1、STD-ITU-R RECMN M-825-3-ENGL 1778 4855212 0535Lb7 lO9 Rec. ITU-R M.825-3 1 RECOMMENDATION ITU-R M.825-3* CHARACTERISTICS OF A TRANSPONDER SYSTEM USING DIGITAL, SELECTIVE CALLING TECHNIQUES FOR USE WITH VESSEL TRAFFIC SERVICES AND SHIP-TO-SHIP IDENTIFICATION (Question ITU-R 2818) (1992-1995-1997-1998
2、) Summary Several administrations have requirements for a radio transponder system for the purpose of obtaining information on ships entering and sailing within vessel traffic service (VTS) areas. In addition, there is a need for a system to provide ship-to-ship identification. This Recommendation c
3、ontains the characteristics of a system which uses digital selective-calling (DSC) techniques, suitable for both applications. The Recommendation is based upon Recommendation ITU-R M.493 and introduces a new message “category” for messages related to VTSs and ship-to-ship identification. It also des
4、cribes the format, composition and contents of such messages. This Recommendation for a transponder system is not intended to meet the requirements for a universal automatic identification system (AIS) which is under consideration in IMO. The ITU Radiocommunication Assembly, considering that the use
5、 of a transponder system would expedite the passing of data between a VTS centre and ships in its a service area; b) c) that several administrations have been developing different systems; that a transponder system should, as far as practicable, make use of existing equipment on board ships; that it
6、 is desirable that one transponder system for VTS purposes should fulfil the requirements of all that the digital selective-calling system having the technical and operational characteristics in accordance with administrations desiring to use it; e) Recommendations ITU-R M.493 and ITU-R M.541 has be
7、en recommended for use in the maritime mobile service; f) that some administrations are planning to make extensive use of transponders for tracking ships in high-traffic waterways and where radar may be unavailable, and for ship-to-ship identification, also outside VTS operating areas; g that some a
8、dministrations are requiring more types of data messages and more data capacity than can be afforded by DSC transmissions on VHF channel 70, but that they wish to use DSC as a common gateway to facilitate the use and implementation of automatic identification systems; h) that administrations plannin
9、g to use transponders for tracking ships in high-traffic waterways with VTS systems utilizing DSC require up to four ships position reports per second, recommends 1 that, where there is a need for a transponder system using digital selective calling techniques to be used in conjunction with a VTS, t
10、he system should be designed in accordance with the Characteristics given in Annex 1; 2 that, in areas where VHF channel 70 is used for public correspondence calling, channel 70 should not be used for vessel traffic services and ship-to-ship identification unless experience indicates that sufficient
11、 spare capacity is available, in accordance with Recommendation ITU-R M.822; * This Recommendation should be brought to the attention of the Intemational Maritime Organization (IMO) and the International Association of Lighthouse Authorities (IALA). COPYRIGHT International Telecommunications Union/I
12、TU RadiocommunicationsLicensed by Information Handling Services3 fiequencies; that Annex 1 may be used as a gateway to identify the transponder system and to assign its operating channel F G H I J K L M N O P Q R S T U 4 that the transponder should be interfaced with the ships systems as required to
13、 perform the intended operation; 32 33 34 35 36 37 38 39 40 41 5 Recommendation IT-R M.1084; that VHF transponders should be capable of operating on frequency channels in accordance with Annex 4 of 6 that, where there is a need when using DSC techniques for a higher update rate than can be achieved
14、by using the characteristics given Annex 1, then the system should be designed to include the additional characteristics given in Annex 2. ANNEX 1 Technical characteristics of a transponder system for use on maritime VHF channels for vessel traffic service purposes and ship-to-ship identification 1
15、General 1.1 Recommendation ITU-R M.493 describing the implementation of DSC in the maritime VHF environment. 1.2 the symbols No. O0 to No. 99 can also be used to represent alphanumeric data, as specified in Table 1. The transponder system is a synchronous system using the transmission techniques det
16、ailed in the sections of In addition to the definitions for the symbols No. O0 to No. 127 as defined in Recommendation ITU-R M.493, TABLE 1 Symbols used to denote alphanumeric data Symbol No. O0 o1 02 03 04 05 06 07 08 09 10 11 12 13 14 15 Character O 1 2 3 4 5 6 7 8 9 Not used A B C D E Symbol No.
17、i6 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 Character I SymbolNo. COPYRIGHT International Telecommunications Union/ITU RadiocommunicationsLicensed by Information Handling Services1.3 The equipment should automatically code and transmit a response to all calls received which contain the symbol No
18、. 117 (acknowledge RQ) as the “end of sequence” character. The automatic response to calls addressed to a “VTS area” should be transmitted after a random delay distributed over the range of O to 20 s providing the signalling channel is clear of other traffic. 2 2.1 The technical format of a transmis
19、sion sequence is identical to that described in Recommenda- tion ITU-R M.493. The construction of the transmission format is given in Table 2. Technical format of a transmission sequence TABLE 2 Format of a transmission sequence Dot pattern Rx7 Rx6 Rx5 Rx4 Rx3 Rx2 RXI RxO A A B1 Bn C Dl Dn El En F G
20、 Rx/DX : A: Bl-B,: C: D 1 -Dn: EI-E,: F: G: phasing sequence format specifier address category self-identification message end of sequence error-check character COPYRIGHT International Telecommunications Union/ITU RadiocommunicationsLicensed by Information Handling Services STD-ITU-R RECMN M.825-3-E
21、NGL 1778 4855212 053517ll 7T3 D 4 Rec. ITU-R M.825-3 2.2 A flow-chart illustrating the message composition is shown in Fig. 1. FIGURE 1 Message composition flow chart composition Format specifier i VTS area geographic coordinates t l t 1 Enter coordinates Category Self-identification Message End of
22、sequence Error-correction character self-identification self-identification Enter message content (broadcast) request? I I No i message a repiyNo I I to a request? I (Ship position t -m- EntzF / 1 Prm;sor 1 Entzm/ compiles reply 1 I 1 Processor 1 I addsend of sequence Processor adds acknowledge RQ P
23、rocessor adds acknowledge BQ II Processor adds acknowledge RQ Processor adds error-correction character I composed 682501 COPYRIGHT International Telecommunications Union/ITU RadiocommunicationsLicensed by Information Handling Services - STD-ITU-R RECMN M=825-3-ENGL 1998 II i855232 0535373 b3T M Rec
24、. ITU-R M.825-3 5 3 Dot pattern and phasing sequence 3.1 operation in the maritime VHF service. The dot pattern and phasing sequence used are formatted as described in Recommendation IT-R M.493 for 4 Format specifier 4.1 The format specifier signals are transmitted per definition in Recommendation I
25、TU-R M.493. The new format specifier (symbol No. 103) is utilized for all VTS DSC operations. The format specifiers relevant to VTS DSC operations are: 4.1.1 symbol No. 103 for a selective call to a group of ships in a specified VTS area; 4.1.2 symbol No. 120 for a selective call to a particular ind
26、ividual station; 4.1.3 symbol No. 116 for an “all ships” call to be used only for broadcast messages. 5 Addresses 5.1 is inserted in the address field following the methodology as described in Recommendation ITU-R M.493. For a selective call directed to an individual station, the maritime mobile ser
27、vice identity (MMSI) of the station 5.2 For a selective call directed to ships in a specified VTS area, a numerical geographic coordinated address consisting of 22 digits (i.e., 11 characters) is constructed. When all ships in the area are addressed, the coordinates shall follow immediately after th
28、e symbol No. 103. However, two characters indicating the course of the ships addressed or one character indicating that ships of a certain type are being addressed may optionally be inserted between the format symbol and the coordinates. 5.2.1 Ships on a certain course When it is required to address
29、 a ship in the defined area which is steering a particular course, the two characters (four digits) to be inserted between the format symbol and the coordinates shall be constructed as follows: - the first digit shall be the digit “4” to indicate that a course follows; - the second, third and fourth
30、 digits shall indicate the designated true course in degrees (from O00 to 359). All leading zeros must be used to “fill” the field; - for example, when addressing ships on a course of 040” true, the two characters inserted between the format specifier and the geographical address would be “40” and “
31、40”. If the course was 205 true, the two characters would be “42” and “05”; - shipborne equipment should be considered “addressed” when the ships heading differs by 2” or less from the course given in the DSC call. 5.2.2 Ships of a certain type When it is required to address all ships of a certain t
32、ype in the defined area, the single character (two digits) to be inserted between the format symbol and the geographic coordinates shall be the appropriate symbol derived from Table 3. The first digit shall be either “5”, “6”, Y“, “8, or “9, as defined in the table. COPYRIGHT International Telecommu
33、nications Union/ITU RadiocommunicationsLicensed by Information Handling ServicesSTD-ITU-R RECMN M-825-3-ENGL 1778 II 4855232 0535172 57b = Rec. ITU-R M.825-3 6 TABLE 3 Symbols to indicate the type of ship and for the address of calls to groups of ships in VTS areas Symbol No. 50 51 52 53 54 55 56 57
34、 58 59 Symbols to be used by ships to report their type and in the address of calls directed to a group of ships in a VTS area Special craft Pilot boats Search and rescue vessels Tugs Port tenders Vessels with anti-pollution facilities or equipment Law enforcement vessels spare -for assignment to lo
35、cal vessels spare -for assignmeni to local vessels Medical transports (as defined in 1949 Geneva Conventions and additional Protocols) Ships according to Resolution 18 (Mob-83) Other ships First digit 6 - Passenger ship(s) 7 - Cargo ship(s) 8 - Tanker(s) 9 - Other types of ships Second digit O - All
36、 ships of this type 1 - Carrying DG, HS or MP IMO hazard or pollutant category A 2 - Carrying DG, HS or MP IMO hazard or pollutant category B 3 - Carrying DG, HS or MP IMO hazard or pollutant category C 4 - Carrying DG, HS or MP IMO hazard or pollutant category D 5 - Not under command 6 - Restricted
37、 by her ability to manoeuvre 7 - Constrained by her draught 8 - Spare 9 - No additional information DG: dangerous goods HS: harmful substances MP: marine pollutants NOTE 1 -The symbol should be constructed by selecting the appropriate first and second digits. For example, a message addressed to “all
38、 tankers” would use symbol No. 80 while an identification report from a passenger ship containing no additional infomation would use symbol No. 69. For example, calls addressed to all pilot boats in a geographical area would insert the character “50” between the format specifier and geographical add
39、ress. Calls addressed to all tanker type ships constrained by draught would use the character “87”. COPYRIGHT International Telecommunications Union/ITU RadiocommunicationsLicensed by Information Handling Services STD-ITU-R RECMN M.825-3-ENGL 1778 = 4855232 0535373 402 m Rec. ITU-R M.825-3 7 5.2.3 T
40、he numerical geographic coordinate address The numerical geographic coordinate address shall be constructed as follows: - - the designated geographical area will be a rectangle in Mercator projection; the upper left hand (i.e., North-West) comer of the rectangle is the reference point for the area;
41、5.2.3.1 - - - - the first digit indicates the azimuth sector in which the reference point is located, as follows: quadrant NE is indicated by the digit “0”; quadrant NW is indicated by the digit “1”; quadrant SE is indicated by the digit “2”; quadrant SW is indicated by the digit “3”; 5.2.3.2 units,
42、 tenths and hundredths of minutes; 5.2.3.3 degrees and tens, units, tenths and hundredths of minutes; 5.2.3.4 units, tenths and hundredths of minutes; the second to the seventh digits indicate the latitude of the reference point in tens and units of degrees and tens, the eighth to the fourteenth dig
43、its indicate the longitude of the reference point in hundreds, tens and units of the fifteenth to the eighteenth digits indicate the vertical (i.e. North to South) side of the rectangle in tens, 5.2.3.5 tens, units, tenths and hundredths of minutes; the nineteenth to the twenty second digits indicat
44、e the horizontal (i.e. West to East) side of the rectangle in 5.2.4 point of 27” 40.30 N and 082 57.80 W, a vertical side of 06.00 and a horizontal side of 17.0 would be: for example, the characters necessaq to compose the geographical address defining an area with a reference 6 Category 6.1 indicat
45、e this purpose. This category definition is an addition to Recommendation ITU-R M.493. The category “information” indicates a safety call related to VTS operation. Symbol No. 103 is used to 7 Self-identification 7.1 self-identification. The MMSI assigned to the calling station, coded as indicated in
46、 Recommendation ITU-R M.493, is used for 8 Messages 8.1 The message included in a transmission sequence will comprise one or more, up to a maximum of 4, of the symbols given in Table 4. Certain symbols from Table 4 are followed by an appropriate symbol or symbols, from No. O0 to No. 99, constructed
47、as follows: 8.1.1 symbol No. 100 should be followed by twelve or thirteen symbols as follows: 8.1.1.1 - - - - the first digit indicates the azimuth sector in which the position is located, as follows: quadrant NE is indicated by the digit “O”; quadrant NW is indicated by the digit “1”; quadrant SE i
48、s indicated by the digit “2”; quadrant SW is indicated by the digit “3”; COPYRIGHT International Telecommunications Union/ITU RadiocommunicationsLicensed by Information Handling ServicesSTD-ITU-R RECMN M-825-3-ENGL 1998 4855212 0535174 347 = 8 Symbol No. 1 O0 101 102 103 104 105 106 107 108 109 110
49、111 112 113 1 i4 115 116 117 118 i 19 120 121 122 123 124 125 126 127 Rec. ITU-R M.825-3 TABLE 4 Symbols for message contents of VTS DSC calls Message 4y position is at time (followed by twelve or thirteen symbols) ,witch to VHC channel for subsequent VTS DSC communications (followed by one Leport your position now and at intervals of . minutes (followed by one symbol) Leport your position iTS expansion messages (see Table 5) ;hip is leaving berth or anchorage or entering the VTS teport next port of call ;hip is berthing, anchoring or
