CONCLUSION
As discussed in this paper, recent technological developments in the miniaturization of
electronics and wireless communication technology have led to the emergence of
Environmental Sensor Networks (ESN). These will greatly enhance monitoring of the natural
environment and in some cases open up new techniques for taking measurements or allow
previously impossible deployments of sensors. WAPMS is an example of such ESN. WAPMS
will be very beneficial for monitoring different high risk regions of the country. It will provide
real-time information about the level of air pollution in these regions, as well as provide alerts in
cases of drastic change in quality of air. This information can then be used by the authorities to
take prompt actions such as evacuating people or sending emergency response team.
WAPMS uses an Air Quality Index to categorise the various levels of air pollution. It also
associates meaningful and very intuitive colours to the different categories, thus the state of air
pollution can be communicated to the user very easily. The major motivation behind our study
and the development of the system is to help the government to devise an indexing system to
categorise air pollution in Mauritius. The system also uses the AQI to evaluate the level of
health concern for a specific area.
WAPMS uses a novel technique to do data aggregation in order to tackle the challenge of power
consumption minimisation in WSN. We have named this novel technique as Recursive
Converging Quartiles. It also uses quartiles to summarise a list of readings of any length to just
three values. This highly reduces the amount of data to be transmitted to the sink, thus reducing
the transmission energy required and at the same time representing the original values
accurately.
Another strength of WAPMS is the high quality of results it produces. The collected readings
are saved in a database and these can be accessed individually in a table or summarised areawise
in a line graph. The table uses the AQI to provide the results using the associated colours
and it also provided the level of health concern for a particular area. The line graph allows the
user to view the trend of air pollution for several areas at a time. WAPMS also displays a map
of the town of Port Louis, showing the locations of the deployed sensors nodes and the readings
collected by each one. Thus, WAPMS is very flexible, very easy and yet very powerful due to
its ability to provide highly summarised results as well as fine-grain results at the level of
sensors.