The DSR protocol [22] has been used for data transmission in WAPMS. The Dynamic Source
Routing protocol is a simple reactive routing protocol designed specifically for use in multi-hop
wireless ad hoc networks. DSR allows the network to be completely self-organizing and selfconfiguring,
without the need for any existing network infrastructure or administration. DSR
contains two phases: Route Discovery (find a path) and Route Maintenance (maintain a path).
These only respond on a request. The protocol operates entirely on-demand, allowing the
routing packet overhead of DSR to scale automatically to only that needed to react to changes in
the routes currently in use.
After a collection, the system displays the nodes in their corresponding AQI colour as shown in
figure 10. The following is an example of such a screen:
Figure 10. Nodes' Deployment after a collection
Given an area and a date, the system display the corresponding AQI readings and the health
concern in this area as shown in figure 11 below.
Figure 11. AQI for a selected area
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Furthermore, the WAPMS system allows fast analysis of received data through line graphs of
selected areas as shown in figure 12.
Figure 12. Line graph generated for selected areas
The performance of WAPMS has been evaluation with increasing load. We have varied the
number of areas simulated from 1 to 6 and for each case, we have varied the number of nodes
per area from 50 to 200 and the execution time of the system has been recorded. The results are
shown in table II and figure 13.
Table 2. Execution Time of WAPMS
As shown in the above table, the maximum running time of our simulator is less than 20
minutes in the worst case of 6 areas and 200 nodes in each area. The short execution time of
WAPMS is massively advantageous comparing to the existing air pollution monitoring unit of
Mauritius that often takes days to measure pollution in an area. Moreover, WAPMS allows
timely monitoring of an area and an abnormal situation can be detected almost immediately.