Digital Selective Calling - Broadcasting and receiving DSC Alerts is one of the major facilities on a VHF radio that is possible by VHF DSC controller. DSC alerts are used to “switch people on” to follow on with voice communication.
DTE, Data Terminal Equipment is an end instrument that converts user information into signals or reconverts received signals.
Duplex channels are normally only used for communication between vessels and CRS and for port operations and ship movement. With duplex channels our transmission can only be heard by the CRS. However, all ship stations listening to the same channel can hear the CRS transmission.