Abstract: Cell Broadcast is the most effective technology of delivering public warning alerts in emergency situation.It has the characteristics of wide audience, realtime, location-specific even under congestion situation to solve the bottleneck of last mile for warning alert transmission. This paper introduces the status quo of public warning system based on cell broadcast, the advantages and main architecure of cell braodcast service, and its standardization progress worldwide.

Key words: public warning system, cell braodcast service, security mechanism