Towards a standard API design for open services in smart buildings

Abstract

The growing number of Internet of Things (IoT) devices gives a great impact on every aspect of our daily lives. To increase interoperability of such devices, they are often equipped with RESTful API. To encourage developers to utilize devices by developing innovative applications, those APIs are open to the public. However, integrating IoT devices as a whole system is challenging because of the lack of API standardization. Each manufacturer defines their own API for their products. Moreover, the traditional RESTful style, which is designed based on a resource-oriented paradigm, lacks in functionality description. Consequently, application development cost increases, which obstructs innovative applications to emerge. In this paper, we present an alternative approach for API standardization, which can realize open services in smart buildings. To deal with a wide variety of devices, we design each device API to have two endpoints: attribute and state, based on device abstraction. To support developers, we provide functionality descriptions by investigating the useful information in application development and include it into attribute endpoint. To evaluate the proposed design, we implemented Smart Building API in the real building environment and developed a Smart Room Application as a use case. The comparison of the development process by using traditional RESTful style and the proposed design is analyzed. The results showed that the proposed API design succeeded in reducing the development cost and supported the developers to create application more easily.