Wireless Sensor Networks

Mr. R. B. Kagade(rbkagade@coe.sveri.ac.in), Department of Computer Science and Engineering, SVERI’s College of Engineering, Pandharpur

The principle behind wireless sensors is simple: many devices, distributed in different locations, are used to monitor physical conditions such as temperature, pressure, or light. This information needs to be transmitted from the different devices to a main location. Sensors are linked together, forming a machine-to-machine (M2M) network. The individual sensors are called nodes. A gateway sensor node provides a link from the network to the main location, where a central processing unit like a computer can record and process the data.

Figure: A wireless sensor network

Applications

Wireless sensor networks are useful in military, scientific and environmental applications. The potential applications are many, ranging from healthcare monitoring, where sensor in the human body transmit information useful for health purposes, to air pollution monitoring, where sensors gather information for environmental purposes. The applications are numerous – some people even use wireless sensors to produce home-made wine!

Challenges

The sensor itself needs to be able to communicate. Therefore, it must contain a processing unit, communication resources like a radio front-end with antenna, and an operating system able to coordinate the numerous functions. Depending on the sensor type, some processing can be performed on the sensor itself. On-sensor processing however leads to trade-offs in the size, weight, and cost of the units. In applications where sensors need to be small, cheap, and light, the amount of processing that can be performed on the sensor is limited.

Another challenge is power consumption. For the sensor to be wireless, energy must be provided to obtain the necessary electricity to run it – be it a battery or an energy-harvesting device that uses the surrounding light, heat, electromagnetic waves, or other source. Obviously, the less power the sensor consumes, the longer its lifetime.

References:

1. S. Zairi, B. Zouari, E. Niel, E. Dumitrescu “Nodes self-scheduling approach for maximizing wireless sensor network lifetime based on remaining energy” Published in IET Wireless Sensor Systems.

2. M. Cardei and D. Du, “Improving Wireless Sensor Network Lifetime through Power Aware Organization”, Wireless Networks , Volume 11 Issue 3, May 2005.

3. M. Cardei, M. Thai, L. Yingshu, W. Weili, “Energy-efficient target coverage in wireless sensor networks”, INFOCOM 2005. 24th Annual Joint Conference of the IEEE Computer and communications Societies.

4. A. Balamurugan and T. Purushothaman “Coverage Eligibility Rule based Coverage Maintenance Protocol for Energy Conservation in Wireless Sensor Networks” Journal of Computer Science 7 (10): 1545- 1553, 2011. ISSN 1549-3636.

5. Zhang, H., Wang, H., Feng, H.: „A distributed optimum algorithm for target coverage in wireless sensor the Workshop on Modeling and Optimization in Mobile, Ad Hoc and networks‟. Asia-Pacific Conf. on Information Processing, 2009, pp. 144–147.

6. http://wsn.eecs.berkeley.edu/?p=128

7. http:/https://www.nutaq.com.wikipedia.org/wiki/Wireless_sensor_network.