WOTPY: A framework for web of things applications

Abstract

The interoperability problems that originate from the heterogeneity in protocols and platforms is one of the main challenges currently faced by the Internet of Things (IoT). The Web of Things (WoT) is an architectural solution to this issue based on leveraging the Web as a means to ensure interoperability. The World Wide Web Consortium (W3C) is currently behind one of the most relevant WoT initiatives—a group of building blocks to serve as a possible foundation for the WoT. This work describes an experimental framework based on the W3C WoT, including a set of concrete and original protocol binding implementations (HTTP, Websockets, MQTT and CoAP). One of the main novelties is that all protocol binding implementations have support for all interaction verbs from the WoT interaction model. The framework is especially adequate to build WoT applications for devices on all layers of the fog computing model; this multi-layer integration is achieved by leveraging the W3C WoT architecture and interaction model. A functional implementation in Python is also described, including low-level designs and implementation details for the binding templates. The behavior of the framework and the protocol bindings is studied by implementing a benchmark application under multiple conditions and hardware platforms. Finally, recommendations are extracted from the obtained results for the most adequate protocols for each scenario and interaction verb.