Draft Details

The present document states the minimum requirements for equipment to be used for generation, transmission and 
reception of Digital Selective Calling (DSC) for use on board ships. DSC is intended to be used in the Medium 
Frequency (MF), High Frequency (HF) and Very High Frequency (VHF) bands of the Maritime Mobile Service 
(MMS), for distress, urgency and safety communication and general communications. 
The present document covers the requirements to be fulfilled by: 
• DSC equipment integrated with a transmitter and/or a receiver; 
• DSC equipment not integrated with a transmitter and/or a receiver. 
These requirements include the relevant provisions of the ITU Radio Regulations [i.4] and Recommendations 
ITU-R M.493-16 [2], M.541-11 [3], M.689-3 [4] and M.1082-1 [5], the International Convention for the Safety Of Life 
At Sea (SOLAS) [i.3], and the following resolutions/circulars of the International Maritime Organization (IMO): 
A.694(17) [14], MSC.511 (105) [15], MSC 512 (105) [16], MSC 302(87) [12] and MSC/Circ.862 [17]. 
Equipment for generation, transmission and reception of DSC designed according to the following equipment classes: 
• Class A: includes all the facilities defined in Annex 1 of Recommendation ITU-R M.493-16 [2] and complies 
Performance Standards MSC.511 (105) for VHF [15], MSC 512 (105) for MF and MF/HF equipment capable 
of voice and DSC [16]. 
• Class D: provides minimum facilities for VHF DSC distress, urgency and safety as well as routine calling and 
reception as recommended by IMO MSC.1/Circ.803 Rev.1 [i.2] for non-SOLAS vessels participating in the 
GMDSS and defined by Recommendation ITU-R M.493-16 [2]. 
• Class E: provides minimum facilities for MF and/or HF DSC distress, urgency and safety as well as routine 
calling and reception as recommended by IMO MSC.1/Circ.803 Rev.1 [i.2] for non-SOLAS vessels 
participating in the GMDSS and Recommendation ITU-R M.493-16 [2]. 
• Class H: provides minimum facilities for handheld VHF DSC distress, urgency and safety as well as routine 
calling and reception as recommended by IMO MSC.1/Circ.803 Rev.1 [i.2] for non-SOLAS vessels 
participating in the GMDSS and Recommendation ITU-R M.493-16 [2]. 
• Class M: provides minimum facilities for VHF Man Overboard devices as defined in Recommendations 
ITU-R M.493-16 [2] and ITU-R M.2135-1 [i.14]. 
NOTE 1: Class A equipment may support the optional semi-automatic/automatic service in accordance with 
Recommendations ITU-R M.689-3 [4], M.1082-1 [5] and M.493-16 [2], tables A1-4.10.1 and A1-4.10.2 
and are encouraged to do so. 
NOTE 2: Class D and Class E equipment may also support the optional semi-automatic/automatic service. 
NOTE 3:  Class D, Class E, Class H should provide a defined list of functions as a closed list for these classes of 
equipment is the preferable approach to ensure safe and simple operation. Optional functions should be 
avoided, with the intention to provide the same functionality of all equipment of one class.