S2O: A smart objects orchestrator framework based on the web of things

Interacting with the Web of Things

New value-added business, generated by Web service composition in BPEL, provides more powerful and flexible features. SOAP-based web services invoked in BPEL are heavy with redundant information and lower performance. RESTful Web service is brought forward to new value-added business as an alternative solution. However, it's a big challenge to compose RESTful Web services with SOAP-based Web Services in SOA BPEL business processes. BPEL is not designed to use RESTful Web services because these types of services do not use WSDL to describe themselves. This paper proposes a novel approach for integrating RESTful Web services and SOAP-based Web services in business processes described in BPEL. The approach is applied to a practical multimedia conference BPEL process, and the experimental data show the stability of the new RESTful BPEL process with a higher performance.

Currently, the paradigm shift in our computing is dramatically moving from PC to mobile devices and many new services are emerging based on the development of broadband network and hardware technologies such as Cloud computing and Web of things. Especially, the popularity of smart devices has increased the demand for sharing multimedia contents at anywhere and on any of user devices with seamless display. In this paper, we introduce a prototype implementation of contents sharing service working on different devices with seamless connectivity. The purpose is that the proposed system allows users to share their media contents and play them continuously regardless of the situation of switching from one device to another. For example, N-screen services allow users to manage their active sessions among multiple devices having different capabilities and architectures. The system implemented has the basic sharing configuration of three devices: PC, Smartphone, and Tablets, and utilize an Open Service Platform based on RESTful Web Services. The prototype was successfully implemented and its performance was simulated with sample 3D videos with different file sizes to estimate load latencies while switching from one device to another. The result shows the feasibility of contents sharing system based on RESTful Web Services with low latency on Smartphone.

The key concept of the Internet of Things (IoT) is linking physical smart things to the Internet to make them active participants on the Internet. The Web of Things (WoT) uses the World Wide Web platform and its associated technologies as a framework to realize IoT. Inspired by WoT, we propose a new paradigm, the Virtual Environment of Things (VEoT), to integrate real-world smart things and virtual-world avatars/objects in a computer generated virtual environment so that entities in either worlds can interact with one another in a real-time manner. To prove the VEoT concept, we design a hierarchical smart gateway, REX (Resources Exchange), to embody smart things as Restful resources that can be combined with networked virtual environments (NVEs) to realize the integration and the interaction of the virtual environments and the real world. In addition, we implement a VEoT-based NVE, called X-Campus, for guiding visitors to navigate a building of National Central University to verify the feasibility of VEoT. This implementation shows the VEoT framework works properly.

RESTful Web service composition with BPEL for REST

Policy-based management provides Web of Things (WoT) system with the ability to describe its requirements and functionality, so that desired service goals are achieved. This requires WoT system provisioning smart things which can work under the guidance of policies. However, policy makers with less awareness of specific safety constraints of smart things may create harmful policies, which make smart things work in unexpected situations and cause safety issues. From the view of smart things, the notion of safety issues is two-fold: First, devices themselves work in an unsound and unsecure state, second, devices are influenced by other devices with same or contradict function. We identify these safety issues as device-centric modality conflicts and interest conflicts, and then define a specific conflict detection approach for these conflicts. In this paper, we demonstrate the use of the conflict detection approach to detect device-centric conflicts in two cases. Finally, we conduct three experiments to evaluate the accuracy and time performance of the detection approach.

The Web of Things is an emerging scenario in which objects are connected to Internet and can answer to HTTP queries. To date, new applications in this field are mainly produced by designers and engineers while we claim that with simple and effective composition rules and easy-to-use building blocks, even users could invent new applications unforeseen by technology experts. In this paper, we describe a solution for modeling, implementing and running simple connections of smart things based on the point-click-and-compose paradigm. We envision a Service-oriented Architecture (SOA) where things are Web Services using WSDL standard and logical connections between things are modeled as Web Services orchestrations using the WS-BPEL language.

Web of Things is a new paradigm, it constitutes the heart of a great research activity. However, most of this work does not take into account its temporal aspect, whereas it is a critical dimension directly related to customer satisfaction, optimization and is considered as a very effective strategy for cost reduction. For this matter, we propose a tool to edit and verify the time constraints added to an abstract BPEL specification. Furthermore, the editor allows the user to edit abstract BPEL specification that orchestrates Web services offered by objects connected to the Web of Things. Through the latter, the input specification is enriched with constraints and time attributes. Then, a temporal verification and validation process is applied to detect any temporal errors or conflicts.

Social needs for ubiquitous computing environment, in which anyone can easily, conveniently and safely receive IT service through computer and network anywhere, anytime increase, as IT technology develops. This paper proposes the Web of Things (WoT) platform and relevant technology to build ubiquitous computing environment. The proposed WoT platform enables to reduce expenses to build ubiquitous computing environment through the standardization of access and control mechanism of various smart things.

Service Oriented Architecture (SOA) has been widely adopted by industries due to its ability to provide increased interoperability among heterogeneous systems. SOA is realized through web services which can be either based on the style of Remote Procedure call(RPC) and SOAP protocol or on the Representational State Transfer(REST) style and HTTP. RESTful web services are increasingly becoming popular in the industry because of their simplicity, uniform interface, statelessness and cacheability benefits. The ability to efficiently select and integrate appropriate heterogeneous services available on the web dynamically at runtime is essential in the development of the applications based on web services. Whenever a single web service cannot satisfy the functionality required by the user, there should be a possibility to combine several existing services together in order to fulfill the request. This need has triggered a considerable number of research efforts on the composition of web services. Although several works have focused on the composition of SOAP based web services, there has not been adequate effort towards the composition of RESTful services. However, due to the above- mentioned advantages offered by the RESTful web services, it will be beneficial to design an application as a composition of such RESTful services. Towards this objective, this paper investigates two different approaches for composing the REStful web services specifically designed for health care domain, one using the Jopera tool and another using hypermedia.

An increasing number of real-world entities is currently being connected to the Internet and the World Wide Web. We argue that this development is the precursor of a Web of Things (WoT), which in turn provides a promising way to prototype UbiComp applications, by significantly lowering the technical barriers for making things smart. In this paper, we outline how sensors, actuators and Web services can easily be combined in the WoT in order to enable rapid prototyping of UbiComp applications.

The need for adaptability in software is growing, driven in part by the emergence of autonomic computing. In many cases, it is desirable to enhance existing programs with adaptive behavior, enabling them to execute effectively in dynamic environments. Existing web service invocation and adaptation mechanisms are limited only to the scope of web service choreography in terms of web service selection. Such a scope hardly leaves ground for a participating service in a choreographed flow to re-adjust itself in terms of changed non functional expectations. In this paper we used Aspect oriented programming (AOP) to invoke Web Services (WS) and Representational State Transfer (REST) web services and to enable dynamic adaptation in existing programs. We propose an approach to implement dynamic adaptability especially in Aspect weaving at the time invoking web services and REST web service. We have used AspectJ; Java based language to create aspects in Eclipse supported framework.

In this paper, an embedded system is used as a host for the intercom and as a chatbot server for this system. The chatbot server controls door locks, cameras, buzzers, and related devices through web services on the WoT (Web of Things) to provide residents and visitors with better functionality and integrational services. This system can greatly improve the security and convenience of the system compared with the traditional intercom system. The resident uses the instant messaging software of the smartphone to replace the handset function, and there is no need to install and learn new apps, reducing the cost of the handset and the wiring indoors and outdoors. Whether or not the residents are at home, they can check whether there are visitors and check the status of their doors through their smartphones. Conversely, any visitor can also contact the resident through this intercom, while there is no way to confirm whether the resident is at home or not, which enhances the security of the house. This system provides flexibility in wireless installation and use and sufficient mobility for residents. The system architecture strikes a good balance between user convenience and home security and between performance and cost, effectively improving home security and reducing costs.

With the great impact of the advancement in the hardware field, major efforts have been made to create large-scale networks of IoT devices (e.g., embedded systems, sensors, and actuators) that can interact with each other as well as their surrounding environments. However, most of the deployments are based on proprietary and tightly-coupled systems. To overwhelm the application layer interoperability issues, the Web of Things (WoT) paradigm aims at making smart things an integral part of the Web and thus, enabling them to communicate through Web standards/protocols. Therefore, applications/services making use of smart things become easier to conceive by means of Web standards/protocols (e.g., HTTP, Websockets). This paper proposes an approach enabling the smart devices to join the Web using features provided by the Stack4Things (S4T) OpenStack-based middleware. Thereby, user agents, typically, Web browsers and/or smart devices can make use of the resources of (other) IoT devices using globally resolvable Uniform Resource Locators (URLs) regardless of their underlying used protocol stacks.

How to create or integrate large Smart Spaces (considered as mash-ups of sensors and actuators) into the paradigm of “Web of Things” has been the motivation of many recent works. A cutting-edge approach deals with developing and deploying web-enabled embedded devices with two major objectives: 1) to integrate sensor and actuator technologies into everyday objects, and 2) to allow a diversity of devices to plug to Internet. Currently, developers who want to use this Internet-oriented approach need have solid understanding about sensorial platforms and semantic technologies. In this paper we propose a Resource-Oriented and Ontology-Driven Development (ROOD) methodology, based on Model Driven Architecture (MDA), to facilitate to any developer the development and deployment of Smart Spaces. Early evaluations of the ROOD methodology have been successfully accomplished through a partial deployment of a Smart Hotel.