This Recommendation provides ways to improve efficiency in the used of the band 156-174 MHz by stations in the maritime mobile service; specifically describes technical characteristics when using channels spaced by 12.5 kHz, migration to narrow-band channels, an example method for implementing interleaved narrow-band channels at 12.5 kHz offset spacing and assignment of channels numbers to interleaved channels and simplex operation of duplex channels.
ITU-R M.1084-5-2012 Referenced Document
ITU-R M.1371 Technical characteristics for an automatic identification system using time division multiple access in the VHF maritime mobile frequency band*， 2014-02-01 Update
ITU-R M.489 Technical Characteristics of VHF Radiotelephone Equipment Operating in the Maritime Mobile Service in Channels Spaced by 25 kHz
ITU-R M.493 Digital Selective-Calling System for Use in the Maritime Mobile Service
ITU-R M.541 Operational Procedures for the Use of Digital Selective-Calling Equipment in the Maritime Mobile Service
ITU-R M.821 Optional expansion of the digital selective-calling system for use in the maritime mobile service
ITU-R M.825 Characteristics of a Transponder System Using Digital Selective Calling Techniques for Use with Vessel Traffic Services and Ship-to-ship Identification
ITU-R M.1084-5-2012 history
2012ITU-R M.1084-5-2012 Interim solutions for improved efficiency in the use of the band 156-174 MHz by stations in the maritime mobile service