Department of Computer Engineering, Jeju National University, Jeju 63243, Korea.
Sensors (Basel). 2018 May 26;18(6):1721. doi: 10.3390/s18061721.
The Internet of Things is comprised of heterogeneous devices, applications, and platforms using multiple communication technologies to connect the Internet for providing seamless services ubiquitously. With the requirement of developing Internet of Things products, many protocols, program libraries, frameworks, and standard specifications have been proposed. Therefore, providing a consistent interface to access services from those environments is difficult. Moreover, bridging the existing web services to sensor and actuator networks is also important for providing Internet of Things services in various industry domains. In this paper, an Internet of Things proxy is proposed that is based on virtual resources to bridge heterogeneous web services from the Internet to the Internet of Things network. The proxy enables clients to have transparent access to Internet of Things devices and web services in the network. The proxy is comprised of server and client to forward messages for different communication environments using the virtual resources which include the server for the message sender and the client for the message receiver. We design the proxy for the Open Connectivity Foundation network where the virtual resources are discovered by the clients as Open Connectivity Foundation resources. The virtual resources represent the resources which expose services in the Internet by web service providers. Although the services are provided by web service providers from the Internet, the client can access services using the consistent communication protocol in the Open Connectivity Foundation network. For discovering the resources to access services, the client also uses the consistent discovery interface to discover the Open Connectivity Foundation devices and virtual resources.
物联网由使用多种通信技术连接互联网以提供无处不在的无缝服务的异构设备、应用程序和平台组成。随着物联网产品的开发需求，已经提出了许多协议、程序库、框架和标准规范。因此，提供一致的接口来访问这些环境中的服务是很困难的。此外，将现有的 Web 服务桥接到传感器和执行器网络对于在各个行业领域提供物联网服务也很重要。在本文中，提出了一种基于虚拟资源的物联网代理，用于将来自互联网的异构 Web 服务桥接到物联网网络中。该代理使客户端能够对网络中的物联网设备和 Web 服务进行透明访问。该代理由服务器和客户端组成，用于使用虚拟资源转发不同通信环境的消息，其中虚拟资源包括消息发送方的服务器和消息接收方的客户端。我们为 Open Connectivity Foundation 网络设计了代理，其中虚拟资源被客户端作为 Open Connectivity Foundation 资源发现。虚拟资源代表由 Web 服务提供商在互联网上公开服务的资源。尽管这些服务是由互联网上的 Web 服务提供商提供的，但客户端可以使用 Open Connectivity Foundation 网络中的一致通信协议访问服务。为了发现访问服务的资源，客户端还使用一致的发现接口来发现 Open Connectivity Foundation 设备和虚拟资源。
