In recent years, wireless communication, sensor of integrated circuits and microcomputer systems in recent years, wireless communication, sensor of integrated circuits and microcomputer systems (MEMS) technology, such as the rapid development of, promoted low-cost, power consumption of wireless sensor for mass production. Is a set sensing function and driven control force, and calculation communications Yu one of resources by limited embedded device, and wireless sensor network (WSN) is is by large wireless sensor constitute of since organization network, its purpose is collaboration to perception, and collection and processing network covering regional within object information, and will pass its purpose is collaboration to perception, and collection and processing network covering regional within object information, and will transfer to needs of user.
WSN is considered one of 21st century's most important technology, it will have a profound impact on mankind's future lifestyle. In the far-reaching health impacts. In February 2003 of the United States top ten emerging technologies produced a profound effect on the future of mankind lives in the WSN is #. The same year, the United States BusinessWeek Technology special editions in the future when addressing the four new, WSN is also included.
WSN composition and characteristics of the composition and characteristics of the composition and characteristics
WSN constructed from large wireless sensor uses ad hoc way (see Figure 1), which benefit from the various sensors built into the node measurement signal in the same environment, thereby detecting all kinds of data needed, and moved over the network to where it is needed.
Wireless sensor generally consists of data acquisition units, processing transmission and wireless sensor generally consists of data acquisition units, such as power transmission and power components (see Figure 2). Monitoring of physical signals form determines the sensor type, such as temperature sensors, monitoring voice strong pressure, and so on. Normally use embedded sensors on several occasions, monitoring voice strong pressure, and so on. Normally use embedded data transmission unit mainly consists of low-power, short-range wireless communication modules. Miniaturization of the operating system selection of transmission unit mainly consists of low-power, short-range wireless communication modules. Miniaturization of the operating system selection of embedded operating systems, such as Vxworks, Mu COS-II, μ Clinux, TinyOS etc.
Characteristics of sensor networks and compared to the Commission some independence, mainly:
1. the node density, each is both a sensor and routing;
2. with limited computing power and communication, and power supply;
3. the unique underlying communication transmission media;
4. sensor nodes without a Center, self-organizing, Multihop communication;
5. at the same time by multiple sources – transferring data routing;
6. network with strong robustness and good scalable.
WSN application areas and overview
Wireless sensor networks with rapidly deployable, self organization, concealment and high fault-tolerance characteristics and therefore very suitable for application in the military. Using wireless sensor networks can be realized on enemy troops and equipment monitoring, real-time monitoring of the battlefield, target location, battlefield assessment and monitoring of nuclear attack and biochemical attacks and search functions. At present many international institutions are based on the subject of battlefield needs as the background. For example, the US military carried out such as the C4KISR programme, SmartSensorWeb, smart sensor network communication group, unattended ground sensors, sensor network system, CEC network sensor system, and so on.
In military area application aspects, the item technology of vision target is: using aircraft or artillery, launches device, will large cheap sensor node in accordance with the must of density cloth placed in to measuring regional within, on around of various parameter, as temperature, and humidity, and sound, and magnetic field, and infrared, various information for collection, then by sensor itself construction of network, through gateway, and Internet, and satellite, channel, pass back information center.
The technology can be used for the enemy and the military intelligence surveillance. Friendly personnel, equipment and installation of sensor nodes on arms for identification, control your own at any time. By deploying a variety of sensors of enemy positions, know thyself, pre-emptive. In addition, this technology can be used to guide of smart weapons, interact with radar, satellite, take advantage of its features close to the environment, to avoid blind spots, the use of weapons effects improved significantly.
Environmental science
Amid growing concern for the environment, the scope of the environmental sciences more and more widely. Through traditional means acquisition of the original data is a difficult task. Sensor networks to facilitate field study on the randomness of data acquisition, for example, tracks migration of migratory birds and insects, study the impact of environmental change on agricultural crops, monitoring of oceans, atmosphere and soil composition, and so on. ALERT systems, there are several kinds of soil moisture sensors to monitor water level and rainfall, rivers, and in accordance with possibilities of outbreak of this forecast flash floods. Similarly, sensor network for accurate and timely forecast of forest fire should be helpful.
Agricultural areas
Wireless sensor network with superior technology advantage. It can be used to monitor crop irrigation, soil air environmental conditions change, livestock and poultry, as well as large areas of ground testing. Precision agriculture, monitoring of crop pests, acidity or alkalinity of the soil and fertilization.
WSN system usually consists of environmental monitoring nodes, base stations, communication systems, the Internet and monitor hardware and software system. As figure by as shown in, under needs, people can in to measuring regional placed different function of sensor and composition network, long-term large area to monitoring tiny of climate changes, include temperature, and humidity, and wind, and atmospheric, and rainfall, collection about land of humidity, and nitrogen concentrated volume and soil PH value,, to for Science forecast, help farmers disaster, and disaster reduction, science planting, obtained higher of crop yield.
Wireless sensor network communication advantages of convenience, easy deployment, applications to make them water-saving irrigation control. At the same time, node also has soil parameters, measurements of meteorological parameters, and the Internet, GPS technology, you can more easily achieve dynamic management, crop water requirements for irrigation area construction of expert system for information collection and in extractive quantity to control, and so as to realize high efficiency and low energy consumption, low investment, the multifunctional platform of agricultural water-saving irrigation. In the greenhouse, Garden Gardens green belt, high speed road, farmland irrigation zones areas, agricultural and ecological water-saving technology, standardized and quantitative model, the integration to promote rapid and healthy development of water-saving industry.
Industrial areas and other areas
Industry, coal mine, petrochemical, metallurgical industries on staff security, inflammable, explosive, toxic material monitoring cost has been high, wireless sensor network operators from high risk parts out of the environment at the same time, improve risk response accuracy and speed.
In building area, used wireless sensor network, can let large used wireless sensor network, can let building, and bridge and other building can itself feeling and realized that they of status, makes installed has pass device network intelligent building dynamic told management itself feeling and realized that they of status, makes installed has pass device network intelligent building dynamic told management sector they of State information, to can let management in accordance with the priority level for regularly maintenance work.
Home, smart home design goal is to House a variety of systems, enabling them to run automatically, mutual cooperation provide residents with more convenience and comfort.
Medical services, wireless sensor networks in detecting human physiological data detection in wireless sensor networks, senior health hospital human physiological data, senior health hospital drug management and telemedicine could play an outstanding role. Patient placement body temperature acquisition, breathing, blood pressure measurement sensors, doctors can remotely understand the patient's condition. Using networks a long time collector of physiological data, which is useful in the process of developing new drugs.
