Cell Broadcast

Cell Broadcast (CB) messaging is a mobile technology feature defined by the ETSI’s GSM committee and is part of the GSM standard. It is also known as Short Message Service - Cell Broadcast (SMS-CB). Cell Broadcast is designed for simultaneous delivery of messages to multiple users in a specified area. Whereas the Short Message Service - Point to Point (SMS-PP) is a one-to-one and one-to-a-few service, Cell Broadcast is a one-to-many geographically focused messaging service. Cell Broadcast messaging is also supported by UMTS, as defined by 3GPP.

Cell Broadcast messaging was technologically demonstrated in Paris for the first time in 1997. Some mobile operators use Cell Broadcast for communicating the area code of the antenna cell to the mobile user (via channel 050), for nationwide or citywide alerting, weather reports, mass messaging, location based news, etc. Not all operators have the Cell Broadcast messaging function activated in their network yet, and many handsets do not have the capability to support cell broadcast.

Cell Broadcast is a technology that allows a text or binary message to be defined and distributed to all mobile terminals connected to a set of cells. Whereas SMS messages are sent point-to-point, Cell Broadcast messages are sent point-to-area. This means that one Cell Broadcast message can reach a huge number of terminalsa at once. In other words, Cell Broadcast messages are directed to radio cells, rather than to a specific terminal. A Cell Broadcast message is an unconfirmed push service, meaning that the originator of the message does not know who has received the message, allowing for services based on anonymity. Mobile telephone user manuals describe how the user can switch the receiving of Cell Broadcast messages on or off.

Cell Broadcast messaging has a number of features that make it particularly appropriate for emergency purposes:

* It is not as affected by traffic load; therefore, it may be usable during a disaster when load spikes tend to crash networks, as the 7 July 2005 London bombings showed. Another example was during the Tsunami catastrophe in Asia. Dialog GSM, an operator in Sri Lanka was able to provide ongoing emergency information to its subscribers, to warn of incoming waves, to give news updates, to direct people to supply and distribution centres, and even to arrange donation collections using Celltick's Cell Broadcast Center, based on Cell Broadcast Technology.

Cell broadcast is widely deployed since year 2008. In Europe, most handsets do have cell broadcast capability, and the major European operators have deployed the technology in their networks.

Cell Broadcast is a mobile technology that allows messages (up to 15 pages of up to 93 characters) to be broadcast to all mobile handsets and similar devices within a designated geographical area. The broadcast range can be varied, from a single cell to the entire network.

Technology

Cell Broadcast Entities (CBE) are connected to the Cell Broadcast Centre. Cell Broadcast messages are then sent from the Cell Broadcast Centres to the cells, in accordance with the CBC's coverage requirements. Advanced infrastructures make use of GIS-based interfaces for definition of the used areas.

A Cell Broadcast message page comprises 82 octets, which, using the default character set, equates to 93 characters. Up to 15 of these pages may be concatenated to form a Cell Broadcast message. Each page of such a CB message will have the same message identifier (indicating the source of the message), and the same serial number. Using this information, the mobile telephone is able to identify and ignore broadcasts of already received messages.

Cell Broadcast doesn't use the frequency space reserved for call setup, calls and data but a separate specially defined area. This area is divided into 65,000 channels, the channels from 0 to 999 can be switched on by the terminal user, from 999 to 65,000 can only be switched on via OTA (over-the-air activation) but all channels can be switched off by the user. Cell Broadcast will be more useful when it keep continuing from 2G network to 3G network and future technology with some sound which can alert the user in case of an emergency rather than just broadcast message which will be more meaningful.

Broadcast messages will be used in the United States to send emergency alerts, using the CMAS C-interface protocol, which has been specified jointly by ATIS and TIA. All four major providers have agreed to take part.

SMS Cell Broadcast

SMS Cell Broadcast is designed for simultaneous delivery of messages to multiple users in a specified area. Whereas the Short Message Service (SMS) is a one-to-one and one-to-a-few service, Cell Broadcast is one-to-many geographically focused service. It enables messages to be communicated to multiple mobile phone customers who are located within a given part of its network coverage area at the time the message is broadcast. Cell Broadcast is more akin to other mass distribution media such as teletext or Radio Data System (RDS).

SMS Cell Broadcast is defined within Phase 2 of the GSM standard in GSM 03.49. Cell Broadcast has some similarities with SMS since both services use the GSM network's signaling path. A (Each) Cell Broadcast message may be from 1 to 15 pages in length. Each page can be up to 93 alphanumeric characters or 82 octets of binary data in length. Additionally, up to 15 Cell Broadcast messages can be concatenated. Cell Broadcast messages are transmitted to the applicable Base Station Controllers (BSCs) for subsequent broadcast. The Message Destination is described in terms of cell identifiers which the BSC uses to route the message content to Base Transceiver Station Cells. Messages are broadcast for a user defined number of broadcasts with a user specified broadcast repetition rate. Cell Broadcast messages may be updated or removed from the BSC and subsequent BTS/ Cells anytime during the message broadcast period. (The BTSs are selected to determine the area over which the message is broadcast).

On Cell Broadcast the GSM operators send different news or data. Often they offer business news, weather forcast and so one. The German GSM operator Mannesmann D2 offers a way to build your own Cell Broadcast channel. The costs of that service will be charged to the owner of the service, to the user of that service or the costs can be shared.

The potential of Cell Broadcast technology

The ability to broadcast messages has been around since the GSM Phase 2 Technology Specification was introduced in 1995. However, only in the last few years have network operators, started to deploy cell broadcast-based services.

Why did they take so long? The answer is simple: business managers at wireless operators did not think they could generate a profit with a one-directional, subscriptionless broadcast service. However, it is now clear that cell broadcast is a useful service with profit potential that enables operators to provide broadcast information to specifically targeted subgroups of their subscriber base.

In today's handsets, selecting a channel can be a tedious task. Another helpful GSM feature is "Over the Air programming of the SIM card." Potentially, subscribers could select their preferred channels on the carrier's Web site and have them downloaded onto the SIM card in their handsets via this technology (under full control of the carrier).

Cell broadcast technology is in an early adoption stage in North America. The technology is available, but work needs to be done to package it and offer it as a product to subscribers. For GSM network operators, it is a challenge to define services that will use the cell broadcast capability of their network. Currently a cell broadcast service is also being defined for CDMA. It is a matter of time before the first cell broadcast-based service will be launched in the U.S. This is yet another opportunity for GSM operators to differentiate themselves from PCS competitors.

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