5.375 in the Radio Frequency Table Allocation of Ireland.

Content Type
ITU FOOTNOTE
Title
5.375
Description
The use of the frequency band 1 645.5-1 646.5 MHz by the mobile-satellite service
(Earth-to-space) and for inter-satellite links is limited to distress, urgency and safety
communications (see Article 31). (WRC-23)
Source
https://search.itu.int/history/HistoryDigitalCollectionDocLibrary/1.43.48.en.101.pdf