KR20120044463A - Energy-saving communication method in wireless sensor networks - Google Patents

Abstract

PURPOSE: An energy saving communication method in a wireless sensor network is provided to save energy by applying optimal transmission voltages to a node by deducting the optimal transmission voltages. CONSTITUTION: A node B transmits synchronization packets in a synchronization process by using maximum voltages. The node B confirms the RSSI(Received Signal Strength Indicator) of a reception unit and an LQI(Link Quality Indicator). The node B applies the power reduction recommendation value of a node A to transmission voltages. The node B establishes previous transmission voltages as optimal voltages.

Description

Energy-saving communication method in wireless sensor network {Energy-saving communication method in wireless sensor networks}

The present invention relates to a method for minimizing power consumption of a wireless sensor network system, and more particularly, to a wireless sensor network system for minimizing power consumption in a transmission / reception step between nodes forming a network in a wireless sensor network.

Recent innovations in ICTs are accelerating convergence between industries. Convergence of IT and traditional industries continues, and by applying u-IT technology to the agricultural sector, which is a traditional industry, convergence technology is emerging as a technology that can increase the added value and productivity of agriculture.

The core of the ubiquitous technology for realizing such u-agriculture is wireless sensor network technology. The wireless sensor network is also called Ubiquitous Sensor Network by another name.

A typical wireless sensor network includes a sensor node having a wireless transceiver which senses surrounding environment information, processing, and transmits it to another node, and a sink node for transmitting collected data received from the sensor node to an external network. It includes. Sensor nodes that can be included to collect environmental information include sensors that can measure temperature, humidity, gas (carbon dioxide, ammonia, methane, hydrogen sulfide, etc.), weight, light quantity, and concentration.

The wireless sensor network may be applied to economic activities such as production, logistics, distribution, welfare activities such as environmental monitoring, and medical care, respectively.

u-Agriculture is implemented in growth monitoring and livestock management system, and various pilot projects are in progress. However, these studies only evaluate the industrial potential of ubiquitous technology. The sensor nodes installed for data collection are not used much and can be used to manage energy by replacing power or connecting expensive wired power modules. There is a continuing need for ways to do this.

FIG. 1 is a diagram illustrating power when data is transmitted from a Received Signal Strength Indicator (RSSI), a Link Quality Indicator (LQI), and a transmitting node to a receiving node according to an embodiment of the disclosed technology. .
2 is a diagram illustrating a process of optimizing transmission power between wireless nodes.

Description of the disclosed technology is only an embodiment for the description of the function to be implemented. The embodiment may be changed in various directions and may have various forms. Therefore, the scope of the disclosed technology should be understood to include equivalents that can realize the technical idea, and should not be construed as limited by the embodiments described in the text.

Hereinafter, a method of minimizing power consumption while transmitting and receiving wireless sensor nodes will be described. The above method may be used in various types of wireless networks in addition to the sensor network, and an example of the sensor network will be described to help the description.

FIG. 1 is a diagram illustrating a method in which a transmitting node retains receiving strength information of a receiving node and transmits using the power that can be received by the receiving node when transmitting data according to the receiving strength information.

Figures such as RSSI (Received Signal Strength Indicator) value or the power used in transmission are shown to help the understanding of the figure, and the figures used in the actual use example may be different from the figure.

In the present invention, the MAC protocol measures the logical distance between sensor nodes and transmits them at the lowest energy possible to receive data at the receiving node, thereby improving the energy efficiency of the sensor node, and receiving errors and retransmissions caused by transmitting at the lowest power. It aims to prolong the life of the entire network by proactively blocking energy waste.

According to the RSSI value measured by the communication module of the sensor node used in the embodiment, data is transmitted by dividing the transmission power into eight levels.In consideration of the LQI at the time of reception, the data is transmitted immediately according to the RSSI value. Measure and use the transmit power at this time.

In the present invention, the transmission power information exchange process will be described in detail. The method of synchronizing between sensor nodes may vary depending on the type of the MAC (Media Access Control) protocol of the sensor network, and the present invention may use a synchronization method of various MAC protocols, and asynchronous Wise-MAC, Z It can also be used for MAC protocols such as -MAC and X-MAC. The synchronization method described in the present embodiment extends the SYNC packet of the S-MAC (Sensor MAC) protocol to additionally insert the receiving node address and the recommended power data into the SYNC packet and use it in the synchronization process.

All sensor nodes have received intensity information measured in an area free of obstructions. The received strength information is the received strength information measured at the receiving node by transmitting the transmitting node and the receiving node at a predetermined distance and transmitting at maximum transmission power.

2 is a diagram illustrating a process of deriving an optimal transmit power by a wireless node participating in transmission and reception. In this case, the first transmitting node is referred to as node B, and the receiving node is referred to as node A.

Node B transmits SYNC packets at full power during synchronization.

② Node B checks the Received Signal Strength Indicator (RSSI) and the Link Quality Indicator (LQI) of the receiving device, checks the transmission power included in the received SYNC packet, and checks the ACK response and Send to Node B including the power down recommendation. At this time, it is determined whether the smooth communication is possible by checking the LQI, and if the communication is difficult when the transmission power is reduced, the power above one level of the power value specified in the RSSI value is applied.

③ Node B sets the transmission power by applying the power reduction recommendation received from A and transmits it to Node A in the next synchronization section.

④ Node B repeatedly executes ② and ③, and when node B sets and transmits the recommended power received from node A in step ③, but does not proceed to ②, it sets the immediately previous transmission power to the optimum power.

⑤ Repeat the process of ②, ③ in Node A to optimize each other's transmission power.

⑥ When the destination node of the data to be sent wants to send the packet to all the neighboring nodes, it transmits at the maximum power that can be transmitted.

The disclosed technique may have the following effects. However, since a specific embodiment does not mean to include all of the following effects or only the following effects, it should not be understood that the scope of the disclosed technology is limited by this.

The wireless network system according to an embodiment may greatly reduce power consumption of the wireless network. The system according to an embodiment may reduce the amount of power consumed for transmission and reception at a wireless node by measuring the reception strength of the reception node and transmitting the transmission node with the least power that the reception node can receive.

According to an embodiment, the system may reduce power consumption of the wireless node, thereby improving lifespan of the network. In addition, the system according to an embodiment may be applied to a network in which power consumption should be minimized, such as a sensor network system, and the network may be efficiently and conveniently managed.

Although described above with reference to an embodiment of the present invention, those skilled in the art will be variously modified and changed within the scope of the invention without departing from the spirit and scope of the invention described in the claims below I can understand that you can.

Claims (3)

In the data transmission and reception method of a wireless network,
In a synchronization process or a preamble exchange in an asynchronous MAC, the receiving node measures the transmission power and the reception strength of the transmitting node and transmits the recommended power to the transmitting node; And
And transmitting the optimal power for transmitting power transmitted by the transmitting node to receive the correct data. The method of claim 1, wherein the transmitting of the recommended power to the transmitting node is performed.
The packet for synchronization includes the destination address, current transmission power, and recommended power information of the receiving node, and the receiving node measures the reception strength of radio waves transmitted from the transmitting node to derive the lowest transmit power that the receiving node can receive. Way; Wireless network data transmission and reception method comprising a. The method of claim 1, wherein exchanging the optimum power is
Measuring a radio wave transmitted from a transmitting node and recommending a lower transmission power if the data reception quality includes a good range even if the reception intensity does not satisfy the reference value; Wireless network data transmission and reception method comprising a.

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