Node positioning and deployment in hazardous places have numerous set back. In this article I intend to show the challenges that are currently been experience for wireless sensor experts. The scope covered so far on node positioning has been two-dimensional (2-D) however, the increased interest in security applications such as under water surveillance, dealing with the connectivity, coverage and detection of intruders in 3-D has totally become a necessity.
Researchers have done a good work with looking at the properties of the network topologies that results from random deployment of nodes in a 3-D region of importance. The challenge facing wireless sensor network experts is how to analyse the implications of the sensing and communication ranges on coverage and connectivity. In a paper published by M. Younis and K. Akkaya, “Strategies and techniques for node placement in wireless sensor networks: A survey,” Ad Hoc Networks achive. Volume 6 Issue 4, June 2008, they claim that using a uniform distribution of nodes can derive the condition for node transmission range “r” that is required for achieving the degree of connectivity “d”, where every node that was used has “d” neighbours. They also estimat that the same analysis goes for the coverage and the sensing range that is required, these are later used to achieve a certain degree in a region using a pre-determined number of nodes.
The issue is that the mechanism they have used has identified the coordinated multi-node repositioning as a problem that needs to be considered in order to tackle practical deployment in hazardous places and underwater surveillance. Other problems that will arise will be how to develop an innovative power source to facilitate the running of advanced sensing and communications technology in hazardous areas considering that power is a major limitation to the actualization of mass deployment of wireless sensor network nodes.
An affordable rugged mobile sensing platform was developed by engineers at NASA’s Glenn Research Center named Mobile And Remote Sensing Hazmat Activity (MARSHA). The idea is that it can operate in different hazardous environments providing first responders with data collection and analysis tools to assess and minimize risks. Their system is equipped with adaptable plug-and-play components with a future incorporation of live video, audio, and/or a suite of sensor packages. ‘Through wireless communication, experts not at the scene can access data and offer guidance’
The result is a user-friendly, quickly-configurable robotic platform that gathers crucial information in dangerous situations without putting team members at risk. The problem remains about the agility of MARSHA. I have illustrated in a 3D video the challenges of WSN as related to sensing and communication in Hazardous place.
About the Author
Celestine Iwendi is a Sensor and Electronics Researcher at the University of Aberdeen, UK