On the need for a reputation system in mobile phone based sensing q Kuan Lun Huang a,⇑ , Salil S. Kanhere a , Wen Hu b a School of Computer Science and Engineering, The University of New South Wales, Sydney, Australia b Autonomous Systems Lab, CSIRO ICT Centre, Australia article info Article history: Received 18 May 2011 Received in revised form 19 September 2011 Accepted 6 December 2011 Available online xxxx Keywords: Participatory sensing Urban sensing Reputation system Trust Data quality abstract The continual advancement in semiconductor technology has enabled vendors to integrate an increasing number of sensors, e.g., accelerometer, gyroscope, digital compass, high res- olution cameras and others, in modern mobile phones. Combining with the ever expanding market penetration of mobile phones, the onboard sensors are driving the sensing commu- nity towards a new paradigm called participatory sensing in which ordinary citizens volun- tarily collect and share information from their local environment using personal mobile devices. The inherent openness of this platform is a double-edged sword. While encourag- ing user participation on the one hand, it also makes it easy to contribute corrupted data. As such, data trustworthiness becomes a key issue which needs to be addressed to ensure sustainable development of this emerging paradigm. In this paper, we propose a reputation system in which a reputation score is calculated for each device as a reflection of the trust- worthiness of its sensor data. We adopt the Gompertz function as a fundamental building block of our system, since it is better suited to deal with the unique characteristics of par- ticipatory sensing. We present an application-agnostic implementation of the system, which can work with a wide variety of participatory sensing applications. We evaluate the performance of our reputation system in the context of two real-world participatory sensing applications. Our results show that the proposed reputation system outperforms existing solutions by up to a factor of six. Ó 2012 Elsevier B.V. All rights reserved. 1. Introduction The recent wave of sensor-rich, Internet-enabled, smart mobile devices such as Apple iPhone has opened the door for a novel sensing paradigm, participatory sensing [2,3], for monitoring the urban landscape and collecting informa- tion about our daily activities. In participatory sensing, ordinary citizens collect data from their surrounding environment using their mobile devices and upload them to an application server using existing communication infrastructure (e.g., 3G service or WiFi access points). The application server then combines data from multiple partic- ipants, extracts the community summary, and uses them to build a spatial and temporal view of the phenomenon of interest. Several exciting participatory sensing applications have emerged in recent years. Cartel [4] is a system that uses mo- bile sensors mounted on vehicles to collect information about traffic, quality of en-route Wi-Fi access points and potholes on the road. Micro-Blog [5] is an architecture which facilitates real-time recording and sharing of multi- media contents. Other applications of participatory sensing include, collecting information about urban air pollution [6], noise pollution [7,8], cyclist experiences [9], diet [10], and pricing information of consumer goods [11,12]. Moreover, 1570-8705/$ - see front matter Ó 2012 Elsevier B.V. All rights reserved. doi:10.1016/j.adhoc.2011.12.002 q Part of this work has been previously published at the 13th ACM International Conference on Modeling, Analysis and Simulation of Wire- less and Mobile Systems (MSWiM ’10) [1]. The extension to the MSWiM paper includes a new feedback reputation system and more thorough evaluations involving a new class of participatory sensing application. ⇑ Corresponding author. E-mail addresses: klh@cse.unsw.edu.au (K.L. Huang), salilk@cse. unsw.edu.au (S.S. Kanhere), Wen.Hu@csiro.au (W. Hu). Ad Hoc Networks xxx (2012) xxx–xxx Contents lists available at SciVerse ScienceDirect Ad Hoc Networks journal homepage: www.elsevier.com/locate/adhoc Please cite this article in press as: K.L. Huang et al., On the need for a reputation system in mobile phone based sensing, Ad Hoc Netw. (2012), doi:10.1016/j.adhoc.2011.12.002