Issues of using wireless sensor network to monitor urban air quality

Frequent monitoring of urban environment has now been regulated in most EU countries. Due to the design and cost of high-quality sensors, the current approach using these sensors may not provide data with an appropriate spatial and temporal resolution. As a result, using a wireless sensor network constructed by a large number of low-cost sensors is becoming increasingly popular to support the monitoring of urban environments. However, in practice, there are many issues that prevent such networks to be widely adopted. In this paper, we use data and lessons learnt from three real deployments to illustrate those issues. The issues are classified into three main categories and discussed according to the different sensing stages. In the end, we summarise a list of open challenges which we believe are significant for the future research.