Overview
ISO 21806-11:2021 specifies the conformance test plan for the 150-Mbit/s coaxial physical layer of Media Oriented Systems Transport (MOST150 cPHY). The standard defines measurement methods and test procedures to verify that MOST networks, nodes, and components comply with the physical-layer requirements referenced in ISO 21806‑10. It focuses on electrical and coaxial-layer behavior for a synchronous time-division-multiplexing automotive network using a 150‑Mbit/s coaxial interconnect.
Key topics and technical requirements
ISO 21806-11:2021 covers a comprehensive set of physical-layer conformance topics, including:
- Operating conditions and measurement tools: required test environment, instrumentation accuracy and calibration for conformance testing.
- Electrical characteristics: tests for LVDS and LVTTL signalling relevant to MOST150 cPHY inputs and outputs.
- Coaxial characteristics: measurement procedures for attenuation, characteristic impedance, return loss (RL) of cables, connectors and PCB interfaces.
- Signal points and stimuli: definitions and generation of SP2/SP3/SP4 stimuli, pattern and arbitrary signal generation, noise injection for stress tests.
- Timing and jitter: methods to measure phase variation, alignment jitter (AJ), transferred jitter (TJ), and timing master delay tolerance.
- Test set-ups: detailed configurations for simplex, duplex and dual-simplex devices; directional coupler usage; compensation setups for duplex measurements.
- Power sequencing and control signals: power‑on/power‑off behavior, wake-up and shutdown functional tests, ECC/CEC parameter measurements.
- System performance & limited conformance: receiver tolerance, port delay drift measurement, limited physical-layer conformance for development tools and restricted-access test scenarios.
- Normative annexes: stress conditions, duplex compensation, two-port node test procedures.
Note: The document references the normative requirements in ISO 21806‑10 for compatibility verification.
Practical applications and who uses this standard
ISO 21806-11:2021 is intended for organizations involved in the development, verification and deployment of MOST150 coaxial physical-layer components and systems:
- Automotive OEMs and system architects verifying network-level interoperability and compliance.
- Tier‑1 and Tier‑2 suppliers designing ECUs, transceivers, connectors, and coaxial harnesses for MOST150.
- Test houses and conformance laboratories implementing standardized test plans and reporting conformance results.
- R&D and validation teams performing lab and field characterization of signal integrity, jitter, and connector/cable performance.
Using this standard helps ensure reliable in-vehicle multimedia and data transport over 150‑Mbit/s coaxial links by establishing repeatable, traceable test methods for physical-layer conformance.
Related standards
- ISO 21806‑10 - MOST150 specifications (normative reference for physical-layer requirements)
- MOST family specifications (Media Oriented Systems Transport) - system and protocol context for MOST150 cPHY
Keywords: ISO 21806-11:2021, MOST150 cPHY, 150-Mbit/s coaxial, conformance test plan, physical layer testing, automotive network test, coaxial impedance, jitter measurement.