Design a process architecture for an environmental monitoring system that collects data from a set of air quality sensors situated around a city. There are 5000 sensors organised into 100 neighbourhoods. Each sensor must be interrogated four times per second. When more than 30% of the sensors in a particular neighbourhood indicate that the air quality is below an acceptable level, local warning lights are activated. All sensors return the readings to a central computer, which generates reports every 15 minutes on the air quality in the city.