JP2019087828A - Communication device, management server, control method, and program - Google Patents

Abstract

To provide a communication device, management server, control method, and program that can measure communication quality with accuracy during a non-communication period.SOLUTION: A communication device is connected to an opposite communication device via a communication path and communicates by a session established on the communication path. The communication device includes: a generation unit for generating a test packet corresponding to a characteristic of the session; and a measuring unit for measuring the communication quality of the communication path by transmitting the test packet to the communication path during a non-communication period when communication is not performed.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a communication apparatus, a management server, a control method, and a program.

  Non-communication networks are susceptible to interference and communication quality is unstable. Therefore, there is known a technique for measuring the communication quality in real time and selecting the communication path with the good communication quality to maintain the stability of the communication. Patent Document 1 can measure communication quality by transmitting and receiving a small amount of test data between transfer apparatuses using PING even in a non-communication period (for example, sleep state) in which communication is not performed. A data transfer device is described.

JP 2012-80394 A

OpenFlow Switch Specification Version 1.4.0. (Wire Protocol 0x05) October 14, 2013

  However, in Patent Document 1, since quality measurement is performed using a small amount of test data, it is difficult to accurately measure the communication quality of actual communication data during communication during a non-communication period.

  The present invention has been made in view of the above problems, and it is an object of the present invention to provide a communication apparatus, a management server, a control method, and a program capable of accurately measuring communication quality during no communication period. Do.

  According to one aspect of the present invention, there is provided a communication device connected to a opposing communication device via a communication path, and performing communication by a session established on the communication path, wherein a test packet corresponding to the characteristics of the session is used. A generation unit generating the measurement unit, and a measurement unit measuring the communication quality of the communication route by transmitting the test packet to the communication route during the non-communication period in which the communication is not performed. A communication device is provided.

  According to another aspect of the present invention, there is provided a control method of a communication apparatus connected to a facing communication apparatus via a communication path and performing communication by a session established on the communication path, according to the characteristics of the session. Generating a test packet, and measuring the communication quality of the communication path by transmitting the test packet to the communication path during a non-communication period in which the communication is not performed. A control method is provided.

  According to another aspect of the present invention, there is provided a program for controlling a communication device connected to a facing communication device via a communication route and performing communication by a session established on the communication route, the computer comprising Generating a test packet according to the characteristics of the session; and measuring the communication quality of the communication path by transmitting the test packet to the communication path during a non-communication period in which the communication is not performed. A program is provided which is characterized in that

  According to the present invention, a communication device, a management server, a control method, and a program capable of accurately measuring communication quality during a non-communication period are provided.

It is a block diagram showing the network composition of the communication system concerning a 1st embodiment. It is a block diagram of a controller concerning a 1st embodiment. It is a hardware block diagram of a controller concerning a 1st embodiment. It is a conceptual diagram of the process in the communication system which concerns on 1st Embodiment. It is a time chart showing communication between gateways concerning a 1st embodiment. It is a flowchart showing operation | movement of the controller which concerns on 1st Embodiment. It is a flowchart showing operation | movement of the controller which concerns on 2nd Embodiment. It is a block diagram showing the network composition of the communication system concerning a 3rd embodiment. It is a block diagram of a controller concerning a 3rd embodiment. It is a flowchart showing operation | movement of the controller which concerns on 3rd Embodiment. It is a schematic block diagram of the communication apparatus which concerns on 4th Embodiment. It is a schematic block diagram of the communication apparatus concerning 5th Embodiment.

First Embodiment
FIG. 1 is a block diagram showing a network configuration of a communication system according to the present embodiment. The communication system is, for example, an in-plant system for monitoring a production line, quality control and the like, and includes a gateway 10, a gateway 20, a terminal device 30, an IP (Internet Protocol) device 40, and a sensor 41. The gateway 10 is a master unit, and can communicate with the gateway 20 which is a slave unit according to a plurality of different wireless communication methods.

  Here, the wireless communication method is, for example, a Wi-Fi defined by IEEE (Institute of Electrical and Electronic Engineers) 802.11a, IEEE 802.11b, IEEE 802.11g, IEEE 802.11n, IEEE 802.11 ac, IEEE 802.11 ah, or the like. (Registered trademark) may be a communication method. Further, the wireless communication method may be BLE (Bluetooth Low Energy) (registered trademark) communication method defined by IEEE 802.15.1, ZigBee (registered trademark) communication method defined by IEEE 802.15.4, or the like. The wireless communication method may be communication based on a mobile communication standard such as LTE (Long Term Evolution) or 4G (4th Generation), in addition to communication based on the wireless local area (LAN) standard.

  The gateway 10 is, for example, a communication device such as an edge computer, a portable terminal, or an embedded device, and is connected to the gateway 20 via a wireless communication network. On the wireless communication network, two communication paths (wlan0, wlan1) having different frequencies (channels) or different wireless communication systems are set, and the communication between the gateway 10 and the gateway 20 is the same as that of these communication paths. It is done using either. The number of communication paths is not limited to two, and three or more communication paths may be established.

  Devices such as an IP device 40 and a sensor 41 are connected to the gateway 20. The device is a device that does not have a network connection function or a device that has a network connection function, and is, for example, a field device installed in a factory or the like. The device may be a machine tool, an industrial robot, a programmable logic controller (PLC), a radio frequency identifier (RFID) tag, or the like in addition to the IP device 40 and the sensor 41. Different devices may be connected to each gateway 20. For example, in FIG. 1, an IP device 40 is connected to one gateway 20, and a sensor 41 is connected to the other gateway 20. The gateway 20 transfers data received from the device to the gateway 10 and transfers data received from the gateway 10 to the device. The number of devices connected to the gateway 20 is not limited. Hereinafter, the IP device 40 will be described as an example of the device.

  The gateway 10 includes a controller 100, a switch 101, and communication interfaces 110, 111, 112. The controller 100 is connected to the communication interfaces 110, 111, 112 via the switch 101. The controller 100 has a function of an OpenFlow controller to which the technology of Non-Patent Document 1 is applied, and selects a communication path to be used for each session based on information acquired from the switch 101. The controller 100 can control the communication path by registering the flow entry specifying the communication path in the flow table of the switch 101.

  The switch 101 has the function of an open flow switch to which the technology of Non-Patent Document 1 is applied, and determines a transfer destination of a packet received from an external apparatus according to a flow entry. For example, the switch 101 transfers the packet received from the terminal device 30 to the communication interface 110 or the communication interface 111 according to the flow entry. The flow entry is registered in the flow table in the switch 101.

  The communication interfaces 110 and 111 are communication modules corresponding to the above-described wireless communication system. In FIG. 1, the communication interface 110 implements communication in the first communication path wlan0, and the communication interface 111 implements communication in the second communication path wlan1. The communication interfaces 110 and 111 also have a function of measuring communication quality (quality information) such as communication bandwidth (communication speed), delay, number of retransmissions, etc., for each communication path. The communication interface 112 is a communication module based on a standard such as Ethernet (registered trademark) or USB (Universal Serial Bus), and implements wired communication with the terminal device 30. Communication between the communication interface 112 and the terminal device 30 may be wireless. Also, the gateway 10 may be connected to the Internet via the communication interface 112, and can also transmit data acquired from the IP device 40 via the gateway 20 to a cloud server or the like on the Internet.

  The gateway 20 may have a communication application program (hereinafter, communication application) installed, or may have an IP device 40 connected. The communication application and the IP device 40 perform communication via a session established using either wlan0 or wlan1.

  The gateway 20 is a communication device similar to the gateway 10, and is connected to the gateway 10 via a wireless communication network. The number of gateways 20 connected to one gateway 10 is not limited. A terminal device 30 is connected to the gateway 10. The terminal device 30 is, for example, a personal computer for managing the IP device 40, and transmits and receives data between the IP device 40 via the gateway 10 and the gateway 20.

  The gateway 20 includes a controller 200, a switch 201, and communication interfaces 210, 211, and 212. The controller 200, the switch 201, and the communication interfaces 210 and 211 have the same functions as the controller 100, the switch 101, and the communication interfaces 110 and 111, respectively. The communication interface 212 is a communication module similar to the communication interface 112, and implements wired or wireless communication with the IP device 40.

  FIG. 2 is a block diagram of a controller according to the present embodiment. The controller 100 includes an information collection unit 121, a packet generation unit 122, a quality measurement unit 123, and a path switching unit 124. The information collection unit 121 collects statistical information for each session from the switch 101. The statistical information includes the number of received packets, the number of received bytes, the session duration time, and the like, and can be acquired, for example, by transmitting an open flow statistical information acquisition request to the switch 101.

  Further, the information collection unit 121 can specify the communication application or device that has established the session based on the packet information acquired from the switch 101. For example, as described in JP-A-2016-178530, the information collecting unit 121 can specify a communication application from system information of an operating system (OS).

  The packet generation unit 122 estimates characteristics for each session based on the statistical information collected by the information collection unit 121, and generates a test packet according to the characteristics of the session. For example, the packet generation unit 122 determines the size of the test packet, the test packet transmission frequency, the transport protocol for processing the test packet, and the like according to the actual data packet (communication packet) being communicated in the session. Do. The transport protocol is, for example, TCP (Transmission Control Protocol) or UDP (User Datagram Protocol).

  The quality measurement unit 123 measures the communication quality of the communication path by transmitting the test packet to the communication path in which the session is established. The measurement by the test packet is performed during a no communication period in which communication is not performed in the session. The quality measurement unit 123 performs quality measurement in cooperation with the quality measurement unit of the gateway 20 that is the transmission destination of the test packet. When there is an intermediate node that relays a packet in the communication path to be subjected to quality measurement, the information on the intermediate node is shared in advance between gateway 10 and gateway 20 so that the influence of the intermediate node is considered. deep. Note that the quality measurement unit 123 may use the test packet to measure the quality of the communication path in which the session is not established. The function of the quality measurement unit 123 can be realized by a dedicated application program (hereinafter, measurement application).

  The path switching unit 124 determines, based on the result of the quality measurement, whether to switch the communication path in which the session is currently established to another communication path. For example, the path switching unit 124 can switch the communication path by registering the flow entry in which the communication path is defined for each session in the switch 101 using the open flow technique.

  FIG. 3 is a hardware block diagram of the controller according to the present embodiment. The controller 100 includes a CPU 131, a memory 132, a storage device 133, and an input / output I / F (Interface) 134. The CPU 131 performs a predetermined operation in accordance with a program stored in the memory 132 and the storage device 133, and has a function of controlling each part of the controller 100. The CPU 131 also executes a program for realizing the functions of the information collection unit 121, the packet generation unit 122, the quality measurement unit 123, and the path switching unit 124.

  The memory 132 is configured by a RAM (Random Access Memory) or the like, and provides a memory area necessary for the operation of the CPU 131. The storage device 133 may be, for example, a flash memory, a solid state drive (SSD), a hard disk drive (HDD), or the like. The storage device 133 stores a basic program such as an OS for operating the controller 100, a communication application, an application program such as a measurement application, information of the communication application, and the like. The input / output I / F 134 is an interface for inputting / outputting data to / from the switch 101 and the communication interfaces 110, 111, and 112.

  The hardware configuration shown in FIG. 3 is an example, and devices other than these may be added, or some devices may not be provided. For example, some functions may be provided by another device via a network, and the functions constituting the present embodiment may be distributed and realized in a plurality of devices.

  FIG. 4 is a conceptual view of processing in the communication system according to the present embodiment, and shows transition of the communication status between the gateway 10 and the gateway 20. As shown in FIG. In FIGS. 4A to 4D, it is assumed that the session is established at wlan1 and wlan0 is not used. First, in FIG. 4A, the session is in communication, and a communication packet is transmitted from the gateway 10 to the gateway 20 via wlan 1. The gateway 10 cooperates with the gateway 20 to collect session information from the switches 101 and 201 and the communication interfaces 111 and 211. The session information may include layer 1 to layer 4 information on communication packets, statistical information on communication packets, and information on communication applications or devices.

  Next, in FIG. 4B, the session is in the non-communication state, and the gateway 10 determines that the non-communication period has come based on the statistical information of the communication packet. Subsequently, in FIG. 4C, the gateway 10 generates a test packet based on the session information. Then, in FIG. 4D, the gateway 10 executes the measurement application and sends out a test packet to wlan1. The gateway 10 cooperates with the gateway 20 to measure the communication quality of wlan 1 based on the information from the communication interfaces 111 and 211.

  FIG. 5 is a time chart showing communication between gateways according to the present embodiment, and shows the state of the communication path in which the session is established. Here, the communication application or device that has established a session is assumed to have a characteristic of periodically transmitting communication packets. More specifically, the communication application or device has a communication period and a non-communication period, and periodically transmits a communication packet in the communication period, but does not transmit a communication packet in the non-communication period.

  At times T0 to T1, the gateway 10 sequentially transmits a plurality of communication packets to the gateway 20. Furthermore, at time T2 to T3, the gateway 10 sequentially transmits a plurality of communication packets to the gateway 20. The number of communication packets transmitted at times T2 to T3, the size of each packet, and the transmission interval are the same as those of the communication packets transmitted at times T0 to T1. That is, the same communication as the communication at time T0 to T1 is performed again at time T2 to T3 after a period of one cycle has elapsed from time T0.

  Time T4 is a time when one cycle of time has elapsed from time T2. The gateway 10 determines that the non-communication period has come when it detects that transmission of a communication packet in the next cycle is not performed although time for one cycle has elapsed from time T2 at time T4. Do. The gateway 10 determines the parameters of the test packet based on the parameters of the communication packet, and transmits the test packet generated based on the parameters to the gateway 20 at time T5.

  The parameters include the number of packets, packet size, transmission interval, protocol and the like. The parameters of the test packet are the same as the parameters of the communication packet transmitted at times T0 to T1 (or times T2 to T3). For example, the length of time T5 to T6 is the same as the length of time T0 to T1 (or time T2 to T3). When the parameters of the communication packet transmitted at time T0 to T1 and at time T2 to T3 are different, an average value of the parameters of the communication packet transmitted at time T0 to T3, for example, as a test packet parameter It can be used. The number of transmissions of the test packet in the non-communication period is not limited, and the test packet may be transmitted periodically.

  At time T7, the gateway 10 detects that a communication packet to be transmitted to the gateway 20 has been received. Thus, the gateway 10 determines that the non-communication period ends at time T7 and returns to the communication period. In the communication period, similarly to time T0 to T1 and time T2 to T3, the gateway 10 sequentially transmits a large number of communication packets to the gateway 20 at each of time T7 to T8 and time T9 to T10.

  FIG. 6 is a flowchart showing the operation of the controller according to the present embodiment. In the following description, it is assumed that a session is established at wlan0. The information collection unit 121 acquires session information for each session (step S101). For example, the information collection unit 121 transmits a Stats Request message to the switch 101, and acquires statistical information for each flow entry by the Stats Reply message from the switch 101. Here, the flow entry corresponds to the session one to one.

  Further, the information collection unit 121 specifies a communication application or device using a session based on the Packet In message received from the switch 101, and acquires information on the communication application or device from the storage device 133. This information includes, for example, QoS (Quality of Service) information required for the communication application. Further, the information collection unit 121 acquires, from the switch 101 and the communication interface 110, information such as a physical port number, a MAC address, an IP address, and a service port number related to a session.

  Next, the information collection unit 121 determines whether the current session state is a no communication period (step S102). The information collection unit 121 can determine that it is a non-communication period when it is detected that communication by a session has not been performed for a predetermined period based on statistical information. The predetermined period is set in advance based on the information of the communication application or the device.

  If it is determined that it is not a non-communication period (NO in step S102), the information collection unit 121 estimates session characteristics based on session information, and stores session characteristics in the storage device 133 (step S103). The session characteristics are represented by bandwidth, delay, jitter, packet loss, etc. according to the communication application or device, in addition to the above-mentioned parameters. Subsequently, the quality measurement unit 123 performs quality measurement using the communication packet (step S104). That is, the quality measurement unit 123 acquires the quality information of wlan 0 obtained from the communication packet communicated in the session from the switch 101 and the communication interface 110.

  If it is determined that it is a no communication period (YES in step S102), the packet generation unit 122 acquires session characteristics from the storage device 133, and generates a test packet according to the session characteristics (step S105). For example, the packet generation unit 122 determines the size of the test packet, the number of packets, the transmission interval, and the protocol as parameters of the test packet. Thus, as shown in FIG. 5, the characteristics of the test packet reflect the characteristics of the communication packet. Subsequently, the quality measurement unit 123 performs quality measurement using a test packet (step S106). That is, the quality measurement unit 123 transmits the test packet to wlan 0, and acquires the quality information of wlan 0 obtained from the test packet from the switch 101 and the communication interface 110.

  The path switching unit 124 selects a communication path to be used for the session based on the quality measurement obtained in the quality measurement process (step S104 or S106) (step S107). For example, when the communication quality of wlan0 currently used for the session does not satisfy the predetermined condition, the path switching unit 124 performs processing for switching wlan0 to wlan1. For example, the path switching unit 124 registers the flow entry in the switch 101 so that the communication packet received from the communication interface 112 to which the terminal device 30 is connected is transferred to the communication interface 111 connected to wlan1. .

  In the present embodiment, a test packet is generated according to the characteristics of the session based on the session information collected within the communication period. The quality measurement by such a test packet can obtain a result close to the quality measurement by an actual communication packet. Therefore, it is possible to accurately measure the communication quality in the non-communication period.

  Conventionally, there is known a technology that enables quality measurement by continuously transmitting communication data (replicated data) similar to that during communication, even during a non-communication period. However, the test packet of the present embodiment is not merely a duplicate of the actual communication packet. In this embodiment, since the test packet can be configured from a relatively small amount of packets that directly represent the characteristics of the communication packet, it is possible to suppress problems such as compression of the communication band by the test packet and an increase in processing load.

Second Embodiment
The communication system according to the second embodiment can perform quality measurement using test packets even for communication paths for which a session has not been established. Hereinafter, the communication system in the present embodiment will be described focusing on differences from the communication system according to the first embodiment.

  FIG. 7 is a flowchart showing the operation of the controller according to the present embodiment. In the following description, it is assumed that a session is established at wlan0. The processing (steps S201 to S206) from acquisition of session information to quality measurement by test packets is the same as steps S101 to S106 in the first embodiment, and thus the description thereof is omitted.

  The information collection unit 121 determines whether or not there is a non-communication route in which communication is not performed for another communication route in which a session is not established (step S207). That is, in the example of FIG. 1, it is determined whether or not communication is being performed in wlan1. The information collection unit 121 can grasp the communication status of wlan 1 based on the information acquired from the communication interface 111 connected to wlan 1, the statistical information acquired from the switch 101, and the like.

  If it is determined that there is a non-communication path (YES in step S207), the quality measurement unit 123 performs quality measurement using a test packet (step S208). That is, the quality measurement unit 123 transmits the test packet to wlan 1, and acquires the quality information of wlan 1 obtained by the test packet from the switch 101 and the communication interface 111. The test packet used here is the same as that generated in step S205. If it is determined that there is no non-communication path (NO in step S207), the quality measurement process using test packets (step S208) is not executed.

  The path switching unit 124 selects a communication path to be used for the session based on the quality information obtained in the quality measurement process (steps S204, S206, and S208) (step S209). For example, when the communication quality of wlan1 is higher than the communication quality of wlan0, the path switching unit 124 performs processing for switching the communication path used by the session to wlan1.

  According to the present embodiment, among the plurality of communication paths that can be used by a session, quality measurement using test packets is possible for other communication paths for which a session has not been established. That is, since the communication quality can be acquired in advance even if the communication path of the switching destination is in the non-communication state, it is possible to appropriately determine the switching of the communication path.

Third Embodiment
The communication system according to the third embodiment can share communication path quality information in a network. Hereinafter, the communication system in the present embodiment will be described focusing on differences from the communication system according to the first embodiment.

  FIG. 8 is a block diagram showing the network configuration of the communication system according to the present embodiment. The communication system is, for example, a wireless communication system built in a factory, and includes a plurality of communication terminals 60a, 60b, 60c and a management server 70. The communication terminal 60a can communicate with the communication terminals 60b and 60c by a plurality of different wireless communication methods. The communication terminals 60a, 60b, 60c have the same configuration. Hereinafter, in the case where the communication terminals are not distinguished, the end of the reference numerals is appropriately omitted.

  The communication terminal 60 is, for example, an edge computer, an embedded device, a portable terminal or the like provided in a mobile. The communication terminal 60a is connected to the communication terminals 60b and 60c via a wireless communication network. The communication terminal 60 includes a controller 600, a switch 601, and communication interfaces 610 and 611. In the present embodiment, the communication terminal 60b and the communication terminal 60c are located adjacent to each other, and located in the coverage area of the same access point in the wireless communication network.

  The controller 600 is connected to the communication interfaces 610 and 611 via the switch 601. The controller 600 has an open flow controller function, and the switch 601 has an open flow switch function. The hardware configuration of the controller 600 is the same as the hardware configuration of the controller 100 in the first embodiment. The communication interfaces 610 and 611 are the same as the communication interfaces 110 and 111 in the first embodiment.

  A communication application is installed in the communication terminal 60. The communication application establishes a session using either wlan0 or wlan1 and performs communication via the session. The communication terminal 60 may have a plurality of different communication applications installed.

  The management server 70 manages the communication status of the entire communication system network. The management server 70 periodically collects, from each of the communication terminals 60a, 60b, and 60c, quality information of the communication path measured by each communication terminal. The management server 70 can store the quality information collected from each communication terminal in a database or the like, and can provide the quality information to each communication terminal in response to a request from each communication terminal.

  The management server 70 also manages position information of the communication terminals 60a, 60b, and 60c. For example, the management server 70 receives GPS (Global Positioning System) information provided to each communication terminal from each of the communication terminals 60a, 60b, and 60c, or each communication terminal is received from an access point in a wireless communication network. Acquire radio wave intensity information. Thereby, the management server 70 can grasp the relative positional relationship between the communication terminals 60a, 60b, 60c.

  FIG. 9 is a block diagram of a controller according to the present embodiment. The controller 600 includes an information collection unit 621, an information sharing unit 622, a quality estimation unit 623, and a path switching unit 624. The information collecting unit 621 has the same function as the information collecting unit 121 in the first embodiment.

  When there is an adjacent communication terminal, the information sharing unit 622 acquires, from the management server 70, quality information measured by the adjacent communication terminal. Here, adjacent means that the relative positional relationship is close. In the example of FIG. 8, the communication terminal 60b acquires the quality information measured by the communication terminal 60c, and the communication terminal 60c acquires the quality information measured by the communication terminal 60b.

  The quality estimation unit 623 estimates the communication quality of the communication path related to the own communication terminal 60 based on the quality information measured by the adjacent communication terminal 60. For example, it is assumed that a first session is established between the communication terminals 60a and 60b, and a second session is established between the communication terminals 60a and 60c. In this case, the communication terminal 60b can estimate the communication quality on the communication path of the first session from the communication quality on the communication path of the second session in the non-communication period of the first session.

  The path switching unit 624 determines whether to switch the communication path in which the session is currently established to another communication path, based on the result of the quality estimation. For example, the path switching unit 624 can switch the communication path by registering the flow entry in which the communication path is defined for each session in the switch 601 using the open flow technique.

  FIG. 10 is a flowchart showing the operation of the controller according to the present embodiment. Here, the operation of the controller 600 of the communication terminal 60b will be described. It is assumed that the first session between the communication terminals 60a and 60b and the second session between the communication terminals 60a and 60c are both established in wlan0. The processes from acquisition of session information to quality measurement by communication packet (steps S301 to S304) are the same as steps S101 to S104 in the first embodiment, and thus the description thereof is omitted.

  If it is determined that it is a no-communication period (YES in step S302), the information sharing unit 622 shares information on wlan0 with a nearby communication device (step S305). For example, the information sharing unit 622 transmits, to the management server 70, the communication characteristics of the first session and the quality information of wlan0 measured during the communication of the first session. The information sharing unit 622 also receives, from the management server 70, the communication characteristics of the second session collected by the communication terminal 60c and the quality information of wlan0 measured during communication of the second session by the communication terminal 60c. Furthermore, the information sharing unit 622 transmits, to the management server 70, positional information on the communication terminal 60b or received radio wave intensity information from an access point to which the communication terminal 60b is connected in the wireless communication network.

  If the communication characteristic of the first session and the communication characteristic of the second session are similar, the quality estimation unit 623 estimates the quality information based on the information from the communication terminal 60c (step S306). That is, the quality estimation unit 623 estimates the quality information of wlan0 at the time of communication of the first session based on the quality information of wlan0 measured during the communication of the second session in the communication terminal 60c. The similarity of the communication characteristics can be determined based on, for example, the type of communication application that has established a session, the QoS required of the communication application, and the like.

  For example, when the communication application is common among the sessions, and the communication terminal 60b and the communication terminal 60c are located within a predetermined range, the quality estimation unit 623 measures the quality information of the communication terminal 60b based on the quality information measured by the communication terminal 60c. Use as information. The predetermined range is, for example, the coverage of the same access point. Also, the quality estimation unit 623 may perform weighting in accordance with the distance between the communication terminals 60b and 60c, the similarity of the communication characteristics of the communication application, and the like. That is, the value obtained by multiplying the quality information in the communication terminal 60c by weighting can be used as the quality information in the communication terminal 60b.

  The path switching unit 624 selects the communication path used for the first session based on the quality information obtained in the quality measurement process (step S304) and the quality estimation process (step S306) (step S307). For example, when the communication quality of wlan0 currently used for the first session does not satisfy the predetermined condition, the path switching unit 624 performs switching processing for switching wlan0 to wlan1.

  According to the present embodiment, when there is a second session in which the communication path is common to the first session, similarity of characteristics is determined between the first session and the second session. Since the quality information in the no session period of the first session can be estimated based on the quality information measured during the communication of the similar second session, the quality information of the first session can be accurately obtained even in the no session period. It is possible to

Fourth Embodiment
FIG. 11 is a schematic configuration diagram of a communication device according to the present embodiment. The communication device 10 is a communication device that is connected to the opposite communication device via a communication path and performs communication by a session established in the communication path, and includes a generation unit 1001 and a measurement unit 1002. The generation unit 1001 generates a test packet according to the characteristics of the session. The measurement unit 1002 measures the communication quality of the communication path by transmitting the test packet to the communication path during a non-communication period in which communication is not performed.

Fifth Embodiment
FIG. 12 is a schematic configuration diagram of a communication apparatus according to the present embodiment. The communication device 60 is a communication device that is connected to the opposing communication device via the communication path and performs communication by the session established in the communication path, and includes a collection unit 1101, an acquisition unit 1102, and an estimation unit 1103. The collection unit 1101 collects characteristics of the session. The acquisition unit 1102 acquires characteristics of another session from another communication device that performs communication by another session having a common communication path with the session. The estimation unit 1103 determines the similarity between the characteristics of the session and the characteristics of the other sessions. If the characteristics are similar to each other, estimation section 1103 calculates the communication path of the session based on the quality information of the communication path of another session measured by another communication device during a non-communication period in which communication by session is not performed. Estimate quality information.

[Modified embodiment]
The present invention is not limited to the above-described embodiment, and can be appropriately modified without departing from the spirit of the present invention. For example, although the controller 100 is described as having the function of the open flow controller in the above embodiment, the function of the open flow controller may be provided separately from the controller 100. In the third embodiment, the management server 70 manages information of the entire network, but the communication terminals 60a, 60b, and 60c may directly transmit and receive position information, quality information, and the like.

  Some or all of the embodiments described above may be described as in the following appendices, but are not limited thereto.

(Supplementary Note 1)
A communication device that is connected to an opposing communication device via a communication path and performs communication by means of a session established on the communication path,
A generation unit that generates a test packet according to the characteristics of the session;
A communication apparatus comprising: a measurement unit configured to measure communication quality of the communication path by transmitting the test packet to the communication path during a non-communication period in which the communication is not performed.

(Supplementary Note 2)
The communication device according to claim 1, further comprising: a collection unit that collects statistical information of the session from a switch that performs packet transfer related to the session.

(Supplementary Note 3)
The communication apparatus according to claim 2, wherein the non-communication period is determined based on the statistical information.

(Supplementary Note 4)
The communication apparatus according to claim 2 or 3, wherein the generation unit estimates the characteristic based on the statistical information collected outside the no-communication period.

(Supplementary Note 5)
The communication according to appendix 4, wherein the generation unit determines at least one of a size of the test packet, a transmission frequency of the test packet, and a transport protocol for processing the test packet. apparatus.

(Supplementary Note 6)
The switch according to any one of appendices 2 to 5, wherein the switch is an open flow switch to which an open flow (OpenFlow) technology is applied, and the session is defined by a flow entry registered in the switch. Communication device.

(Appendix 7)
The measurement unit is characterized by performing measurement of communication quality by the test packet with respect to the other communication path which can be used by the session, which is another communication path not in communication. The communication device according to any one of 1 to 6.

(Supplementary Note 8)
The communication apparatus according to claim 7, wherein when the communication quality of the other communication path is higher than that of the communication path, the communication path is switched to the other communication path.

(Appendix 9)
The communication apparatus according to any one of the above 1 to 8, wherein the measurement unit performs measurement using the test packet in cooperation with the opposing communication apparatus.

(Supplementary Note 10)
A control method of a communication apparatus which is connected to an opposing communication apparatus via a communication path and performs communication by a session established in the communication path,
Generating a test packet according to the characteristics of the session;
Measuring the communication quality of the communication path by transmitting the test packet to the communication path during a non-communication period in which the communication is not performed.

(Supplementary Note 11)
A program for controlling a communication apparatus connected to an opposing communication apparatus via a communication path and performing communication by a session established on the communication path,
On the computer
Generating a test packet according to the characteristics of the session;
And transmitting the test packet to the communication path during a non-communication period in which the communication is not performed, thereby performing the step of measuring the communication quality of the communication path.

(Supplementary Note 12)
A communication device that is connected to an opposing communication device via a communication path and performs communication by means of a session established on the communication path,
A collection unit that collects characteristics of the session;
An acquisition unit configured to acquire characteristics of the other session from another communication device performing communication by another session having a common communication path with the session;
When the characteristics of the session and the characteristics of the other session are similar, the communication path quality information of the other session measured by the other communication device during a non-communication period in which communication by the session is not performed And an estimation unit configured to estimate quality information of the communication path of the session based on the above.

(Supplementary Note 13)
A management server which provides the characteristics of the other session and the quality information collected by the other communication device to the communication device according to appendix 12.

10, 20 gateway (communication device)
30 terminal device 40 IP device 41 sensor 60 communication terminal (communication device)
70 management server 100, 200 controller 101, 201 switch 110, 111, 112, 210, 211, 212 communication interface 121 information collection unit 122 packet generation unit 123 quality measurement unit 124 path switching unit 131 CPU
132 Memory 133 Storage Device 134 Input / output I / F
600 controller 601 switch 610, 611 communication interface 621 information collection unit 622 information sharing unit 623 quality estimation unit 624 route switching unit 1001 generation unit 1002 measurement unit 1101 collection unit 1102 acquisition unit 1103 estimation unit

Claims (13)

A communication device that is connected to an opposing communication device via a communication path and performs communication by means of a session established on the communication path,
A generation unit that generates a test packet according to the characteristics of the session;
A communication apparatus comprising: a measurement unit configured to measure communication quality of the communication path by transmitting the test packet to the communication path during a non-communication period in which the communication is not performed.   The communication apparatus according to claim 1, further comprising: a collection unit that collects statistical information of the session from a switch that performs packet transfer related to the session.   The communication apparatus according to claim 2, wherein the non-communication period is determined based on the statistical information.   The communication apparatus according to claim 2, wherein the generation unit estimates the characteristic based on the statistical information collected outside the no-communication period.   5. The apparatus according to claim 4, wherein the generation unit determines at least one of a size of the test packet, a transmission frequency of the test packet, and a transport protocol for processing the test packet. Communication device.   The switch according to any one of claims 2 to 5, wherein the switch is an open flow switch to which an open flow (OpenFlow) technology is applied, and the session is defined by a flow entry registered in the switch. The communication device according to claim 1.   The measurement unit is characterized in that measurement of communication quality by the test packet is performed on the other communication path that is not in communication and that can be used by the session. The communication device according to any one of Items 1 to 6.   8. The communication apparatus according to claim 7, wherein the communication path is switched to the other communication path when the communication quality of the other communication path is higher than the communication quality of the communication path.   The communication device according to any one of claims 1 to 8, wherein the measurement unit performs measurement using the test packet in cooperation with the opposing communication device. A collection unit that collects characteristics of the session;
An acquisition unit configured to acquire characteristics of the other session from another communication device performing communication by another session having a common communication path with the session;
When the characteristics of the session and the characteristics of the other session are similar, the communication path quality information of the other session measured by the other communication device during a non-communication period in which communication by the session is not performed The communication apparatus according to claim 1, further comprising: an estimation unit configured to estimate quality information of the communication path of the session based on the above.   A management server which provides the characteristics of the other session and the quality information collected by the other communication device to the communication device according to claim 10. A control method of a communication apparatus which is connected to an opposing communication apparatus via a communication path and performs communication by a session established in the communication path,
Generating a test packet according to the characteristics of the session;
Measuring the communication quality of the communication path by transmitting the test packet to the communication path during a non-communication period in which the communication is not performed. A program for controlling a communication apparatus connected to an opposing communication apparatus via a communication path and performing communication by a session established on the communication path,
On the computer
Generating a test packet according to the characteristics of the session;
And transmitting the test packet to the communication path during a non-communication period in which the communication is not performed, thereby performing the step of measuring the communication quality of the communication path.

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