A Web of Things Based Eco-System for Urban Computing - Towards Smarter Cities Andreas Kamilaris * , Andreas Pitsillides † , Francesc X. Prenafeta-Bold * and Muhammad Intizar Ali ‡ * GIRO Joint Research Unit IRTA-UPC, Barcelona, Spain Emails: andreas.kamilaris@irta.cat, francesc.prenafeta@irta.cat † Department of Computer Science, University of Cyprus, Nicosia, Cyprus Email: Andreas.Pitsillides@ucy.ac.cy ‡ Insight Centre for Data Analytics, National University of Ireland, Galway, Ireland Email: ali.intizar@insight-centre.org Abstract—Environmental awareness and knowledge may help people to take more informed decisions in their everyday lives, ensuring their health and safety. The Web of Things enables embedded sensors to become easily deployed in urban areas for environmental monitoring such as air quality, electromagnetism, radiation, etc. In this paper, we propose an eco-system for urban computing which combines the concept of the Web of Things, together with big data analysis and event processing, towards the vision of smarter cities that offer real-time information to their habitants about the urban environment. We touch upon near real- time web-based discovery of sensory services, citizen participa- tion, semantic technologies and mobile computing, helping people to take more informed everyday decisions when interacting with their urban landscape. We then present a case study where we demonstrate the feasibility and usefulness of this eco-system to the everyday lives of citizens. I. I NTRODUCTION Urban environments are becoming largely congested, host- ing more citizens than they were designed and developed to support. Today, urban areas host around 50% of the world’s population and the cities’ population is expected to double in the next 40 years [1]. Increasing urbanism implies negative effects to the people and the city. Traffic is heavily increased and levels of pollution are rising. Some areas become dirty and polluted while health and security are compromised. In recent years however, miniaturized sensors appeared at the market, which are capable of measuring with high preci- sion environmental conditions and phenomena, such as tem- perature, humidity, radiation, electromagnetism, noise, chem- icals, air quality etc. These sensor devices, when deployed to urban environments, could provide rich content about the environmental context of these areas. Through the practice of enabling these tiny devices to the web [2], [3], based on the concepts of the Web of Things (WoT) [4], [5], [6], [7], numerous new possibilities arise, in regard to helping citizens to better interact with their urban landscape. In this case, sensors start operating as tiny Web servers, being able to expose their capabilities as Web services [2], [3]. Hence, the information gathered by their sensing capabilities can be shared by means of open Web standards and semantic technologies 1 , creating easier integrations with other web-based information, towards advanced knowledge. Since the Web penetrated deeply in our everyday lives, it can con- stitute the platform for supporting environmental monitoring, exploiting big data analysis and mobile computing [8]. Then, citizens who have access to this knowledge may take more informed decisions during their everyday lives, ensuring their general health, well-being and security. These decisions include avoiding congested regions when driving, deciding which means of transportation to take depending on weather, avoiding polluted areas with bad air quality etc. In this way, people could acquire more sustainable lifestyles, becoming more aware about the impact of their actions (and other people’s actions) on the environment [9], [10], [11]. Since all the building blocks for this web-based integration are already there, in this paper, we introduce a complete eco- system that exploits WoT advancements, suggesting a scalable and flexible approach to discover web-connected embedded devices deployed in the urban environment, analyze their data streams through big data analysis and complex event processing (CEP), and then share their services with citizens through information and communication technologies (ICT). The contribution of this paper is to summarize and connect together our work in WoT, semantic technologies, big data analysis and smart city applications. Hence, this paper serves as a survey in urban computing, focusing on the previous relevant projects completed by the authors, tied together under the umbrella of a WoT-based smart city eco-system. II. RELATED WORK Our paper spans the following research domains: a) urban computing and mobile remote sensing, b) real-time analytics based on big data analysis and CEP, and c) discovery methods for WoT-based devices and data streams. A. Urban Computing and Mobile Remote Sensing Urban computing is an emerging research area that focuses on the use of technology in public environments such as cities, parks and suburbs and their interaction possibilities with 1 For example, REST, MQTT, XMPP, RDF, OWL, SWE and SensorML.