An IoT-DaaS Approach for the Interoperability of Heterogeneous Sensor Data Sources

The Internet of Things (IoT) consists of network connections among devices for the development of predefined activities. A difficulty in IoT is the integration among services, which hinders interoperability and is related to the creation of a procedure that collects, stores and processes data from different sources and formats. This paper introduces an approach for the storage and retrieval of multiple sensor data sources that provides a RESTful API for the management of multiple database types and data formats. The evaluation scenario consists of the integration of the procedure with a data source containing information on the climate of worldwide cities. Data were imported through a process that enables their storage in PostgreSQL and MongoDB exposing an API that supports JSON and XML data format. The performance evaluation methodology includes a workload test and an influence factor analysis. The results show a comparison of different strategies for data conversion and storage and better performance of PostgreSQL and JSON in comparison to MongoDB and XML.