Air pollution monitoring with secure low-cost Vehicular Sensor Networks

Counteracting the effects of air quality degradation is one of the main challenges in large cities today. To achieve such a goal, the first step is to control the emissions of various pollutant gases which in turn requires their concentrations to be measured such that proper methods can be applied. In this work we present a low cost urban air pollution monitoring system which we developed as proof-of-concept in Timisoara, Romania. The proposed solution is a Vehicular Sensor Network (VSN), with affordable midclass sensor nodes being installed on moving vehicles, ideally on the public transportation busses. The system measures temperature, humidity, the concentration of CO2 and dust, along with Volatile Organic Compounds (VOC). The aim of collecting weather data is to build correlations between air pollution levels and different weather conditions. In addition to technical constraints for measuring air quality, one of the challenges that we address is to implement secure transmissions between the devices. This raises several difficulties on microcontrollers that we use due to their low memory and computational resources. To answer both privacy and security issues, the proposed data transmission protocol of the measuring system, builds upon a modified version of the Station to Station (STS) protocol which allows secure tunnelling in an anonymous manner