1、 Recommendation ITU-R M.1174-3 (03/2015) Technical characteristics of equipment used for on-board vessel communications in the bands between 450 and 470 MHz M Series Mobile, radiodetermination, amateur and related satellite services ii Rec. ITU-R M.1174-3 Foreword The role of the Radiocommunication
2、Sector is to ensure the rational, equitable, efficient and economical use of the radio-frequency spectrum by all radiocommunication services, including satellite services, and carry out studies without limit of frequency range on the basis of which Recommendations are adopted. The regulatory and pol
3、icy functions of the Radiocommunication Sector are performed by World and Regional Radiocommunication Conferences and Radiocommunication Assemblies supported by Study Groups. Policy on Intellectual Property Right (IPR) ITU-R policy on IPR is described in the Common Patent Policy for ITU-T/ITU-R/ISO/
4、IEC referenced in Annex 1 of Resolution ITU-R 1. Forms to be used for the submission of patent statements and licensing declarations by patent holders are available from http:/www.itu.int/ITU-R/go/patents/en where the Guidelines for Implementation of the Common Patent Policy for ITU-T/ITU-R/ISO/IEC
5、and the ITU-R patent information database can also be found. Series of ITU-R Recommendations (Also available online at http:/www.itu.int/publ/R-REC/en) Series Title BO Satellite delivery BR Recording for production, archival and play-out; film for television BS Broadcasting service (sound) BT Broadc
6、asting service (television) F Fixed service M Mobile, radiodetermination, amateur and related satellite services P Radiowave propagation RA Radio astronomy RS Remote sensing systems S Fixed-satellite service SA Space applications and meteorology SF Frequency sharing and coordination between fixed-sa
7、tellite and fixed service systems SM Spectrum management SNG Satellite news gathering TF Time signals and frequency standards emissions V Vocabulary and related subjects Note: This ITU-R Recommendation was approved in English under the procedure detailed in Resolution ITU-R 1. Electronic Publication
8、 Geneva, 2015 ITU 2015 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without written permission of ITU. Rec. ITU-R M.1174-3 1 RECOMMENDATION ITU-R M.1174-3 Technical characteristics of equipment used for on-board vessel communications in the bands betwe
9、en 450 and 470 MHz (1995-1998-2004-2015) Scope This Recommendation describes the technical characteristics for equipment operating in the maritime mobile services in accordance with the provisions of No. 5.287 of the Radio Regulations (RR) for on-board vessel communications. Provision is made for 25
10、 kHz or 12.5 kHz channel spacing for analogue and digital technologies. In addition, 6.25 kHz channel spacing may also be used for digital technology. Keywords Maritime, on-board communication, territorial waters, channel spacing, frequency arrangement, UHF Abbreviations/Glossary Ch. Channel number
11、FSK Frequency-shift keying modulation The ITU Radiocommunication Assembly, considering a) that there is a need to describe the characteristics of equipment for on-board vessel communications in the bands between 450 and 470 MHz; b) that changes have recently been made to the frequency availability,
12、recommends 1 that transmitters and receivers used in the maritime mobile service for on-board vessel communications in the bands between 450 and 470 MHz should conform to the technical characteristics shown in Annex 1; 2 that for analogue technology the use of continuous tone coded squelch systems o
13、r digital coded squelch (DCS) constitute an effective means of mitigating the impression of congestion to the user; 3 that for digital technology the use of DCS or a similar operational system should be used as a way to mitigate the impression of congestion to user; 4 that during operation, to detec
14、t whether there is an available channel for operation, it is advised that a method of listen before talk be employed as a possible mitigation technique; 5 that ship owners when replacing or installing communications equipment upon vessels are encouraged to fit equipment using 12.5 kHz or 6.25 kHz ch
15、annel spacing. This Recommendation should be brought to the attention of the International Maritime Organization (IMO) and the International Maritime Radio Committee (CIRM). 2 Rec. ITU-R M.1174-3 Annex 1 Technical characteristics of equipment used for on-board vessel communications in the bands betw
16、een 450 and 470 MHz 1 The equipment should be fitted with sufficient channels for satisfactory operation in the area of intended use. 2 The effective radiated power should be limited to the maximum required for satisfactory operations, but should in no case exceed 2 W. Wherever practicable the equip
17、ment should be fitted with a suitable device to reduce readily the output power by at least 10 dB. 3 In the case of equipment installed at a fixed point on the ship, the height of its antenna should not be more than 3.5 m above the uppermost level of the deck. 25 kHz channels analogue technology 12.
18、5 kHz channels analogue technology 4 Only frequency modulation with a pre-emphasis of 6 dB/octave (phase modulation) should be used. Only frequency modulation with a pre-emphasis of 6 dB/octave (phase modulation) should be used. 5 The frequency deviation corresponding to 100% modulation should appro
19、ach 5 kHz as nearly as practicable. In no event should the frequency deviation exceed 5 kHz. The frequency deviation corresponding to 100% modulation should approach 2.5 kHz as nearly as practicable. In no event should the frequency deviation exceed 2.5 kHz. 6 The frequency tolerance should be 5 par
20、ts in 106. The frequency tolerance should be 2.5 parts in 106. 7 The audio-frequency band should be limited to 3 000 Hz. The audio-frequency band should be limited to 2 550 Hz. 12.5 kHz channels digital technology 6.25 kHz channels digital technology 8 Only constant-envelope modulation, entitled 4FS
21、K (Four-level frequency-shift keying modulation) should be used. Only constant-envelope modulation, entitled 4FSK (Four-level frequency-shift keying modulation) should be used. 9 The frequency deviation is limited to 3 024 Hz. The frequency deviation is limited to 1 324 Hz. 10 The maximum transmit f
22、requency error: 2 ppm. The maximum time base clock drift error: 2 ppm. The maximum transmit frequency error: 1.5 ppm. The maximum time base clock drift error: 2 ppm. 11 Control, telemetry and other non-voice signals such as paging, should be coded in such a manner as to minimize the possibility of f
23、alse response to interfering signals. The frequencies specified in 15 below for on-board communications may be used for single frequency and two-frequency simplex operation. 12 When used in the duplex mode the base transmitter frequency should be selected from the lower range for improved operabilit
24、y. Rec. ITU-R M.1174-3 3 13 In general, if the use of a repeater station is required on board a ship, the frequency bands described in RR Nos. 5.287 and 5.288 should be used. The detailed duplex frequency arrangement is described in 15 below. 14 Within territorial waters, these frequencies should be
25、 used subject to national regulations. 15 Frequencies The frequency bands specified in RR No. 5.287 (subject to national regulations) shall be used with the following arrangement: Lower channel Upper channel 25 kHz channel 12.5 kHz channel 6.25 kHz channel 25 kHz channel 12.5 kHz channel 6.25 kHz ch
26、annel Ch. MHz Ch. MHz Ch. MHz Ch. MHz Ch. MHz Ch. MHz 1 457.525 102 457.515625 4 467.525 202 467.515625 11 457.5250 111 457.521875 21 467.5250 211 467.521875 112 457.528125 212 467.528125 12 457.5375 121 457.534375 22 467.5375 221 467.534375 2 457.550 122 457.540625 5 467.550 222 467.540625 13 457.5
27、500 131 457.546875 23 467.5500 231 467.546875 132 457.553125 232 467.553125 14 457.5625 141 457.559375 24 467.5625 241 467.559375 3 457.575 142 457.565625 6 467.575 242 467.565625 15 457.5750 151 457.571875 25 467.5750 251 467.571875 152 457.578125 252 467.578125 161 457.584375 261 467.584375 NOTE T
28、he repeater station should be used as pairs of lower channel and upper channel with frequency separation exactly 10 MHz (e.g. Ch. 2 and Ch. 5, Ch. 11 and Ch. 21). Interference from digital system to existing analogue system is concerned. Administrations are invited to consider the impact of analogue communication especially those operating lower channel. _
