Wireless Sensor network (WSN)

Electric System (Micro Electro - Mechanism System -, MEMS), Chip System (SOC), the System on Chip cluster generator attempts, Wireless communication and low-power embedded technology rapid development, spawned a Wireless Sensor network (WSN) Wireless grow independently, be, and with its low power consumption, low cost, distributed and self-organizing feature to bring information perception of a revolution. Wireless sensor network is deployed in monitoring area by large amounts of cheap miniature sensor node component, formed through wireless communication more than a jump self-organization network.

Network characteristics

Many people think that the importance of this technology can be comparable with the Internet, as the Internet makes the computer can access to a variety of digital information and may, no matter its preservation in any place, sensor network will be able to expand people interact with the real world the ability of remote. It even be called a new type of computer systems, this is because it is distinguished from the past hardware can of characteristic and collective spreading analytical capability. However, in many ways, now of wireless sensor networks like the Internet can 1970, when the Internet just connected less than 200 university and military lab, and researchers are still in the experimental various communication protocols and addressing scheme. And now, most sensor network is connected only less than 100 node, more nodes and communications lines will make its become complex tough and doesn't work. Another reason is that a single sensor node price is still don't come cheap, and battery life in the best case also can maintain a few months. But these problems are not insurmountable, some wireless sensor network products have been listed, and have the function of gripping the new products will appear in a few years.

Wireless sensor networks have many kinds of sensors, which can detect including earthquake, electromagnetic, temperature, humidity, noise, light intensity, pressure, soil composition, a moving object size, speed and direction, and other peripheral environment varied phenomenon. Based on MEMS micro sensing technology and wireless networking technology for wireless sensor network endow with a broad application prospects. These potential applications can be summarized as: military, aviation, counter-terrorism, explosion-proof, relief, environmental, health, health care, household, industrial, commercial, etc.

Wireless sensor network (WSN) is a kind of brand-new information platform, can real-time monitoring and acquisition network distribution area the various testing object information, and will these messages to gateway node, in order to achieve the goal of complex to the extent specified detection and tracking, have fast development, invulnerability strong sexual characteristics, has the broad application prospect.

American Business Weekly and MIT technology review in predicting the future technological development report, wireless sensor network respectively as the 21st century the most influential 21 technology and change the world's 10 big technical one. Sensor network, plastic electronics and bionic human organs is also known as the global future three high-tech industry.

Network protocol

Wireless sensor network using five layer protocol standards: the application layer, the transport layer, network layer, data link layer, physicality.

The data link layer is the most studied a layer, multimedia research access control, the reason is that the limitations of wireless sensor carry energy. The limited makes carry energy power control in each tache appears especially important, media access control study designed to reduce the node visit media power consumption.

Main application

Although wireless sensor network, because the large scale commercial application technique aspects restriction remains to be time, but in recent years, with a decline in the cost of computation and microprocessor volume more and more small, has a number of wireless sensor network began to put into use. At present the application of wireless sensor networks are mainly concentrated in the following areas:

1. Environmental monitoring and protection

As people focus on environmental issues, need to increasingly high degree of environmental data collection is also more and more the emergence of wireless sensor network, the research data acquisition for randomness provides a convenient, and can also avoid the traditional way to collecting data environment from the invasive damage. For example, Intel research laboratory researchers would ever 32 small sensor into the Internet, even with great duck island in Maine "read" the climate, to evaluate a haiyan nest conditions. Wireless sensor networks can also tracking migratory birds and insects migration, the study of environmental changes on the influence of crops, monitoring sea, air and soil composition, etc. In addition, it can also be used in precision agriculture, to monitor the pests, soil crops such as ph and fertilization condition.

2 medical care

Wireless sensor network in medical research, nursing domain can also lengths. Scientists at the university of rochester, the use of wireless sensor created an intelligent medical room, use dust to measure an important marker of habitant blood pressure, pulse and breath (), sleeping posture and the activity 24 hours a day. Intel company also launched a wireless sensor network family care technology. This technology is discussed the Aging society as to Aging Center for technical project Technologies (CAST) Services for the development of a link. The system through in shoes, furniture with household appliances home prop and equipment, semiconductor sensor embedded in aged people, help with alzheimer's and disabled family life. Using wireless communications will each sensor networks can be efficient transfer the necessary information which makes it easy to accept nursing. And still can alleviate the burden of nursing staff. Intel competent preventive health insurance research director the Eric Dishman said, "in the development of family use nursing techniques, wireless sensor network is very promising areas".

Three military field

Because wireless sensor networks with intensive, the characteristics of random distribution, making it very suitable for bad battlefield environment, make it very suitable for bad battlefield environment, including conduct reconnaissance, surveillance, equipment and supplies, military judge biochemistry attack, etc. purposes. U.S. defense vision has invested tens of millions of dollars plan research, to help university "smart dust" sensor technology research and development. Hubble research company President al MenDing lattice prediction: smart dust sensor and relevant technical sales will from $10 million in 2004 increased to 2010 billions of dollars.

Four other purposes

Wireless sensor network also be applied to other areas. Such as some dangerous industrial environments such as well mineral, nuclear, etc, the staff can pass it to implement safety monitoring. Also can be used in transportation as a powerful tool monitoring vehicles. In addition, and still can be in many fields such as industrial automation line, Intel is in the factory a wireless network, the network test by 40 machine consisting of 210 sensor composed of monitoring system, this will be greatly improved the operation conditions. Factory It can dramatically reduce the cost of inspection equipment, at the same time because can advance find problem, so it will be able to shorten the down time, improve efficiency, and the use of prolonging equipment time. Although the wireless sensor technology still in preliminary application stage, but already shows special application value, believe that with the development of related technologies and propulsion, will get larger application.