SOP11-Narrowband Emergency Messaging System (NBEMS)

Introduction
NBEMS is a non-infrastructure dependent digital messaging system that is suitable for passing short text and data spreadsheets
messages between two or more amateur radio stations using audio tones. It can be applied to short range, VHF & UHF radio circuits, as well as HF NVIS and HF long haul circuits. Experience
has shown that it will work over analog FM voice repeater
systems.