On the Bulk Ingestion of IoT Devices from Heterogeneous IoT Brokers

In smart cities, there has been a significant growth of IoT brokers by mean of which IoT applications can subscribe to the real-time events produced by sensors. However, these brokers follow different communication protocols (e.g. mqtt, amqp, ngsi), event formats, structures and sometimes meaning. This makes the development of horizontal applications across heterogeneous IoT platforms complicated and demanding. In light of this, we developed the IoT-Directory for the management of heterogeneous brokers in an Ontology based way. In this paper we present a newly added facility of the IoT-Directory for addressing the issue of the massive acquisition of devices and sensors directly from the IoT brokers, and for supporting the user in providing missing and/or incorrect information not available in the IoT brokers. For the former issue, we exploit brokers' functionalities for querying and extracting the available data and we automatically ingest them in the IoT-Directory, for the latter one we offer graphical interfaces by means of which users can specify 'IFTTT' rules to easily update several devices and sensors in a single shot.