KR100934856B1 - How to Transfer Data Between Nodes in Wireless Network Environment - Google Patents

Abstract

The present invention relates to a method for transmitting data between nodes in a wireless network environment. When an upper node requests data transmission to a plurality of lower nodes and then fails to transmit data from any one or more of the lower nodes, the upper node receives data. Request for a retransmission command, and the neighboring node of the lower node that failed to transmit data retransmits the data of the lower node that failed to transmit data to the upper node.

According to the present invention, when data transmission is not smooth due to a difference in transmission performance of a specific lower node or a communication environment, data reception rate of the entire network can be improved by transmitting data through neighboring nodes with smooth data transmission around. .

Communication, Data, Communication, Node, Wireless Network

Description

Method for data transferring among nodes in wireless network environment}

The present invention relates to a method of transmitting data between nodes in a wireless network environment, and more particularly, a method of transmitting data between nodes in a wireless network environment in which a neighboring node having a good communication environment transmits data of a lower node having a poor communication environment instead. It is about.

Wireless network technology is increasingly used in various environments. Although there are disadvantages in that communication noise or shadow area occurs due to the nature of wireless network environment, it has advantages of convenient installation environment and excellent mobility without the need for cable connection, so sensor network and automatic meter reading (AMR) Wireless network technology is used in the network.

The sensor network, which has been used for military operations in the past, has been miniaturized and improved in performance due to the improvement of semiconductor technology, and the increase in memory capacity and low cost have been realized. In addition, due to the development of technology such as wireless communication, application cases have been proposed in the private sector, and some application cases are being implemented.

Application cases of sensor network technology that are currently proposed are diverse such as unmanned security, environmental monitoring, remote meter reading, and facility monitoring to monitor the temperature or pollution level in a certain area or water area, and interwork with home network system and Internet network. There are also examples of applications that work.

And today, electricity, gas, water, etc. are essential resources for living, and it is necessary to read the meter periodically to accurately measure usage for billing. The conventional conventional meter reading method is a manual meter reading (MMR) method in which the meter reader visits the customer, reads and records the meter's instructions, and calculates the amount of usage by converting the difference from the previous month's guidelines. The labor costs and operating costs of meter reading personnel are enormous, and a considerable amount of time is required for meter reading, and when a user is absent, there is a disadvantage of causing inconvenience such as missing or revisiting the meter.

On the contrary, the Automatic Meter Reading (AMR) method, which connects the meter and the metering device through a specific communication medium and automatically collects instructions and status of each meter, has a low cost due to the recent development of communication technology. As a way to build a reliable system, the interest and demand for this is increasing. Accordingly, discussions about the remote metering technology and its system specifications have been actively conducted by electric power companies, water works, and gas companies. .

In the sensor network, the upper node requesting data and the lower node acquiring and providing the data are formed in a centralized network structure, and the remote meter reading network is characterized in that the upper node and the lower node are formed in a tree structure.

The centralized network structure and the tree structure are configured to acquire data from various lower nodes and transmit the obtained data to one highest node.

1 is a diagram illustrating a flow of data between nodes in a conventional wireless network environment.

As shown therein, the upper node requests data transmission and the lower node acquires data and transmits the data. That is, a data request command is transmitted from node A to node B and node C, and the data request command continues to be transmitted to lower nodes D, E, F, and G.

Then, data transmission starts from the last nodes D, E, F, and G by the data request command. At this time, the data transmitted from the last node (D, E) is merged in the node B located in the middle, and the data transmitted from the last node (F, G) are merged in the node C located in the middle and returned to the top node A. It has a structure to be delivered.

In a wireless network, in general, it is assumed that the two-way communication performance between the two nodes is the same, but in practice, all terminals in the wireless network have a slight output deviation depending on the surrounding environment and the RF performance of the wireless device. The difference in communication output can be seen.

For example, referring to nodes B, D, and E in FIG. 1, it can be seen that the communication distance between the node B-D and the node B-E are different from each other.

Here, assuming that the communication output of the upper node B can reach the nodes D and E, the node B can communicate up to the distance of the node E, but in the case of the node E, the communication output is small so that the communication output of the node B cannot communicate to the distance of the node B. Can be.

In this case, both node D and node E receive a data request from node B, but the data transmission according to the data request reaches node B only from node D, and node E fails to communicate.

This phenomenon may be caused by an incorrect network configuration or a difference in communication output between terminals.

Accordingly, there is a need for a method capable of receiving data transmitted from a lower node having a short communication distance in order to improve a data reception rate of a wireless network.

In a wireless network environment of the present invention devised to solve this problem, a preferred embodiment of the method for transmitting data between nodes includes a step in which an upper node requests data transmission to a plurality of lower nodes, and the lower nodes are sent to the upper node. Transmitting data; if data transmission from any one or more of the lower nodes fails, the upper node requests data retransmission; and neighboring nodes of the lower node for which the data transmission fails fail to transmit the data. And retransmitting data of the failed lower node to the upper node.

In this case, the data transmission includes a command for detecting data transmission to the upper node between the neighboring lower nodes, and thus stores data transmitted by the lower node neighboring to the upper node. It is characterized by.

The retransmitting of data of the lower node for which the data transmission has failed to the upper node may include performing a synchronization process between the lower node for which the data transmission has failed and the neighboring node of the lower node for which the data transmission has failed. And transmitting, by the neighboring node of the lower node that failed to transmit, the data of the lower node that failed to transmit the data at the time of transmission, and retransmitting the data of the lower node that failed to transmit the data to the higher node. do.

Here, the performing of the synchronization process may be performed by a synchronization signal provided from the upper node, or may be performed by a synchronization signal provided from a lower node in which data transmission fails to a neighbor node of a lower node in which data transmission fails. It is characterized by.

According to the present invention, in a sensor network or an AMR network, when data transmission is not smooth due to a difference in transmission performance or a communication environment of a specific lower node, the data is transmitted through a neighboring node with smooth data transmission around, Improve the data reception rate of the network.

Hereinafter, a method of transmitting data between nodes in a wireless network environment of the present invention will be described in detail with reference to FIGS. 2 and 3.

In describing the present invention, when it is determined that the detailed description of the known technology related to the present invention may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted. In addition, terms to be described below are terms defined in consideration of functions in the present invention, which may vary according to the intention or custom of a user or an operator. Therefore, the definition should be made based on the contents throughout the specification.

In general, a request for data transmission from an upper node to a lower node is broadcasted to the lower node as a broadcast. That is, the upper node requests data transmission for all the lower nodes belonging to the upper node. Therefore, each lower node belonging to one higher node can know that the neighboring lower node transmits data to the upper node.

In addition, it is possible to calculate when a neighboring lower node transmits data in response to a data transmission request of an upper node.

For example, if a data transmission request is sent to a specific subnode, the data transmission request is immediately transmitted. If a data transmission request is transmitted to all subnodes, it is necessary to transmit by competition through carry sensing or fixed communication timing. In general, the data transmission time of neighboring subordinate nodes can be known.

According to the present invention, a neighboring node located within a distance of the communication output of the lower node assists the data transmission of the lower node that has received a data transmission request from the upper node but has a weak communication output and failed to transmit the data to the upper node. There is a characteristic.

2 is a diagram illustrating a communication environment for explaining a method of transmitting data between nodes in a wireless network environment of the present invention.

Looking at the case of the upper node B and the lower nodes D and E, it can be seen that the node D is located closer to the node B than the node E, and not far from the node E. Therefore, it can be said that the node D is in a better communication environment for data transmission with the node B than the node E.

The present invention relates to a method of transmitting data by using a neighboring node D when the strength of the communication output of the node E is not strong enough to transmit data to the node B. The node D assists the node E in transmitting data. By the communication algorithm as shown in 3.

1. The upper node B requests data transmission to the lower nodes D and E (S100).

In this case, the upper node B may transmit an additional command by adding an additional command to the data transmission packet. For example, the upper node B may add a command to detect data transmission of a lower node neighboring the data area of the data transmission packet.

Generally, these additional commands are given to all of the child nodes that belong to it, but if the parent node B knows that the communication environment of child node E is poor or that the communication output is small, these additional commands are It can be given only to the subordinate node E and the subordinate node D neighboring.

2. The lower nodes D and E transmit their own data to the upper node B for the data transmission (S 110).

Here, according to an additional command to detect data transmission of the neighboring lower node, the lower node D receives a response transmitted by the lower node E to the upper node B, and the lower node E indicates that the lower node D is the upper node B. You will hear a response sent to.

Each of the lower nodes D and E stores data transmitted from the neighboring lower node to the upper node B in its own memory.

On the other hand, the data transmitted by the lower node D to the upper node B is transmitted to the upper node B, but the data transmitted by the lower node E to the upper node B is not transmitted to the upper node B due to the difference in communication output.

3. If the data transmitted by the lower node E does not reach the upper node B due to a difference in communication output or is transmitted due to a deterioration of the communication environment (S 120), the upper node B requests data retransmission (S 130). .

4. When data retransmission is requested from the upper node B to the lower node E, the lower node D transmits the data that the lower node E intends to transmit to the upper node B to the upper node B instead (S 140).

At this time, the lower node D transmits the same data to the upper node B at the timing at which the lower node E transmits data in order to prevent collision with data transmitted by the lower node E. FIG.

That is, the lower nodes D and E are synchronized with each other to transmit the same data to the upper node B at the same time. The synchronization between the two nodes D and E may be configured by transmitting a synchronization signal between the two nodes D and E. In addition, it may be configured to receive a synchronization signal from the upper node B and to be made by the received synchronization signal.

Here, the lower node D may know that its data transmission is successful by requesting a data retransmission command for the lower node E, and it may be understood that the lower node E has failed to transmit data.

Therefore, when the lower node D transmits the data to be transmitted by the lower node E stored in the memory to the upper node B, the lower node D transmits the source as the lower node E instead of itself.

In this way, the upper node B can recognize the received data as the data transmitted by the lower node E, and can successfully transmit the data of the lower node E having a short communication distance to the upper node B.

In the present invention, data transmission is complemented with each other through a pair (pair between two nodes or more nodes) between lower nodes (here, D and E).

That is, in order to perform the data transmission method between the nodes in the wireless network environment of the present invention, the upper node pairs with its lower nodes to complement the data transmission, and the pair between the lower nodes is random according to the position of the lower nodes. It can be configured in the same way, or paired with lower nodes with mutually opposed communication environments.

In this case, the lower nodes that are paired with each other may be preset and recognized in the entire network system, and the upper nodes may be separately commanded to recognize that the lower nodes are paired with each other.

As described above, according to the present invention, in the sensor network or the AMR network, when data transmission is not smooth due to a difference in transmission performance or a communication environment of a specific lower node, the data is transmitted through a neighboring node with smooth data transmission around. In addition, the data reception rate of the entire network can be improved.

Although the present invention has been described in detail with reference to exemplary embodiments above, those skilled in the art to which the present invention pertains can make various modifications to the above-described embodiments without departing from the scope of the present invention. I will understand.

Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined by the claims below and equivalents thereof.

1 is a flow diagram of inter-node data in a conventional wireless network environment.

2 is a diagram illustrating a communication environment for explaining a method of transmitting data between nodes in a wireless network environment of the present invention.

3 is a flowchart illustrating a method for transmitting data between nodes in a wireless network environment of the present invention.

Claims (6)

Requesting, by an upper node, data transmission to a plurality of lower nodes; The lower nodes transmitting data to the upper node; Requesting data retransmission by the higher node if data transmission from any one or more of the lower nodes fails; And Retransmitting, by the neighboring node of the lower node whose data transmission failed, the lower node where the data transmission failed, to the upper node; And transmitting the data to the neighboring lower nodes with a command to sense data transmission to the upper node. delete The method of claim 1, After the lower nodes transmit data to the higher node, And storing data transmitted by neighboring lower nodes to the upper node, wherein the lower nodes are neighboring nodes. The method of claim 3, Retransmitting the data of the lower node where the data transmission has failed by the neighboring node of the lower node that has failed the data transmission to the upper node, Performing a synchronization process between a lower node where the data transmission fails and a neighbor node of the lower node where the data transmission fails; And And retransmitting the data of the lower node, which failed to transmit the data, to a higher node, by the neighboring node of the lower node, which failed to transmit the data, matches the data of the lower node, which failed to transmit the data, at the time of transmission. A method for transmitting data between nodes in a wireless network environment. The method of claim 4, wherein Performing the synchronization process, A method for transmitting data between nodes in a wireless network environment, characterized by the synchronization signal provided from the upper node. The method of claim 4, wherein Performing the synchronization process, A method of transmitting data between nodes in a wireless network environment, characterized by the synchronization signal provided from the lower node where the data transmission failed to the neighboring node of the lower node where the data transmission failed.

Images