Bridging the ECHONET Lite Protocol and the W3C Web of Things for Smart Homes in Japan

The ECHONET Lite (ENL) protocol, a smart home interoperability networking protocol popular in Japan, has entered its second phase with the objective of addressing the problem of integrating with other service platforms in order to bring services from various domains into smart homes. In this paper, we address one such integration case, namely that of ENL and the World Wide Web Consortium (W3C) Web of Things (WoT). To achieve this integration, we first chose to represent ENL devices as WoT Things, by generating WoT Thing Descriptions for each device. Then, after considering the most relevant integration patterns, we settled on an ENL Web API proxy implementation. This approach is compatible with future ENL specification releases. We deployed our solution in an experimental smart home equipped with ENL devices and during the W3CWoT September 2021 Plugfest, the participants reported a 100% success rate in interacting with the ENL devices through our proxy solution, with the time delay introduced by our system being negligible.