Wireless Sensor Network is a computer network of sensor nodes, in an infrastructure-based base stations or in a self either organizing ad hoc network to cooperate within their environment by means of sensors to query and submit the information. The targeted size of future sensor nodes made ??the idea under the heading smart dust. If you are reading about Wireless Sensor Network for the first time, understand the basics of Sensor, Watchdog timer etcetera topics.
Basics of Wireless Sensor Network
Wireless Sensor network was been designed as a military warning system for monitoring borders. Modern research, however, sees it as a replacement for costly sensor systems in automotive, product manager in warehouses and supervisor of natural areas for pollutants, forest fires and animal migrations and the possible applications are as varied as the available sensors has.
Wireless Sensor networks are always in the stage of development, there are practical applications for experimental and demonstration purposes. Wireless Sensor Networks are widely used for professional applications. The most well known among the Wireless sensor network those are used in weather stations are from different from vendors to vendors, however, the crosslinking is performed by conventional telecommunications networks.
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As a precursor of the modern wireless sensor network, research on Sound Surveillance System (SOSUS) are considered leaders during a Cold War by the United States wherein network was installed on underwater buoys, the submarines which used tracking using acoustic sensors. Although SOSUS is not a computer network, however, it brought the idea of ??a comprehensive sensor assembly.
Communication in Wireless Sensor Network
Wireless sensor networks are ad hoc networks, i.e. networks are without fixed infrastructure between devices. Ad-hoc networks are meshed networks in which network nodes are connected to one or more neighbors. This results in a multi-hop communication, which pass the messages from node to node until they reach their destination. Such networks are characterized by an unpredictable, dynamic behavior; because unlike fixed computer networks is network topology : the number and locations of the network nodes and “line quality” can not be foreseen during the operational nodes which in turn can be added or fail without warning.
Hardware
A wireless sensor node is a normal computer as the core of a processor and a data storage, typically flash memory are used, contributing each to one or more sensors and a module for wireless communication. All parts are a battery powered. In newer models all components are on a single computer chip, which greatly reduces the size compared to the composite components.
All nodes of a network have the same sensory equipment, either a homogeneous sensor network, else a heterogeneous. Heterogeneous sensor networks are particularly useful if the sensors have different usage patterns, so for example in measuring frequency, measuring time and accumulating data volume are very different. As a promising means of communication that is currently radio technology are used, but there are also other communication media such as light or sound.
It is assumed that the communication module as a radio ready to send and receive data knows two states between which they can switch with low delay time. The battery power of a wireless sensor node must therefore be as efficient as possible, while all other parts must have a very low power consumption. To reduce the power consumption further, each sensor node is set in a standby state, in which all parts to be switched to the internal processor clock.
Networking
Wireless sensor networks are ad hoc networks, i.e. networks without fixed infrastructure between devices. Ad-hoc networks are meshed networks in which network nodes are connected to one or more neighbors. This results in a multi-hop communication, which are passed in the messages from node to node until they reach their destination. Such networks are characterized by an unpredictable, dynamic behavior, because unlike fixed computer networks is network topology uncertain: the number and locations of the network nodes can not be foreseen during the operation nodes can be added or fail without warning.
