CONTENTS

RECOMMENDATION  ITU-R  M.1842     2
Characteristics of VHF radio system and equipment for the exchange of data and electronic mail in the maritime mobile service RR Appendix 18 channels     2
Scope     2
Annex 1  VHF data system example 1     3
 1     General characteristics  3
 2     Transmitters  4
 3     Receivers  4
 4     Sample emissions spectrum based on variations of ETSI TETRA standard modulation  4
 5     Conclusions on emissions  7
 6     System interoperability  7
        6.1     Ship-to-shore  7
        6.2     Shore-to-ship  8
        6.3     Ship-to-ship  8
        6.4     Efficient use of the VHF data link (VDL) 8
Annex 2  VHF data system example 2     8
 1     General characteristics  8
 2     Transmitters  9
 3     Receivers  9
 4     Possibilities and advantages  9
        4.1 Coverage and stability  9
        4.2 IP – Ethernet 10
        4.3     Fixed IP address at the radio on board the ship  10
        4.4 Always connected  10
        4.5 Several services in parallel from one radio on the ship  10
        4.6 Automatic reconnection after disruption  10
        4.7 Integrated data router  10
        4.8 Several inputs to the radio  10
        4.9 Connection to local WLAN   10
       4.10 External communication carriers  10
 5     Applications  10
 6     System interoperability  11
        6.1 Ship-to-shore  11
        6.2 Shore-to-ship  11