A meta service is the smallest unit. Including the basic interface of sensors and actuators of the car. The basic service is the middle layer service. On the basis of using the meta-service, the car business module can be customized, such as using the car status service and radar sensor services to combine the service of environmental information fusion. Application services are the top-level services that can access and invoke basic services to help them solve business problems.
In the design, the upper-level service calls the lower-level service, and the lower-level service does not call the upper-level service. This principle helps to build a clear and simple SOA automotive software architecture. BMW has introduced the SOA method in the new generation of E/E architecture, as shown in Figure 4. SOA provides a large number of abstract services for the whole system. Strict encapsulation and hierarchy allow testing against interfaces and using agile methodologies, and they reduce system complexity. It will be easier to reuse software components between vehicle generations.