Global maritime distress and safety system (GMDSS) - Part 9: Shipborne transmitters and receivers for use in the MF and HF bands suitable for telephony, digital selective calling (DSC) and reception of maritime safety information and search and rescue related information - Operational and performance requirements, test methods and required test results

IEC 61097-9:2025 specifies the minimum operational and performance requirements and test methods with required test results for transmitters and receivers capable of voice communication and digital selective calling for the GMDSS operating in either the medium frequency band only or in medium and high frequency bands allocated in the ITU Radio Regulations to the Maritime Mobile Service, as required by Chapter IV of SOLAS 1974 as amended. It is based on IMO resolution MSC.512(105) and takes account of Recommendation ITU-R M.493 for digital selective calling including the automatic connection system.

This second edition cancels and replaces the first edition published in 1997. This edition constitutes a technical revision.

This edition includes the following significant technical changes with respect to the previous edition:

a) the text has been updated to incorporate the provisions of the new IMO performance standards given in Resolution MSC.512(105) and new ITU-R recommendations given in M.493-16. These provisions in particular add new requirements for reception of maritime safety information and for the automatic connection system;

b) the provisions for digital selective calli