Cell Broadcast

Cell Broadcast (CB) is a method of simultaneously sending short messages to multiple mobile telephone users in a defined area.

Cell broadcast has been widely deployed since 2008 by major Asian, US, Canadian, South American and European network operators.

[1] Cell Broadcast is compliant with the latest EU General Data Protection Regulation (GDPR) as mobile phone numbers are not required by CB.

If the start-time is left open, the CBC system will assume an immediate start, which will be the case for Public Warning messages.

The BSC's/RNC's/MME/AMF responsibility is to deliver the CB messages to the base stations (BTSs), Node Bs, ENodeBs and gNodeBs which handle the requested cells.

Cell Broadcast is not affected by traffic load; therefore, it is very suitable during a disaster when load spikes of data (social media and mobile apps), regular SMS and voice calls usage (mass call events) tend to significantly congest mobile networks, as multiple events have shown.

The alert category or level is defined by the severity of the warning, e.g. threat to life, imminent danger or advisory message.

[10][8] Cell Broadcast messages can use a CAP (Common Alerting Protocol) message as an input as specified by OASIS (organization) or the Wireless Emergency Alerts (WEA) C-interface protocol, which has been specified jointly by the Alliance for Telecommunications Industry Solutions (ATIS) and the Telecommunications Industry Association (TIA).

[5][14] In case a national civil defence organisation is adopting one of the 3GPP's Public Warning System standards, PWS - also known as CMAS in North America, EU-Alert in Europe, LAT-Alert in South America, Earthquake and Tsunami Warning System in Japan, each subscriber in that country either making use of the home network or its roaming automatically makes use of the embedded Public warning Cell Broadcast feature present in every Android (operating system)[5] and iOS mobile device.

The following countries and regions have selected Cell Broadcast to use for their national public warning system but are currently in the process of implementing.