WO2018016183A1

WO2018016183A1 - Communication system and communication device

Info

Publication number: WO2018016183A1
Application number: PCT/JP2017/019823
Authority: WO
Inventors: 貴之佐々木; 勇太原
Original assignee: パナソニックＩｐマネジメント株式会社
Priority date: 2016-07-22
Filing date: 2017-05-29
Publication date: 2018-01-25
Also published as: JP6601774B2; JP2018014692A

Abstract

The present invention provides a communication system and a communication device which make it possible to create a state where a slave machine has entered a communication network in a shorter time even if a master machine and/or the slave machine is restarted. In a communication system (1), a salve machine (20) enters a communication network after search processing and authentication processing, and communicates with a master machine (10). The master machine (10) is provided with a processing unit (12) and a nonvolatile storage unit (13), and the slave machine (20) is provided with a processing unit (22) and a nonvolatile storage unit (23). The storage unit (13) and the storage unit (23) store entry information. A case where at least one of the slave machine (20) and the master machine (10) is restarted after the entry of the slave machine (20) into the communication network is assumed. In this case, the processing unit of this machine uses the entry information stored in the storage unit of the machine immediately before restarting to bring the slave machine (20) into the state of having entered the communication network without performing communication related to the search processing and the authentication processing with the other machine.

Description

Communication system and communication apparatus

The present invention relates to a communication system and a communication device, and more particularly to a communication system and a communication device that enable communication through a search process and an authentication process.

Conventionally, there is a communication system in which a child device searches for a communication network including the parent device, performs authentication processing with the parent device, and enters the communication network (for example, Patent Document 1).

Patent Document 1 discloses a technology in which a meter-reading device (child device) that has entered a certain network (communication network) searches for another network having better communication quality and enters.

Consider a case where a power failure occurs in the communication system described in Patent Document 1 and a management device (master device) and a plurality of meter-reading devices (slave devices) belonging to the network (communication network) are restarted after the power failure is restored. In this case, the plurality of meter-reading devices that have entered the network need to search for a management device and perform authentication processing with the management device. In other words, when the management device and multiple meter-reading devices are restarted, communication traffic on the network increases, and it takes time for all of the multiple meter-reading devices to enter the network of management devices. Long time is required.

Japanese Patent Laying-Open No. 2015-201721

The present invention has been made in view of the above reasons, and even when at least one of the parent device and the child device is restarted, the child device can enter the communication network in a shorter time. An object is to provide a communication system and a communication apparatus.

In a communication system according to an aspect of the present invention, a child device enters the communication network through a search process for searching for a parent device included in an enterable communication network and an authentication process for entering the communication network. Communicate with the parent device. Each of the master unit and the slave unit includes a processing unit and a nonvolatile storage unit. The storage unit stores entry information. The entry information includes at least path information representing a communication path from the slave unit to the master unit, and an encryption key used when encrypting and decrypting communication between the slave unit and the master unit. . When the search process and the authentication process are performed, the processing unit uses the path information and the encryption key obtained by the search process and the authentication process to make the slave unit enter the communication network. . When at least one device of the child device and the parent device is restarted after the child device enters the communication network, the processing unit of the device is stored in the storage unit of the device immediately before the restart. The slave unit is made to enter the communication network without performing communication related to the search process and the authentication process with the other device.

In a communication system according to an aspect of the present invention, a child device enters the communication network through a search process for searching for a parent device included in an enterable communication network and an authentication process for entering the communication network. Communicate with the parent device. Each of the master unit and the slave unit includes a processing unit and a nonvolatile storage unit. The storage unit stores entry information. The entry information includes at least path information representing a communication path from the slave unit to the master unit, and an encryption key used when encrypting and decrypting communication between the slave unit and the master unit. . When the search process and the authentication process are performed, the processing unit uses the path information and the encryption key obtained by the search process and the authentication process to make the slave unit enter the communication network. . When at least one device of the child device and the parent device is restarted after the child device enters the communication network, the processing unit of the device is stored in the storage unit of the device immediately before the restart. It is determined whether or not the entry information is valid. The processing unit of the device uses the entry information when the entry information is valid, and communicates the slave unit with the other device without performing communication related to the search process and the authentication process. Enter the network.

The communication device according to one aspect of the present invention is used as a parent device or a child device of any one of the above communication systems.

According to the present invention, even when at least one of the parent device and the child device is restarted, the child device can enter the communication network in a shorter time.

FIG. 1 is a block diagram of a communication system according to Embodiment 1 of the present invention. FIG. 2 is a sequence diagram showing a flow of processing when a child device newly enters the communication network of the parent device in the communication system same as above. FIG. 3 is a sequence diagram showing a flow of processing related to re-entry when the parent device and the child device are restarted in the communication system. FIG. 4 is a flowchart showing the base unit side setting process in the communication system same as above. FIG. 5 is a block diagram of a communication system according to a modification of the above. FIG. 6 is a flowchart showing parent device side setting processing in the communication system according to the second embodiment of the present invention. FIG. 7 is a flowchart showing a slave unit side setting process in the above communication system.

Embodiments and modifications described below are merely examples of the present invention, and the present invention is not limited to the embodiments and modifications, and the present invention is not limited to the following embodiments and modifications. Various modifications can be made in accordance with the design and the like as long as they do not depart from the technical idea of the above.

(Embodiment 1)
(1) Overview A multi-hop communication system (hereinafter referred to as a communication system) 1 according to the present embodiment includes a single parent device 10 and a plurality of child devices 20, as shown in FIG. Each of the master unit 10 and the plurality of slave units 20 is connected to a power line W1 that supplies power from the supplier to the customer facility. The customer facility is a detached house, an office, a store, a dwelling unit of an apartment house, a tenant of a building, and the form is not limited.

Each of the master unit 10 and the slave unit 20 is a communication device that performs power line carrier communication according to G3-PLC (Power Line Communication), which is a communication protocol for power line carrier communication. Each of the parent device 10 and the child device 20 constitutes a network (communication network) that performs power line carrier communication with each other via the power line W1. In addition, when identifying the some subunit | mobile_unit 20 separately, it describes as the subunit | mobile_unit 20a, the subunit | mobile_unit 20b, ..., subunit | mobile_unit 20n.

The subunit | mobile_unit 20 is provided for every customer facility, and has the function to transmit the predetermined data regarding each customer facility to the one main | base station 10. FIG. The base unit 10 has a function of acquiring predetermined data relating to each of the customer facilities from the plurality of slave units 20 and transmitting the data to a higher-level management device using an optical fiber line, a wide-area communication network such as the Internet, or the like. For example, a remote meter-reading system can be comprised when the main | base station 10 acquires meter-reading data, such as the electric power usage-amount, gas usage-amount, and water-use amount in each consumer facility, from the subunit | mobile_unit 20. FIG. In addition, each of the remote monitoring system and the customer facility in which the parent device 10 monitors the state of each device in the customer facility by transmitting and receiving predetermined information set in advance to and from the child device 20. It is also possible to configure a remote control system or the like that controls the state of the device.

In this communication network, the parent device 10 and the child device 20 normally transmit and receive signals to each other by proactive multi-hop communication. That is, in this communication network, communication is performed directly or indirectly between the parent device 10 and each child device 20, and the child device 20 that cannot directly communicate with the parent device 10 is connected to another child device within a communicable distance. Communication with the parent device 10 can be performed by the relaying of the communication packets by 20 in sequence.

(2) Structure Next, the structure of the main | base station 10 and the subunit | mobile_unit 20 which concern on this embodiment is demonstrated.

(2.1) Base Unit The base unit 10 includes a communication unit 11, a processing unit 12, and a storage unit 13, as shown in FIG. The base unit 10 has a CPU (Central Processing Unit) and a memory. The function of the processing unit 12 is realized by the CPU executing a program stored in the memory. Here, the program is provided through an electric communication line such as the Internet or recorded in a recording medium such as a memory card, but may be recorded in advance in a memory of a computer.

The communication unit 11 is a communication module that functions as a communication interface for performing communication with other communication devices (slave devices 20). As illustrated in FIG. 1, the communication unit 11 includes a RAM (Random Access Memory) 15 that is a volatile memory. The RAM 15 stores information necessary for communication. For example, information (PAN ID) for identifying a communication network, a slave device information table, a routing information table, an encryption key used when performing communication by encrypted communication, and the like are stored in the RAM 15. Here, the subunit | mobile_unit information table contains the identification information which identifies each of the subunit | mobile_unit 20 which has entered the communication network. The routing information table includes route information representing a communication route for each slave 20 that has entered the communication network. The path information includes at least identification information of the corresponding slave unit 20 and identification information of other slave units 20 existing on the communication path between the slave unit 20 and the master unit 10. The identification information is an address (short address) of the child device 20 in the communication network in which the child device 20 has entered. When communicating with the child device 20, the communication unit 11 realizes multi-hop communication using the route information of the communication target child device 20 included in the routing information table. The encryption key is used for encryption and decryption of information.

The processing unit 12 controls the entire processing of the base unit 10. The process part 12 performs the process regarding entry between the subunit | mobile_unit 20 which newly enters the communication network mentioned above. In addition, when the base unit 10 is restarted, the processing unit 12 performs processing related to re-entry with all the slave units 20 that have entered the communication network immediately before the restart.

The storage unit 13 includes a rewritable nonvolatile memory such as an EEPROM (Electrically-Erasable-and Programmable-Read-Only Memory), a flash memory, or the like. The storage unit 13 stores information (parent device entry information) obtained by the processing performed by the processing unit 12 (processing related to entry of a communication network with the child device 20). The entry information for the parent device includes the PAN ID, the address assigned to the own device (parent device address), the identification information of each child device 20 that has entered the communication network, and the child device 20 that has entered the communication network. Each communication path (path information) and an encryption key are included. Further, the entry information for the parent device stored in the storage unit 13 is updated by the processing unit 12.

(2.2) Handset Next, the configuration of handset 20 will be described. The subunit | mobile_unit 20 is provided with the communication part 21, the process part 22, and the memory | storage part 23 as shown in FIG. The subunit | mobile_unit 20 has CPU and memory. The function of the processing unit 22 is realized by the CPU executing a program stored in the memory. Here, the program is provided through an electric communication line such as the Internet or recorded in a recording medium such as a memory card, but may be recorded in advance in a memory of a computer.

The communication unit 21 is a communication module that functions as a communication interface that performs communication with other communication devices (the parent device 10 and the other child devices 20). As shown in FIG. 1, the communication unit 21 includes a RAM 25 that is a volatile memory. The RAM 25 stores information necessary for communication. For example, the PAN ID of the communication network to which the own device has entered, information for identifying the parent device 10 (parent device address), the identification information of the own device in the communication network to which it has entered (short address), the parent device 10 The path information and the encryption key are stored in the RAM 25. The communication unit 21 implements multi-hop communication using route information when performing communication with the parent device 10 or another child device 20.

The processing unit 22 controls the entire processing of the slave unit 20. When newly entering the communication network described above, the processing unit 22 performs processing related to entry between the parent device 10 and another child device 20 that has already entered the communication network. Moreover, the process part 22 performs the process regarding the reentry to the communication network which entered before the restart at the time of restart of the subunit | mobile_unit 20. FIG.

The storage unit 23 includes a rewritable nonvolatile memory such as an EEPROM or a flash memory. The storage unit 23 stores information (slave unit entry information) obtained by the process performed by the processing unit 22 (process related to entry of a communication network between the master unit 10 and another slave unit 20). Is done. The slave unit entry information includes identification information (short address) for identifying the own unit, a PAN ID of the communication network, a base unit address, a communication path (route information) to the base unit 10, and encrypted communication. And the encryption key used. Further, the slave unit entry information stored in the storage unit 23 is updated by the processing unit 22.

(3) Operation Here, operations of the parent device 10 and the child device 20 will be described.

(3.1) Operation of communication system (at the time of entry)
First, the operation when the handset 20 newly enters the communication system 1 will be described with reference to FIG. Here, the case where the subunit | mobile_unit 20n newly enters is assumed. Other slave units 20 (20a, 20b,...) Have already entered the communication network, and a communication path with the master unit 10 has been established.

The processing unit 22 of the slave unit 20n broadcasts a beacon request to the communication unit 21 (step S1).

The device that has received the beacon request from the child device 20n (here, the parent device 10 and the

child devices

20a and 20b), as its response, communication indicating the communication quality between the device that has received the beacon request and the parent device 10. A beacon response including information including quality information and information (route information) indicating a communication route to the parent device 10 and identification information for identifying the own device is transmitted (steps S2 to S4).

The processing unit 22 of the child device 20n determines an appropriate communication path using one or more beacon responses received by the communication unit 21. Specifically, the processing unit 22 of the slave unit 20n determines an appropriate communication path using at least one of the communication quality of the signal received as the beacon response, the number of hops to the master unit 10, and the like. For example, when communication quality is used, the processing unit 22 of the slave unit 20n determines a communication path through a device that has transmitted a beacon response having the highest communication quality among a plurality of beacon responses as an appropriate communication path. When the hop count is used, the communication path having the smallest hop count from the own device to the parent device 10 is determined as an appropriate communication route. The communication quality is calculated based on the signal S / N ratio.

The processing unit 22 of the child device 20n transmits an entry request including route information representing the determined communication route to the parent device 10 (step S5). When receiving the entry request from the child device 20n, the processing unit 12 of the parent device 10 transmits information (key information) related to the encryption key to the child device 20n via the communication path (step S6). The key information is information necessary for generating an encryption key stored in the RAM 15 and the storage unit 13, for example. The processing unit 22 of the slave unit 20n generates an encryption key based on the key information received from the master unit 10.

The processing unit 12 of the parent device 10 transmits address information in the communication network (information including the PAN ID, the parent device address, and identification information) to the child device 20n via the communication path (step S7). The timing at which the processing unit 12 of the parent device 10 transmits the address information is, for example, after transmitting the encryption key in step S6 and after receiving information indicating that the key information has been received from the child device 20n. The address information may be encrypted with an encryption key.

The processing unit 12 of the parent device 10 transmits completion information indicating completion of entry into the communication network to the child device 20n via the communication path (step S8). The timing at which the processing unit 12 of the parent device 10 transmits the completion information is, for example, after transmitting the address information in step S7 and after receiving information indicating that the address information has been received from the child device 20n. The completion information may be encrypted with an encryption key.

After transmitting the completion information, the processing unit 12 of the parent device 10 performs an update process for updating the information stored in the RAM 15 and the storage unit 13 (step S9). First, the processing unit 12 of the parent device 10 updates the child device information table and the routing information table stored in the RAM 15. The processing unit 12 of the parent device 10 adds the identification information (short address) of the child device 20n to the child device information table and the route information indicating the communication route from the own device to the child device 20n to the routing information table. Next, the processing unit 12 of the parent device 10 updates the parent device entry information by adding information related to the child device 20n to the parent device entry information stored in the storage unit 13. The information related to the child device 20n includes identification information of the child device 20n and route information indicating a communication route from the own device to the child device 20n. Thereby, the main | base station 10 can update the information memorize | stored in RAM15 and the memory | storage part 13 based on the information (identification information, path | route information) of the subunit | mobile_unit 20 which entered the communication network. Note that the processing unit 12 of the parent device 10 may update the information stored in the RAM 15 after updating the information stored in the storage unit 13.

In addition, when the subunit | mobile_unit 20 enters in the state where there is no subunit | mobile_unit 20 which has entered the communication network, the process part 12 of the main | base station 10 identifies the subunit | mobile_unit 20 in RAM15 in the subunit | mobile_unit information table. Information is registered in the routing information table as route information of the slave unit 20. Further, the processing unit 12 of the parent device 10 stores the PAN ID and parent device address of the communication network in the RAM 15. The processing unit 12 of the parent device 10 adds the PAN ID, the parent device address, the identification information of the child device 20, the route information of the child device 20, and the encryption key to the entry information for the parent device.

When receiving the completion information from the parent device 10, the processing unit 22 of the child device 20n performs a registration process for registering the child device entry information in the RAM 25 and the storage unit 23 (step S10). The processing unit 22 of the child device 20 includes a PAN ID, a parent device address, and identification information included in the address information received from the parent device 10, route information indicating a communication route to the parent device 10, and a processing unit of the child device 20n. The encryption key generated at 22 is written (retained) in the RAM 25. The processing unit 22 of the slave unit 20n writes (holds) the slave unit entry information including the PAN ID and the identification information, the route information indicating the communication route to the master unit 10, and the encryption key in the storage unit 23.

The processing unit 12 of the parent device 10 updates the encryption key at a predetermined timing (step S11). The processing unit 12 of the base unit 10 updates the encryption key stored in the RAM 15 to a new encryption key, and uses the encryption key included in the entry information for the base unit stored in the storage unit 13 as a new encryption key. Update to As a result, the processing unit 12 of the parent device 10 transmits information related to the new encryption key (new key information) to all the child devices 20 (20a, 20b,..., 20n) that have entered the communication network. (Step S12). The slave unit 20 (20a, 20b,..., 20n) that has received the new key information from the base unit 10 generates a new encryption key based on the new key information and updates the encryption key ( Steps S13 to S15). The processing units 22 of the slave units 20 a,..., 20 n use the encryption key stored in the RAM 25 and the encryption key included in the slave unit entry information stored in the storage unit 23 as new encryption keys. Update to Thereby, the process part 22 of the subunit | mobile_unit 20 can update the entry information for subunit | mobile_units.

Note that the update process performed by the processing unit 12 of the parent device 10 in step S9 is also performed when the child device 20 that has entered the communication network leaves the communication network. In this case, the processing unit 12 of the parent device 10 deletes information (identification information, route information) about the child device 20 to be detached from the child device information table and the routing information table in the RAM 15, and the child device information table and the routing information table. Update. The processing unit 12 of the parent device 10 deletes information (identification information, route information) related to the child device 20 leaving the parent device entry information stored in the storage unit 13 and updates the parent device entry information. . That is, when there is a change in the number of child devices 20 that have entered the communication network, the processing unit 12 of the parent device 10 updates the entry information for the parent device according to the change.

The series of processing from steps S1 to S4 is referred to as search processing (active scan) A1. A series of processing from steps S5 to S8 is referred to as authentication processing A2, and in particular, a series of processing from steps S5 to S6 is referred to as key distribution processing A3. The search process A1 is a process of searching for a parent device 10 in a communication network that can be entered in a communication network including the parent device 10. The authentication process A2 is a process for entering the communication network, and the key distribution process A3 is a process for distributing the encryption key from the parent device 10.

Further, in the communication system 1, the communication path (path information) stored in the RAM 15 and RAM 25 is periodically updated by the operation of the routing protocol. The communication path included in the slave unit entry information and the master unit entry information may be updated at a timing at which the communication paths stored in the RAM 15 and the RAM 25 are updated.

(3.2) Operation of communication system (when restarting)
Next, processing related to re-entry into the communication network when the parent device 10 and the child device 20 are restarted will be described with reference to FIG. Here, a power failure occurs in a state in which the slave units 20 (20a,..., 20n) have entered the communication network of the master unit 10, and after recovery from the power failure, the master unit 10 and the slave units 20 (20a,. .., 20n) will be described.

When the base unit 10 is restarted after the power failure is restored, the processing unit 12 of the base unit 10 performs base unit side setting processing (step S21). Details of the base unit setting process will be described later.

When the child device 20 (20a,..., 20n) is restarted after the power failure is restored, the processing unit 12 of the child device 20 performs a child device side setting process (steps S22 to S24). Specifically, the processing unit 22 of the child device 20 includes the identification information of the own device, the PAN ID, the parent device address, and the communication path to the parent device 10 included in the child device entry information stored in the storage unit 23. (Route information) and the encryption key are read from the storage unit 23. The processing unit 22 of the slave unit 20 sets the read identification information, PAN ID, master unit address, route information, and encryption key in the RAM 25 of the communication unit 21. Thereby, the subunit | mobile_unit 20 can enter into the communication network of the main | base station 10 again, without performing the search process A1 and the authentication process A2 which were mentioned above, ie, without communicating with the main | base station 10. FIG.

Next, details of the base unit setting process will be described with reference to FIG.

The processing unit 12 of the parent device 10 includes a PAN ID, a parent device address, identification information of each of the child devices 20a,..., 20n included in the parent device entry information stored in the storage unit 13, and the child device 20a. ,..., 20n and the encryption key are read from the storage unit 13 (step S31).

The processing unit 12 of the parent device 10 reads the read PAN ID, parent device address, identification information of each of the child devices 20a,..., 20n, route information and encryption keys of the child devices 20a,. The setting is made in the RAM 15 of the communication unit 11 (step S32). The processing unit 12 of the parent device 10 generates a child device information table including identification information of each of the child devices 20a, ..., 20n and a routing information table including route information of the child devices 20a, ..., 20n. And stored in the RAM 15. The processing unit 12 of the parent device 10 stores the PAN ID and the parent device address in the RAM 15. Thereby, the main | base station 10 can re-enter the subunit | mobile_unit 20 to a communication network, without performing the search process A1 and authentication process A2 which were mentioned above, ie, without communicating with the subunit | mobile_unit 20. FIG.

The processing unit 12 of the parent device 10 compares the child device information table with the routing information table, and information on the child device 20 managed by the child device information table and the child device 20 managed by the routing information table. It is determined whether or not there is a difference between the information (steps S33 and S34). Specifically, the processing unit 12 of the parent device 10 determines whether or not the child device 20 managed by only one of the child device information table and the routing information table exists. At this time, the processing unit 12 of the parent device 10 deletes information managed by only one table.

If it is determined that there is a difference (there is a child device 20 that is managed by only one table) (“Yes” in step S34), the processing unit 12 has the child device 20 that is managed by only one table. The communication unit 11 is controlled to transmit a withdrawal request to the terminal (step S35).

If it is determined that there is no difference (“No” in step S34), the process ends.

Hereinafter, the operation of the slave unit 20 when the master unit 10 transmits a withdrawal request to the slave unit 20 will be described.

When the communication unit 21 receives a withdrawal request from the parent device 10, the processing unit 22 of the child device 20 receives the PAN ID, its own identification information (short address) stored in its own RAM 25, Discard path information and encryption key. The processing unit 22 of the child device 20 further discards the child device entry information stored in the storage unit 23 of the own device. After leaving the communication network, the slave unit 20 performs the above-described search process A1 and authentication process A2 through communication with the master unit 10, and reenters the communication network.

(4) Modifications Modifications of the above embodiment are listed below. Note that the modifications described below can be applied in appropriate combination with the above embodiment.

In the above embodiment, the address information is transmitted after the encryption key is transmitted in the operation when entering the communication network. However, the present invention is not limited to this configuration. The address information may be transmitted simultaneously with the encryption key.

In the above embodiment, in the base unit 10, the slave unit information table, the routing information table, and the encryption key are stored in the RAM 15 of the communication unit 11. The RAM 25 is configured to be held respectively. However, it is not limited to this configuration. In the parent device 10, the child device information table, the routing information table, and the encryption key may be held in the RAM 16 provided in the processing unit 12 (see FIG. 5). Moreover, in the subunit | mobile_unit 20, PAN ID, identification information, route information, and an encryption key may be hold | maintained at RAM26 provided in the process part 22 (refer FIG. 5). In this case, the processing unit 12 of the parent device 10 includes hardware such as a CPU and a RAM 16 and various programs (software) executed by the CPU. The processing unit 22 of the slave unit 20 includes hardware such as a CPU and a RAM 26 and various programs (software) executed by the CPU. After the search process A1 and the authentication process A2 are performed, the processing unit 12 of the base unit 10 stores the identification information and path information of the mobile unit 20 that has newly entered the communication network, a mobile unit information table held in the RAM 16, Each table is updated by adding to the routing information table. The update of the entry information for the master unit is the same as that in the above embodiment. After the search processing A1 and the authentication processing A2 are performed, the processing unit 22 of the slave device 20 writes (holds) the identification information and route information of the own device in the RAM 26. The registration of the slave unit entry information in the storage unit 23 is the same as in the above embodiment.

Further, the base unit 10 may store the handset information table, the routing information table, and the encryption key in a distributed manner in the RAM 15 and the RAM 16 of the communication unit 11. Similarly, the subunit | mobile_unit 20 may distribute | distribute and store PAN ID, identification information, path | route information, and an encryption key in RAM25 of the communication part 21, and RAM26.

In the above embodiment, the timing for performing re-entry processing is after restoration from a power failure. The timing for performing the re-entry process is not limited to this timing. The re-entry process is performed when at least one of the parent device 10 and the child device 20 needs to be restarted for some reason. For example, the re-entry process may be performed when the firmware of the parent device 10 is restarted after being updated. In this case, in the re-entry process, only the parent device side setting process shown in FIG. 3 is performed, and the child device 20 is not processed. Alternatively, the re-entry process may be performed at the time of restart after the firmware of the slave unit 20 is updated. In this case, in the re-entry process, only the slave unit setting process shown in FIG. 3 is performed, and the master unit 10 does not perform the process.

In the above embodiment, the slave unit 20 that has received the withdrawal request from the master unit 10 stores the PAN ID, identification information, path information, and encryption key stored in the RAM 25 of the host unit in the storage unit 23 of the host unit. The entry information for each handset is discarded. However, it is not limited to this configuration. The slave device 20 that has received the withdrawal request from the master device 10 is in a state where both the search process A1 and the authentication process A2 are performed, a state where only the search process A1 is performed, a state where only the authentication process A2 is performed, and a part of the authentication process A2 Any of the states in which the above process is performed may be set. Specifically, the slave unit 20 that has received the withdrawal request from the master unit 10 discards at least one information or data among the PAN ID, identification information, path information, and encryption key stored in the RAM 25 of the own unit. That's fine. In this case, the slave unit 20 that has received the withdrawal request from the master unit 10 discards the same information or data as the information or data to be discarded from the RAM 25 from the slave unit entry information. For example, the slave unit 20 that has received a withdrawal request from the master unit 10 discards the encryption key from its own RAM 25 and discards the encryption key from the slave unit entry information stored in the storage unit 23 of its own unit. Also good. When transmitting the entry request to the master unit 10 to obtain the encryption key, the slave unit 20 transmits the identification information in addition to the route information. In the parent device 10, it is possible to distinguish whether it is an entry request from the child device 20 that has received the withdrawal request or an entry request from the child device 20 that requests a new entry.

In the above embodiment, the communication is performed between the parent device 10 and the child device 20 by multi-hop communication using G3-PLC. However, the present invention is not limited to this configuration. The communication between the parent device 10 and the child device 20 may be wireless multi-hop communication.

In the above embodiment, communication is performed between the parent device 10 and the child device 20 by multi-hop communication, but the communication method is not limited to this. You may communicate between the main | base station 10 and the subunit | mobile_unit 20 by another communication system.

In the above embodiment, the base unit 10 performs the processing of steps S33 to S35 shown in FIG. However, the processing of steps S33 to S35 is not limited to when the parent device 10 is restarted, and may be performed periodically.

(Embodiment 2)
The communication system 1 according to the present embodiment will be described with reference to FIGS. 6 and 7 with a focus on differences from the first embodiment. The communication system 1 of the present embodiment is different from the first embodiment in that an expiration date is set for the encryption key. Hereinafter, the same components as those of the first embodiment are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

In the communication system 1 of the present embodiment, the processing when at least one of the parent device 10 and the child device 20 is restarted is different from that of the first embodiment. That is, the parent device side setting process performed by the parent device 10 of the present embodiment is different from the processing content shown in FIG. The handset side setting process performed by the handset 20 of this embodiment is different from the processing content described in the first embodiment.

First, the master unit side setting process performed by the master unit 10 of the present embodiment will be described with reference to FIG.

The processing unit 12 of the parent device 10 includes identification information of each of the child devices 20a,..., 20n included in the entry information for the parent device stored in the storage unit 13, and the child devices 20a,. The path information and the encryption key are read from the storage unit 13 (step S41).

The processing unit 12 of the parent device 10 determines whether or not the parent device entry information is valid. Specifically, the processing unit 12 of the parent device 10 determines whether or not the encryption key read from the storage unit 13 is valid (step S42). For example, the processing unit 12 of the parent device 10 determines whether or not the current date and time is within the expiration date set in the encryption key.

The processing unit 12 of the parent device 10 determines that the encryption key is valid (the parent device entry information is valid), that is, determines that the current date and time is within the expiration date (“Yes” in step S42). ), A setting process is performed (step S43). Specifically, the processing unit 12 of the parent device 10 includes the child device information table including the identification information of each child device 20 read from the storage unit 13 and the path information of each child device 20 read from the storage unit 13. Is generated and stored in the RAM 15. Thereby, the main | base station 10 can re-enter the subunit | mobile_unit 20 to a communication network, without performing the search process A1 and authentication process A2 which were mentioned above, ie, without communicating with the subunit | mobile_unit 20. FIG.

The processing unit 12 of the parent device 10 compares the child device information table with the routing information table, and information on the child device 20 managed by the child device information table and the child device 20 managed by the routing information table. It is determined whether or not there is a difference between the information (steps S44 and S45). Specifically, the processing unit 12 of the parent device 10 determines whether or not the child device 20 managed by only one of the child device information table and the routing information table exists.

If it is determined that there is a difference (there is a child device 20 that is managed by only one table) ("Yes" in step S45), the processing unit 12 has the child device 20 that is managed by only one table. The communication unit 11 is controlled to transmit a withdrawal request to the terminal (step S46). If it is determined that there is no difference (“No” in step S45), the process ends.

When determining that the encryption key is not valid (“No” in step S42), the processing unit 12 of the parent device 10 transmits a withdrawal request to all the child devices 20 that have joined the communication network immediately before restarting. The communication unit 11 is controlled (step S47).

Since the operation when the slave unit 20 receives the withdrawal request is the same as that of the first embodiment, description thereof is omitted here.

Next, the slave unit side setting process performed by the slave unit 20 of the present embodiment will be described with reference to FIG.

The processing unit 22 of the child device 20 receives the identification information of the own device, the PAN ID, the communication path (route information) to the parent device 10, and the encryption key included in the child device entry information stored in the storage unit 23. Read from the storage unit 23 (step S51).

The processing unit 22 of the child device 20 determines whether or not the child device entry information is valid. Specifically, the processing unit 22 of the child device 20 determines whether or not the encryption key read from the storage unit 23 is valid (step S52). For example, the processing unit 22 of the child device 20 determines whether or not the current date and time is within the expiration date set in the encryption key.

When the processing unit 22 of the slave unit 20 determines that the encryption key is valid (the slave unit entry information is valid), that is, determines that the current date and time is within the expiration date ("Yes" in step S52). ), A setting process is performed (step S53). Specifically, the processing unit 22 of the child device 20 sets the identification information, PAN ID, path information, and encryption key read from the storage unit 23 in the RAM 25 of the communication unit 21. Thereby, the subunit | mobile_unit 20 can enter into the communication network of the main | base station 10 again, without performing the search process A1 and the authentication process A2 which were mentioned above, ie, without performing communication with the main | base station 10. FIG.

When it is determined that the encryption key is not valid (“No” in step S52), the processing unit 22 of the child device 20 performs processing related to acquisition of the encryption key (step S54). Specifically, the processing unit 22 of the child device 20 acquires the key information from the parent device 10 by performing the key distribution process A3 described in the first embodiment with the parent device 10. The processing unit 22 of the child device 20 generates an encryption key based on the acquired key information.

The processing unit 22 of the slave unit 20 sets the identification information, PAN ID, path information, and generated encryption key read from the storage unit 23 in the RAM 25 of the communication unit 21 (step S55).

Next, a modification of the above embodiment will be described.

In the present embodiment, the processing unit 22 of the child device 20 is configured to perform the key distribution processing A3 with the parent device 10 when determining that the encryption key is not valid (the entry information for the child device is not valid). However, it is not limited to this configuration. When determining that the encryption key is not valid, the processing unit 22 of the child device 20 may perform the authentication process A2 with the parent device 10.

That is, when the processing unit 22 of the slave unit 20 determines that the encryption key is not valid, the search unit A1 is not performed with the master unit 10, and at least the key distribution process A3 is performed in the authentication process A2. That's fine.

In addition, the present embodiment and the above-described modification examples can be applied in appropriate combination with the modification examples described in the first embodiment and the first embodiment.

(Summary)
As described above, in the communication system (1) according to the first aspect, the slave unit (20) enters the communication network through the search process (A1) and the authentication process (A2), and the master unit (10). Communicate. The search process (A1) is a process of searching for a parent device (10) included in a communication network that can be entered. The authentication process (A2) is a process for entering the communication network. The parent device (10) includes a processing unit (12) and a nonvolatile storage unit (13). A memory | storage part (13) memorize | stores entry information (entrance information for main | base stations). The entry information is used when encrypting and decrypting route information indicating a communication route from the child device (20) to the parent device (10) and communication between the child device (20) and the parent device (10). And at least an encryption key to be used. The subunit | mobile_unit (20) is provided with a process part (22) and a non-volatile memory | storage part (23). The storage unit (23) encrypts and decrypts route information indicating a communication route from the child device (20) to the parent device (10) and communication between the child device (20) and the parent device (10). The entry information (entry information for the slave unit) including at least the encryption key used at the time is stored. When the search process (A1) and the authentication process (A2) are performed, the processing units (12, 22) use the path information and the encryption key obtained by the search process (A1) and the authentication process (A2) to The machine (20) is put into a state of entering the communication network. Assume a case where at least one of the child device (20) and the parent device (10) is restarted after the child device (20) enters the communication network. In this case, the processing unit of the device uses the entry information stored in the storage unit of the device immediately before restarting, and does not communicate with the other device for search processing and authentication processing. The slave (20) is put into a state where it has entered the communication network.

According to this configuration, communication is not performed for the search process (A1) and the authentication process (A2) even when at least one of the parent device (10) and the child device (20) is restarted. The slave unit (20) can enter the communication network in a shorter time.

In the communication system (1) of the second mode, the slave unit (20) enters the communication network through the search process (A1) and the authentication process (A2) and communicates with the master unit (10). The search process (A1) is a process of searching for a parent device (10) included in a communication network that can be entered. The authentication process (A2) is a process for entering the communication network. The parent device (10) includes a processing unit (12) and a nonvolatile storage unit (13). A memory | storage part (13) memorize | stores entry information (entrance information for main | base stations). The entry information is used when encrypting and decrypting route information indicating a communication route from the child device (20) to the parent device (10) and communication between the child device (20) and the parent device (10). And at least an encryption key to be used. The subunit | mobile_unit (20) is provided with a process part (22) and a non-volatile memory | storage part (23). The storage unit (23) encrypts and decrypts route information indicating a communication route from the child device (20) to the parent device (10) and communication between the child device (20) and the parent device (10). The entry information (entry information for the slave unit) including at least the encryption key used at the time is stored. When the search process (A1) and the authentication process (A2) are performed, the processing units (12, 22) use the path information and the encryption key obtained by the search process (A1) and the authentication process (A2) to The machine (20) is put into a state of entering the communication network. Assume a case where at least one of the child device (20) and the parent device (10) is restarted after the child device (20) enters the communication network. In this case, the processing unit of the device determines whether or not the entry information stored in the storage unit of the device is valid immediately before restarting. When the entry information is valid, the processing unit of the device uses the entry information to make the slave (20) a communication network without performing communication related to the search process and the authentication process with the other device. Enter the state.

According to this configuration, even when at least one of the parent device (10) and the child device (20) is restarted, communication is not performed for search processing and authentication processing when the entry information is valid. Therefore, it can be made the state which the subunit | mobile_unit (20) entered the communication network in a shorter time.

In the communication system (1) according to the third aspect, in the second aspect, the authentication process (A2) includes a key distribution process (A3) in which the parent device (10) distributes the encryption key to the child device (20). It is out. The processing unit (22) of the slave unit (20) determines whether or not the encryption key included in the entry information stored in the storage unit (23) of the slave unit (20) is valid. The processing unit (22) of the slave unit (20) assumes that the entry information is valid when the encryption key is valid, and performs the authentication process (A2) without performing the search process (A1) when the encryption key is not valid. Among them, an encryption key is acquired from the parent device (10) by at least the key distribution process (A3). According to this configuration, even when the encryption key is not valid, that is, when the entry information is not valid, the communication traffic by the search process (A1) can be suppressed and the original operation can be performed.

In the communication system (1) of the fourth mode, in the second or third mode, the processing unit (12) of the base unit (10) is stored in the storage unit (13) of the base unit (10). It is determined whether or not the encryption key included in the entry information is valid. The processing unit (12) of the parent device (10) determines that the entry information is valid when the encryption key is valid, and disconnects the child device (20) from the communication network when the encryption key is not valid. According to this configuration, since the slave unit (20) needs to perform the authentication process again by leaving the communication network, the slave unit (20) can quickly recover from a communication disabled state due to an invalid encryption key.

In the communication system (1) according to the fifth aspect, in any one of the first to fourth aspects, the processing unit (22) of the slave unit (20) The encryption key included in the entry information stored in the storage unit (23) is changed to the updated encryption key. According to this configuration, the communication system (1) can update the entry information stored in the storage unit (23) at the timing when the encryption key is updated.

In the communication system (1) of the sixth aspect, in any one of the first to fifth aspects, when the processing unit (12) of the parent device (10) generates a new encryption key, The encryption key included in the entry information stored in the storage unit (13) is updated to a new encryption key. According to this configuration, the communication system (1) can update the entry information stored in the storage unit (13) at the latest timing when the encryption key is updated.

In the communication system (1) of the seventh aspect, in any one of the first to sixth aspects, the processing unit (12) of the parent device (10) is connected to the child device (20) participating in the communication network. When there is a change in the number, the entry information stored in the storage unit (13) of the own device is updated according to the change in the number of child devices (20). According to this configuration, the communication system (1) can update the entry information stored in the storage unit (13) at the timing when the number of slave units (20) varies.

In the communication system (1) of the eighth aspect, in any of the first to seventh aspects, there are a plurality of slave units (20) that have entered the communication network. Each of the master unit (10) and the slave unit (20) performs communication by multi-hop communication. The storage unit (13) of the parent device (10) includes a child device information table including information for identifying each child device (20) that has entered the communication network, and information for each child device (20). A routing information table including information representing a slave unit existing on the communication path to the master unit (10) is stored. When there is a slave unit registered in only one of the slave unit information table and the routing information table, the processing unit (22) of the master unit (10) causes the slave unit to leave the communication network. According to this configuration, the communication system (1) can eliminate inconsistencies between the slave unit information table and the routing information table.

The communication device of the ninth aspect is used as the parent device (10) or the child device (20) of the communication system (1) of any of the first to eighth aspects. According to this configuration, even when the communication device is restarted, the communication device does not perform communication for the search process (A1) and the authentication process (A2), so the slave unit (20 ) Entered the communication network.

1 Communication system 10 Master unit (communication device)
12 processing unit 13

storage unit

20, 20a, 20b, ..., 20n slave unit (communication device)
22 processing unit 23 storage unit

Claims

A communication system in which a slave unit enters the communication network and communicates with the master unit through a search process for searching for a master unit included in a communication network that can be entered and an authentication process for entering the communication network. And
Each of the master unit and the slave unit is
A processing unit;
Stores entry information including at least path information representing a communication path from the slave unit to the master unit and an encryption key used when encrypting and decrypting communication between the slave unit and the master unit. A non-volatile storage unit,
The processor is
When the search process and the authentication process are performed, the path information obtained by the search process and the authentication process and the encryption key are used to make the slave unit enter the communication network,
When at least one device of the child device and the parent device is restarted after the child device enters the communication network, the processing unit of the device is stored in the storage unit of the device immediately before the restart. A communication system, wherein the slave unit is put into the communication network without performing communication related to the search process and the authentication process with the other device.
A communication system in which a slave unit enters the communication network and communicates with the master unit through a search process for searching for a master unit included in a communication network that can be entered and an authentication process for entering the communication network. And
Each of the master unit and the slave unit is
A processing unit;
Stores entry information including at least path information representing a communication path from the slave unit to the master unit and an encryption key used when encrypting and decrypting communication between the slave unit and the master unit. A non-volatile storage unit,
The processor is
When the search process and the authentication process are performed, the path information obtained by the search process and the authentication process and the encryption key are used to make the slave unit enter the communication network,
When at least one device of the child device and the parent device is restarted after the child device enters the communication network, the processing unit of the device is stored in the storage unit of the device immediately before the restart. Is determined to be valid, and when the entry information is valid, the entry information is used to communicate with the other device for the search process and the authentication process. A communication system characterized in that the slave unit is put into a state of entering the communication network.
The authentication process includes a key distribution process in which the parent device distributes the encryption key to the child device,
The processing unit of the slave unit is
It is determined whether or not the encryption key included in the entry information stored in the storage unit of the slave unit is valid, and the entry information is valid when the encryption key is valid, 3. The communication system according to claim 2, wherein when the encryption key is not valid, the search process is not performed, and the encryption key is acquired from the parent device by at least the key distribution process in the authentication process.
The processing unit of the base unit determines whether or not the encryption key included in the entry information stored in the storage unit of the base unit is valid, and when the encryption key is valid The communication system according to claim 2 or 3, wherein the entry information is valid, and the slave unit is detached from the communication network when the encryption key is not valid.
The processing unit of the slave unit is
When the encryption key is updated, the encryption key included in the entry information stored in the storage unit of the own device is changed to an updated encryption key. 5. The communication system according to any one of 1 to 4.
The processing unit of the base unit is
2. When a new encryption key is generated, the encryption key included in the entry information stored in the storage unit of the own device is updated to the new encryption key. The communication system according to claim 5.
The processing unit of the base unit is
When there is a change in the number of the child devices that have entered the communication network, the entry information stored in the storage unit of the own device is updated according to the change in the number of the child devices. The communication system according to any one of claims 1 to 6, wherein:
There are a plurality of slave units that have entered the communication network,
Each of the master unit and the slave unit performs communication by multi-hop communication,
The storage unit of the parent device is a child device information table including information for identifying each of the child devices that have entered the communication network, and information for each child device, up to the parent device Storing a routing information table including information representing a slave unit existing on the communication path;
The processing unit of the base unit is
The slave unit is disconnected from the communication network when there is a slave unit registered in only one of the slave unit information table and the routing information table. A communication system according to claim 1.
A communication apparatus, characterized in that it is used as a parent device or a child device of the communication system according to any one of claims 1 to 8.