Publish/Subscribe Communication for Crowd-sourcing Based Smart City Applications

Collecting data and monitoring our environment give the basis for smart city applications which are getting popular today. However, the traditional approach to deploy a sensing and monitoring infrastructure is usually expensive and not always practical. Mobile crowd-sourcing can open new ways for data collection and smart city services. In this case, mobile devices with their built-in sensors and their owners are used to monitor the environment. For instance, the timetable of a smart travel planner service can be updated in real-time based on the continuously monitored time gap by passengers between consecutive buses on a public transportation route. This requires a common communication model facilitating crowd-sourced data collection. In this paper, we overview the design considerations of crowd-sourcing based smart city applications, propose data collection via using the publish/subscribe communication model and investigate the possible use of the Extensible Messaging and Presence Protocol (XMPP) for such applications.