from the first communication interface 404. Processor 401 converts the destination IP address of the IP packet received by the first communication interface 404 to an internal local address, and then sends the converted IP packet out from the second communication interface 405.

[0046] [4. Functions of the communication system] Figure 4 is a functional block diagram showing an example of the functions of the communication system according to this embodiment. Although Figure 4 shows one GW device 400, each GW device 400A, 400B, and 400C has the same function.

[0047] When processor 101 executes server program 105, the following functions are realized in server 100: attribute information receiving unit 111, GW list generation unit 112, GW list transmission unit 113, priority list receiving unit 114, route arbitration unit 115, and arbitration result transmission unit 116. When processor 401 executes setting program 406, the following functions are realized in GW device 400: attribute information transmission unit 411, GW list receiving unit 412, GW setting unit 413, priority list generation unit 414, route setting unit 415, priority list transmission unit 416, and arbitration result receiving unit 417.

[0048] The attribute information transmission unit 411 transmits attribute information to the server 100 that indicates the attributes of the communication path, including the base station 300 to which the device is connected. The attribute information includes PLMN (Public Land Mobile Network), CELL ID, and GW ID. PLMN is information for identifying the operator that operates the base station 300, and the first three digits are MCC (Mobile Country Code). CELL ID is information for identifying the base station 300. GW ID is information for identifying the GW device 400. The attribute information transmitted from the GW device 400 includes the PLMN assigned to the operator that operates the base station 300 connected to the transmitting GW device 400, the CELL ID assigned to the base station 300 connected to the transmitting GW device 400, and the GW ID of the transmitting GW device.

[0049] The attribute information receiving unit 111 receives attribute information transmitted from the GW device 400.

[0050] The GW list generation unit 112 generates a GW list 600 for the GW device 400 to set up a communication path, based on the attribute information received by the attribute information receiving unit 111. The GW list generation unit 112 is an example of a "generation unit," and the GW list is an example of "path setting information." The generated GW list 600 is stored, for example, in a non-volatile memory 102 (see Figure 2).

[0051] The GW list generation unit 112 determines the second IP address to be assigned to the GW device 400 that is the source of the attribute information. The GW list generation unit 112 determines a unique second IP address for each GW device 400. Specifically, the second IP addresses assigned to each GW device 400 belong to different subnets. For example, the GW list generation unit 112 assigns "192.168.0.1" as the second IP address to the GW device 400 with GW ID "00111", "192.168.1.1" as the second IP address to the GW device 400 with GW ID "02222", and "192.168.2.1" as the second IP address to the GW device 400 with GW ID "00333".

[0052] Figure 5 shows an example of a GW list according to this embodiment. The GW list 600 includes one or more GW information. The GW information includes a GW ID, PLMN, CELL ID, and a second IP address. Each row in the table shown in Figure 5 is GW information. Specifically, each GW information in the GW list 600 is assigned a number. In the example in Figure 5, number "1" is associated with GW ID "00111", PLMN "44032", CELL ID "123456789", and the second IP address "192.168.0.1", number "2" is associated with GW ID "02222", PLMN "44032", CELL ID "234567890", and the second IP address "192.168.1.1", number "3" is associated with GW ID "00333", PLMN "44051", CELL ID "345678901", and the second IP address "192.168.2.1", number "4" is associated with GW ID "00004", PLMN "44032", CELL The ID "123456789" is associated with the second IP address "192.168.3.1", and the number "5" is associated with the GW ID "55555", PLMN "44053", CELL ID "123456789", and the second IP address "192.168.4.1".

[0053] Returning to Figure 4, the GW list transmission unit 113 transmits the GW list 600 generated by the GW list generation unit 112 to the GW device 400. The GW list receiving unit 412 receives the GW list 600 transmitted from the server 100.

[0054] The GW setting unit 413 sets the second IP address assigned to its own device to the second communication interface based on the GW list 600 received by the GW list receiving unit 412. Specifically, the GW setting unit 413 obtains the second IP address corresponding to its own device's GW ID from the GW list 600 and sets the obtained second IP address to the second communication interface.

[0055] Furthermore, the GW setting unit 413 can set IP addresses belonging to the same subnet as the device's second IP address for the sensors 500 connected to the device. For example, if the device's second IP address is "192,168.0.1", then each sensor 500 connected to the GW device 400 will be set to an IP address belonging to the subnet "192.168.0.0". The IP addresses assigned to the sensors 500 are unique. For example, one sensor 500 may be assigned the IP address "192.168.0.101", and another sensor 500 may be assigned the IP address "192.168.0.102".

[0056] The priority list generation unit 414 generates a priority list 650 (see Figure 3) indicating the priority of each of the multiple redundant paths based on the GW list 600 received by the GW list receiving unit 412. The priority list 650 is an example of "priority information". GW information in the GW list 600 other than the GW information of the own device is redundant path information indicating the redundant paths of the own device. In other words, the GW device 400 can set redundant paths using GW information other than the GW information of its own device in the GW list 600. For example, in Figure 5, for a GW device 400 with GW ID "00111", the GW information with number "1" is the information of the own device, and the GW information other than number "1" is redundant path information. Similarly, for a GW device 400 with GW ID "02222", the GW information with number "2" is the information of the own device, and the GW information other than number "2" is redundant path information. The priority list generation unit 414 assigns priorities to at least some of the redundant route information included in the GW list 600.

[0057] In this embodiment, the priority of redundant routes is determined by considering the PLMN and CELL ID. Specifically, the priority list generation unit 414 determines the priority of redundant routes by comparing the PLMN and CELL ID included in the redundant route information with the PLMN and CELL ID of its own device (or the base station 300 connected to it). For example, the priority list generation unit 414 can set the priority of redundant route information containing a PLMN different from that of its own device to be higher than the priority of redundant route information containing a PLMN identical to that of its own device. For example, the priority list generation unit 414 can set the priority of redundant route information containing a CELL ID different from that of its own device to be higher than the priority of redundant route information containing a CELL ID identical to that of its own device.

[0058] In a specific example, the priority list generation unit 414 classifies redundant route information into four groups: Group 1 to Group 4. Group 1 is the highest priority group, Group 2 is the second highest priority group, Group 3 is the third highest priority group, and Group 4 is the lowest priority group. The priority list generation unit 414 assigns redundant route information that includes a PLMN different from the PLMN of its own device and a CELL ID different from the CELL ID of its own device to Group 1. The priority list generation unit 414 assigns redundant route information that includes a PLMN different from the PLMN of its own device and a CELL ID identical to the CELL ID of its own device to Group 2. The priority list generation unit 414 assigns redundant route information that includes a PLMN identical to the PLMN of its own device and a CELL ID different from the CELL ID of its own device to Group 3. The priority list generation unit 414 assigns redundant route information that includes a PLMN identical to the PLMN of its own device and a CELL ID identical to the CELL ID of its own device to Group 4.

[0059] The priority list generation unit 414 determines the priority of each redundant path information in the order of the first to fourth groups. For example, the priority list generation unit 414 can determine the priority for each of the first to fourth groups based on the measurement results of the communication delay time for each redundant path. In this case, the shorter the communication delay time, the higher the priority can be.

[0060] The priority list generation unit 414 generates a priority list 650 containing redundant route information to which priorities have been assigned. Figure 6 shows an example of a priority list. The priority list 650 is a list in which redundant route information is arranged in order of priority. The redundant route information includes the GW ID, PLMN, CELL ID, GW address, and skip flag. The GW address is the second IP address assigned to a GW device 400 other than the local device. The GW address is the IP address of the default gateway when the GW device 400 sends packets via the redundant route through that GW address.

[0061] The skip flag indicates whether or not to prohibit the use of redundant routes. If the skip flag is set to 0, the redundant route corresponding to that skip flag is permitted for use. If the skip flag is set to 1, the redundant route corresponding to that skip flag is prohibited for use. A skip flag set to 1 is an example of prohibition information.

[0062] The priority list generation unit 414 sets the skip flag to 0 for all redundant routes. In other words, at the stage when the priority list 650 is generated, the use of all redundant routes is not prohibited.

[0063] The priority list generation unit 414 creates a priority list 650 containing a specified number of redundant route information entries. Figure 6 shows a priority list 650 with a specified number of entries = 5. This priority list 650 contains redundant route information for priorities 1 through 5.

[0064] Returning to Figure 4, the routing unit 415 configures redundant routes based on the priority list 650. The routing unit 415 can select redundant route information in the priority list 650 in order of priority, and configure redundant routes according to the selected redundant route information.

[0065] Specifically, the routing unit 415 determines an IP address (hereinafter referred to as the "third IP address") that belongs to the same subnet as the GW address stored in the priority list 650. The third IP address is different from the IP addresses of other devices (GW device 400 and sensor 500) that belong to the same subnet. For example, when GW400B and 400C configure a redundant route via GW device 400A, whose second IP address is "192.168.0.1", GW400B determines an IP address belonging to the subnet "192.168.0.0". Here, GW devices 400B and 400C determine an IP address different from the IP address of GW device 400A, "192.168.0.1", and the IP addresses of sensor 500 connected to GW device 400A, "192.168.0.101" and "192.168.0.102". Furthermore, GW400B and 400C must determine different IP addresses from each other. For example, GW400B could determine its own IP address as "192.168.0.2", while GW400C could determine its own IP address as "192.168.0.3".

[0066] The routing unit 415 may determine the third IP address using the number N assigned to its device in the GW list 600. For example, the lower 8 bits (host portion) of the third IP address can be N + a constant. If the subnet is "192.168.0.0" and the host portion is N+1, then if N=1 the third IP address will be "192.168.0.2", and if N=2 the third IP address will be "192.168.0.3". By standardizing the rules for determining the third IP address in this way, duplication of the third IP address can be avoided at each GW device 400 without the need for adjustments at each GW device 400.

[0067] The routing unit 415 sets the determined third IP address to the communication port. The communication port may be a physical port or a virtual port. Furthermore, the routing unit 415 sets the GW address (a GW address belonging to the same subnet as the third IP address) included in the selected redundant routing information to the IP address of the communication port as the default gateway. With this, the redundant route (subflow) is configured.

[0068] After one redundant route is configured, the route setting unit 415 selects redundant route information of the next priority and configures redundant routes based on the selected redundant route information.

[0069] The route setting unit 415 refers to the skip flag included in the selected redundant route information. If the skip flag is 0, it sets the redundant route using that redundant route information; if the skip flag is 1, it does not set the redundant route. In other words, the route setting unit 415 skips setting the redundant route for which the skip flag is 1.

[0070] In the GW device 400, redundant paths are selected in the configured order using multipath protocols such as MPTCP (MultiPath Transmission Control Protocol) and SCTP (Stream Control Transmission Protocol), and communication is performed. Specifically, if the primary path, i.e., the communication path via the base station 300 directly connected to the device, is unavailable, communication is performed using the first configured redundant path. If that redundant path is unavailable, communication is performed using the second configured redundant path. Note that instead of an L2 (Layer 2) protocol such as MPTCP, a Layer 3 (Layer 3) protocol or an application layer may be used to form a multi-session using primary and redundant paths.

[0071] The priority list transmission unit 416 transmits the priority list 650 generated by the priority list generation unit 414 to the server 100. The priority list reception unit 114 receives the priority list 650 transmitted from the GW device 400.

[0072] The route arbitration unit 115 arbitrates redundant routes among multiple GW devices 400. Based on multiple priority lists 650 received from multiple GW devices 400, the route arbitration unit 115 determines which redundant routes to prohibit the use of for each GW device 400. Specifically, the route arbitration unit 115 refers to the multiple priority lists 650 received from multiple GW devices 400 to prevent redundant routes passing through a particular GW device from being too concentrated among multiple GW devices 400. For example, if the skip flag corresponding to a particular GW ID is 0 in some of the priority lists 650 (i.e., the use of a redundant route is permitted), the route arbitration unit 115 changes the skip flag corresponding to that GW ID to 1 in some of the priority lists 650 (i.e., the use of a redundant route is prohibited).

[0073] In the example shown in Figure 6, the skip flag for priority 2 has been changed to 1.

[0074] The route arbitration unit 115 can determine redundant routes whose skip flags are changed to 1 based on the priorities specified in the priority list 650. For example, if the priorities corresponding to the same GW ID are different in two priority lists 650, the route arbitration unit 115 can maintain the skip flag corresponding to the higher priority GW ID at 0 and change the skip flag corresponding to the lower priority GW ID to 1.

[0075] The arbitration result transmission unit 116 transmits the priority list 650, edited by the route arbitration unit 115, to the GW device 400, the source of the priority list 650. The arbitration result receiving unit 417 receives the priority list 650 transmitted from the server 100.

[0076] The routing unit 415 updates the redundant route settings based on the priority list 650 received by the arbitration result receiving unit 417. For example, the routing unit 415 disables communication ports where the GW address with a skip flag of 1 in the priority list 650 is set as the default gateway.

[0077] In the example shown in Figure 6, the communication port with the GW address "192.168.10.1" as the default gateway, where the skip flag is set to 1, is disabled. This suppresses traffic congestion on the communication path via "192.168.10.1".

[0078] When a new GW device 400 (hereinafter referred to as "new GW device 400") is added, the attribute information transmission unit 411 of the new GW device 400 transmits attribute information indicating the attributes of the communication path, including the base station 300 connected to the new GW device 400, to the server 100. The GW list generation unit 112 updates the GW list 600 by adding the GW information of the new GW device 400 to the GW list 600 based on the attribute information received from the new GW device 400. The GW list transmission unit 113 transmits the updated GW list 600 to each GW device 400.

[0079] The GW setting unit 413 of the new GW device 400 sets the second IP address assigned to itself to the second communication interface based on the received GW list 600. The priority list generation unit 414 of the new GW device 400 generates a priority list 650 based on the GW list 600. The routing unit 415 of the new GW device 400 sets redundant routes based on the priority list 650.

[0080] The gateway list receiving unit 412 of the gateway device 400 that was installed before the new gateway device 400 was installed (hereinafter referred to as the "existing gateway device 400") receives the updated gateway list 600 from the server 100. The priority list generation unit 414 of the existing gateway device 400 creates the priority list 650 again based on the updated gateway list 600. The updated priority list 650 may include redundant route information that passes through the new gateway device 400.

[0081] The routing unit 415 of the existing GW device 400 reconfigures redundant routes based on the updated priority list 650. If redundant route information via the new GW device 400 has been added to the priority list 650, a new redundant route via the new GW device 400 is configured.

[0082] If a GW device 400 is removed, for example, due to the power supply of one GW device 400 being shut off, each GW device 400 detects the removal of the GW device 400 (hereinafter referred to as the "removed GW device 400"). When the removal of the removed GW device 400 is detected, the priority list generation unit 414 of the remaining GW devices 400 (hereinafter referred to as the "remaining GW devices 400") updates the priority list 650 by removing redundant route information that passes through the removed GW device 400 from the priority list 650 if such information is included in the priority list 650.

[0083] The routing unit 415 of the remaining gateway device 400 reconfigures the redundant routes based on the updated priority list 650. As a result, the configuration of redundant routes passing through the deleted gateway device 400 is removed from the remaining gateway device 400.

[0084] Once the communication failure on the main path is resolved, the priority list generation unit 414 resets all skip flags to 0 in the priority list 650.

[0085] [5. Operation of the communication system] Figure 7 is a sequence diagram showing an example of the operation of the communication system according to this embodiment. Figure 7 shows an example of the operation of the GW devices 400A and 400C and the server 100.

[0086] The GW device 400 establishes a connection with the mobile communication network via the base station 300 during startup. When this connection is established, the GW device 400 obtains the PLMN and CELL ID of the base station 300 to which it is connected. The processor 401 of the GW devices 400A and 400C transmits attribute information, including the PLMN, CELL ID, and GW ID, to the server 100 (step S101).

[0087] When the server 100's processor 101 receives attribute information, it determines the second IP addresses of the GW devices 400A and 400C based on the received attribute information and generates a GW list 600 (step S102). The processor 101 then sends the generated GW list 600 to the GW devices 400A and 400C that sent the attribute information (step S103).

[0088] When the processor 401 of the GW devices 400A and 400C receives the GW list 600, it sets the second IP address corresponding to its own GW_ID on the second communication interface 405 (step S104). Furthermore, the processor 401 assigns an IP address belonging to the same subnet as the second IP address to the sensor 500 connected to its own device.

[0089] Processor 401 generates a priority list 650 based on the GW list 600 (step S105).

[0090] Figure 8 is a flowchart showing an example of the priority list generation process in the GW device according to this embodiment.

[0091] The processor 401 selects one GW ID from the GW list 600 that corresponds to a GW device 400 other than its own device (step S121).

[0092] The processor 401 determines whether the PLMN corresponding to the selected GW ID is different from the PLMN of the base station 300 connected to its own device (step S122).

[0093] If the PLMN corresponding to the selected GW ID is different from the PLMN of the base station 300 connected to the device (YES in step S122), the processor 401 determines whether the CELL ID corresponding to the selected GW ID is different from the CELL ID of the base station 300 connected to the device (step S123).

[0094] If the CELL ID corresponding to the selected GW ID is different from the CELL ID of the base station 300 connected to the device (YES in step S123), the processor 401 assigns the selected GW ID to the first group (step S124).

[0095] If the CELL ID corresponding to the selected GW ID is the same as the CELL ID of the base station 300 connected to the device (NO in step S123), the processor 401 assigns the selected GW ID to the second group (step S125).

[0096] If the PLMN corresponding to the selected GW ID is the same as the PLMN of the base station 300 connected to the device (NO in step S122), the processor 401 determines whether the CELL ID corresponding to the selected GW ID is different from the CELL ID of the base station 300 connected to the device (step S126).

[0097] If the CELL ID corresponding to the selected GW ID is different from the CELL ID of the base station 300 connected to the device (YES in step S126), the processor 401 assigns the selected GW ID to the third group (step S127).

[0098] If the CELL ID corresponding to the selected GW ID is the same as the CELL ID of the base station 300 connected to the device (NO in step S126), the processor 401 assigns the selected GW ID to the fourth group (step S128).

[0099] When the selected GW ID is assigned to one of the first to fourth groups, the processor 401 determines whether all other GW IDs in the GW list 600 have already been selected (step S129).

[0100] If there are any unselected GW IDs remaining in the GW list 600 (NO in step S129), the processor 401 returns to step S121 and selects one GW ID from among the unselected GW IDs.

[0101] If all GW IDs other than the current device included in the GW list 600 have been selected (YES in step S129), the processor 401 measures the communication delay time for each communication path through the GW device 400 identified by the GW_ID included in the GW list 600 (step S130).

[0102] The processor 401 determines the priority for each of the first to fourth groups based on the measured communication delay time and creates a priority list 650 containing a specified number of redundant route information (step S131). This completes the priority list generation process.

[0103] Returning to Figure 7, the processor 401 sets up redundant routes in order of priority according to the priority list 650 (step S106). That is, the processor 401 determines a third IP address that has the same GW address and subnet, and sets the determined third IP address to the communication port. The processor 401 sets the GW address to the default gateway of the communication port.

[0104] For example, when the processor 401 of the GW device 400A detects a communication failure in the main path (step S107), it sends a priority list 650 to the server 100 (step S108).

[0105] The processor 101 of server 100 arbitrates redundant routes based on priority lists 650 received from multiple GW devices 400 (step S109). Specifically, the processor 101 determines which redundant routes to prohibit use in each priority list 650 and changes the skip flag to 1.

[0106] The processor 101 of server 100 sends the edited priority list 650 to the GW device 400A that originated the priority list 650 (step S110).

[0107] The processor 401 of the GW device 400A updates the redundant route configuration based on the received priority list 650 (step S111). Specifically, the processor 401 disables the communication port whose default gateway is a GW address with a skip flag of 1.

[0108] Figure 9 is a diagram illustrating redundant paths in the communication system according to this embodiment. In the example in Figure 9, the primary path of the GW device 400A is the communication path via base station 300A, and the redundant paths are the communication path via GW device 400C and base station 300B (hereinafter referred to as "redundant path R1") and the communication path via GW device 400D and base station 300C (hereinafter referred to as "redundant path R2").

[0109] The secondary IP address of GW device 400A is "192.168.0.1". Therefore, the network address of the subnet with GW device 400A as the default gateway is "192.168.0.0".

[0110] The secondary IP address of GW device 400C is "192.168.2.1". Therefore, the network address of the subnet with GW device 400C as the gateway is "192.168.2.0". GW device 400A sets the IP address "192.168.2.2" belonging to that subnet as its communication port, and sets the IP address of the default gateway for that communication port to "192.168.2.1".

[0111] The secondary IP address of GW device 400D is "192.168.12.1". Therefore, the network address of the subnet with GW device 400D as the gateway is "192.168.12.0". GW device 400A sets the IP address "192.168.12.2", which belongs to the subnet, as its communication port, and sets the IP address of the default gateway for that communication port to "192.168.12.1".

[0112] Assume that in the priority list 650 of GW device 400A, the priority of redundant path R1 is "1" and the priority of redundant path R2 is "2".

[0113] If GW device 400A detects a failure in the main path via base station 300A, GW device 400A selects the redundant path R1, which has the highest priority, using a multipath protocol such as MPTCP or SCTP, and communicates with external device 210 connected to network 200 via redundant path R1. IP packets sent from GW device 400A are received by GW device 400C's second communication interface 405 (LAN-side communication interface). GW device 400C functions as a router, converting the source IP address (192.168.2.2) of IP packets received from LAN 450 to an internal global address (the first IP address assigned to GW device 400C) and sending it out from the first communication interface 404 (WAN-side communication interface). IP packets sent from external device 210 are received by GW device 400C's first communication interface 404. The GW device 400C translates the destination IP address of the IP packet received from the WAN side to an internal local address (192.168.2.2) and sends it out from the second communication interface 405.

[0114] When the GW device 400 detects that the communication failure on the main path has been resolved, it resets all skip flags in the priority list 650 to 0. Furthermore, the GW device 400 enables any communication ports that had been disabled.

[0115] [6. Examples of Variations] In this modified example, each of the GW devices 400 is connected to each other by wireless LAN, rather than by wired LAN 450. Each of the GW devices 400 functions as an access point.

[0116] Referring to Figure 3, the second communication I / F 405 of the GW device 400 is a wireless LAN interface.

[0117] Referring to Figure 4, the GW list generation unit 112 determines the second IP address and SSID (Service Set Identifier) ​​to be assigned to the GW device 400 that is the source of the attribute information. The GW list generation unit 112 determines a unique SSID for each GW device 400. For example, the GW list generation unit 112 assigns "AAAAA" as the SSID to the GW device 400 with GW ID "00111", assigns "BBBBB" as the SSID to the GW device 400 with GW ID "02222", and assigns "CCCCC" as the SSID to the GW device 400 with GW ID "00333".

[0118] Figure 10 shows a modified version of the GW list. The GW list 600 includes one or more GW information. In this modified version, the GW information includes the GW ID, PLMN, CELL ID, second IP address, and SSID. In the example in Figure 10, number "1" is associated with GW ID "00111", PLMN "44032", CELL ID "123456789", 2nd IP address "192.168.0.1", and SSID "AAAAA", number "2" is associated with GW ID "02222", PLMN "44032", CELL ID "234567890", 2nd IP address "192.168.1.1", and SSID "BBBBB", number "3" is associated with GW ID "00333", PLMN "44051", CELL ID "345678901", 2nd IP address "192.168.2.1", and SSID "CCCCC", and number "4" is associated with GW ID "00004", PLMN "44032", CELL ID "123456789", 2nd IP address "192.168.3.1", and SSID "DDDDD" are associated with number "5", GW ID "55555", PLMN "44053", CELL ID "123456789", 2nd IP address "192.168.4.1", and SSID "EEEEE".

[0119] In this modified example, the priority of redundant paths is determined by considering the received signal strength (RSSI) in the wireless LAN, in addition to the PLMN and CELL ID. Returning to Figure 4, the priority list generation unit 414 selects SSIDs in order of highest received signal strength, and determines the priority of redundant paths by comparing the PLMN and CELL ID corresponding to the selected SSID with the PLMN and CELL ID of its own device (the base station 300 connected to it).

[0120] Figure 11 is a flowchart showing a modified example of the priority list generation process in a GW device.

[0121] Each of the GW devices 400 sets the SSID associated with its own GW ID in the GW list 600 to the second communication interface 405. Each of the GW devices transmits a beacon containing the SSID.

[0122] The GW device 400 receives a beacon via the second communication I / F 405. The processor 401 detects the SSID contained in the beacon and the received signal strength of the beacon (step S201).

[0123] Processor 401 sets the variable n, which indicates the selection order of the SSIDs, to an initial value of "1" (step S202). Note that in the initial state, priority list 650 is empty (does not contain any redundant route information).

[0124] The processor 401 selects the nth SSID with the highest received signal strength from among the SSIDs other than its own device in the GW list 600 (step S203).

[0125] The processor 401 compares the PLMN and CELL ID corresponding to the selected SSID with the PLMN and CELL ID of the base station 300 connected to its own device (step S204).

[0126] If at least one of the PLMN and CELL IDs corresponding to the selected SSID is different from at least one of the PLMN and CELL IDs of the base station 300 connected to the device (YES in step S204), the processor 401 adds redundant routing information, including the GW ID corresponding to the selected SSID, to the end of the priority list 650 (step S205). In other words, redundant routing information is added to the priority list 650 in order of priority.

[0127] The processor 401 determines whether the number of redundant route information (i.e., GW IDs) included in the priority list 650 has reached a specified value (step S206).

[0128] If the number of redundant route information entries in priority list 650 reaches a specified value (YES in step S206), the priority list generation process terminates.

[0129] If the number of redundant route information entries in priority list 650 does not reach a specified value (NO in step S206), processor 401 determines whether all SSIDs other than its own device's SSID in GW list 600 have already been selected (step S207).

[0130] If there are any unselected SSIDs remaining in the GW list 600 (NO in step S207), the processor 401 increments n (step S208). The processor 401 returns to step S203 and selects one SSID from the unselected SSIDs.

[0131] In step S204, if both the PLMN and CELL ID corresponding to the selected SSID are different from both the PLMN and CELL ID of the base station 300 connected to the device (NO in step S204), the processor 401 adds redundant route information, including the GW ID corresponding to the selected SSID, to the end of the backup list (step S209). The backup list is a list for storing unregistered redundant route information. In the initial state, the backup list is empty.

[0132] After adding the redundant path information to the backup list, processor 401 proceeds to step S207.

[0133] If all SSIDs other than the device's own SSID included in the GW list 600 have already been selected (YES in step S207), the processor 401 selects redundant route information equal to the difference between the default value and the number of redundant route information registered in the priority list 650 (i.e., the shortfall in the priority list 650) in order from the top of the backup list, and adds the selected redundant route information to the end of the priority list 650 (step S210). This completes the priority list generation process.

[0134] [7. Other variations] Attribute information may include either a PLMN or a CELL ID. For example, if the attribute information does not include a CELL ID, the GW device 400 can compare the PLMN of a base station 300 connected to another GW device 400 with the PLMN of a base station 300 connected to itself, and determine priority based on the comparison result.

[0135] Instead of PLMN, MCC or MNC may be used as information regarding telecommunications carriers.

[0136] [8. Effects] The communication system 10 includes a GW device 400A (first communication device), a GW device 400C (second communication device), and a server 100. The GW device 400A is connected to the network 200 via a communication path (first communication path) through a base station 300A (second base station). The GW device 400C is connected to the network 200 via a communication path (second communication path) through a base station 300B (second base station). The server 100 can communicate with both the GW device 400A and the GW device 400C. The GW device 400C transmits attribute information indicating the attributes of the communication path including the base station 300B to the server 100. Based on the received attribute information, the server 100 generates a GW list 600 for the GW device 400A to configure the communication path. The GW device 400A configures redundant routes via GW400C and base station 300B based on the GW list 600 generated by server 100. This allows the GW device 400A to configure redundant routes while taking base station 300 into consideration.

[0137] The GW list 600 may include the CELL ID of base station 300B. The GW device 400A may configure redundant routes based on the CELL ID of base station 300B included in the GW list 600. This allows the GW device 400A to configure redundant routes using the CELL ID of base station 300B.

[0138] The GW list 600 may include PLMNs relating to the telecommunications carrier operating base station 300B. The GW device 400A may configure redundant routes based further on the PLMNs included in the GW list 600. This allows the GW device 400A to configure redundant routes with further consideration of the telecommunications carrier operating base station 300B.

[0139] Server 100 may generate a GW list based on attribute information received from each of the multiple GW devices 400. GW device 400A may configure multiple redundant routes based on the GW list 600 generated by Server 100. This allows GW device 400A to configure multiple redundant routes that pass through each of the multiple GW devices 400.

[0140] The GW device 400A may generate a priority list 650 indicating the priority of each of the multiple redundant paths based on the GW list 600. The GW device 400A may configure multiple redundant paths based on the generated priority list 650. This allows the GW device 400A to configure appropriate redundant paths according to priority.

[0141] The GW device 400A may determine the priority of each of the multiple redundant paths based on at least one of the following determination results: whether base stations 300A and 300B are the same, and whether the operator operating base station 300A (first operator) and the operator operating base station 300B (second operator) are the same. This allows the GW device 400A to determine the priority considering at least one of the base station 300 and the telecommunications carrier.

[0142] If a failure is detected in the main path (first communication path), the GW device 400A may send a priority list 650 to the server 100. The server 100 may add a skip flag value of "1" (prohibition information) to the received priority list 650, indicating a redundant path that should not be used from among multiple redundant paths. The GW device 400A may configure multiple redundant paths based on the priority list 650 with the skip flag value of "1" added. This allows the GW device 400A to configure appropriate redundant paths, excluding the redundant path that has been prohibited from use.

[0143] The server 100 may determine which redundant routes to prohibit the use of for each of the multiple GW devices 400 based on the priority list 650 received from each of the multiple GW devices 400. This allows the server 100 to arbitrate redundant routes among the multiple GW devices 400.

[0144] Server 100 determines the second IP address of GW device 400C, and GW device 400A may set the second IP address of GW device 400C determined by Server 100 as the gateway address when configuring redundant routes. This allows Server 100 to determine the second IP address of GW device 400C in a way that does not conflict with the IP addresses of other devices, and allows GW device 400A to set an appropriate gateway address.

[0145] The second IP address of GW device 400C may belong to a different subnet than the second IP address of GW device 400A, which is used when GW device 400A communicates via the primary path. This makes it possible to distinguish communication on the redundant path from communication on the primary path.

[0146] [9. Supplementary Notes] The embodiments disclosed herein are illustrative in all respects and are not restrictive. The scope of the present invention is indicated by the claims rather than by the embodiments described above, and includes the meaning of equivalents to the claims and all modifications within that scope. [Explanation of symbols]

[0147] 10 Communication Systems 100 servers 101 Processors 102 Non-volatile memory 103 Volatile memory 104 Communication Interface (Communication I / F) 105 Server Programs 111 Attribute Information Receiving Unit 112 GW List Generation Unit 113 GW List Sending Section 114 Priority List Receiving Unit 115 Route Mediation Department 116 Mediation Result Transmission Section 200 Networks 210 External device 300 base stations 300A base station (1st base station) 300B,300C base station (2nd base station) 400 Gateway device (GW device) 400A Gateway device (First communication device) 400B, 400C, 400D Gateway device (second communication device) 401 Processor 402 Non-volatile memory 403 Volatile memory 404 First Communication Interface (First Communication I / F) 405 Second Communication Interface (Second Communication I / F) 406 Configuration Program 411 Attribute Information Transmission Unit 412 GW List Receiving Unit 413 GW setting section 414 Priority List Generation Unit 415 Route setting section 416 Priority List Transmission Unit 417 Mediation Result Receiving Department 450 Wired LAN 500 sensors 600 GW List 630 NAT tables 650 Priority List R1, R2 Redundant Path

Claims

1. A first communication device connected to the network via a first communication path through a first base station, A second communication device connected to the network via a second communication path through a second base station, A server capable of communicating with the first communication device and the second communication device, Equipped with, The second communication device transmits attribute information indicating the attributes of the second communication path, including the second base station, to the server. The server generates routing information for the first communication device to set a communication path based on the received attribute information. The first communication device sets up a redundant communication path via the second communication device and the second base station based on the routing information generated by the server. Communication system.

2. The routing information includes the identification information of the second base station, The first communication device sets the redundant communication route based on the identification information of the second base station included in the route setting information. The communication system according to claim 1.

3. The routing information includes carrier information relating to the telecommunications carrier operating the second base station, The first communication device sets the redundant communication route based on the carrier information included in the route setting information. The communication system according to claim 1.

4. The server generates the route setting information based on the attribute information received from each of the multiple second communication devices. The first communication device sets up a plurality of redundant communication paths based on the routing information generated by the server. The communication system according to claim 1.

5. The first communication device generates priority information indicating the priority of each of the multiple redundant communication paths based on the route setting information, and sets the multiple redundant communication paths based on the generated priority information. The communication system according to claim 4.

6. The first communication device determines the priority of each of the plurality of redundant communication paths based on at least one determination result of whether the first base station and the second base station are the same, and whether the first operator operating the first base station and the second operator operating the second base station are the same. The communication system according to claim 5.

7. When a failure is detected in the first communication path, the first communication device transmits the priority information to the server. The server adds prohibition information to the received priority information, indicating a redundant communication path that is prohibited from use among the multiple redundant communication paths. The first communication device sets up the plurality of redundant communication paths based on the priority information to which the prohibition information has been added. The communication system according to claim 5.

8. The prohibition information is determined for each of the multiple first communication devices based on the priority information received by the server from each of the first communication devices. The communication system according to claim 7.

9. The server determines the address of the second communication device, When the first communication device sets up the redundant communication path, it sets the address of the second communication device determined by the server as the gateway address. A communication system according to any one of claims 1 to 8.

10. A server capable of communicating with a first communication device connected to the network via a first communication path through a first base station, and a second communication device connected to the network via a second communication path through a second base station, A receiving unit that receives attribute information indicating the attributes of the second communication path, including the second base station, transmitted from the second communication device, A generation unit generates routing information for the first communication device to set a communication path based on the attribute information received by the receiving unit, A transmitting unit transmits the route setting information generated by the generation unit to the first communication device in order for the first communication device to set up a redundant communication route via the second communication device and the second base station, Equipped with, server.

11. A communication device that is connected to a network via a first communication path through a first base station, A receiving unit that receives routing information from a server, which is generated based on attribute information indicating the attributes of the second communication path, including the second base station, transmitted from other communication devices connected to the network via the second communication path through the second base station, A routing unit sets a redundant communication route via the other communication device and the second base station based on the routing information received by the receiving unit, Equipped with, Communication device.

12. A computer program for causing a computer to function as a server capable of communicating with a first communication device connected to a network via a first communication path through a first base station, and a second communication device connected to the network via a second communication path through a second base station, To the aforementioned computer, The steps include receiving attribute information indicating the attributes of the second communication path, including the second base station, transmitted from the second communication device, The steps include: generating routing information for the first communication device to set a communication path based on the received attribute information; The first communication device transmits the generated routing information to the first communication device in order to configure a redundant communication route via the second communication device and the second base station. To execute Computer program.

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