Page 27 - U4SSC Data and API requirements for centralized smart city platforms
P. 27
Figure 10: The technology layer of the SCHub (Anthopoulos et al�, 2022)
Finally, the Data Transmission Function (DFS) represents the message transmission middleware of
the reference architecture, it receives requests, forwards them to the appropriate resources, and
collects responses (Pourzolfaghar and Helfert, 2017)) with the use of an access gate for systems’
interoperability (Pourzolfaghar et al., 2017). The DFS connects data producers with consumers,
registers new services, while it will be calibrated by the context layer and triggered by the API layer.
The above technologies require an operating system, while the SCHub could become a physical
facility. The SCHub will enable the following indicative use cases (Figure 11):
1) Data consuming: a registered user/application can gain access to SC data.
2) Data provisioning: a registered user/application can transmit data to the SC.
3) Service provisioning: a service provider can connect its web service or App to the SCHub. A
service catalogue will contain the available services, together with their SDKs and guides.
4) IoT access to registered users for data collection.
17
