Modulo: Drive-by Sensing at City-scale on the Cheap

TL;DR

Modulo is a system designed to optimize city-scale drive-by sensing deployments by selecting suitable vehicles, effectively balancing coverage, budget, and deployment constraints, demonstrated through real-world datasets and deployment.

Contribution

This paper introduces Modulo, a novel system for optimizing vehicle selection in drive-by sensing networks considering coverage, budget, and deployment constraints.

Findings

Modulo marginally outperforms baselines with random-route taxis.

Modulo significantly outperforms baselines with mixed vehicle fleets.

Successful real-world deployment for air pollution sensing.

Abstract

Drive-by sensing is gaining popularity as an inexpensive way to perform fine-grained, city-scale, spatiotemporal monitoring of physical phenomena. Prior work explores several challenges in the design of low-cost sensors, the reliability of these sensors, and their application for specific use-cases like pothole detection and pollution monitoring. However, the process of deployment of a drive-by sensing network at a city-scale is still unexplored. Despite the rise of ride-sharing services, there is still no way to optimally select vehicles from a fleet that can accomplish the sensing task by providing enough coverage of the city. In this paper, we propose Modulo -- a system to bootstrap drive-by sensing deployment by taking into consideration a variety of aspects such as spatiotemporal coverage, budget constraints. Further, Modulo is well-suited to satisfy unique deployment constraints such as colocations with other sensors (needed for gas and PM sensor calibration), etc. We compare Modulo with two baseline algorithms on real-world taxi and bus datasets. We find that Modulo marginally outperforms the two baselines for datasets with just random-routes vehicles such as taxis. However, it significantly outperforms the baselines when a fleet comprises of both taxis and fixed-route vehicles such as public transport buses. Finally, we present a real-deployment that uses Modulo to select vehicles for an air pollution sensing application.