Interworking Models of Smart City with Heterogeneous Internet of Things Standards

Towards Interoperability of Smart City Data Platforms

“…Following Hwang et al [23] we distinguish three patterns repeatedly found in the analysed papers and interviews: interoperability via a central data platform, interoperability via middleware, and interoperability via APIs. They differ in, whether same API standards are needed in general and where the data is stored [23]. A concept for interoperability of different data platforms via APIs is e.g.…”

“…Moreover, Danneels et al [14], Hwang et al [23], and Fahmideh and Zowghi [17] introduce evaluation frameworks for SC data platforms, for example presenting 34 questions to evaluate the suitability of SC platforms' architectures by analysing architectural characteristics and their fit to the requirements [17].…”

“…Bhatt et al [5] describe in their work a concept called pivotal points of interoperability, which provides common architecture principles for SC systems, so only at specific common points standardized interfaces need to be used to make these systems interoperable. However, in both cases, platforms (and services) have to use the same API standards (at least in the pivotal points) to gain access or exchange data with the other data platforms [23]. On the contrary, for interoperability via specific middleware the data platforms do not need to use the same standards, since a middleware is used to convert the data representation of the source platform to another's platform needs [23].…”

“…However, in both cases, platforms (and services) have to use the same API standards (at least in the pivotal points) to gain access or exchange data with the other data platforms [23]. On the contrary, for interoperability via specific middleware the data platforms do not need to use the same standards, since a middleware is used to convert the data representation of the source platform to another's platform needs [23]. This approach is used among others from Chaturvedi et al [11], Lopes et al [30], and Zarko et al [45].…”

“…The third approach in this dimension is interoperability via a central data platform, which is discussed among others by Cohen et al [13], Soe [38], and Tolcha et al [40]. The basic concept is, that a "federation layer is created on top of cities' IoT platforms" [23]. Since a middleware can be used to connect different data platforms and restore their data centrally, the demarcation between interoperability via specific middleware and via a central data platform is not always clear.…”