Embedded Communications

Embedded Communications

he increasing complexity of electronic architectures embedded in a vehicle, and
locality constraints for sensors and actuators, has led the automotive industry to
adopt a distributed approach for implementing the set of functions. In this context,
networks and protocols are of primary importance. hey are the key support for
integrating functions, reducing the cost and complexity of wiring, and furnishing
a means for fault tolerance. heir impact in terms of performance and dependabil-
ity is crucial as a large amount of data is made available to the embedded functions
through the networks. his part includes three chapters dedicated to networks and
protocols.
Chapter 4, “A Review of Embedded Automotive Protocols,” outlines the main pro-
tocols used in automotive systems; it presents the features and functioning schemes
of CAN, J1850, FlexRay, TTCAN, and the basic concepts of sensor/actuator networks
(LIN, TTP/A) and multimedia networks (MOST, IDB1394).he identiication of the
communication-related services commonly ofered by a middleware layer and an
overview of the AUTOSAR proposals conclude the chapter.
CAN is at present the network that is the most widely implemented in vehicles.
Nevertheless, despite its eiciency and performance, CAN does not possess all the
features that are required for safety-critical applications. he purpose of the chap-
ter, “Dependable Automotive CANs,” is to point out CAN’s limitations, which reduce
dependability, and to present technical solutions to overcome or minimize these lim-
itations. In particular, the authors describe techniques, protocols, and architectures
based on CANthat improve the dependability of the original protocol in some aspects
while still maintaining a high level of lexibility, namely (Re)CANcentrate, CANELy,
FTT-CAN, and FlexCAN.
With the development of technology, there has been an increasing number of func-
tions with strong needs in terms of data bandwidth. In addition, safety requirements
have become more and more stringent. To answer to both of these constraints, in
2012, the automotive industry began to develop a new protocol—FlexRay. Chapter5 “FlexRay Protocol,” explains the rationale of FlexRay and gives a comprehensive
overview of its features and functioning scheme. Finally, an evaluation of the impact
of FlexRay on the development process concludes the chapter.