JP2018014692A - Communication system and communication device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a communication system and a communication device that can cause a slave unit to enter into a communications network in shorter time even when at least one unit of a master unit and the slave unit is reactivated.SOLUTION: In a communication system 1, a slave unit 20 enters into a communications network through search processing and authentication processing, and communicates with a master unit 10. The master unit 10 comprises a processing section 12 and a non-volatile storage section 13, and the slave unit 20 comprises a processing section 22 and a non-volatile storage section 23. The storage section 13 and the storage section 23 store entry information. After the slave unit 20 enters into the communications network, it is assumed that at least one unit of the slave unit 20 and the master unit 10 is reactivated. In this case, the processing section of the unit causes the slave unit 20 to enter into the communications network without performing communication associated with the search processing and the authentication processing, with other unit using the entry information stored in the storage section of the unit immediately before reactivation.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a communication system and a communication apparatus, and more particularly to a communication system and a communication apparatus 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 technique in which a meter-reading device (slave device) entering a certain network (communication network) searches for another network having better communication quality and enters.

JP, 2015-201721, A

  Consider a case where a power failure occurs in the communication system described in Patent Document 1 and the management device (master device) and a plurality of meter-reading devices (slave devices) belonging to the network (communication network) are restarted after recovery from the power failure. 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.

  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. The master unit and the slave unit each include a processing unit and a nonvolatile storage unit. The storage unit 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. Store entry information. 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. The master unit and the slave unit each include a processing unit and a nonvolatile storage unit. The storage unit 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. Store entry information. 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.

  A communication device according to one embodiment 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.

  And each of the main | base station 10 and the subunit | mobile_unit 20 is a communication apparatus which performs power line carrier communication according to G3-PLC (Power Line Communication) which is a communication protocol of 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 that performs communication with another communication device (slave device 20). As shown 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 handset 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 overall processing of the parent device 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) or a flash memory. 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 illustrated in FIG. 1, the communication unit 11 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 in 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 entering communication network (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 overall 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 device 20n causes the communication unit 21 to broadcast a beacon request (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 path 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 slave 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 slave device 20n transmits an entry request including route information representing the determined communication route to the parent device 10 using the determined communication route (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 (information including PAN ID, parent device address, and identification information) in the communication network 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 receiving the information indicating that the key information has been received from the child device 20n after transmitting the encryption key in step S6. 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 the address information is transmitted in step S7 and then the 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 22 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 20 n performs a registration process for registering the child device entry information in the RAM 25 and the storage unit 23 (step S <b> 10). The processing unit 22 of the slave unit 20 includes a PAN ID, a master unit address and identification information included in the address information received from the master unit 10, path information indicating a communication path to the master unit 10, and a processing unit of the slave unit 20n. The encryption key generated at 22 is written (retained) in the RAM 25. The processing unit 22 of the child device 20n writes (holds) the child device entry information including the PAN ID and the identification information, the route information indicating the communication route to the parent device 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.

  A series of processes from step S1 to S4 is referred to as a search process (active scan) A1. A series of processing from step S5 to S8 is referred to as authentication processing A2, and in particular, a series of processing from step 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 route (route 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 a base unit side setting process (step S21). Details of the base unit setting process will be described later.

  If the subunit | mobile_unit 20 (20a, ..., 20n) is restarted after a power failure recovery, the process part 12 of the subunit | mobile_unit 20 will perform a subunit | mobile_unit side setting process (step S22-S24). Specifically, the processing unit 22 of the child device 20 includes the own device identification information, PAN ID, parent device address, and 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 side 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 entry information for the parent device 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 base unit 10 reads the read PAN ID, base unit address, identification information of each of the slave units 20a, ..., 20n, path information and encryption keys of the slave units 20a, ..., 20n, 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 stored in the RAM 25 of the own device, identification information (short address) of the own device, 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, path | 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 13 is the same as in the above embodiment.

  Master device 10 may store the slave device information table, the routing information table, and the encryption key in a distributed manner in RAM 15 and RAM 16 of communication unit 11. Similarly, the handset 20 may store the PAN ID, the identification information, the path information, and the encryption key in a distributed manner in the RAM 25 and the RAM 26 of the communication unit 21.

  In the said embodiment, the timing which performs a reentry process was after a power failure restoration. 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 said embodiment, although communication was comprised between the main | base station 10 and the subunit | mobile_unit 20 by the multihop communication by G3-PLC, it is not limited to this structure. 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 embodiment described above, the base unit 10 performs the processes in steps S33 to S35 illustrated in FIG. However, the processing of steps S33 to S35 is not limited to the case where 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 parent device side setting process performed by the child device 20 of the present embodiment is different from the processing content described in the first embodiment.

  First, the parent device side setting process performed by the parent device 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 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, the 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 slave unit 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 determining that the encryption key is not valid (“No” in step S52), the processing unit 22 of the slave 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 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.

  Further, 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.

(6) Summary As described above, in the communication system 1 according to the first aspect of the present invention, the slave unit 20 enters the communication network through the search process and the authentication process, and communicates with the master unit 10. The search process is a process of searching for the parent device 10 included in a communication network that can be entered. The authentication process is a process for entering the communication network. The base unit 10 includes a processing unit 12 and a nonvolatile storage unit 13. The storage unit 13 includes at least path information representing a communication path from the child device 20 to the parent device 10 and an encryption key used when encrypting and decrypting communication between the child device 20 and the parent device 10. Stores entry information (entry information for base unit). The subunit | mobile_unit 20 is provided with the process part 22 and the non-volatile memory | storage part 23. FIG. The storage unit 23 includes at least path information indicating a communication path from the child device 20 to the parent device 10 and an encryption key used when encrypting and decrypting communication between the child device 20 and the parent device 10. Stores entry information (entry information for handset). When the search process and the authentication process are performed, the processing unit 12 (the process unit 22) uses the path information and the encryption key obtained by the search process and the authentication process to make the slave unit 20 enter the communication network. . It is assumed that at least one of the slave device 20 and the master device 10 is restarted after the slave 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 subunit | mobile_unit 20 is made into the state which entered the communication network.

  According to this configuration, even when at least one of the parent device and the child device is restarted, communication is not performed for the search process and the authentication process, so the child device enters the communication network in a shorter time. It can be in the state.

  In the communication system 1 according to the second aspect of the present invention, the slave unit 20 enters the communication network through the search process and the authentication process, and communicates with the master unit 10. The search process is a process of searching for the parent device 10 included in a communication network that can be entered. The authentication process is a process for entering the communication network. The base unit 10 includes a processing unit 12 and a nonvolatile storage unit 13. The storage unit 13 includes at least path information representing a communication path from the child device 20 to the parent device 10 and an encryption key used when encrypting and decrypting communication between the child device 20 and the parent device 10. Stores entry information (entry information for base unit). The subunit | mobile_unit 20 is provided with the process part 22 and the non-volatile memory | storage part 23. FIG. The storage unit 23 includes at least path information indicating a communication path from the child device 20 to the parent device 10 and an encryption key used when encrypting and decrypting communication between the child device 20 and the parent device 10. Stores entry information (entry information for handset). When the search process and the authentication process are performed, the processing unit 12 (the process unit 22) uses the path information and the encryption key obtained by the search process and the authentication process to make the slave unit 20 enter the communication network. . It is assumed that at least one of the slave device 20 and the master device 10 is restarted after the slave 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 enter the slave device 20 into the communication network without performing communication related to the search process and the authentication process with the other device. Put it in a state.

  According to this configuration, even when at least one of the master device and the slave device is restarted, when the entry information is valid, communication is not performed for the search process and the authentication process. The slave unit can enter the communication network.

  In the communication system according to the third aspect of the present invention, in the second aspect, the authentication process includes a key distribution process in which the parent device 10 distributes the encryption key to the child device 20. The processing unit 22 of the child device 20 determines whether or not the encryption key included in the entry information stored in the storage unit 23 of the child device 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. If the encryption key is not valid, the processing unit 22 does not perform the search process and performs at least the key distribution process in the authentication process. Get encryption key from. According to this configuration, even when the encryption key is not valid, that is, when the entry information is not valid, the communication traffic due to the search process can be suppressed and the original operation can be performed.

  In the communication system according to the fourth aspect of the present invention, in the second or third aspect, the processing unit 12 of the base unit 10 includes the encryption key included in the entry information stored in the storage unit 13 of the base unit 10. It is determined whether or not 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 causes the child device 20 to leave the communication network when the encryption key is not valid. According to this configuration, since the handset 20 needs to perform the authentication process again by leaving the communication network, the handset 20 can quickly recover from the communication disabled state due to the encryption key not being valid.

  In the communication system according to the fifth aspect of the present invention, in any of the first to fourth aspects, the processing unit 22 of the slave unit 20 stores the storage unit of its own unit when the encryption key is updated. The encryption key included in the entry information stored in 23 is changed to the updated encryption key. According to this configuration, the entry information stored in the storage unit 23 can be updated to the latest state at the timing when the encryption key is updated.

  In the communication system according to the sixth aspect of the present invention, in any of the first to fifth aspects, when the processing unit 12 of the base unit 10 generates a new encryption key, the storage unit of its own unit The encryption key included in the entry information stored in 13 is updated to a new encryption key. According to this configuration, the entry information stored in the storage unit 13 can be updated to the latest state at the timing when the encryption key is updated.

  In the communication system according to the seventh aspect of the present invention, in any one of the first to sixth aspects, the processing unit 12 of the parent device 10 has a variation in the number of child devices 20 that have entered the communication network. In the case of the change, 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 entry information stored in the storage unit 13 can be updated to the latest state at the timing when the number of slave units 20 varies.

  In the communication system according to the eighth aspect of the present invention, in any one of the first to seventh aspects, there are a plurality of slave units 20 entering the communication network. Each of the parent device 10 and the child device 20 performs communication by multi-hop communication. The storage unit 13 of the parent device 10 includes a child device information table that includes information for identifying each child device 20 that has entered the communication network, and information for each child device 20 that communicates with the parent device 10. A routing information table including information indicating the slave units existing on the route 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, inconsistency between the slave device information table and the routing information table can be resolved.

  The communication device according to the ninth aspect of the present invention is used as the parent device 10 or the child device 20 of the communication system 1 according to any one of the first to eighth aspects. According to this configuration, even if the communication device is restarted, communication is not performed for the search process and the authentication process, so that the slave unit can enter the communication network in a shorter time.

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 (9)

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
The master unit and the slave unit are
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
The master unit and the slave unit are
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. The communication system as described in any one of -4. The processing unit of the base unit is
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. 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, which is used as a parent device or a child device of the communication system according to any one of claims 1 to 8.

Images