1、 Recommendation ITU-R M.689-3(03/2012)International maritime VHF radiotelephone system with automatic facilities based on DSC signalling formatM SeriesMobile, radiodetermination, amateurand related satellite servicesii Rec. ITU-R M.689-3 Foreword The role of the Radiocommunication Sector is to ensur
2、e 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 policy functions of t
3、he 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/IEC referenced in
4、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 and the ITU-R pate
5、nt 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 Broadcasting service (te
6、levision) 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-satellite and fixed
7、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 Geneva, 2012 ITU
8、2012 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without written permission of ITU. Rec. ITU-R M.689-3 1 RECOMMENDATION ITU-R M.689-3*International maritime VHF radiotelephone system with automatic facilities based on DSC signalling format*(1990-1992-
9、1994-2012) Scope This Recommendation describes the operational requirements for an International maritime VHF radiotelephone system with automatic facilities, which is based upon the digital selective calling (DSC) signalling format. This radiotelephone system is designed to work in the channels det
10、ailed in Radio Regulations (RR) Appendix 18. The ITU Radiocommunication Assembly, considering a) that an automated maritime VHF radiotelephone system expedites the handling of traffic and increase the efficient use of the radio channels; b) that international standardization is of great importance i
11、n the maritime mobile service; c) that the existing public correspondence channels listed in Appendix 18 to the RR are in widespread use by ships and coast stations in the maritime mobile service; d) that no other VHF channels are available for the exclusive use of the maritime mobile service; e) th
12、at Article 52 of the RR do not permit coast stations to emit signals on idle VHF radiotelephone working channels; f) that the DSC system described in Recommendations ITU-R M.493 and ITU-R M.541 can be used for signalling over the radio path for an automatic system using a common VHF DSC channel; g)
13、that the existing RR Appendix 18 channels can be used in such an automatic system without impairing their use for manual operations from ships or coast stations, recommends 1 that the operational procedures described in Annex 1 should be observed when operating an international radiotelephone system
14、 with automatic facilities based on the DSC signalling format, and using the public correspondence channels listed in RR Appendix 18; 2 that the same RR Appendix 18 channel may be used for both automatic and manual operation by the same coast station depending on the requirements of the ship station
15、s; 3 that the technical characteristics of the ship and coast station equipment should be in accordance with Annex 2. *This Recommendation should be brought to the attention of the Telecommunication Standardization Sector. *Coast stations may also use other procedures with automatic facilities based
16、 on DSC signalling format directly on VHF radiotelephone working channels. 2 Rec. ITU-R M.689-3 Annex 1 Operational procedures 1 Introduction These procedures are initiated by using DSC on the VHF calling channel and based on the technical characteristics and operational procedures detailed in Recom
17、mendations ITU-R M.493 and ITU-R M.541. Connection to the PSTN is effected using any appropriate VHF public correspondence working channel listed in RR Appendix 18 without in any way impairing their use for manual operation. Appendix 1 illustrates the timing of the call set-up, calling and acknowled
18、gement sequences described by these procedures in the ship-to-shore direction and in the shore-to-ship direction. 2 Operational procedures in the ship-to-shore direction 2.1 Ship station initiates call 2.1.1 The user aboard the ship (hereafter referred to as the user) composes the calling sequence (
19、see Note 1) on his DSC equipment as follows: selects the format specifier 123 (automatic/semi-automatic service); enters address (identification) of required VHF coast station; selects the category routine (100); (the ship station self-identification is entered automatically); selects first telecomm
20、and 101 (duplex F3E/G3E) or 100 (simplex F3E/G3E) or 106 (data) (see Note 2) and second telecommand as appropriate; inserts subscriber number required (e.g. telephone number); selects “end of sequence” signal “RQ”. NOTE 1 It is assumed that commercial equipment will be produced which simplifies the
21、composition of the calling sequence. In practice the user should only need to key the VHF coast station address and the required subscriber number, all other information being inserted automatically. NOTE 2 Duplex mode of operation should be used for data communications. 2.1.2 The user selects the V
22、HF DSC calling channel (channel 70 of RR Appendix 18) and initiates transmission of the sequence on the calling channel. In order to reduce the probability of call collisions, the DSC equipment should automatically inhibit transmission of this sequence until the calling channel is clear of any signa
23、l. 2.1.3 If the ship station does not receive an error-free acknowledgement from the called coast station (see 2.2) within 5 s, the calling sequence should be automatically repeated. If an error-free acknowledgement is still not received within a further 5 s, then any further repetitions should be e
24、ffected by manually initiating a new calling sequence. Such further repetitions to the same coast station should not, however, be initiated until at least 15 min have elapsed. Rec. ITU-R M.689-3 3 2.2 Coast station acknowledgement 2.2.1 The coast station should, within 3 s of receipt of the calling
25、sequence, initiate the transmission of an acknowledgement sequence on the DSC calling channel. The coast station equipment should also automatically inhibit transmission of the acknowledgement until the calling channel is clear. 2.2.2 If the coast station can comply immediately with the call request
26、, then it should immediately: radiate an “engaged channel” signal on the coast station transmit frequency of the appropriate working channel; transmit the acknowledgement sequence which should contain the same information as in the call request with the following exceptions: the address will be that
27、 of the ship; the self-identification will be that of the coast station; the working channel number will be included; the “end of sequence” signal will be “BQ”. 2.2.3 If the coast station cannot comply immediately with the call request due to the appropriate working channel(s) being busy, then the a
28、cknowledgement sequence should be as in 2.2.2 except that the first telecommand will be 104 (unable to comply) and the second telecommand will be 103 (queue) if the optional ring-back procedure is applied, else 102 (busy) and three symbols No. 126 should be included in the channel information field.
29、 2.2.4 If the coast station cannot comply for other reasons, the acknowledgement sequence should be as in 2.2.3, except that the second telecommand signal should be one of symbol numbers 100-109 as appropriate. 2.2.5 The ship station, on receipt of an error-free acknowledgement in accordance with 2.
30、2.2 (ability to comply), should, within 5 s of receipt, change to the working channel indicated in the acknowledgement and transmit, on that working channel, a carrier for a minimum period of 2 s. Fully automated ship station equipment should, within that transmission, transmit a DSC call which is i
31、dentical to the initial call (see 2.1.1) except that the “end of sequence” signal should be 127 (see Note 1). NOTE 1 In some regional applications, ships do not transmit DSC signals on the working channels. Equipment on ships sailing beyond these regional applications and participating in the automa
32、ted service, should be able to comply with the requirements for the fully automated service. 2.2.6 If the ship station receives an error-free acknowledgement in accordance with 2.2.3 indicating “unable to comply queue” then, if the user still requires the call connection, the ship station should con
33、tinue to monitor the DSC calling channel for any calls from the coast station. 2.2.7 The ship station, on receipt of an acknowledgement indicating “unable to comply” in accordance with 2.2.4 (or, if the coast station does not operate the “ring-back” procedure ( 2.3.2), in accordance with 2.2.3), sho
34、uld, if an automatic connection is still required, initiate an appropriate new call in accordance with 2.1. 2.2.8 If the coast station transmitted an acknowledgement indicating “unable to comply” in accordance with 2.2.4 (or, if the coast station does not operate the “ring-back” procedure ( 2.3.2),
35、in accordance with 2.2.3), then it should take no further action with respect to the call request. 4 Rec. ITU-R M.689-3 2.3 Procedures subsequent to the exchange of initial DSC calls 2.3.1 Mandatory procedure 2.3.1.1 If the coast station transmitted an acknowledgement indicating “able to comply” ( 2
36、.2.2) then, if a DSC call ( 2.2.5) containing the same self-identification as that of the calling ship is detected on the coast station receive frequency of the working channel, the coast station should immediately start to dial the required subscriber number (see Note 1, 2.3.1.2). 2.3.1.2 If a furt
37、her call identical to the original calling sequence is received from the ship station within 16 s of receipt of the original calling sequence (see 2.1.1) then the coast station should repeat the acknowledgement ( 2.2.2). If a DSC call in accordance with 2.3.1.1 (Note 1) is not detected within this 1
38、6 s period then the coast station should remove the “engaged channel” signal. NOTE 1 Some coast stations detect only the presence of a carrier at this stage. In areas of high-traffic density, carrier detection may not ensure that the calling ship has transferred to the working channel and should be
39、avoided where practicable. 2.3.2 Optional “ring-back” procedure The following additional sequence will tend to reduce repetitive ship calling and provide a better service to the ship: 2.3.2.1 If the coast station transmitted an “unable to comply queue” acknowledgement (see 2.2.3) then the ships iden
40、tification and required subscriber number should be stored until an appropriate working channel becomes available. This information should be retained for a period of 15 min. 2.3.2.2 If an appropriate working channel becomes available within the 15 min period, the coast station should immediately ra
41、diate an “engaged channel” signal on the coast station transmit frequency of that working channel and initiate a DSC call on the DSC calling channel to the ship station with the same format as the acknowledgement (see 2.2.2) except that the “end of sequence” should be “RQ”. If no appropriate working
42、 channel becomes available within this 15 min period then the information should be cleared and no further action taken by the coast station. 2.3.2.3 If an acknowledgement of the above call is not received from the ship station (see 2.3.2.4) within 5 s then the coast station should repeat the call.
43、If there is no acknowledgement to this second call then the ships call details should be cleared and the “engaged channel” signal removed. 2.3.2.4 The ship station, on receipt of such a calling sequence ( 2.3.2.2) should, if the call connection is still required, automatically initiate an acknowledg
44、ement within 2 s on the calling channel (the acknowledgement being transmitted only when the channel is clear). This acknowledgement should be identical to the received calling sequence except that the address should be that of the coast station, the self-identification should be that of the ship st
45、ation and the “end of sequence” should be “BQ”. 2.3.2.5 The ship station should then continue to listen to the calling channel for a further 5 s, then change to the working channel and transmit a carrier and DSC call as described in 2.2.5. If a further calling sequence is received within this 5 s pe
46、riod, the acknowledgement should be repeated. 2.3.2.6 The coast station, after receipt of an acknowledgement from the ship station, should, when a DSC call in accordance with 2.3.1.1 (see Note 1, 2.3.1.2) is detected on this working channel, immediately start to dial the subscriber number. 2.3.2.7 I
47、f, after a period of 15 min a ship has not received a call as indicated in 2.3.2.2 then, if the call connection is still required, a new call should be manually initiated in accordance with 2.1.1. Rec. ITU-R M.689-3 5 2.4 Call connection 2.4.1 Once the coast station begins dialling the subscriber nu
48、mber it should connect the line circuit to the radio path. Timing of the call for billing purposes should commence after the subscriber answers, i.e. “off-hook” condition detected. The call connection is now retained and the user should commence communication as soon as the subscriber answers. For a
49、 ship working on a duplex basis (see Note 1) the carrier must be transmitted for the total duration of the call. For a ship not working on a duplex basis the carrier must be activated at least once every 45 s. Such activation, when it does not occur naturally (due to the ship transmitting) should preferably be automatic. If automatic activation is not provided then means could be provided to timely alert the user that carrier activation is necessary. NOTE 1 Ships capable of working duplex but usin
