Deploying W3C Web of Things-Based Interoperable Mash-up Applications for Industry 4.0: A Testbed

Abstract

In Industry 4.0 scenarios, novel applications are enabled by the capability to gather large amount of data from pervasive sensors and to process them in order to devise the "digital twin" of a physical equipment. The heterogeneity of hardware sensors, communication protocols and data formats constitutes one of the main challenge toward the large-scale adoption of the Internet of Things (IoT) paradigm on industrial environments. To this purpose, the W3C Web of Things (WoT) group is working on the definition of some reference standards intended to describe in a uniform way the software interfaces of IoT devices and services, and hence to achieve the full interoperability among different IoT components regardless of their implementation. At the same time, due also to the recent appearance of the WoT W3C draft, few testbed and real-world deployments of the W3C WoT architecture has been proposed so far in the literature. In this paper, we attempt to fill such gap by describing the realization of a WoT monitoring application of a generic indoor production site: the system is able to orchestrate the sensing operations from three heterogeneous Wireless Sensor Networks (WSNs). We describe how the components of the W3C WoT architecture have been instantiated in our scenario. Moreover, we demonstrate the possibility to decouple the mash-up policies from the network functionalities, and we evaluate the overhead introduced by the WoT approach.

A Survey on the Web of Things

“…Data Format Web protocols (Access approach) Programming Languages Ruppen et al [122] -HTTP/HTTPS, WS -Corredor et al [31] CAP (XML), JSON HTTP (Webhook), HTTPS Android, JAVA Paganelli et al [112] HTML, XML, JSON HTTP JAVA, Javascript Karim et al [73] JSON HTTP C Chakraborty and Datta [22] multiple (W3C WoT) multiple (W3C WoT) Android/NodeJS El Jaouhari et al [36] -WEBRTC/HTTP NodeJS, Javascript Thuluva et al [145] multiple (W3C WoT) --Patel et al [113] ---Klotz et al [80] -COAP, HTTP JAVA Ji et al [67] -HTTP -Tobarra et al [146] -MQTT NodeJS Sciullo et al [129] JSON MQTT, HTTP, COAP NodeJS, Typescript Terius-Padron et al [144] JSON HTTPS -Bauer et al [11] ---Sciullo et al [130] XML, JSON MQTT, HTTP, COAP NodeJS, Typescript Collins et al [30] JSON HTTP Python Aguzzi et al [3] JSON HTTP NodeJS, Typescript Ibaseta et al [62] -HTTP Python Zyrianoff et al [163] JSON HTTP, MQTT NodeJS, Typescript…”

“…[22] 2017 Academic India Smart Home W3C WoT El Jaouhari et al [36] 2017 Academic France Healthcare Legacy WoT Thuluva et al [145] 2017 Industrial Germany Industry 4.0 W3C WoT Patel et al [113] 2018 Academic USA Industry 4.0 SWoT Klotz et al [80] 2018 Industrial Germany Automotive W3C WoT Ji et al [67] 2018 Academic South Korea Env. Monitoring W3C WoT Tobarra et al [146] 2019 Academic Spain Education Legacy WoT Sciullo et al [129] 2019 Academic Italy Industry 4.0 W3C WoT Terius-Padron et al [144] 2020 Academic Spain Smart Home W3C WoT Bauer et al [11] 2020 Industrial Germany Smart Home Mozilla WT Sciullo et al [130] 2020 Industrial Germany, Italy Industry 4.0 W3C WoT Collins et al [30] 2021 Academic UK Industry 4.0 W3C WoT Aguzzi et al [3] 2021 Industrial Italy SHM W3C WoT Ibaseta et al [62] 2021 Industrial Spain, Italy Smart City W3C WoT Zyrianoff et al [163] 2021 Academic Brazil, Italy Smart Agriculture W3C WoT air quality monitoring cycle through actuators that control windows, all supervised by a custom WoT gateway. Finally, we also cite the ongoing effort, within the ForeSight project, in integrating AI-based Smart Living platforms, such as OpenHAB, with the WoT at the control layer [11].…”

“…In particular, the proposed platform, namely SWeTI, is specifically oriented to tackle three major industrial challenges: (i) deep integration, which includes data heterogeneity from different domains, (ii) horizontal integration, which includes the interaction of different actors, and (iii) autonomous operations, in order to reduce manual effort in organization, manufacturing and fault tolerance. A more concrete testbed is presented in [129], where the W3C WoT standard is fully unleashed. Here, the authors show how to map heterogeneous sensing infrastructures based on different M2M technologies (WiFi, BLE, Zigbee) to the W3C WoT.…”

From Cloud to Edge: Seamless Software Migration at the Era of the Web of Things

“…Due to the recent appearance of the standard, the literature on W3C WoT is still scarce and limited to few applications and supporting tools. The mapping of real-world IoT devices to W3C WTs have been explored in [16], [17], [18] and [19], respectively for the case of mobile phones, automotive industry and wireless sensor networks. Specifically, in the latter, the authors demonstrate how to deploy WoT-based interoperable sensing applications able to manage heterogeneous sensors equipped with three different wireless access technologies (Wi-Fi, BLE and Zigbee).…”

“…The interoperability support is managed at the application level by defining a standard interface for IoT components (physical or virtual), known as the Thing Description (TD) [15], which formally states the Web Things' (WTs) capabilities or affordances. Despite the recent appearance, some interesting applications of the W3C WoT have been proposed so far on different IoT domains [16] [17] [18] [19] [20]. At the same time, the WoT reference implementation [21] does not support mobility of software components among cloud/edge nodes, since the runtime environment of a WT (called Servient in [21]) must be statically deployed on a device.…”