2G

For other uses, see 2G (disambiguation).

2G (or 2-G) is short for second-generation wireless telephone technology. Second generation 2G cellular telecom networks were commercially launched on the GSM standard in Finland by Radiolinja (now part of Elisa Oyj) in 1991.[1] Three primary benefits of 2G networks over their predecessors were that phone conversations were digitally encrypted; 2G systems were significantly more efficient on the spectrum allowing for far greater mobile phone penetration levels; and 2G introduced data services for mobile, starting with SMS text messages. 2G technologies enabled the various mobile phone networks to provide the services such as text messages, picture messages and MMS (multi media messages). All text messages sent over 2G are digitally encrypted, allowing for the transfer of data in such a way that only the intended receiver can receive and read it.

After 2G was launched, the previous mobile telephone systems were retroactively dubbed 1G. While radio signals on 1G networks are analog, radio signals on 2G networks are digital. Both systems use digital signaling to connect the radio towers (which listen to the handsets) to the rest of the telephone system.

2G has been superseded by newer technologies such as 2.5G, 2.75G, 3G, and 4G; however, 2G networks are still used in most parts of the world.

2G Technologies

2G technologies can be divided into Time Division Multiple Access (TDMA)-based and Code Division Multiple Access (CDMA)-based standards depending on the type of multiplexing used. The main 2G standards are:

2G services are frequently referred as Personal Communications Service, or PCS, in the United States.

Capacities, advantages, and disadvantages

Capacity

Using digital signals between the handsets and the towers increases system capacity in two key ways:

2G Data Transmission Capacity:[3]

Disadvantages

Advantage

Evolution

2G networks were built mainly for voice services and slow data transmission (defined in IMT-2000 specification documents), but are considered by the general public to be 2.5G or 2.75G services because they are several times slower than present-day 3G service.

2.5G (GPRS)

2.5G ("second and a half generation") is used to describe 2G-systems that have implemented a packet-switched domain in addition to the circuit-switched domain. It does not necessarily provide faster services because bundling of timeslots is used for circuit-switched data services (HSCSD) as well. The first major step in the evolution of GSM networks to 3G occurred with the introduction of General Packet Radio Service (GPRS). CDMA2000 networks similarly evolved through the introduction of 2.5G. Its approach centred on the use of packet data. Up until this time all circuits had been dedicated to a given user in an approach known as circuit switched, i.e. where a complete circuit is switched for a given user. This was inefficient when a channel was only carrying data for a small percentage of the time. The new packet switched approach routed individual packets of data from the transmitter to the receiver allowing the same circuit to be used by different users. This enabled circuits to be used more efficiently and charges to be metered according to the data transferred.

2.75G (EDGE)

GPRS networks evolved to EDGE networks with the introduction of 8PSK encoding, Whilst the symbol rate remained the same at 270.833 samples per second, each symbol carried three bits instead of one. Enhanced Data rates for GSM Evolution (EDGE), Enhanced GPRS (EGPRS), or IMT Single Carrier (IMT-SC) is a backward-compatible digital mobile phone technology that allows improved data transmission rates, as an extension on top of standard GSM. EDGE was deployed on GSM networks beginning in 2003—initially by AT&T in the United States.

EDGE is standardized by 3GPP as part of the GSM family and it is an upgrade that provides a potential three-fold increase in capacity of GSM/GPRS networks.The 2G digital service provided very useful features, such as caller ID, call forwarding and short messaging.

2G shutdown

Australia

Telstra announced that they will shut down their GSM network by the end of 2016.[4]

Optus announced that they will shut down their GSM network in April 2017.[5]

Canada

Rogers is the only provider still having 2G network.

Singapore

The NEA which is the national authority for radiation protection in Singapore, only requires to comply with the World Health Organisation recommendation,[6] compared to bigger markets, where the statutory requirements have 10 times stricter exposure limits even with more topography challenges.[7]

Singtel, M1 and StarHub will cease 2G services effective 1 April 2017[8] [9] .[10]

Switzerland

Telecommunications in Switzerland is mainly operated by state-owned Swisscom, and the two privately held Salt and Sunrise as these companies have a license to operate 2G.

Swisscom will cease 2G services due to its "public service requirements" only by 1 January 2021.[11]

United States

Various carriers such as AT&T have made announcements that 2G GSM technology in the United States is in the process of being shut down so that carriers can reclaim those radio bands and re-purpose them for future technology needs. The shut down will be complete by the end of 2016. All 2G GSM devices will lose service at some point between now and the end of 2016.[12] However, T-Mobile has no plan of shutting down their 2G network.

This shut down is having a notable impact on the electronic security industry where many 2G GSM radios are in use for alarm signal communication to Central Station dispatch centers. 2G GSM radios must be replaced by newer generation radios to avoid service outages.[13]

See also

References

Preceded by
1st Generation (1G)		 Mobile Telephony Generations Succeeded by
3rd Generation (3G)
This article is issued from Wikipedia - version of the Sunday, May 01, 2016. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.