ICNS 2015 : The Eleventh International Conference on Networking and Services An Integrated Testbed Environment for the Web of Things Mina Younan Sherif Khattab, Reem Bahgat Computer Science Department Computer Science Department FCI - Minia University FCI - Cairo University Minia, Egypt Cairo, Egypt E-mail: [email protected] E-mails: {s.khattab, r.bahgat}@fci-cu.edu.eg Abstract – This paper proposes a testbed architecture for the The Web of Things (WoT) virtualizes the IoT and Web of Things (WoT) using simple components. Sensor focuses on the application layer needed for building useful networks have become one of the most researched topics applications over the IoT. Services, such as searching for currently, due to proliferation of devices equipped with sensors SThs and Entities of Interest (EoIs) in the WoT, in addition and actuators for monitoring and controlling their to Web-based applications for controlling and monitoring surrounding environment (e.g., places and devices). Although services in smart spaces using friendly user interfaces are simulators, like Cooja, and Web sites, like Thingspeak, give the core power features in the WoT. However, there is no ability to build simple Internet of Things (IoT) and WoT general method for testing and benchmarking research in applications, they are not compatible with many testing purposes in WoT. Getting real datasets that cover the main IoT and WoT [4][5][6][7]. features of WoT is one of the most important factors in WoT Muhammad et al. [6] summarize differences between testing and research. The proposed testbed environment allows concepts of emulators, simulators, and physical testbeds. for generating datasets and using them offline and online. It They concluded that physical testbeds provide more integrates small equipment elements (sensors and actuators) accurate results. MoteLab [4] is a testbed for Wireless that convert things into Smart Things (SThs). Moreover, it Sensor Networks (WSNs). It addresses challenges related to augments IoT by SThs virtualization through Web sensors‟ deployment and the time consumed for building a applications. The main components and detailed design of the WSN. It features a Web application to be accessed remotely. testbed are described. Then, a case study of searching for SThs and Entities of Interest (EoIs) is explained using a real dataset The need for WSN testbeds is highlighted by challenges and generated from the proposed testbed. The proposed testbed research topics, which shed light on a specific set of features architecture incorporates the sense of smart environments and, to be embedded within the testbed and its tools [6] [7]. For hence, is expected to enhance testing results in WoT. instance, not only datasets about sensor readings are needed but integrating the readings with information about the Keywords – Internet of Things (IoT); Web of Things (WoT); underlying infrastructure (i.e., the IoT layer) is needed as searching in WoT; Smart Things; Test Environment. well; this integration is the goal of the testbed proposed in this paper. I. INTRODUCTION This paper proposes a testbed architecture for WoT. It The number of devices and things connected to the addresses the general needs of WoT testing and focuses on Internet will be increasing and is expected to reach the order the Web search problem and its related issues, such as of billions by 2020 [1][2], as soon as the Internet Protocol crawling (i.e., preparing WoT pages for crawling). The (IP) becomes the core standard in the fields of embedded problem of how to find SThs and EoIs that have dynamic devices. As a result, the number of Internet users will be less state that change according to environment events [8][9] has than the number of devices connected to it. The Internet of sheer importance in drawing conclusions, deductions, and Things (IoT) focuses on the infrastructure layer needed for analysis in various fields. The proposed testbed can be used connecting things and devices to the Internet. IoT addresses as a WoT application, which monitors real devices in real- the connectivity challenge by using IP and IPv6 for time and can be used as a WoT simulator to do the same embedded devices (i.e., 6LoWPAN) [3]. Sensor networks process on WoT datasets instead of devices. It aims at have become one of the most researched topics currently [2] collecting datasets that contain information about things [4]. This is due to the proliferation of devices equipped with (i.e., properties and readings) formatted using multiple sensors and actuators that provide information about and markup languages. The collected datasets are designed to control of their surrounding environments. Sensors allow help in testing in many problem domains [8] [10]. the state of things (e.g., places, devices, etc.,) that sensors The remainder of the paper is organized as follows. The represent to be inferred. In a sense, sensors and actuators next section defines dataset requirements. In Section 3, the convert things to Smart Things (SThs) and things‟ related work of creating searchable IoT and WoT domains environments to smart spaces. using IoT and WoT simulators and datasets is discussed. Section 4 describes the proposed system architecture. In Copyright (c) IARIA, 2015. ISBN: 978-1-61208-404-6 69 ICNS 2015 : The Eleventh International Conference on Networking and Services Section 5, the implementation of the proposed system is these files will be described later. For accessing these files, described followed by a case study. Finally, conclusions and headers of tables (sensor definitions) should follow a certain important ideas for future work are presented in Section 6. structure for creation and accessing (e.g., sensor name and virtual and physical location). II. DATASET REQUIREMENTS Things, SThs, resources, and EoIs are main concepts in III. RELATED WORK IoT and WoT. They have differences in meaning but the In the light of the previous requirements, this section main goal is that they are used for integrating the physical discusses the usage of sensor datasets in the literature. To world into the virtual world [11]. In WoT, what needs to be summarize our observations, if the research is only retrieved (i.e., searched for) includes SThs (e.g., TV sets), interested in values measured by sensors or in states of EoIs EoIs (e.g., buildings), IP addresses, current values [8], and (e.g., being online or offline), then the used dataset is based general information like device‟s web banners [9]. on the WoT level, whereas if the research is interested in the Generally, searching is done on SThs and EoIs that have sensor network infrastructure, then the used dataset is based dynamic locality [8][12][13] caused and fired by other on the IoT level. An integrated dataset contains information events or objects in the network. For testing and evaluating about both sensor readings and network infrastructure, that the search process in IoT and WoT, simulators should is, it is based on both IoT and WoT levels. reflect as many IoT and WoT challenges to achieve accurate A. IoT Simulations results. To achieve this, datasets are used and replayed by applications that act as emulators of WoT. There is no general way for simulating IoT [5][6][16]. In general, the main challenges that face testing of Moreover, there are situations in which simulators and real smart spaces, IoT, and WoT are: (1) the huge number of datasets containing raw information (e.g., sensor readings sensors and SThs, which makes communication services, [17]) or information about the IoT layer are not enough for monitoring, and analysis of sensor information require non- modeling an environment under testing, as the datasets miss trivial amounts of CPU time and storage, (2) the dynamic the sense of one or more of the challenges mentioned earlier state of SThs, which means that sensor readings and and thus, miss the main factors for accurate WoT information about SThs properties and devices to which evaluation. Also, many datasets are not actually related to they are attached are in continuous change, and (3) the non- the problem under investigation, but were generated for standardized naming of SThs properties (e.g., name, testing and evaluating different algorithms or methods in services, and location) and formats (e.g., microformats and other researches. For instance, an evaluation of WSNs‟ microdata) that are used in WoT applications, which makes simulators according to a different set of criteria, such as retrieval of information about objects and their attached Graphical User Interface (GUI) support, simulator platform, sensors difficult. and available models and protocols, concludes that there is To identify dataset requirements for testing the Web no general way for simulating WSNs, and hence IoT and search process in WoT, WoT data are classified according WoT [5][16]. None of these criteria address the previous to type, static or dynamic. The first type is static challenges. So, it is desirable to embed the unique IoT and information (IoT level), which includes (1) information WoT challenges within datasets and to make simulators about sensors (e.g., information about sensor properties like support as much of these challenges. ID, name, brand, image, description, authoritative URL, WSN Simulators. Several studies [5][6][16] manufacturer, and list of services that it offers) and (2) summarize the differences between existing simulators information about entities (e.g., device, thing, and place) according to a set of criteria. The Cooja simulator is one of including entity properties, such as logical paths, list of the most valuable tools [5][16] in WSNs that aids hosted devices, and possible states by which the entity is researchers to simulate WSNs relatively easily using a described. The second WoT data type is dynamic supported GUI. Cooja allows to add different types of information (WoT level), which includes (1) sensor sensors (motes) and to attach them to binaries or source readings or state, (2) current entity state, which changes codes that have been previously developed.