Maritime mobile-satellite service

Maritime mobile-satellite service (MMSS, or maritime mobile-satellite radiocommunication service) is – according to Article 1.29 of the International Telecommunication Union's Radio Regulations (RR) – "A mobile-satellite service in which mobile earth stations are located on board ships; survival craft stations and emergency position-indicating radiobeacon stations may also participate in this service".

This radiocommunication service is classified in accordance with ITU Radio Regulations (article 1) as follows:
Mobile service

The allocation of radio frequencies is provided according to Article 5 of the ITU Radio Regulations (edition 2012).

In order to improve harmonisation in spectrum utilisation, the majority of service-allocations stipulated in this document were incorporated in national Tables of Frequency Allocations and Utilisations which is with-in the responsibility of the appropriate national administration. The allocation might be primary, secondary, exclusive, and shared.

Space radio station, Inmarsat-3 satellite

Earth station, telephone terminal

Inmarsat aerial (stern of the yacht)

Inmarsat aerial of the US Navy

Hand-held radios of the MMSS

Inmarsat satellite telephone

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