Standard CBC Architecture / Topology – PWS Public Warning System

Cell Broadcast 2G, 3G, 4G and 5G


  • 3GPP TS 23.048, Security mechanisms for the (U)SIM application toolkit
  • 3GPP TR 22 968, Study for requirements for a PWS service
  • 3GPP TS 22 268, PWS Requirements
  • 3GPP TS 23.038, version 9.1.1 Alphabets and language-specific information
  • 3GPP TS 23 041, Technical realization of Cell Broadcast Service (CBS)
  • 3GPP TS 48 049, Base Station Controller – Cell Broadcast Centre (BSC-CBC)
  • 3GPP TS 25 419, 3G, UTRAN Iu-BC Interface: Service Area Broadcast Protocol
  • 3GPP TS 29 168, 4G, Cell Broadcast Centre interfaces with Evolved Packet Core
  • 3GPP TS 29.518, 5G, for AMF (5G) Access and Mobility Management Services
  • 3GPP TS 38.413, NG-RAN; NG Application Protocol (NGAP)

EU-ALERT and ETSI standards for PWS:

  • ETSI TS 102 182, Requirements for communications from authorities/organizations to individuals, groups or the general public during emergencies
  • ETSI TS 102 900, EU-Alert using the Cell Broadcast Service
  • ETSI TR 102 850, Analyses of Mobile Device Functionality for PWS
  • ETSI TR 103 582, Study of use cases and communications involving IoT devices in provision of emergency situations

Commercial Mobile Alert System (CMAS) standards:

  • ATIS 0700006, WEA 3.0 via GSM/UMTS Cell Broadcast Service Specification
  • ATIS 0700010, WEA 3.0 via EPS Public Warning System Specification
  • ATIS-0700013, Mobile Device Support of Multi-Language CMAS
  • ATIS 0700008, CBE-to-CBC Interface Specification (note: does not apply to WEA 3.0)
  • ATIS 0700025, WEA International Roaming Specification
  • ATIS 0700036, WEA 3.0 Mobile Device Behavior (MDB) Specification
  • ATIS 0700037, WEA 3.0 Federal Alert Gateway to CMSP Gateway Interface Specification
  • ATIS 0700038, WEA 3.0 Federal Alert Gateway to CMSP Gateway Interface Test Specification
  • ATIS-0700041, WEA 3.0 Device-Based Geo-Fencing
  • ATIS-0700043, WEA 3.0 via 5G Public Warning System Specification


2G – System Information Type 4 CBCH

Cell Broadcast 3G – SIB 5 CTCH = True

4G – SIB 10, 11 (ETWS) and 12 (CMAS)

5G – SIB6, SIB7 (ETWS) and SIB8 (CMAS)

Centralized Topology Cell Broadcast

Distributed Topology Cell Broadcast

Cell Broadcast (Extreme Emergency Warning Alerts) – Saudi Arabia


Hong Kong implements cell broadcast alert system

The Hong Kong government launched an emergency alert system (EAS) allowing it to send real-time messages to mobile subscribers during situations including extreme weather conditions or major public safety incidents.

In a statement, the Office of the Communications Authority (OFCA) said government departments can disseminate messages using the system to advise people to take contingency measures.

Messages can be classified as either emergency or extreme emergency depending on the severity of the incident.

OFCA said handset suppliers are gradually releasing updates of firmware or operating systems for various models to support the EAS, which uses cell broadcast technology.

A government representative recommended users download and install updates when available.

The agency noted subscribers will not be charged for receiving EAS messages and no personal data will be shared.

It added other channels including radio, TV and social media will continue to be used to send important information to the public, alongside the new EAS system.


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);