Mobile Publish/Subscribe System for Intelligent Transport Systems over a Cloud Environment

Abstract

With the advent of Smart Cities, public transport authorities are more and more interested in Intelligent Transport System (ITS) applications that allow to process a large amount of static and real time data in order to make public transport smarter. However, deploying such applications in a large scale distributed environment is challenging and requires an automated, scalable, flexible, elastic, loosely-coupled communication models in order to dynamically link information providers and consumers. To this end, Publish/Subscribe (Pub/Sub) systems offer an asynchronous, dynamic, decoupled interaction scheme that is perfectly suitable for developing upto-date, large-scale distributed applications within the ITS domain. In addition, cloud computing offers computational resources as services to utility driven model regardless of considering geographical locations in a scalable, elastic, fault tolerant and cost-effective way. In this work, we build an ITS application "Real-time Public Transit Tracking" on top of a Mobile Pub/Sub System (MoPS), and deploy it over an open source cloud platform, OpenStack, in order to achieve high performance and flexible management. We conduct a set of experiments to evaluate the performance of the implemented ITS application in terms of scalability, resource usage, and efficiency of the underlying matching algorithm under automated mobility of the subscribers. Our experimental results show that the ITS application can handle a large number of subscribers and publishers with proper reliability and negligible notification delay under real-time constraints. Further, we present a measurement study to characterize the impact of different workloads on the performance of OpenStack.