GB/T 20068-2025Technical requirements of shipborne automatic identification system (AIS) (English PDF)

Foreword

This document complies with the provisions of GB/T 1.1-2020 "Standardization Work Guidelines Part 1: Structure and Drafting Rules of Standardization Documents".

Drafting.

This document supersedes GB/T 20068-2017 "Technical Requirements for Shipborne Automatic Identification Systems (AIS)" and is consistent with GB/T 20068-2017.

Compared to previous versions, aside from structural adjustments and editorial changes, the main technical changes are as follows.

a) The content regarding "AIS-restricted base stations" has been removed (see section 4.2.1.3 in the 2017 version);

b) Added content on "AIS Receiving Station" (see 4.2.1.3);

c) The requirement in the AIS search and rescue transmitter that "AIS-SART stations should use pulse transmission messages 1 and 14" has been changed, and the following changes have been made.

The definition of "pulse" (see 4.2.1.6, 11.1, 11.5; 4.2.1.6, 12.1, 12.5 in the 2017 edition);

d) Added "Personnel Search and Rescue Beacon - AIS Component (AIS-MOB)" and "Emergency Radio Position Beacon - AIS Component (EPIRB-AIS)".

The provisions (see 4.2.1.7, 4.2.1.8);

e) The definition of AIS stations has been changed (see 4.4.1, 2017 version 4.4.1);

f) The wording of "signal station" has been changed to "time base" (see 4.4.3, 5.5.1.4, and 4.4.3 in the 2017 version).

5.5.1.4);

g) Added provisions for "long-distance broadcast messages" (see 4.4.3, 6.2.3.1, 6.2.3.3, 6.2.3.4, and 10.2.3);

h) The regulations for "reporting intervals for non-Category A vessels" have been amended (see 4.4.3, 2017 version of 4.4.3);

i) Added provisions for a "dedicated long-distance AIS channel" (see 4.5, 5.4.2.2, 5.4.2.3, 5.4.2.6.1, 5.6.1.4, 6.2.3.1,...).

6.2.3.3, 6.2.3.5);

j) Added some provisions for "Type B 'SO'" (see 5.3.4.1, 5.5.1.4.3.3, 5.6.2, 5.6.1.1.3.3, 6.2.2, 10.2.5, 10.2.7,...

10.2.11, 10.2.13, 10.2.22);

k) Added some provisions to "Message 22" (see 5.4.2.2, 5.4.6, 5.6.1.3);

l) DSC-related content has been removed (see sections 5.4.2.2, 5.4.2.5, 5.4.2.7, 5.4.2.9, 5.6.1.3, and Chapter 6 of the 2017 version).

10.3.1, 10.3.2, 10.3.5.4, 10.4.1.2.1, 10.4.1.2.7, 10.4.3.2, 10.4.3.3, 10.4.5, 11.3.17);

m) The provision regarding "buffer areas" has been removed (see 5.4.2.6.2 in the 2017 version);

n) The relevant provisions regarding the "storage time of channel management command actions" have been changed (see 5.4.2.9, 2017 version 5.4.2.9);

o) Changed the station requirement for "in assignment mode, when the required RI for a heading change is shorter than the assigned RI".

(See 5.4.4.2.2, 2017 version 5.4.4.2.2);

p) The description of time slot classification in "Active Multiplexing of Time Slots by This Station" has been revised (see 5.4.5.1, 5.4.5.2 in the 2017 version);

q) The provision regarding "duplex transponders" has been removed (see 5.4.7.3 in the 2017 version);

r) Modified the content related to "Synchronization with base station and synchronization with mobile station" (see 5.5.1.2.4, 5.5.1.2.5, and 5.5.1.2.4 in the 2017 version).

5.5.1.2.5);

t) The specification in "Distance Delay" has been changed (see 5.5.2.2.9, 5.5.2.2.9.3 in the 2017 version);

u) The "Twister Delay" section has been removed (see version 5.5.2.2.9.4 in 2017).

v) The time position corresponding to 80% RF power in Figure 12 has been changed (see 5.5.2.2.10, 2017 version 5.5.2.2.10);

w) Added content on "MSSA Data Access Method" (see 5.5.3.1.1);

x) The application of ITDMA has been changed (see 5.5.3.4.1, version 5.5.3.4.2.1 of 2017);

y) The description of "LME.ITINC" in the ITDMA parameters has been changed (see 5.5.3.4.3, version 5.5.3.4.2.3 of 2017);

z) The content of "RATDMA" has been changed (see 5.5.3.5, version 5.5.3.4.3 of 2017);

aa) The content of "First Frame Phase" has been changed (see 5.5.3.8.3, version 5.5.3.5.3.6 of 2017);

ab) Added provisions for "extreme conditions" to the "Minimum Requirements for Transmitter Characteristics" (see 5.6.2, 9.4.1.3);

ac) The relevant provisions for physical layer "emission protection" have been changed (see 5.6.12, 2017 version of 5.6.12);

(ad) Added some provisions for messages 25 and 26 (see 7.1, 7.8.1, 10.2);

(ae) changed the relevant content for DAC (see 7.3, 8.3 in the 2017 version);

(af) Added the case where Class B "CS" AIS mobile stations send messages 18 and 24 (see 9.3.3);

(ag) Added a representation that allows Class B "CS" to provide information via message 24 (see 9.3.5.1.1);

(ah) The unit symbol for the "Modulation Mask" value in the "Minimum Requirements for CSTDMA Transmitters" has been changed from "dBW" to "dBc".

(See 9.4.1.3, 10.4.1.3 in the 2017 edition);

(AI) The unit of "Start Time" in the link layer "Power and Time Mask" diagram has been changed (see 9.4.2.2.5, 2017 version).

10.4.2.2.5);

aj) The description related to "specifying timeout value for messages" has been changed (see 9.4.2.2.6, version 10.4.2.2.6 in 2017).

(ak) The description related to "data transfer" has been changed (see 9.4.2.3.1, 10.4.2.3.1 in the 2017 version);

al) The "Figure 38 Synchronization Sequence NRZI Encoding Rule Diagram" has been modified (see 9.4.2.3.2, 10.4.2.3.3.5 in the 2017 version);

The regulations for Category B "CS" have been added (see 9.4.2.4.6, 10.2.5, and 10.2.24).

(a) The wording regarding "Message 20 specifies timeout value" in Class B "CS" has been changed (see 9.4.2.4.6, 10.4.2.4.6 in the 2017 version);

(ao) Some provisions concerning message 19 have been deleted (see 10.4.2.3.6, 10.4.2.4.3.4, and 11.2 in the 2017 version);

The requirement for "responding to base station queries in message 19" has been removed (see 10.4.2.4.6 in the 2017 version).

aq) Added message 23, which states that "it should be determined whether the 120 nautical mile rule is met based on the received message 4" (see 9.4.2.4.6).

10.2.3, 10.2.21);

(ar) Modified the content of the Class B "CS" AIS transmission message (see 9.4.4.2, 10.4.4.2 in the 2017 version);

The specification for "maximum value of continuously occupied AIS time slots" has been added (see 10.2, 10.2.25);

(at) Added identifiers related to EPFS systems such as BeiDou in messages 4, 5, 19, 21, and 24 (see 10.2.3, 10.2.4, 10.2.18, 10.2.20, 10.2.23);

au) changed some provisions regarding message 24 (see 10.2.14, 10.2.23, and 11.3.14 and 11.3.23 in the 2017 version).

Please note that some content in this document may involve patents. The issuing organization of this document assumes no responsibility for identifying patents.

This document was proposed and is under the jurisdiction of the Ministry of Transport of the People's Republic of China.

1 Scope

This document specifies the technical requirements for the use of Time Division Multiple Access (TDMO) Automatic Identification Systems (AIS) on ships within the VHF maritime mobile frequency band, mainly including ship...

Operating characteristics, technical characteristics, long-range applications, special application messages, transmission packet sequencing, and adoption of CSTDMA technology in the Automatic Identification System (AIS) Requirements for Class B AIS, AIS messages, and AIS pulse transmitter stations.

This document applies to the design, production, use, and management of AIS-related equipment.

2 Normative references

The contents of the following documents, through normative references within the text, constitute essential provisions of this document. Dated citations are not included.

For references to documents, only the version corresponding to that date applies to this document; for undated references, the latest version (including all amendments) applies.

This document.

GB/T 7421 High-level data link control (HDLC) specification for remote communication and information exchange between information technology systems GB/T 16162 Global Maritime Distress and Safety System (GMDSS) Terminology JT/T 1276 Automatic Identification System (AIS) China Region Binary Information Technology Specification IEC 61162-1 Digital interfaces for marine navigation and radio communication equipment and systems – Part 1: Single transmitters and multiple receivers timemobileservice) ITU-R-RM.1084-5.2012 Provisional solution for improving the efficiency of site use in the 156MHz–174MHz band during maritime mobile services ITU-RM.1371-1 Technical characteristics of a universal shipborne automatic identification system using time division multiple access in the VHF maritime mobile band.

ITU-RM.1371-3 Technical characteristics of Automatic Identification Systems using Time Division Multiple Access in the VHF Maritime Mobile Band ITU-RM.1371-5 Technical characteristics of Automatic Identification Systems using Time Division Multiple Access in the VHF Maritime Mobile Band ITU-RRR (2024) Radio Regulations