High-Reliability Physical Layer for In-Vehicle High-Speed Local Area Network 910464
Recently, because of the requirements of performance and safety, it has become the concern to adopt intercommunication functions for the coordinated real-time control of the power train, brakes, suspension, and so on. For the transmission of these real-time control signals, a type of controller area network (CAN) for CSMA/CD with a non-destructive arbitration (NDA) protocol has been proposed.
In such protocols it is considered essential to have a physical layer having a high degree of reliability, but at high speeds conventional physical layers have not yet been achieved the nine requirements of fault tolerance that are included in ISO recommendations.
To overcome this difficulty a physical layer has recently been built that provides these fault tolerance requirements at a transmission speed of 1 Mbps. This paper reports on its configuration, and on the results of evaluation.
This physical layer utilizes shielded twisted pair wires as the transmission medium, effecting balanced-mode transmission at normal times and unbalanced-mode transmission during the occurrence of faults, thereby achieving the nine fault tolerance requirements.
Evaluation under in-vehicle environments has confirmed that this physical layer provides high levels of performance and reliability.