KR101110675B1 - asynchronous COMMAND ACHIEVING METHOD OF REMOTE METER READING SYSTEM - Google Patents

Abstract

The present invention relates to a method for performing asynchronous commands in a remote meter reading system. Asynchronous command execution method of the remote meter reading system according to the present invention, receiving a command signal from the meter server, receiving an active notification signal from the Zigbee node, and transmitting to the Zigbee node in the order of the command signal corresponding to the priority And receiving a command execution result according to a command signal from a Zigbee node and delivering the result to a meter reading server. As described above, according to the present invention, in the case of a Zigbee network capable of ZigBee communication only at a specific time, the command received from the meter reading server can be processed asynchronously, thereby effectively performing command processing while reducing power consumption. In addition, according to the present invention, the result of the transaction is separated into data and code, so that only the result code can be transmitted by the Zigbee node if necessary, thereby minimizing the use of communication resources.

Zigbee, Sleepy Mesh Network, Concentrator, Asynchronous, Transaction

Description

Asynchronous COMMAND ACHIEVING METHOD OF REMOTE METER READING SYSTEM}

The present invention relates to a remote meter reading system using a Zigbee network, and more particularly, to an asynchronous command performing method of a remote meter reading system that can perform Zigbee communication asynchronously with the Zigbee node.

In each home or business, people need water, gas, and electricity supplies to maintain a smooth life and activities. Businesses that supply such water, gas, and power to each customer will install a meter for each customer to measure the amount of water, gas, and power supplied to each customer.

However, when a large number of subjects charge the usage fee, the method of imposing a usage fee by checking the meter by the meter reader becomes inappropriate. Various remote meter reading systems have been proposed to solve these problems.

Such a remote meter reading system is evolving from a remote meter reading system through a wire to a remote meter reading system through a wireless system, and the wireless remote meter reading system is particularly useful for wide area remote meter reading because no communication line is required.

Meanwhile, with the recent release of the ZigBee standard, it is slowly emerging as the next-generation short-range wireless communication to replace Bluetooth. ZigBee is a technology suitable for the ultra-small, low-power, low-cost market that requires simple functions, and is expected to be able to replace power line communication, which has been delayed by standards, and Bluetooth, which is becoming less commercially available. Zigbee is mainly applied to home network fields such as home automation.

ZigBee is one of the IEEE 802.15.4 standards supporting near field communication. It is a technology for near field communication and ubiquitous computing within 10m ~ 1km in wireless networking field such as home and office. It is also economical and easy to manage because it can be used for many years with only two AA alkaline batteries used in real life. Unlike other wireless communication technologies, ZigBee has low power consumption and low-cost products, which can be applied to various ubiquitous environments such as intelligent home network, building and industrial device automation, logistics, environmental monitoring, human interface, telematics, and military.

Due to the advantages of Zigbee, the Zigbee communication method has recently been adopted for short range wireless communication between a remote meter wireless modem equipped with a meter in a wireless remote meter reading system and a concentrator collecting meter data from the remote meter wireless modem.

According to the wireless metering system according to the related art, in a shaded area, a gas metering area, or a high-rise building where electricity supply is difficult, a separate battery must be used to always keep the Zigbee node active. There is a problem in that it is not economical. Accordingly, although a wireless meter reading system has been developed in which ZigBee communication is possible only for a certain time of the day, there is a problem that ZigBee communication is not effectively performed because it becomes active for a very short period of time.

Accordingly, an aspect of the present invention is to provide an asynchronous command execution method of a remote meter reading system that can effectively communicate with a Zigbee node that is active only for a certain time.

In accordance with an aspect of the present invention, there is provided a method of performing an asynchronous command in a remote meter reading system, the method comprising receiving a command signal from a meter reading server, receiving an active notification signal from a Zigbee node, and a priority corresponding to the priority. And transmitting the result of command execution according to the command signal from the Zigbee node to the meter reading server.

The Zigbee node may be included in a sleepy mesh network that becomes active only at a specific time.

When the command signal is requested from the meter reading server, a transaction is generated and the transaction may be in a waiting state while receiving an active notification signal from the Zigbee node.

When the active notification signal is received from the Zigbee node, the transaction is in an order waiting state. If the command signal is not transmitted to the Zigbee node for a predetermined time in the order waiting state, the transaction may return to the waiting state.

If the command signal is not transmitted to the Zigbee node more than a predetermined number of times in the order waiting state, the transaction may be deleted.

When the remote meter reading system according to an embodiment of the present invention receives a command signal from a meter reading server and receives an active notification signal from a Zigbee node, the remote meter reading system transmits the command signal to the Zigbee node in order of priority. And a concentrator that receives a command execution result according to the command signal from the Zigbee node and transmits the result to the meter reading server.

As described above, according to the present invention, in the case of a Zigbee network capable of ZigBee communication only at a specific time, the command received from the meter reading server can be processed asynchronously, thereby effectively performing command processing while reducing power consumption. In addition, according to the present invention, the result of the transaction is separated into data and code, so that only the result code can be transmitted by the Zigbee node if necessary, thereby minimizing the use of communication resources.

DETAILED DESCRIPTION OF THE EMBODIMENTS Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention.

1 is a view schematically showing a remote management system according to an embodiment of the present invention. As shown in FIG. 1, the wireless remote meter reading system according to the present invention collects meter reading data transmitted from a ZigBee node 10 and a ZigBee node 10 by wirelessly reading metered data. The concentrator 20 transmits a command signal transmitted from the meter reading server 40 to the Zigbee node 10 through a communication network. Here, the Zigbee node 10 and the concentrator 20 communicate with each other through the Zigbee communication network 30 as a short range wireless communication method. In addition, the Zigbee node 10 is grouped into a plurality of groups (10G_1) (10G_2) (10G_3) (10G_4) to form a Zigbee network, and communicates with the meter reading server 40 through the concentrator 20.

The Zigbee node 10 is a terminal for reading power, energy, battery, and the like, and includes a ZigBee Router (ZR) and a ZigBee End Device (ZED). Here, the ZigBee router (ZR) that performs the routing function of the network may be implemented by a full function device (FFD), and the ZigBee end device that only acquires meter data and acquires the metering data but does not perform the routing function. The ZED may be implemented as a reduced function device (RFD). ZigBee Router (ZR) and ZigBee Termination Device (ZED) can operate at 2.4GHz, which is an international method, and can be applied to small MCUs by lightening the protocol stack.

FIG. 2 is a diagram for describing a remote meter reading system using a Zigbee network according to FIG. 1. As shown in FIG. 2, the Zigbee network may be a hybrid of the hybrid network 100 and the sleepy mesh network 200. In FIG. 2, the concentrator 20 is shown as being included in the hybrid network 100, but may be included in the sleepy mesh network 100. In FIG. 2, only the concentrator 20 and the ZigBee node 10 are illustrated for convenience of description, and the ZigBee node is illustrated as a ZigBee router (ZR) and a ZigBee end device (ZED).

First of all, the Zigbee network is described as Zigbee, a word that comes from the way Bees travel in Zigzag and communicate with each other precisely where flowers and honey are located. Unlike Bluetooth, which aims to be one of PAN (Personal Area Network) communication standard, which is characterized by low capacity data transmission and low power.

According to FIG. 2, in the hybrid network 100, a concentrator 20, a ZigBee Router (ZR), and a ZigBee End Device (ZED) are connected in a network form, and each device is a star type. (STAR TYPE) and mesh type (MESH TYPE) is a hybrid method of networking.

Here, the star method refers to a topology that performs communication around a PAN (Personal Area Network) coordinator, and the mesh method does not depend on the hierarchical structure of Zigbee, and communicates freely through an optimal path within a transmission range. It can mean a topology.

The concentrator 20 is a node existing at the top layer, and forms a Zigbee network, and has a routing function of assigning an address or relaying data to ZigBee nodes participating in the network.

In addition, the Zigbee router (ZR) is located at the lower level of the existing concentrator 20 of the top layer and the Zigbee routers (ZRs) already participating in the network, and relays data or any Zigbee newly participating in the Zigbee network. It is responsible for assigning addresses to nodes.

Finally, the Zigbee End Device (ZED) is located at the lower layer of the concentrator 20 and the ZigBee Router (ZR) and has only minimal functionality for the application and does not perform address assignment and routing functions. The ZigBee end device (ZED) is provided with or connected with a sensor having a meter reading function, and receives various meter reading data detected from the sensor and transmits it to the upper layer ZigBee router (ZR).

ZigBee Termination Device (ZED) has a relatively small amount of transmitted data compared to Bluetooth, but it is a low power standard that can be used for more than one year with a single battery.It also minimizes software and related components, so the cost is much lower than that of Bluetooth. A communication network, that is, networked, and on the other hand, is one of the IEEE 802.15.4 standards supporting near field communication, which can be very usefully applied to the present invention.

ZigBee Termination Device (ZED) is usually installed in STAR type of 30 ~ 80m intervals, and the meter reading data of ZigBee Termination Device (ZED) arranged in a star manner with respect to ZigBee Router (ZR) is meshed (MESH). Communication is sensed by ZigBee routers (ZRs) connected by networking. The meter reading data transmitted from the Zigbee router (ZR) is collected by the concentrator 20 and then propagated remotely to the meter reading server.

In the sleepy mesh network 200, a plurality of ZigBee routers ZR are networked and formed in a mesh manner, and the ZigBee end device ZED is not included. The plurality of Zigbee routers (ZR) included in the sleepy mesh network 200 mainly perform Zigbee communication with the concentrator 20 installed in a shaded area, a gas metering area, or a high-rise building, which are difficult to supply power. .

The Zigbee router (ZR) included in the sleepy mesh network 200 switches from a sleep mode to an active mode at a predetermined period and communicates in a mesh manner. That is, the meter data transmitted through the sensor provided in the Zigbee router (ZR) is transmitted to the concentrator 20 in a mesh manner.

Meanwhile, the ZigBee router ZR and the ZigBee end device ZED included in the hybrid network 100 shown in FIG. 2 transmit meter reading data from time to time to keep most of the time active. Therefore, when the meter reading server 40 transmits the metering data request signal to the concentrator included in the hybrid network 100, the Zigbee router ZR and the Zigbee end device ZED included in the hybrid network 100 are in real time. Commands can be executed concurrently.

On the other hand, since the sleepy mesh network 200 remains active for a short period of time at a specific time, even if the meter reading server 40 transmits a request, the sleepy mesh network 200 cannot respond to the command in real time. That is, in the on-demand state in which the meter reading server 40 requests to read the read data, the sleepy mesh network 200 may perform the command after the sleepy mesh network 200 becomes active. Therefore, the Zigbee router (ZR) included in the sleepy mesh network 200 may perform the command of the meter reading server 40 asynchronously only at a specific time.

Meanwhile, although FIG. 2 illustrates the execution of an asynchronous (aynchronous) command by taking the Zigbee router (ZR) included in the sleepy mesh network 200 as an example, the Zigbee router (ZR) and the Zigbee end device (included in the hybrid network 100). In the case of ZED), if the possibility of Zigbee communication is not immediately known, the command can be executed asynchronously.

Hereinafter, the asynchronous command execution method of the remote meter reading system will be described with reference to FIG. 3.

3 is a diagram for explaining asynchronous command execution in a Zigbee network according to an embodiment of the present invention. As described above, the ZigBee Node 10 includes a ZigBee Router (ZR) and a ZigBee End Device (ZED).

First, the meter reading server 40 transmits a command for the execution request (Operation Request) to the concentrator 20 (S10). Here, the meter reading server 40 requests execution of various control commands related to the Zigbee node 10, such as meter reading data collection, power off, power recovery, and setting change.

The concentrator 20 that receives the request command from the meter reading server 40 is in charge of managing the transaction. That is, the concentrator 20 wraps the request signal of the meter reading server 40 in a transaction and controls the operation of the Zigbee node 10 until the Zigbee node 10 performs the requested operation asynchronously.

The concentrator 20 allows the Zigbee node to wait until it receives an Active Notification for Wake-up. In other words, when the Zigbee node 10 is included in the sleepy mesh network 200, the Zigbee node 10 becomes active only at a specific time, and thus, the Zigbee node 10 is in a wait state WAIT until the Zigbee node 10 becomes active. In addition, even if the Zigbee node 10 is included in the hybrid network 100, even if the possibility of Zigbee communication is not immediately known, since the access to the Zigbee node is not guaranteed, the wait state until the Zigbee node becomes active (WAIT) ) For example, if a Zigbee node is recently installed and initialized, the communication path may not be set, and thus access to the Zigbee node is not guaranteed.

When the Zigbee node 10 becomes active, the Zigbee node 10 notifies the concentrator 20 of the information indicating that the active state is active (S20).

At this time, the concentrator 20 transmits the command signal to Zigbee node 10 according to the priority, in which the command signal in the subordinated order is waited until the execution of the command of the priority is completed. QUUEUE) (S30). That is, since the concentrator 20 has a limited network resource that can communicate with the Zigbee node 10, a plurality of command signals cannot be sent at the same time. Therefore, the concentrator 20 transmits a command signal in a priority order first, and transmits a command signal corresponding to a next rank when execution of the command is completed.

For example, assuming that only three network resources are available and 10 command signals should be transmitted to the Zigbee node 10, three command signals corresponding to priorities are transmitted first, and the remaining 7 command signals are transmitted. It is in QUUEUE state. When execution of one of the transmitted command signals is terminated, the command signal in the fourth rank is transmitted. In this way, the transaction is in QUUEUE until its order is reached.

The concentrator 20 sequentially transmits the command signal corresponding to the priority to the corresponding Zigbee node, and the Zigbee node executes the operation (RUN) in response to the requested command (S40). In particular, in the case of the Zigbee node included in the sleepy mesh network 200, the active state for about 38 seconds, step S40 is performed during this period. Accordingly, the Zigbee node collects the metering data in the active state and transmits the meter data to the concentrator 20 or executes a task in response to the requested command.

When the Zigbee node completes the command execution (TERMINATE), the concentrator 20 deletes the command processing data (Transaction) (DELEATE). In this case, the sleepy mesh network 200 becomes active only for a short period of about 38 seconds in 24 hours, so that the instruction execution and deletion process is performed within a short period of time.

The concentrator 20 transmits the transaction processing result to the meter reading server 40 (S50). That is, the concentrator 20 reports to the meter reading server 40 whether the Zigbee node 10 is successful or failed about the transaction processing.

Hereinafter, the transaction state change process will be described in more detail with reference to FIGS. 4 and 1. 4 is a diagram illustrating a state transition diagram of a transaction according to FIG. 3.

As soon as a transaction is created, it will be in one of four states: 'WAIT'-> 'QUEUE'-> 'RUN'-> 'TERMINATE'. In Table 1, the transaction is defined as 'DELETE', but when the 'DELETE' operation is executed, the transaction is deleted, so a transaction in 'DELETE' cannot exist. The transition conditions of each state are shown in Table 1 below.

As shown in FIG. 4 and Table 1, in the case of Normal, the transaction proceeds with 'WAIT'-> 'QUEUE'-> 'RUN'-> 'TERMINATE' at the same time as the creation, which is described in FIG. Since the duplicated content will be briefly described.

First, when the transaction is in the WAIT state, when the concentrator 20 receives an Active Notification from the Zigbee node 10, the transaction is in the QUEUE state (Normal). However, if the concentrator 20 does not receive an Active Notification from the Zigbee node within a certain period of time (TIME OUT), the transaction is terminated, and if there is a request from the meter reading server 40, the transaction is deleted. (DELEATE).

When a transaction is queued and a command is transmitted to a ZigBee node within a time limit, the ZigBee node RUNs a job in response to a request signal. However, if the transaction is in the QUEUE state and the priority does not fall within the time limit (TIME OUT), it will be in the WAIT state again to prepare for a retry. That is, in the case of the Zigbee node included in the sleepy mesh network 200, the active state is maintained only for 38 seconds, and therefore, the transaction must execute the command within 38 seconds. However, if the priority is low and the command is not executed within 38 seconds, the transaction will return to the WAIT state. If it fails more than a few times and returns to the WAIT state, the next time the meter server ( At the request of 40), the transaction is deleted.

If the transaction is normally executed in the RUN state, the transaction is terminated (TERMINATE) and the terminated transaction is normally deleted (DELEATE). However, if the Zigbee node terminates the command abnormally while the transaction is in the RUN state, the transaction will return to the WAIT state.

As described above, according to the embodiment of the present invention, in the Zigbee network capable of ZigBee communication only at a specific time, the command received from the meter reading server is asynchronously processed, thereby effectively performing command processing while reducing power consumption. In addition, according to an embodiment of the present invention, the result of the transaction is separated into data and code, so that only the result code can be transmitted by the Zigbee node if necessary, thereby minimizing the use of communication resources.

Although the present invention has been described with reference to the embodiments shown in the drawings, this is merely exemplary, and it will be understood by those skilled in the art that various modifications and equivalent other embodiments are possible. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

1 is a view schematically showing a remote management system according to an embodiment of the present invention.

FIG. 2 is a diagram for describing a remote meter reading system using a Zigbee network according to FIG. 1.

3 is a diagram for explaining asynchronous command execution in a Zigbee network according to an embodiment of the present invention.

4 is a diagram illustrating a state transition diagram of a transaction according to FIG. 3.

Claims (10)

Receiving a command signal from a meter reading server, Receiving an active notification signal from a Zigbee node, Transmitting command signals corresponding to priorities to the Zigbee node in order; and Receiving a command execution result according to the command signal from the Zigbee node and transmitting the result to the meter reading server, When a command signal is requested from the meter reading server, a transaction is generated, and the transaction is queued while receiving an active notification signal from the Zigbee node. The method of claim 1, And the Zigbee node is included in a sleepy mesh network which becomes active only at a specific time. delete 3. The method of claim 2, When the active notification signal is received from the Zigbee node, the transaction is placed in a waiting state, and if the command signal is not transmitted to the Zigbee node for a predetermined time in the waiting state, the transaction returns to the waiting state. How to Perform Asynchronous Commands in. 5. The method of claim 4, If the command signal is not transmitted to the Zigbee node more than a predetermined number of times in the waiting sequence, the transaction is deleted. When the command signal is received from the meter reading server, when the active notification signal is received from the Zigbee node, the command signals corresponding to the priorities are sequentially transmitted to the Zigbee node, and the Zigbee node receives the command execution result according to the command signal. It includes a concentrator that receives and delivers to the meter reading server, Upon receiving a command signal from the metering server, a transaction is generated and the transaction is queued while receiving an active notification signal from the Zigbee node. The method of claim 6, The Zigbee node is included in a sleepy mesh network that is only active at a specific time. delete The method of claim 7, wherein When the active notification signal is received from the Zigbee node, the transaction is placed in a waiting state, and if the command signal is not transmitted to the Zigbee node for a predetermined time in the waiting state, the transaction returns to the waiting state. . 10. The method of claim 9, And if the command signal is not delivered to the Zigbee node more than a predetermined number of times in the waiting sequence, the transaction is deleted.

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