User's Manual

8
1.2 Class A vs. SOTDMA Class B vs. CSTDMA Class B
A brief comparison between class A and class B AIS is illustrated in the following table.
WideLink B600 is an SOTDMA class B AIS transponder.
Type of AIS
Class A AIS
Class B SOTDMA
Class B CSTDMA
Primary Access
Scheme
SOTDMA
(Self-organizing)
SOTDMA
(Self-organizing)
CSTDMA
(Carrier-Sense)
Standard
IEC 61993-2
IEC 62287-2
IEC 62287-1
Transmit Power
and range
12.5W
5W
2W
IMO Mandate
Mandatory for all
SOLAS vessels
No mandate
No mandate
Reporting rate
dynamic data
Highest (transmission
up to every 2 sec)
Higher (transmission
up to every 5 sec)
Low (transmission up
to every 30 sec)
AIS data
presented
Static, Dynamic,
Voyage
Static and Dynamic
data
Static and Dynamic
data
Applications
Commercial vessels,
fishing boats, working
boats, passenger
boats with more than
12 passengers
Smaller commercial,
fishing and work
boats, recreational
vessels
Recreational vessels
and small fishing
boats