CONTENTS

 1 The emergence of modern shore-based eNAV infrastructure  2
2 Rationale for the EMC assessment of eNAV infrastructure  3
        2.1 Compatibility of various eNAV infrastructure on adjacent RR Appendix 18 channels  3
        2.2 Compatibility of the transmitter emissions used for the eNAV   3
3 Maritime radiocommunications in Appendix 18 with the eNAV and the AIS requires EMC assessment     3
        3.1 Channels for voice and data exchange  3
        3.2 The impact of providing for a 225 kHz wideband VHF data system in RR Appendix 18     4
                  3.2.1 Inter-system EMC issues with the 225 kHz bandwidth VHF data exchange system     4
                  3.2.2 Technical assessment of the 225 kHz bandwidth Reference Example  5
Types of radios     9
Channel spacing     9
Emission designator     9
Modulation symbol rate     9
Test conditions, power sources and ambient temperatures     9
Transmitter frequency error     9
Transmitter carrier power     9
Transmitter spectral mask based on the 225 kHz data channel (refer to Fig. 1)     9
4 An alternative method for data transmission based on the ETSI TETRA Standard  12
5 Comparison of the two ETSI Standards (ETS300113 and TETRA-TEDS) 15
        5.1 Impact on ITU RR Appendix 18  16
        5.2 Spectrum efficiency (bits/s/Hz of bandwidth) 16
        5.3 EMC (electromagnetic compatibility) 16
        5.4 Service effectiveness  16
        5.5 EMC of the VPC with the AIS  16
        5.6 Summary and conclusion concerning the Reference Example and alternatives  17
6 EMC assessment of the eNAV and advanced technologies  17
        6.1 EMC assessment of site-based eNAV infrastructure  17
        6.2 EMC assessment of area-based eNAV infrastructure  18
        6.3 Assessing technical advances in AIS receiver sensitivity and VPC transmitter emissions     18
        6.4 EMC analysis of technically advanced AIS and VPC systems  19
        6.5 Computer propagation models could be used to enhance EMC analysis  21
                  6.5.1 Estimates for distance separation (free-space propagation) 21
                  6.5.2 Distance separation from computer propagation models (ITU-R P.525 model and NTIA ITM (irregular terrain model))     22
        6.6 Technical possibilities for interference mitigation  23
        6.7 The benefit of automatic continuous interference detection capability in the AIS  24