Cell Broadcast (SMS-CB)

Cell Broadcast is a function of cellular networks like GSM, UMTS and CDMA2000 for the simultaneous delivery of messages to all mobile phones within a specified area. Whereas the Short Message Service (SMS) allows to deliver messages to one or more specified mobile telephones, Cell Broadcast allows to broadcast a message to all mobile phones within a specified area. The area can be as small as a single radio cell, as big as the entire network and any cluster of areas in between.

Cell Broadcast can be used to send text messages depending on the location. The message can be used to send information about emergency situations or localized news, such as severe weather and other alarm messages, local weather forecasts and local traffic information. Probably the best known service is the broadcast of cell information.

A Cell Broadcast message can be up to 1395 characters. Each message consists of 1 up to 15 pages. Each page can be up to 93 alphanumeric characters or 82 bytes of binary data in length.

Cell Broadcast provides for 65.536 (2¹⁶) broadcast channels. The channels above 999 have to be activated over-the-air (OTA) by the operator. Which gives the ability to start subscription based services. Other channels have to be activated on the handset. The cell information is in most networks on channel 50.

Cell Broadcasting is sometimes referred to as SMS-CB.