IEC 61097-9:2025

Overview

IEC 61097-9:2025 defines minimum operational and performance requirements and test methods for shipborne transmitters and receivers operating in the MF and HF bands for the Global Maritime Distress and Safety System (GMDSS). The standard covers equipment capable of voice (telephony), digital selective calling (DSC), reception of maritime safety information (MSI) and search and rescue related data. It implements SOLAS Chapter IV obligations and is aligned with IMO Resolution MSC.512(105) and ITU‑R Recommendation M.493-16. This second edition (2025) updates and consolidates previous IEC parts, constituting a technical revision of the 1997 edition.

Key Topics

• Scope and applicability: MF-only and MF/HF shipborne radio equipment designed for GMDSS use.
• Performance requirements: Frequency accuracy/stability, output power, modulation characteristics, spurious emissions and receiver sensitivity.
• Operational requirements: Controls, indicators, distress controls, control panel priority, labels and safety precautions.
• Digital Selective Calling (DSC): DSC capabilities, message storage, bit error testing and required DSC characteristics (newly integrated from IEC 61097-3).
• Maritime Safety Information (MSI): Reception, display, storage, alerting and test facilities for MSI and SAR information.
• Automatic Connection System (ACS): Requirements and tests for automatic call connection features (new Annex F).
• Bridge Alert Management (BAM): Annexes for integration with bridge alerting systems (new Annex D and G).
• Software maintenance: New provisions for software maintenance and lifecycle support.
• Test methods: Detailed test conditions, measurement uncertainty, transmitter and receiver test procedures and required test results.
• Additional annexes: Guidance on DSC (A–C), MSI (E, I), equipment manuals (H), remote control operation (J), and deleted obsolete annexes.

Applications

IEC 61097-9:2025 is used for:

• Type approval and certification of shipborne MF/HF radio equipment for GMDSS compliance.
• Design and manufacturing guidance for radio equipment vendors and module designers.
• Factory and laboratory testing: Conformance testing, performance verification, and acceptance tests.
• Procurement and installation: Specifying equipment for new builds and retrofits to meet SOLAS Chapter IV requirements.
• Ship operators, flag states and surveyors: Ensuring equipment meets regulatory and operational safety standards.

Who should use this standard

• Radio equipment manufacturers and test laboratories
• Classification societies, flag administrations and maritime authorities
• Shipyards, ship owners/operators and marine system integrators
• Design engineers and procurement specialists specifying GMDSS capabilities

Related Standards

• IMO Resolution MSC.512(105) - GMDSS performance standards
• ITU‑R Recommendation M.493 (incl. M.493-16) - DSC requirements
• IEC 61097 series (previous parts such as 61097-3 and 61097-8 - now incorporated)

Keywords: IEC 61097-9:2025, GMDSS, shipborne transmitters, MF HF bands, DSC, maritime safety information, MSI, SOLAS, IMO MSC.512(105), ITU‑R M.493.