ISO 17458-1:2013

Overview

ISO 17458-1:2013 - Road vehicles - FlexRay communications system - Part 1 provides the foundational overview and use-case definitions for the FlexRay communications system used in modern automotive networks. This Part 1 document defines the common terminology, shows the structure and partitioning of the ISO 17458 series, maps FlexRay functionality to the OSI model, and outlines the primary use-case clusters where FlexRay is applied. It is the reference for implementers who need to understand how the rest of the ISO 17458 parts relate and where they apply.

Key Topics and Technical Scope

ISO 17458-1 covers high-level concepts and requirements without prescribing detailed protocol bytes or hardware designs. Key technical topics include:

• FlexRay system capabilities: synchronous and asynchronous frame transfer, deterministic cycle-based message transport, guaranteed latency and jitter for synchronous transfers, prioritized asynchronous frames, and scalable fault tolerance.
• Time and clock services: single- or multi-master clock synchronization and time synchronization across networks.
• System services: synchronization, autonomous start-up, error management (detection and signalling), and wakeup/power-management support.
• Communication cycle structure: segmentation into static segment, optional dynamic segment, optional symbol window and network idle time (used for clock correction).
• Topology and physical layer concepts: clusters, channels (A/B), active and passive stars, bus drivers (BD), communication controllers (CC), wiring harness elements, splices, stubs and hybrid topologies.
• Use-case clusters and organization: Part 1 defines use-case clusters such as FlexRay processes, time-triggered (TT) modes in clusters, communication protocol scenarios, and electrical physical layer situations.

Practical Applications

FlexRay is specified for advanced in-vehicle, high-speed control applications that require deterministic, low-latency, and reliable communications. Typical applications include:

• Safety-critical control domains (braking, steering, chassis control)
• Coordinated distributed control systems requiring precise time synchronization
• High-bandwidth sensor and actuator networks within vehicles
• Gatewayed architectures coupling multiple networks or domains

Who Uses ISO 17458-1

• Vehicle manufacturers and system architects defining in-vehicle networks
• ECU vendors and communication-controller (CC) implementers
• Hardware suppliers (bus drivers, active stars, wiring harness components)
• Test laboratories and conformance engineers for ISO 17458 series
• Systems integrators and automotive software teams designing deterministic communication

Related Standards

ISO 17458-1 is part of the ISO 17458 series and references OSI and diagnostic/transport standards:

• ISO 17458-2 / -3 (Data link layer spec & conformance tests)
• ISO 17458-4 / -5 (Electrical physical layer spec & conformance tests)
• ISO/IEC 7498-1, ISO/IEC 10731 (OSI model and service conventions)
• ISO 14229 series (UDS diagnostics), ISO 10681-2 (transport/network services)

ISO 17458-1 is essential reading when planning FlexRay-based automotive networks, ensuring consistent terminology, use cases, and mapping to the rest of the FlexRay standard series.