AP-LET: Enabling deterministic Pub/Sub communication in AUTOSAR Adaptive

The automotive software industry is facing a paradigm shift driven by the need to develop more and more advanced functionality distributed on multiple electronic control units. The AUTOSAR Adaptive standard has been designed as a service-oriented architecture on top of a general-purpose operating system to tackle this paradigm shift. Nevertheless, it does not provide means to ensure deterministic communication, as required in safety-related components. This paper studies the integration of the System-Level Logical Execution Time (SL-LET) paradigm in AUTOSAR Adaptive. The key design challenges and requirements to support SL-LET in AUTOSAR Adaptive are described, highlighting how to overcome the considerable differences between the AUTOSAR Classic and Adaptive domains. Then, a meta-protocol named AP-LET is presented, together with two concrete instances: one based on high-priority tasks and another leveraging timestamps in the message payload to handle communications and ensure determinism. A complete implementation of both protocols is also described. AP-LET was finally evaluated with a realistic automotive application, showing its feasibility and effectiveness.