ETWS (Earthquake and Tsunami Warning System) – Japan – (Cell Broadcast)

ETWS is a kind of public warning system (PWS) to notify all the UEs in a specific area of emergency situation like Earthquake or Tsunami.

Currently one of the best notification solutions is ETWS for mobile users who are receiving pop-up messages on their phones’ screens.

Unique vibration for CB messages, Text-to-speech support Android for CB messages and maximum speed of dissemination (all citizens in 4-9 seconds).

Simultenous reception, will people in disaster area receive the alert message on the same moment.

For Cell Broadcast messages a Government can set up different channels for different types of alerts and a citizen can determine to subscribe to receive these alerts.

The cell broadcast service is mainly used to notify the subscribers about the disasters in GSM, WCDMA, LTE and 5G.

Following radio channels are used for broadcasting:

CBCH: Cell Broadcast Channel in GSM.
CTCH: Common Traffic Channel in WCDMA.

In LTE, the subscribers are notified with system information messages:

1 – Paging : ETWS Indication.

2 – SIB 10 : Primary Notification.

3 – SIB 11 : Second Notification.


SIB Type 12

EU-Alert (Europe);
KPAS (South Korea);

Countries with Cell Broadcast PWS (Public Warning System)

2009 – Japan
2009 – Sri Lanka
2012 – Netherlands
2012 – Lithuania
2012 – Turkey
2012 – Chile
2012 – USA
2014 – Taiwan
2014 – South Korea
2015 – Russia
2016 – Philippines
2016 – United Arabic Emirates
2017 – New Zealand
2018 – Romania
2018 – Canada
2018 – Oman
2019 – Greece
2020 – Peru
2020 – Hong Kong
2020 – To be revealed soon