Finding Internet of Things resources: A state-of-the-art study

Since its emergence, the Internet of Things (IoT) has aimed to join the physical world to the virtual world with a basic vision, which is to create intelligent spaces in which users interact seamlessly with IoT objects. Therefore, the user will be surrounded by a large number of services offered by these connected objects which he/she will inevitably interact with them. However, the IoT environments are characterized by a large number of heterogeneous connected objects. These characteristics make it difficult to find their adjacent resources. Importantly, because the traditional discovery solutions are inefficient, therefore, a mechanism that makes it possible to dynamically inventory and control the resources present in an IoT environment is crucial. In fact, a resource discovery mechanism basically aims to dynamically and regularly update the base of available resources in the IoT environment. To meet these needs, many research works were conducted where many architectures have been proposed to provide solutions for resource discovery in the IoT environment. In this work, we provide a state-of-the-art study of resource discovery techniques in IoT environment. First, the resource discovery techniques are classified according to their search approaches. Then, a review of a selection of recent works that propose solutions for resource discovery in the IoT environment is provided. Finally, the study gives some implications for further study and a number of guidelines that helps to meet a large part of the requirements of a resource discovery solution in the IoT environment.