Overview
ISO/IEC 9314-20:2001 - titled Information technology - Fibre Distributed Data Interface (FDDI) - Part 20: Abstract test suite for FDDI physical medium dependent conformance testing (FDDI PMD ATS) - defines an abstract test suite to verify that FDDI stations conform to the physical medium requirements of ISO/IEC 9314-3. The standard focuses on measurable, physical-layer properties (optical power, wavelength, timing and jitter, BER, connector mechanics) rather than protocol exchanges, and is intended to be implemented by conformance test labs and equipment manufacturers for PMD testing of multimode optical FDDI interfaces.
Key Topics
- Scope and intent
- Test suite for PMD conformance to ISO/IEC 9314-3 requirements.
- Abstract tests allow multiple detailed implementations while preserving test intent.
- Primary measurements
- Optical characteristics: average optical power, center wavelength, source spectral width (FWHM), extinction ratio, pulse envelope and optical spectrum.
- Timing and signal integrity: rise/fall time, duty cycle distortion (DCD), random jitter (RJ), data-dependent jitter (DDJ) and overall jitter budget.
- Receiver characteristics: sensitivity threshold, saturation power, and bit error rate (BER) performance (note: requirement example - station-to-station BER target specified in ISO/IEC 9314-3 as 2.5 × 10^-10 under conforming conditions).
- Interface signals and mechanics: Signal_Detect threshold/hysteresis, station bypass behavior (attenuation, switching time, interruption time), and Media Interface Connector (MIC) receptacle keying.
- Measurement practice and statistics
- Explicit treatment of measurement error, repeatability and statistical sampling.
- BER testing designed with a 90% confidence level; optical measurements use multiple samples with a safety margin (three times standard deviation) to account for variability.
Applications
- Conformance testing and certification of FDDI transceivers, station ports and cable plants.
- Manufacturer production tests and qualification of optical modules for FDDI systems.
- Interoperability verification for legacy FDDI networks and equipment refurbishing.
- Laboratory verification during R&D and during procurement to ensure PMD compliance.
Who should use this standard
- Conformance test laboratories and certification bodies
- Optical transceiver and network equipment manufacturers
- System integrators and network engineers working with legacy FDDI installations
- Test equipment vendors implementing PMD ATS test suites
Related Standards
- ISO/IEC 9314-3:1990 (FDDI Physical Layer PMD) - normative reference for PMD requirements
- ISO/IEC 9314-1 (PHY), 9314-2 (MAC), 9314-6 (SMT) - other FDDI conformance parts
- ISO/IEC 9314-13 (PICS proforma) - conformance statement proforma for testing
Keywords: ISO/IEC 9314-20, FDDI PMD ATS, FDDI conformance testing, PMD testing, optical BER, optical power, jitter, MIC connector.