Abstract:
With the increased need for mobility and the overcrowding of cities, the area of Intelligent
Transportation aims at improving the efficiency, safety, and productivity of transportation
systems by relying on communication and sensing technologies. One of the
main challenges faced in Intelligent Transportation Systems (ITS) pertains to the real time
collection of traffic and road related data, in a cost effective, efficient, and scalable manner.
The current approaches still suffer from problems related to the mobile devices energy
consumption and overhead in terms of communications and processing. To tackle
the aforementioned challenges, we propose in this thesis a novel infrastructure-less ondemand
vehicular sensing framework that provides accurate road condition monitoring,
while reducing the number of participating vehicles, energy consumption, and communication
overhead. Our approach is adopting the concept of Mobile Sensing as a Service
(MSaaS), in which mobile owners participate in the data collection activities and decide
to offer the sensing capabilities of their phones as services to other users. Unlike existing
approaches that rely on opportunistic continuous sensing from all available cars, this
ability to offer sensory data to consumers on demand can bring significant benefits to ITS
and can constitute an efficient and flexible solution to the problem of real-time traffic/road
data collection. Moreover, we extend our approach by elaborating (1) cellular networks
based model for selecting suitable set of mobile devices acting as data collectors and (2)
inference rules based on deductive logic for traffic status classification inferred from both
density and mean speed. A combination of prototyping and traffic simulation traces are used to realize the system, and a variety of test cases are used to evaluate its performance.
When compared to the traditional continuous sensing, our proposed on-demand sensing
approach provides comparable high traffic estimation accuracy while significantly reducing
the resource consumption.This is achieved by selecting the smallest number of data
collectors that can provided the best quality of sensed data, in order to maintain a good
traffic estimation accuracy and an improved system performance (i.e., lower response time
and network load). Other benefits of the proposed on-demand sensing approach include:
an overall improved resource efficiency; a better quality of sensed information; more flexible
and individual sensing as a service operations; and more users’ control over their
devices related information.