JPWO2012131853A1 - Management server and gateway - Google Patents

Abstract

A communication system according to the present invention includes a wireless mesh network formed by a gateway and a smart meter, a management server that manages the number of smart meters accommodated in each gateway and collects and manages the measurement results by the smart meter. When the management server detects that the gateway has started, it changes the entry wireless mesh network based on the number of smart meters contained in each managed gateway and the location information of each smart meter. The smart meter to be determined is determined, and each determined smart meter is instructed to change to the wireless mesh network managed by the gateway that started the entry wireless mesh network.

Description

  The present invention relates to a communication system including a mesh network used in an automatic meter reading system such as electric power.

  In a conventional wireless mesh (otherwise referred to as ad hoc or multi-hop, but referred to as a mesh in this specification) communication technology, when a wireless terminal newly enters a wireless mesh network, a wireless terminal that wants to enter Determines communication channel status based on information such as received signal strength, power consumption, security level, and anti-interference characteristics in wireless communication with the wireless terminal or base station of the communication partner, and determines the communication quality. And enter the network where the transmission speed is optimal (for example, Patent Document 1).

  As an application example of the wireless mesh communication technology, an automatic meter reading system that performs automatic meter reading of power or the like using the wireless mesh communication technology is known. In a conventional automatic meter reading system, a wireless communication device is installed in the electricity, gas, and water meter installed in each customer's house such as a detached house or apartment house. The acquired meter reading data such as electric power, gas, and water volume is transmitted to a host system (meter reading data management device, business management device, etc.) directly or via other communication devices in the vicinity. Since this automatic meter reading system is a wide-area and large-scale system, a gateway (otherwise referred to as a concentrator or a concentrator, but referred to as a gateway in this specification) is installed on a utility pole, etc. It is proposed that data is collected in stages, and when data is transmitted from each house, the meter reading data is collected efficiently by applying a mechanism such as a routing function by wireless mesh communication ( For example, Non-Patent Document 1). A meter equipped with a communication device (communication function) is called a smart meter.

JP 2003-324443 A

Gotoda et al., “Automated Meter Reading (AMI) Solution by Fusion of Information and Control,” Hitachi Review, August 2010, pages 34-37

  In the conventional automatic meter reading system to which the wireless mesh communication technology is applied, the state of the communication path is judged and the wireless mesh network to be entered is selected, but the number of meters (smart meters) accommodated by each gateway is balanced, that is, the gateway There was a problem that the load distribution between them was not considered.

  The present invention has been made in view of the above, and obtains a communication system that realizes a mesh network capable of autonomously distributing loads between gateways by balancing the number of smart meters accommodated by each gateway. For the purpose.

  In order to solve the above-described problems and achieve the object, the present invention is a single gateway and a node accommodated in the gateway, which is installed in a consumer and is in power, gas and water. Manages the number of nodes accommodated in each of the plurality of wireless mesh networks formed by one or more nodes that measure usage for at least one of the gateways, and collects the measurement results by the nodes Management server, and when the management server detects that the gateway is activated, based on the number of nodes accommodated in each managed gateway and the position information of each node, the management server A node to change the wireless mesh network is determined, and the entry wireless mesh network is determined for each determined node. And performing an instruction to change the wireless mesh network gateway work was the activation is managed.

  According to the communication system of the present invention, when the management server detects the activation of the gateway, the management server is accommodated in the gateway adjacent to the activated gateway among the smart meters that have entered the wireless mesh network of each gateway. Some smart meters are instructed to change the entry destination to the wireless mesh network managed by the activated gateway, so the number of smart meters accommodated by the gateway is balanced, that is, load distribution between gateways is autonomous. There is an effect that can be achieved.

FIG. 1 is a diagram showing a configuration example of a communication system according to the present invention. FIG. 2A is a sequence diagram illustrating an operation example when adjusting the load between gateways in the communication system according to the first exemplary embodiment. 2B is a sequence diagram illustrating a load adjustment operation between gateways in the communication system according to Embodiment 1. FIG. 2C is a sequence diagram illustrating a load adjustment operation between gateways in the communication system according to Embodiment 1. FIG. 2D is a sequence diagram illustrating a load adjustment operation between gateways in the communication system according to Embodiment 1. FIG. FIG. 3 is a sequence diagram illustrating a load adjustment operation between gateways in the communication system according to the first embodiment. FIG. 4 is a diagram illustrating a control operation in the communication system according to the second embodiment. FIG. 5 is a diagram illustrating a control operation in the communication system according to the third embodiment. FIG. 6A is a diagram illustrating a control operation in the communication system according to the fourth embodiment. FIG. 6B is a diagram illustrating a control operation in the communication system according to the fourth embodiment. FIG. 6C is a diagram illustrating a control operation in the communication system according to the fourth embodiment.

  Embodiments of a communication system according to the present invention will be described below in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

Embodiment 1 FIG.
FIG. 1 is a diagram showing a configuration example of a communication system according to the present invention. A communication system according to the present invention includes server devices 1 and 2, a gateway 10 (hereinafter also referred to as GW # 1) connected to these server devices via a wide area network 3, and a gateway 20 (hereinafter referred to as GW # 1). , GW # 2) and gateway 30 (hereinafter also referred to as GW # 3), and a plurality of smart meters 101-109 connected directly or indirectly to the gateway 10, 20 or 30 And 201-209. Each gateway forms a wireless mesh network with the subordinate smart meter.

  In the communication system shown in FIG. 1, the server apparatus 1 receives meter reading data such as electric power, gas, or water amount from a smart meter (a smart meter that has already entered the wireless mesh network) via the gateway 10, 20, or 30. collect. The server device 2 manages the route and state (number of smart meters accommodated in each gateway, installation position of each smart meter, etc.) in each wireless mesh network. Each gateway (GW # 1, GW # 2, GW # 3) connects the wireless mesh network formed with the subordinate smart meter and the wide area network 3. Each smart meter (smart meters 101 to 109, 201 to 209) has a function of connecting to other smart meters or gateways by wireless communication, and a function of measuring usage of electric power, gas, water, etc. (meter reading function) Have. In the meter reading function, at least one of the usage amounts such as electric power is measured. The smart meters 101 to 109 perform bidirectional data communication with the server apparatuses 1 and 2 via the gateway 10 (GW # 1). The smart meters 201 to 209 perform bidirectional data communication with the server apparatuses 1 and 2 via the gateway 20 (GW # 2). In FIG. 1, GW # 3 is in a state immediately after being activated, and there is no smart meter under GW # 3 (a smart meter that has already entered the wireless mesh network managed by GW # 3). Does not exist). Moreover, in FIG. 1, the dotted line which connects each gateway and a smart meter, and the dotted line which connects smart meters show the communication path | route of a wireless mesh network.

  The wireless communication function of the smart meter conforms to one or a plurality of specific low power wireless, wireless LAN (Local Area Network) (IEEE802.11), ZigBee (IEEE802.15.4), or the like. The server devices 1 and 2 have different functions and are therefore separate devices. However, the server devices 1 and 2 may be realized by a single device having a function of collecting meter reading data and a function of managing routes and states in the wireless mesh network. . The wide area network 3 is a network between each gateway and each server device, and is a wireless system such as a mobile phone or a wired system using an optical fiber or a telephone line (modem, ADSL (Asymmetric Digital Subscriber Line)). It is a wide area network.

  In the communication system having such a configuration, the server device 2 (hereinafter, referred to as the network management server 2 to be distinguished from the server device 1) monitors the status of the smart meter accommodated in each gateway, and between the gateways. If it is determined that the processing load needs to be adjusted, and if it is determined that adjustment is necessary, a part of the smart meter that has already entered the wireless mesh network is moved to the adjacent wireless mesh network (participant) To adjust the load. Hereinafter, the operation of adjusting the processing load between gateways will be described in detail.

  2A to 2D and FIG. 3 are sequence diagrams illustrating an operation example in the case of adjusting the load between gateways in the communication system according to the first embodiment. FIG. 2A to FIG. 2D show that the smart meter that has entered the wireless mesh network of the gateway 10 (GW # 1) reenters the wireless mesh network of the adjacent gateway 30 (GW # 3) to enter the wireless mesh network of the entry destination. The sequence of the operation when switching is shown. FIG. 3 shows a case where a smart meter that has entered the wireless mesh network of the gateway 20 (GW # 2) is re-entered into the wireless mesh network of the adjacent gateway 30 (GW # 3) and the wireless mesh network of the entry destination is switched. The operation | movement sequence is shown.

  When the GW # 3 is newly installed or recovered from a device failure, as shown in FIG. 2A, first, the GW # 3 sends an activation completion notification message indicating the completion of device activation to the network management server 2. Transmit (step S101). Upon receiving the activation completion notification message, the network management server 2 adds the gateway (GW # 3) that is the transmission source of this message to the gateway to be managed and starts state management (such as load status monitoring) and starts A completion response message is returned (step S102).

  Furthermore, the network management server 2 receives the position information of each smart meter that has entered the wireless mesh networks of GW # 1 and GW # 2 adjacent to the newly started GW # 3, and GW # 1 and GW #. The number of smart meters accommodated by each gateway is balanced based on the number of accommodating 2 (number of smart meters accommodated by GW # 1 and the number of smart meters accommodated by GW # 2). The smart meter to be re-entered into the wireless mesh network of GW # 3 is selected and the order of re-entry is determined (step S103). The order of re-entry is such that the smart meter that can directly participate in the re-entry destination GW # 3 wireless mesh network is first, and the smart meter that can participate via the first smart meter is second. The third and subsequent determinations are made in the same manner, and the reentry of all the smart meters selected to be reentered is executed efficiently.

  Here, the network management server 2 has a smart meter 102 that can be connected to the GW # 3 (a smart meter 102 that is installed at a position where it can communicate with the GW # 3), and a smart meter 106 that can be connected to the smart meter 102. The description will be continued assuming that the smart meter 107 that can be connected to the smart meter 106 is selected and it is decided to re-enter the wireless mesh network of the GW # 3 in the order of the smart meter 102 → 106 → 107. In step S103, the number of accommodated gateways (GW # 1) in which the selected smart meter has entered is also updated.

  When the process of step S103 is completed, an entry switching operation is performed as step S104. In this switching operation, the network management server 2 indicates the re-entry destination wireless mesh network in order from the later entry order (start time) to the smart meters 102, 106 and 107 selected in step S103. The gateway ID (= # 3) and the re-entry instruction message with the entry start time are transmitted (steps S105 to S107).

  The smart meters 102, 106, and 107 that have received the re-entry instruction message perform adjacent search operations (steps S108, S120, and S132) in order to enter the wireless mesh network according to the specified entry start time.

  If the entry start time is not indicated in the re-entry instruction message, for example, the entry operation by each smart meter instructed to re-entry may be performed at the same timing. From the positional relationship of GW # 3 managing the wireless mesh network, the smart meter 106, 107 does not re-enter the smart meter 102 until the re-entry operation is completed, and the re-entry operation is repeated. Therefore, traffic and power consumption increase unnecessarily. In addition, the operation (transmission) of the smart meters 106 and 107 may interfere with the communication of the smart meter 102, which may increase processing delay. In the present embodiment, the network management server 2 determines the entry start time instructed to each smart meter in consideration of such a case, so that each operation described later is executed efficiently and entered in a short time. It is possible to switch destinations.

  In the adjacent search operation in step S108, the smart meter 102 instructed to start immediately activates a timer for waiting for reception of a search response message and broadcasts a search request message (step S109), as shown in FIG. 2B. The broadcast search request message reaches the GW # 1, GW # 3 and the adjacent smart meter 106 existing within the radio wave reach of the smart meter 102, and the GW # 1 and GW # 3 receive the wireless mesh of the entry destination. The ID (# 1 or # 3) of the gateway indicating the network and the number of hops to the gateway are placed in the search response message and transmitted to the smart meter 102 (steps S110 and S111). Here, the number of hops is a number indicating how many smart meters reach the local node from the gateway, and in the case of being able to communicate directly with the gateway, when passing through one or one smart meter. Is N + 1 when passing through 2 or N smart meters.

  The smart meter 106 starts the entry start wait timer to wait for the time until the start of entry specified in the re-entry instruction message received in step S106. Do not send messages.

  When the timer for waiting for reception of the search response message times out, the smart meter 102 selects the gateway 30 (GW #) specified by the re-entry instruction message from the single or multiple search response messages received so far. The one having the smallest number of hops up to 3) is selected, and the smart meter or gateway that is the transmission source of the selected message is set as the connection destination of the wireless mesh network to be entered (step S112). In the illustrated example, GW # 3 is a connection destination of a wireless mesh network that enters.

  When no search response message has been received when the search response message reception wait timer has timed out, the search response message reception wait timer is started again to broadcast the search request message (step S109). This operation (neighbor search operation) is repeated until a search response message can be received.

  When the neighbor search operation in step SS108 (steps S109 to S111 in FIG. 2B) is performed and the selection of the entry destination is completed, the smart meter 102 then starts a response waiting timer and connects to the wireless mesh network to enter. An entry registration request message is transmitted to GW # 3 selected as the destination (step S113). At this time, if there is a wireless mesh network (wireless mesh network managed by a GW other than GW # 3) that can be entered in the previous step S108 (adjacent search operation), GW ID indicating the wireless mesh network is also notified. Here, the ID of GW # 1 (= # 1) is also notified as the ID of the adjacent GW. Although not shown, the entry registration request message includes information (authentication information) necessary for authentication processing on the gateway side.

  If the entry registration response message from GW # 3 cannot be received before the response waiting timer times out, the smart meter 102 transmits the entry registration message again, and from GW # 3 before the response waiting timer times out. When the entry registration response message is received, the response waiting timer is stopped.

  GW # 3 authenticates the smart meter 102 using the authentication information included in the received entry registration request message (step S114), updates the accommodation number (step S115), and grants registration acceptance (OK). An entry registration response message is transmitted to the smart meter 102 (step S116).

  After transmitting the entry registration response message, GW # 3 transmits a registration request message with the ID of the smart meter 102 that has entered the network management server 2 (step S117). The network management server 2 updates the number of accommodated GW # 3 (step S118), and transmits an entry registration response message to which registration acceptance is permitted (OK) to GW # 3 (step S119).

  On the other hand, the smart meter 106 that has received the re-entry instruction message in step S106 activates an entry start wait timer in order to wait for the designated entry start time, and when this timer times out, an adjacent search operation (step S120). ).

  The smart meter 106 stops the operation for entering the mesh network from the time when the entry start waiting timer is activated until the time-out occurs.

  In the adjacent search operation in step S120, the smart meter 106 activates a search response message reception waiting timer and broadcasts a search request message (step S121), as shown in FIG. 2C. The broadcast search request message reaches adjacent smart meters 101, 102, and 107 that are within the radio wave reach of the smart meter 106, and the smart meters 101 and 102 have the gateway ID indicating the wireless mesh network of the entry destination. (# 1 or # 3) and the number of hops to the gateway are placed in the search response message and transmitted to the smart meter 106 (steps S122 and S123).

  The smart meter 107 activates an entry start waiting timer to wait for the time until entry start specified in the re-entry instruction message received in step S105, and at this point in time, the search response Do not send messages.

  When the timer for waiting for reception of the search response message times out, the smart meter 106 selects the gateway 30 (GW #) specified by the re-entry instruction message from the single or multiple search response messages received so far. The one having the smallest number of hops up to 3) is selected, and the smart meter or gateway that is the transmission source of the selected message is set as the connection destination of the participating wireless mesh network (step S124). In the illustrated example, only the smart meter 102 is connected to the GW # 3, and therefore the smart meter 102 is assumed to be a connection destination of the wireless mesh network to be entered here.

  If no search response message has been received when the search response message reception wait timer has timed out, the search response message reception wait timer is activated again to broadcast the search request message (step S121). This operation (neighbor search operation) is repeated until a search response message can be received.

  When the neighbor search operation in step S120 (steps S121 to S124 in FIG. 2C) is performed and the entry destination selection is completed, the smart meter 106 then activates a response wait timer to connect the wireless mesh network to be entered. An entry registration request message is transmitted to GW # 3 that manages the wireless mesh network of the entry destination via the smart meter 102 selected as the destination (step S125). At this time, if there is another wireless mesh network (wireless mesh network managed by a GW other than GW # 3) that can be entered in step S120 (adjacent search operation), GW ID indicating the wireless mesh network is also notified. Here, the ID of GW # 1 (= # 1) is also notified as the ID of the adjacent GW.

  If the entry registration response message from GW # 3 cannot be received before the response waiting timer times out, smart meter 106 transmits the entry registration message again, and from GW # 3 before the response waiting timer times out. When the entry registration response message is received, the response waiting timer is stopped.

  GW # 3 authenticates the smart meter 106 using the authentication information included in the received entry registration request message (step S126), updates the accommodation number (step S127), and grants registration acceptance (OK). An entry registration response message is transmitted to the smart meter 106 (step S128).

  After transmitting the entry registration response message, GW # 3 transmits a registration request message with the ID of the smart meter 106 that has entered the network management server 2 (step S129). The network management server 2 updates the number of accommodated GW # 3 (step S130) and transmits an entry registration response message to which registration acceptance is permitted (OK) to GW # 3 (step S131).

  The smart meter 107 that has received the re-entry instruction message in step S105 activates an entry start wait timer in order to wait for the designated entry start time, and when this timer times out, an adjacent search operation (step S132). ).

  The smart meter 107 stops the operation for entering the mesh network from the time when the entry start waiting timer is activated until the time-out occurs.

  In the adjacent search operation in step S132, the smart meter 107 activates a search response message reception waiting timer and broadcasts a search request message as shown in FIG. 2D (step S133). The broadcast search request message reaches the adjacent smart meters 102 and 106 existing within the radio wave reach of the smart meter 107, and the smart meters 102 and 106 have the gateway ID (# 3) and the number of hops to the gateway are included in the search response message and transmitted to the smart meter 107 (steps S134 and S135).

  When the timer for waiting for reception of the search response message times out, the smart meter 107 selects the gateway 30 (GW #) specified by the re-entry instruction message from the single or multiple search response messages received so far. The one having the smallest number of hops up to 3) is selected, and the smart meter or gateway that is the transmission source of the selected message is set as the connection destination of the wireless mesh network to be entered (step S136). In the illustrated example, since the smart meter 102 has the smallest number of hops up to GW # 3, the smart meter 102 is assumed to be a connection destination of the wireless mesh network to enter here.

  If no search response message has been received when the search response message reception wait timer has timed out, the search response message reception wait timer is activated again to broadcast the search request message (step S133). This operation (neighbor search operation) is repeated until a search response message can be received.

  When the neighbor search operation in Step SS132 (Steps S133 to S136 in FIG. 2D) is completed and the selection of the entry destination is completed, the smart meter 107 then starts a response wait timer and connects to the wireless mesh network to enter. An entry registration request message is transmitted to GW # 3 that manages the wireless mesh network of the entry destination via the smart meter 102 selected as the destination (step S137). At this time, if there is another wireless mesh network (wireless mesh network managed by a GW other than GW # 3) that can be entered in step S132 (adjacent search operation), GW ID indicating the wireless mesh network is also notified. Here, there is no other wireless mesh network that can be entered, so the ID of the adjacent GW is not notified.

  If the entry registration response message from GW # 3 cannot be received before the response waiting timer times out, smart meter 107 transmits the entry registration message again, and from GW # 3 before the response waiting timer times out. When the entry registration response message is received, the response waiting timer is stopped.

  GW # 3 authenticates the smart meter 107 using the authentication information included in the received entry registration request message (step S138), updates the accommodation number (step S139), and grants registration acceptance (OK). An entry registration response message is transmitted to the smart meter 107 (step S140).

  After transmitting the entry registration response message, GW # 3 transmits a registration request message with the ID of the smart meter 107 that has entered the network management server 2 (step S141). The network management server 2 updates the number of accommodated GW # 3 (step S142), and transmits an entry registration response message to which registration acceptance (OK) is given to GW # 3 (step S143).

  The control operation when the network management server 2 determines that the processing load adjustment between the gateways is necessary and moves a part of the smart meters of the GW # 1 to the adjacent GW # 3 (changes the entry destination), Specifically, among smart meters that have entered the high-load state GW # 1 wireless mesh network, the operation of switching the entry destinations of the smart meters 102, 106, and 107 to the adjacent GW # 3 wireless mesh network It is. Further, the control operation when a part of the smart meters of the GW 21 is moved to the adjacent GW # 3 is as shown in FIG. This FIG. 3 shows the operation | movement in the case of switching the entry place of smart meter 201,204 and 205 to the wireless mesh network of adjacent GW # 3 among the smart meters which have entered the wireless mesh network of GW # 2. However, the operations of the network management server 2, each gateway (GW # 1, GW # 2, GW # 3) and each smart meter (smart meter 201, 204, 205) for switching the entry destination are shown in FIG. Since it is the same as the operation | movement shown, description is abbreviate | omitted.

  Thus, in this embodiment, when the network management server detects the activation of the gateway and adds this gateway as a management target, the number of smart meters accommodated in each gateway to be managed is balanced. As for each smart meter that has entered the wireless mesh network of each gateway, for some smart meters accommodated in the gateway adjacent to the activated gateway, the neighboring wireless mesh network, that is, activated Instructed to re-enter the wireless mesh network managed by the gateway (change entry destination). In addition, the entry start time, which is the timing for executing the re-entry operation, is also indicated. As a result, each smart meter instructed to re-enter performs re-registration registration at the specified timing, so it is possible to efficiently change the entry destination change sequence and balance the number of smart meters accommodated by the gateway In other words, load distribution between gateways can be autonomously achieved.

Embodiment 2. FIG.
Next, the second embodiment will be described. The configuration of the communication system will be described assuming that it is the same as that of the first embodiment (see FIG. 1). FIG. 4 is a diagram for explaining a control operation in the communication system according to the second embodiment. As in the first embodiment, the control operation when GW # 3 is newly activated will be described.

  In the communication system of the present embodiment, as an operation before GW # 3 is newly installed or restored from a device failure, each gateway collects periodic meter reading values as shown in FIG. Then, the periodic meter reading value collection timer is started, and a meter reading data request message with an adjacent search request is transmitted to each smart meter accommodated at regular intervals (steps S201 and S211). That is, when the periodic meter reading value collection timer times out, the gateway transmits a meter reading data request message with an adjacent search request. Although details will be described later, a response message to the meter reading data request message is received, the search result obtained as a result is notified to the network management server 2, and then the periodic meter reading value collection timer is restarted. In FIG. 4, the transmission / reception operation of the meter reading data request / response message is described focusing on GW # 1 and smart meter 102, but the operation between GW # 1 and another smart meter, and other gateways The operation between smart meters is the same.

  The smart meter 102 that has received the meter reading data request message executes an adjacent search operation (step S202). In this adjacent search operation, first, a timer for waiting for reception of a search response message is activated to broadcast a search request message (step S203). The broadcast search request message reaches the adjacent smart meter 106 and GW # 1 existing within the radio wave reach of the smart meter 102, and the smart meter 106 and GW # 1 are gateways indicating the wireless mesh network of the entry destination. The ID (# 1) and the number of hops to the gateway are included in the search response message and transmitted to the smart meter 102 (steps S204 and S205).

  When the timer for waiting for reception of the search response message times out, the smart meter 102 sets the combination of the gateway ID and the hop number indicating the wireless mesh network based on the single or multiple search response messages received so far. Is extracted as a search result, and a periodic meter reading value (power consumption (kWh) at a constant interval) and a meter reading data response message to which the search result is added are transmitted to GW # 1 (step S206).

  GW # 1, which has received the meter reading data response message to which the periodic meter reading value (power consumption (kWh) at regular intervals) and the search result are added, searches the network management server 2 for the search notification message to which the search result is added. (Step S207), and the network management server 2 holds the search result of the smart meter 102 (step S208).

  In a state in which the above periodic meter reading value collection operation is periodically executed, GW # 3 indicates the completion of device startup to the network management server 2 when newly installed or recovered from a device failure. An activation completion notification message is transmitted (step S209), and the network management server 2 transmits an activation completion response message to GW # 3 (step S210).

  GW # 1 sends a search notification message to the network management server 2 in step S207, and then starts a periodic meter-reading collection timer. When the timer times out, the GW # 1 gives an adjacent search request to the smart meter 102 again. The meter reading data request message is transmitted (step S211).

  The smart meter 102 that has received the meter reading data request message in step S211 performs an adjacent search operation in the same manner as when the meter reading data request message has been received in step S201 (step S212). That is, a timer for waiting for reception of a search response message is started and a search request message is broadcast (step S213).

  The broadcast search request message reaches the adjacent smart meter 106 and GW # 1 existing within the radio wave reach of the smart meter 102, and also reaches the GW # 3 where the activation of the device is completed. GW # 1 and GW # 3 put the ID (# 1, # 3) of the gateway indicating the wireless mesh network of the entry destination and the number of hops to the gateway in the search response message, and transmit to the smart meter 102 (Steps S214 to S216).

  When the timer for waiting for reception of the search response message times out, the smart meter 102 sets the combination of the gateway ID and the hop number indicating the wireless mesh network based on the single or multiple search response messages received so far. Is extracted as a search result, and a periodic meter reading value (power consumption (kWh) at a constant interval) and a meter reading data response message to which the search result is added are transmitted to GW # 1 (step S217).

  GW # 1, which has received the meter reading data response message to which the periodic meter reading value (power consumption (kWh) at regular intervals) and the search result are added, searches the network management server 2 for the search notification message to which the search result is added. (Step S218), and the network management server 2 holds the search result of the smart meter 102 (step S219).

  Each gateway performs the above-described operation (adjacent search operation such as step S202) and notifies the search result to the network management server 2, so that the network management server 2 can obtain the search result by each smart meter, The reachability of wireless communication between smart meters entering each wireless mesh network in the communication system can be grasped. That is, for each smart meter, it is possible to grasp an adjacent smart meter that can be connected (direct wireless communication is possible).

  Thereafter, as described in the first embodiment, the network management server 2 determines whether or not load adjustment between the gateways is necessary, and switches the wireless mesh network to which the smart meter enters (step S104 in FIG. 2A). When performing the operation corresponding to step S144 in FIG. 3, not only the position information of each smart meter, but also the neighbor search result (reachability of wireless communication between smart meters) is considered, and the wireless mesh of GW # 3 The selection of the smart meter to re-enter the network and the order in which the selected smart meter re-enters are determined.

  After selecting the smart meter to re-enter the GW # 3 wireless mesh network and determining the re-entry order, the selected smart meter re-enters the adjacent wireless mesh network (GW # 3 wireless mesh network). Is the same as the operation described in the first embodiment (step S104 in FIG. 2A and step S144 in FIG. 3), and thus description thereof is omitted.

  As described above, in this embodiment, each gateway transmits a periodic meter reading value request message to which an adjacent search request is given at regular intervals, and each smart meter requests a periodic meter reading value to which an adjacent search request is given. When the message is received, the neighbor search is performed, and the neighbor search result is transmitted to the gateway together with the meter reading data. The gateway forwards the neighbor search result received from the stored smart meter to the network management server. Based on the received neighbor search result, the reachability of the wireless communication between the smart meters is grasped. In addition, when performing load adjustment between gateways, the network management server selects a smart meter that changes the entry wireless network based on the position information of each smart meter and the reachability of wireless communication between smart meters, And we decided to decide the order to change the entry. As a result, the selected smart meter can be re-entered into the adjacent wireless mesh network reliably and efficiently, and the balance of the number of smart meters accommodated by each gateway, that is, load balancing between gateways can be autonomous. I can plan.

Embodiment 3 FIG.
Next, Embodiment 3 will be described. The configuration of the communication system will be described assuming that it is the same as that of the first embodiment (see FIG. 1). FIG. 5 is a diagram for explaining a control operation in the communication system according to the third embodiment. As in the first and second embodiments, a control operation when GW # 3 is newly activated will be described.

  When GW # 3 is newly installed or recovered from a device failure, first, as shown in FIG. 5, a startup completion notification message indicating that the device has been started is sent to the network management server 2. Transmit (step S301). Here, the gateway according to the present embodiment (which is GW # 3 in the illustrated example) transmits the activation completion notification with the reason for activation (whether newly installed or recovery from a device failure). In the illustrated example, the GW # 3 transmits an activation completion notification message to which an activation reason indicating recovery from a failure is added. Upon receiving the activation completion notification message, the network management server 2 adds the gateway (GW # 3) that is the transmission source of this message to the gateway to be managed and starts state management (such as load status monitoring) and starts A completion response message is returned (step S302).

  The network management server 2 further confirms the reason for starting GW # 3 (step S303), and in the case of new installation (step S303: new installation), the wireless networks of GW # 1 and GW # 2 adjacent to GW # 3 The position information of each smart meter that has entered is read out (step S305). On the other hand, when recovering from a device failure (step S303: failure recovery), each smart that has entered the GW # 3 wireless network (that is, accommodated by GW # 3 before the device failure occurred). The meter information is read (step S304).

  After executing step S304 or S305, the network management server 2 reads the information (each smart meter accommodated in the adjacent gateway of GW # 3) in order to balance the number of smart meters accommodated in each gateway. Based on the position information of each or the smart meter accommodated by GW # 3), the smart meter to be re-entered into the wireless mesh network of GW # 3 is selected and the order of re-entry is determined (step S306). ).

  After selecting the smart meter to re-enter the GW # 3 wireless mesh network and determining the re-entry order, the selected smart meter re-enters the adjacent wireless mesh network (GW # 3 wireless mesh network). Is the same as the operation described in the first embodiment (step S104 in FIG. 2A and step S144 in FIG. 3), and thus description thereof is omitted.

  As described above, in the present embodiment, when each gateway is activated by new installation or recovery from a failure, the activation reason is added to the activation completion notification message and the network management server 2 determines that the activation reason is a device. In case of recovery from failure, selection of smart meter to change entry wireless network and change entry based on information of smart meter previously accommodated by activated gateway (before failure occurred) We decided to decide the order to make it. In addition, when the activation reason is newly installed, the selection of the smart meter that changes the entry wireless network based on the position information of the smart meter accommodated by the gateway adjacent to the activated gateway, and the entry destination We decided to decide the order to change. As a result, the selected smart meter can be re-entered into the adjacent wireless mesh network reliably and efficiently, and the balance of the number of smart meters accommodated by each gateway, that is, load balancing between gateways can be autonomous. I can plan.

  In the above description, the activated gateway notifies the network management server of the reason for activation, and based on the notification content, it is determined whether the network management server is recovering from a device failure. Even if not, the reason for activation can be determined on the network management server side. In other words, when the network management server receives a startup completion notification, it checks whether it holds information about the notification source gateway (information on the smart meter that it contained), and if so, recovers from a device failure What is necessary is just to judge that it was a gateway.

Embodiment 4 FIG.
Next, the fourth embodiment will be described. The configuration of the communication system will be described assuming that it is the same as that of the first embodiment (see FIG. 1). 6A to 6C are diagrams for describing a control operation in the communication system according to the fourth embodiment. As in the first embodiment, the control operation when GW # 3 is newly activated will be described. 6A shows the operation of the first hop smart meter from GW # 3 (smart meter that can be directly connected to GE # 3), and FIG. 6B shows the second hop smart meter from GW # 3. FIG. 6C shows the operation of a smart meter (a smart meter that can be connected to GE # 3 via one smart meter), and FIG. 6C shows a smart meter at the third hop from GW # 3 (via two smart meters). Is a diagram showing the operation of a smart meter that can be connected to GE # 3.

  When GW # 3 is newly installed or recovered from a device failure, as shown in FIG. 6A, first, a startup completion notification message indicating the completion of device startup is sent to the network management server 2. Transmit (step S401). Upon receiving the activation completion notification message, the network management server 2 adds the gateway (GW # 3) that is the transmission source of this message to the gateway to be managed and starts state management (such as load status monitoring) and starts A completion response message is returned (step S402).

  When GW # 3 receives the activation completion response message, GW # 3 next activates a broadcast timer for transmitting broadcast information indicating the start of operation (hereinafter referred to as an operational start broadcast information transmission timer), and broadcast information message with the hop count set to 1 Is broadcast (step S403). This notification information message includes identification information of the transmission source device GW # 3 and information indicating that the transmission source device has started operation. Only the smart meters 102 and 201 existing at the first hop from GW # 3 receive the broadcast notification information message and perform adjacent search operations (steps S404 and S416). Since the number of hops in the broadcast information message is 1, each smart meter that has received the broadcast information message does not transfer the received message.

  In the adjacent search operation in steps S404 and S416, the smart meters 102 and 201 each start a search response message reception waiting timer and broadcast a search request message (steps S405 and S417). The search request message broadcast from the smart meter 102 reaches the GW # 1 and GW # 3 that exist within the radio wave reach of the smart meter 102, and the GW # 1 and GW # 3 respectively enter the wireless of the entry destination. The gateway ID (# 1 or # 3) indicating the mesh network and the number of hops to the gateway are included in the search response message and transmitted to the smart meter 102 (steps S406 and S407). Similarly, the search request message broadcast from the smart meter 201 reaches GW # 2 and GW # 3 that exist within the radio wave reach of the smart meter 201, and GW # 2 and GW # 3 enter, respectively. The gateway ID (# 2 or # 3) indicating the previous wireless mesh network and the number of hops to the gateway are placed in the search response message and transmitted to the smart meter 201 (steps S418 and S419).

  When the timer for waiting for reception of the search response message times out, the smart meters 102 and 201 each of the notification information message received in step S403 from the single or multiple search response messages received so far. The one having the smallest number of hops to the transmission source gateway 30 (GW # 3) is selected, and the transmission source smart meter or gateway of the selected message is set as the connection destination of the wireless mesh network to be entered (step S408, S420). In the illustrated example, the smart meters 102 and 201 are connected to a wireless mesh network that enters GW # 3.

  When no search response message is received when the search response message reception waiting timer times out, the smart meters 102 and 201 again activate the search response message reception wait timer and broadcast the search request message. This operation (adjacent search operation) is repeated until a search response message is received (steps S405 and S417).

  When the neighbor search operation is performed and selection of the entry destination is completed, next, the smart meters 102 and 201 each start a response waiting timer to the GW # 3 selected as the connection destination of the wireless mesh network to enter. In response, an entry registration request message is transmitted (steps S409 and S421). At this time, if there is a wireless mesh network (wireless mesh network managed by a GW other than GW # 3) that can be entered in the previous neighbor search operation (steps S404 and S416), this entry is possible. The GW ID indicating another wireless mesh network is also notified. Here, the smart meter 102 uses the ID of GW # 1 (= # 1) as the ID of the adjacent GW, and the smart meter 201 uses the ID of GW # 2 (= # 2) as the ID of the adjacent GW. Notice.

  When the smart meter 102 and 201 cannot receive the entry registration response message from the GW # 3 before the response waiting timer times out, the smart meters 102 and 201 transmit the entry registration message again, and the GW # 3 before the response waiting timer times out. When the entry registration response message from is received, the response waiting timer is stopped.

  When the GW # 3 receives the entry registration request message from the smart meter 102, the GW # 3 authenticates the smart meter 102 using the authentication information included in the received entry registration request message (step S410), and updates the accommodation number (step S410). S411), an entry registration response message to which registration acceptance (OK) is given is transmitted to the smart meter 102 (step S412). Similarly, when the entry registration request message is received from the smart meter 201, the smart meter 201 is authenticated using the authentication information included in the received entry registration request message (step S422), and the accommodation number is updated (step S423). Then, an entry registration response message giving registration acceptance (OK) is transmitted to the smart meter 201 (step S424).

  After transmitting the entry registration response message, GW # 3 sends a registration request message with the ID of the smart meter 102 that has entered the network management server 2 and a registration request with the ID of the smart meter 201 that has entered. Each message is transmitted (steps S413 and S425). The network management server 2 updates the number of accommodated GW # 3 every time a registration request message is received (steps S414 and S426), and sends an entry registration response message to which registration acceptance (OK) is given to GW # 3. Transmit (steps S415 and S427).

  Further, when the operation start notification information transmission timer activated at the time of executing step S403 times out, GW # 3 adds 1 to the number of hops and broadcasts the notification information message again (step S428). At this time, the operation start notification information transmission timer is restarted. The smart meters 102 and 201 existing at the first hop from GW # 3 receive this broadcast information message and the number of hops is set to 2, so 1 is subtracted from the set number of hops and updated to 1. Then forward.

  The notification information message transferred by the smart meter 102 or 201 is received by the smart meters 106 and 204 existing at the second hop from the GW # 3, and the smart meters 106 and 204 respectively perform a neighbor search operation (FIG. 6B). Steps S429 and S440).

  In the adjacent search operation in steps S429 and S440, the smart meters 106 and 204 each start a search response message reception waiting timer and broadcast a search request message (steps S430 and S441). The search request message broadcast from the smart meter 106 reaches the smart meter 102, which is an adjacent smart meter existing within the radio wave reach of the smart meter 106, and the smart meter 102 is a gateway indicating the wireless mesh network of the entry destination. The ID (# 3) and the number of hops to the gateway are included in the search response message and transmitted to the smart meter 106 (step S431). Similarly, the search request message broadcast from the smart meter 204 reaches the smart meter 201 which is an adjacent smart meter within the radio wave reach of the smart meter 204, and the smart meter 201 receives the wireless mesh network of the entry destination. The ID (# 3) of the gateway indicating the number of hops to the gateway and the number of hops to the gateway are placed in the search response message and transmitted to the smart meter 204 (step S442).

  When the timer for waiting for reception of the search response message times out, the smart meters 106 and 204 each receive the notification information message received in step S428 from the single or multiple search response messages received so far. The one having the smallest number of hops to the transmission source gateway 30 (GW # 3) is selected, and the transmission source smart meter or gateway of the selected message is set as the connection destination of the wireless mesh network to be entered (step S432). S443). In the illustrated example, the smart meter 106 is a connection destination of a wireless mesh network that enters the smart meter 102, and the smart meter 204 is a connection destination of a wireless mesh network that enters the smart meter 201.

  If no search response message is received when the search response message reception waiting timer times out, the smart meters 106 and 204 again activate the search response message reception wait timer and broadcast the search request message. (Steps S430 and S441), and this operation (adjacent search operation) is repeated until a search response message is received.

  When the neighbor search operation is performed and selection of the entry destination is completed, each of the smart meters 106 and 204 then activates a response waiting timer and passes through the smart meter selected as the connection destination of the wireless mesh network to enter. Then, an entry registration request message is transmitted to GW # 3 that manages the entry destination wireless mesh network (steps S433 and S444). At this time, if there is another wireless mesh network (wireless mesh network managed by a GW other than GW # 3) that can be entered in the previous neighbor search operation (steps S429 and S440), this entry is possible. The GW ID indicating another wireless mesh network is also notified. Here, the smart meter 106 uses the ID of GW # 1 (= # 1) as the ID of the adjacent GW, and the smart meter 204 uses the ID of GW # 2 (= # 2) as the ID of the adjacent GW. Notice.

  When the smart meter 106 and 204 cannot receive the entry registration response message from the GW # 3 before the response waiting timer times out, the smart meters 106 and 204 transmit the entry registration message again, and the GW # 3 before the response waiting timer times out. When the entry registration response message from is received, the response waiting timer is stopped.

  When the GW # 3 receives the entry registration request message from the smart meter 106, the GW # 3 authenticates the smart meter 106 using the authentication information included in the received entry registration request message (step S434), and updates the accommodation number (step S434). S435), an entry registration response message to which registration acceptance is permitted (OK) is transmitted (step S436). Similarly, when the entry registration request message is received from the smart meter 204, the smart meter 204 is authenticated using the authentication information included in the received entry registration request message (step S445), and the accommodation number is updated (step S446). Then, an entry registration response message to which registration acceptance (OK) is given is transmitted (step S447).

  GW # 3 transmits the entry registration response message, and then sends a registration request message with the ID of the smart meter 106 that has entered the network management server 2 and a registration request with the ID of the smart meter 204 that has entered. Each message is transmitted (steps S437 and S448). The network management server 2 updates the number of accommodated GW # 3 every time a registration request message is received (steps S438 and S449), and sends an entry registration response message to the GW # 3 with registration acceptance possible (OK). Transmit (steps S439 and S450).

  Also, when the operation start notification information transmission timer activated at the time of executing step S428 times out, GW # 3 adds 1 to the number of hops and broadcasts the notification information message again (step S451). At this time, the operation start notification information transmission timer is restarted. The smart meters 102 and 201 existing at the first hop from GW # 3 receive this broadcast information message and the number of hops is set to 3, so 1 is subtracted from the set number of hops and updated to 2. Then forward. The smart meters 106 and 204 existing at the second hop from GW # 3 receive the broadcast information message transferred by the smart meter at the first hop and the number of hops is set to 2. Therefore, the set number of hops 1 is subtracted from 1 to update it to 1, and then transferred.

  The notification information message transferred by the smart meter 106 or 204 is received by the smart meters 107 and 205 existing at the third hop from the GW # 3, and the smart meters 107 and 205 respectively perform an adjacent search operation (FIG. 6C). Steps S452, S464).

  In the adjacent search operation in steps S452 and S464, the smart meters 107 and 205 each start a search response message reception waiting timer and broadcast a search request message (steps S453 and S465). The search request message broadcast from the smart meter 107 reaches a smart meter 106 that is an adjacent smart meter within the radio wave reach of the smart meter 107, and the smart meter 106 is a gateway indicating the wireless mesh network of the entry destination. The ID (# 3) and the number of hops to the gateway are placed in the search response message and transmitted to the smart meter 107 (step S454). Similarly, the search request message broadcast from the smart meter 205 reaches the smart meter 204, which is an adjacent smart meter within the radio wave reach of the smart meter 205, and the smart meter 204 enters the wireless mesh network of the entry destination. The ID (# 3) of the gateway indicating the number of hops to the gateway and the number of hops to the gateway are placed in the search response message and transmitted to the smart meter 205 (step S466).

  When the timer for waiting for reception of the search response message times out, the smart meters 107 and 205 each receive the notification information message received in step S451 from the single or multiple search response messages received so far. The one having the smallest number of hops to the transmission source gateway 30 (GW # 3) is selected, and the transmission source smart meter or gateway of the selected message is set as the connection destination of the wireless mesh network to be entered (step S456, step S456). S467). In the illustrated example, the smart meter 107 is a connection destination of a wireless mesh network that enters the smart meter 106, and the smart meter 205 is a connection destination of a wireless mesh network that enters the smart meter 204.

  If no search response message has been received when the search response message reception waiting timer has timed out, the smart meters 107 and 205 again activate the search response message reception wait timer and broadcast the search request message. This operation (neighboring search operation) is repeated until a search response message is received (steps S453 and S465).

  When the neighbor search operation is performed and the entry destination selection is completed, each of the smart meters 107 and 205 then activates a response waiting timer, via the smart meter selected as the connection destination of the wireless mesh network to enter. Then, an entry registration request message is transmitted to GW # 3 that manages the entry destination wireless mesh network (steps S457 and S468). At this time, if there is a wireless mesh network (wireless mesh network managed by a GW other than GW # 3) that can be entered in the previous neighbor search operation (steps S452 and S464), this entry is possible. The GW ID indicating another wireless mesh network is also notified. Here, the smart meter 107 uses the ID of GW # 1 (= # 1) as the ID of the adjacent GW, and the smart meter 205 uses the ID of GW # 2 (= # 2) as the ID of the adjacent GW. Notice.

  If the entry registration response message from GW # 3 cannot be received before the response waiting timer times out, the smart meters 107 and 205 transmit the entry registration message again, and GW # 3 before the response waiting timer times out. When the entry registration response message from is received, the response waiting timer is stopped.

  When the GW # 3 receives the entry registration request message from the smart meter 107, the GW # 3 authenticates the smart meter 107 using the authentication information included in the received entry registration request message (step S458), and updates the accommodation number (step S458). S459), an entry registration response message to which registration acceptance is permitted (OK) is transmitted to the smart meter 107 (step S460). Similarly, when an entry registration request message is received from the smart meter 205, the smart meter 205 is authenticated using the authentication information included in the received entry registration request message (step S469), and the accommodation number is updated (step S470). Then, an entry registration response message giving registration acceptance (OK) is transmitted to the smart meter 205 (step S471).

  GW # 3 transmits a registration request message to which the ID of the smart meter 107 that has entered the network management server 2 and a registration request to which the ID of the smart meter 205 to which it has entered are registered to the network management server 2 after transmitting the entry registration response message. Each message is transmitted (steps S461 and S472). The network management server 2 updates the number of accommodated GW # 3 every time a registration request message is received (steps S462 and S473), and sends an entry registration response message to the GW # 3 to which registration acceptance is permitted (OK). Transmit (steps S463 and S474).

  Thus, in this embodiment, after each gateway is started and started to operate, broadcast information indicating the start of operation is sequentially propagated from the first hop smart meter side to the next hop smart meter. The wireless mesh network of the entry destination is reselected in order from the first hop smart meter, so that the number of smart meters accommodated by each gateway, that is, the load between the gateways Distributed autonomously.

  In the present embodiment, the case of reselecting the entry destination for the smart meter from the activated gateway (GW # 3) to the third hop has been shown, but even if the range for reselecting the entry destination is further expanded Good or narrow. In addition, re-selection of the entry destination may be continuously performed until the network management server determines that the number of smart meters accommodated in each gateway is balanced. That is, the network management server instructs the activated gateway to transmit a broadcast information message indicating the start of operation (a broadcast information message transmitted in step S403 above), and then receives an entry registration request message. When the gateway capacity is updated, it is determined whether or not to continue the reselection operation of the entry destination.

  As described above, the present invention is useful as a communication system including a plurality of wireless mesh networks formed by smart meters that are nodes having a function of metering power and the like. It is suitable for a communication system capable of achieving additional distribution among existing gateways.

1 server device 2 server device (network management server)
3 Wide area network 10, 20, 30 Gateway 101-109, 201-209 Smart meter

Claims (6)

Formed by a single gateway and one or more nodes housed in the gateway that are installed at the consumer and measure usage for at least one of power, gas and water A plurality of wireless mesh networks, and a management server that manages the number of nodes accommodated in each of the gateways and collects and manages measurement results by the nodes,
When the management server detects that the gateway has been activated, the management server determines a node to change the entry wireless mesh network based on the number of nodes accommodated in each managed gateway and the position information of each node. Then, an instruction is given to each determined node to change the wireless mesh network of the entry destination to a wireless mesh network managed by the activated gateway. The gateway periodically sends a message for requesting notification of the measurement result of the usage amount to each node accommodated by the gateway, and uses the message to send an adjacent node to each node. The search operation is periodically executed, and each search result obtained as a result is notified to the management server,
The management server determines a node to change the entry-target wireless mesh network based on the number of nodes accommodated in each gateway to be managed, position information of each node, and the search result. The communication system according to claim 1. The activated gateway notifies the management server of the reason for activation,
The management server, when the activation reason indicates recovery from a device failure, based on the management information of the gateway that was used before the failure occurred in the activated gateway, The communication system according to claim 1, further comprising: determining a node that is to be changed. 2. The communication according to claim 1, wherein the management server instructs a timing of executing an entry change operation for each of the selected nodes, and causes the entry change operation to be executed at different timings. system. The communication system according to claim 4, wherein the management server executes an entry change operation in order from a node installed near the activated gateway. Formed by a single gateway and one or more nodes housed in the gateway that are installed at the consumer and measure usage for at least one of power, gas and water A plurality of wireless mesh networks, and a management server that manages the number of nodes accommodated in each of the gateways and collects and manages measurement results by the nodes,
After the gateway is activated, the gateway instructs to reselect the wireless mesh network of the entry destination in order from the node having the smallest number of hops to the node having the largest number of hops. A communication system characterized by causing a part of a node entering the wireless mesh network to enter a wireless mesh network managed by itself.

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