Type Description of Notice Advisory to BDS Users (NABU)
Notice Advisory to BDS Users (RNSS) are divided into three categories, namely planned operations, unplanned outages, and others.
Planned operations include orbital maneuvering (RNSS_SCH_ORBMNV), upgrade maintenance (RNSS_UPD_MTNC) and on-orbit maintenance (RNSS_SCH_MTNC), orbital maneuvering refers to the adjustment of satellite orbit parameters and attitude, etc., upgrade maintenance refers to software upgrade operations on satellites in orbit, and on-orbit maintenance refers to software and hardware maintenance work on satellites in orbit.
Unplanned outage (RNSS_UNSCH_UNUSABLE) indicate the system service does not meet the specification requirements due to unplanned reasons.
Other advisory include satellite commissioning (RNSS_SCH_COM) and satellite decommissioning (RNSS_SCH_DECOM). Satellite commission means that a new satellite officially joins the network to provide services after testing to meet the requirements, and satellite decommissioning refers to the ending of a satellite from service due to its lifespan or other reasons.