WSN Wireless Sensor Network basics, WSN Architecture, WSN Security

This article covers Wireless Sensor Network (WSN) basics, WSN features, WSN architecture and security. It mentions WSN monitor devices and applications for various wireless networks.

The function of Wireless Sensor Network also referred as WSN is to collect information using sensors and deliver it to the place of choice. In order to achieve this, communication system deployed should have efficient and reliable networking protocols. The network should be scalable and also should be secure. The most popular technology behind this is zigbee. Zigbee is low power wireless personal area network technology.

WSN,Wireless Sensor Network

Figure depicts typical WSN network architecture. It consists of sensor nodes, routing nodes and a base station. WSN has become very popular due to availability of low cost sensors as well as long life of the power supply batteries. It can also be deployed anywhere.

WSN is a variant of Ad-hoc network. In a typical Ad-hoc network, multiple nodes can transmit packets to the base station. In WSN collaboration is needed between multiple different types of sensor nodes.

Following are silent features of Wireless Sensor Network:

•  Sensor nodes are usually immobile.

•  Can be easily be deployed in worst environments

•  Communication is data centric instead of address centric. Decisions at router takes place based on data and not address. Depending upon this packet can be dropped, compressed or priotized.

•  Communication is done using very short packet size to reduce the overhead.
•  Most of the wireless sensor devices utilizes energy harvesting techniques in order to extend the battery life. Using these techniques WSN sensors generate energy from ambient sources and stores the same or uses the same to recharge the battery or capacitor.

WSN Architecture

As shown in the WSN architecture, WSN will have three main components as mentioned above viz. distributed sensor nodes, sink nodes (Base station or Gateway) and Software. Each sensor node usually will have single omnidirectional antenna and tranceiver, power supply and DSP embedded. Gateway is located at the boundary of the monitoring coverage area. The gateway helps connect micro-sensor network with the outside world such as internet or similar other WSN.

Sensor network will have thousands of sensors distributed randomly and densely about 10-20 per square meter. Availability of flash memories and energy efficient batteries provide better wireless sensor networks.

The algorithms based on wireless standards take care of collision and congestion situations in the wireless sensor networks(WSNs).

WSNs have been classified based on network type, clustering type, communication method, protocol, application and coverage.

As this system is wireless in nature, it is prone to security risk. Various considerations have been taken care in order to provide safety in this wireless sensor network. Refer article on Zigbee home security system to know more about it.

Also refer web application security testing tools article which provides security test tools, tools types and web application based security testing. It also provides difference between various security tools such as OWASP ZAP, Wapiti, Netsparker etc.

The WSN monitor software is basically user interface which takes care of real time measurements of sensors. It connects with WSN Open API Base Station or Gateway with the use of API messages. Refer following link for more.

RF and Wireless Terminologies

What is Difference between

difference between FDM and OFDM
Difference between SC-FDMA and OFDM
Difference between SISO and MIMO
Difference between TDD and FDD
Difference between 802.11 standards viz.11-a,11-b,11-g and 11-n