Where Searching Will Go in Internet of Things? Xin Jin §, , Daqiang Zhang †,‡ , Qin Zou ,£ , Genlin Ji †,‡ , Xiaojun Qian †,‡ § Telecom SudParis – Institut Telecom, 91011, France ♮ Pierre and Marie Curie University, 75012, France † School of Computer Science, Nanjing Normal University, 210097, China ‡ Jiangsu Research Center of Information Security & Condential Engineering, 210046, China  School of Remote Sensing and Information Engineering, Wuhan University, 430079, China £ Transporation Research Center, Wuhan University, 430079, China xin.jin@it-sudparis.eu, dqzhang@njnu.edu.cn, qzou@whu.edu.cn Abstract—Internet of Things (IoT) is coming into birth as pervasive hand-held devices, Radio Frequency IDentication (RFID), and embedded sensors connect to the Internet. IoT enables objects to interact and cooperate with each other anytime and anywhere. Owing to the new challenges imposed by IoT — search locality and real-time, searching in IoT is challenging. To explore what way is appropriate to satisfy requirements of searching in IoT, we report our undertaking project — IoT Search Engine (ISE), accompanied with our initial experimental results. I. I NTRODUCTION The proliferation of pervasive computing, mobile comput- ing, handheld devices, Radio Frequency IDentication (RFID) and sensors has fostered a growing interest in Internet of Things (IoT). It refers to a connected network of everyday objects, which allows things (including beings and objects) to interact and cooperate anytime and anywhere [1] [2]. To some extent, IoT transforms the way that people perform daily activities with immense technical challenges, as well as tremendous opportunities for economy and industry. Searching is a fundamental function in IoT. However, it is challenging owing to the characteristics of IoT. One is huge and dynamic sensor readings from massive sensors and hand-held devices [3]. By 2015, there will be more than billions of RFID-tagged objects [4], capturing a huge number of readings about physical environments and things. This implies that searching in IoT works in a much larger information space than that of Internet. Another is that sensor readings are seriously infected by environments that keep changing [5]. Take tracking a visitor by GPS (Global Position Systems) for instance, the raw readings about his / her location evolve rapidly owing to a short life span of every reading [6]. In contrast, the majority of Internet web pages are updated at regular intervals, e.g., days, weeks, months and years. This is much slower that of sensor readings. The third is that in IoT people usually concern physical things in their vicinity, rather than information that may distribute remotely in most circumstance. This is because people would like to handle or operate physical things by manual. Finally, searching in IoT must take care of privacy. As a matter of fact, physical things sometimes reveal the people privacy, which may be illegal. In this paper, we investigate what searching technical challenges and risks are confronted by IoT, albeit it has been well established in previous IoT computing paradigms — distributed computing, mobile computing and pervasive computing. We attempt to identify challenging issues and open problems in searching of IoT, and to get ndings that are benecial to rapidly design a universal searching engine in IoT. We start with the investigation on missing functions of existing efforts to satisfy requirements of IoT searching. What follows the investigation is introduction to our undertaking work toward this direction — IoT Search Engine (ISE) as well as experimental results. To summarize, the main contributions of this paper are two-fold. • It investigates the characteristics of searching in IoT and then identies the challenging issues – search locality, and real-time. • It proposes our ongoing project ISE that is designed based on IoT requirements. To the best of our knowledge, ISE is the rst searching project in IoT. This paper also reports our preliminary results. The rest of this paper is organized as follows. Section II rstly identies challenging issues of the searching in IoT. and then comes up with a couple of considerations that may be potential directions to IoT’s search engines. Section III introduces our undertaking project ISE. Section IV concludes the paper with pointing out future work. II. CHALLENGING I SSUES OF THE SEARCHING IN I OT In this section, this paper identies the challenges issues of searching in IoT. Note that throughout this paper, the term ”things” and ”objects” are used interchangeably in the contexts without ambiguity. Things are a collective concept, which consist of objects and users. A. Characteristics of Internet of Things IoT evolves from pervasive computing, and has been widely adopted in various elds, e.g., object tracking. It is char- acterized by networked interconnection, real-time, semantic coherence and spontaneous interaction [7].  ©4233 KGGG