This part of International Standard IEC 62287 specifies operational & performance requirements, methods of testing and required test results for Class B SO shipborne AIS equipment using Self-organised TDMA (SOTDMA) techniques as described in Recommendation ITU-R M.1371. This Standard takes into account other associated IEC International Standards and existing National Standards, as applicable. The main differences between Class B CS (IEC 62287-1) and Class B SO units are that the Class B SO : " covers all 25 kHz channels listed in Recommendation ITU-R M.1084-4 " only uses the internal GNSS, no position sensor input is allowed " uses VDL Message 17 for correction of the internal GNSS " has a presentation interface " has additional reporting intervals, down to 5 s " has two power settings, with a high level of 5 W " has the capability to transmit binary messages, VDL Messages 6 and 8 It is applicable for AIS equipment used on craft that are not covered by a mandatory carriage requirement of AIS under SOLAS Chapter V.