Integration framework

Urban Strategy runs on the Inter Model Broker (IMB) framework, an integration framework for building modern digital twins, described in Lohman et al. (2023).

The core system components of Urban Strategy are:

Component	Description
Hub	Handles communication within the platform and uses a publish-subscribe mechanism.
MC Node	Handles model administration (i.e. starting and stopping calculation models) and can be interfaced with MC Control
RestAPI	Representational state transfer application programming interface based on the OpenAPI 3.0 specification.
Schema	Translates Google's Protocol Buffers field names to keys (Protocol Buffers tag/wire-type).
Store	The store listens to data changes. In essence IMB is a memory bases system and only changes in the data are communicated.

Data flows asynchronously

The Urban Strategy data exchange system is asynchronous by design. This means that a component does not wait for another to respond before continuing, and does not need to know which other components exist or what they are doing. It publishes data to the hub, or reads data from it, and reacts whenever relevant data changes.