Timing verification of real-time automotive Ethernet networks: what can we expect from simulation?

Scientific Conference (2015, May 23)

Switched Ethernet is a technology that may profoundly reshape automotive communication architectures as it did in other application domains such as avionics with the use of AFDX backbones. Ethernet is ... [more ▼]

Switched Ethernet is a technology that may profoundly reshape automotive communication architectures as it did in other application domains such as avionics with the use of AFDX backbones. Ethernet is meant in vehicles not only for the support of infotainment applications but also to transmit time-sensitive data used for the real-time control of the vehicle and ADAS functions. In such use-cases, the temporal behavior of the communication architecture must be carefully validated. Early stage timing verification of critical embedded networks typically relies on simulation and worst-case schedulability analysis, which basically consists in building a mathematical model of the worst possible situations that can be encountered at run-time. The two basic questions that we aim to study here is what can we expect from simulation? And how to use it properly? This empirical study explores these questions and provides methodological guidelines for the use of simulation in the design of switched Ethernet networks. A broader objective of the study is to compare the outcomes of schedulability analyses and simulation, and conclude about the scope of usability of simulation in the design of critical Ethernet networks. [less ▲]

Formal Analysis of the Startup Delay of SOME/IP Service Discovery

in Proceedings of the 2015 Design, Automation & Test in Europe Conference & Exhibition (2015)

An automotive network needs to start up within the millisecond range. This includes the physical startup, the software boot time, and the configuration of the network. The introduction of Ethernet into ... [more ▼]

An automotive network needs to start up within the millisecond range. This includes the physical startup, the software boot time, and the configuration of the network. The introduction of Ethernet into the automotive industry expanded the design space drastically and is increasing the complexity of configuring every element in the network. To add more flexibility to automotive Ethernet networks, the concept of Service Discovery was migrated from consumer electronics to AUTOSAR within the SOME/IP middleware. A network is not fully functional until every client has found its service. Consequently, this time interval adds to the startup time of a network. This work presents a formal analysis model to calculate the waiting time of every client to receive the first offer from its service. The model is able to determine the worst case of a given parameter set. Based on this, a method for calculating the total startup time of a system is derived. The model is implemented in a free-to-use octave program and validated by comparing the analytical results to a timing-accurate simulation and an experimental setup. In every case the worst-case assumption holds true -- the gap between the maximum of the simulation and the presented method is less than 1.3%. [less ▲]