A Disruption-Tolerant RESTful Support for the Web of Things

The Web of Things (WoT) extends the Internet of Things (IoT) considering that each physical object can be accessed and controlled using Web-based languages and protocols. However, due to the mobility of physical objects and to the short radio range of the wireless interfaces they are equipped with, frequent and unpredictable connectivity disruptions may occur between the physical objects and the Web clients used to control and access these objects. This paper presents a disruption-tolerant RESTful support for the WoT, in which resources offered by physical objects are identified by URIs and accessed through stateless services. Service requests and responses are forwarded using the store-carry-and-forward principle, and can be cached by intermediate nodes. A complete service invocation model is provided, allowing to perform unicast, anycast, multicast and broadcast service invocations either using HTTP or CoAP, which makes it particularly suited for the WoT. This disruption-tolerant support is illustrated by a scenario in the context of agricultural robotics.