The first generation of mobile telephony (denoted 1G) Operated using analogue and that were relatively bulky devices. This was primarily the following standards:
- AMPS (Advanced Mobile Phone System), appeared in 1976 in the US, is the first standard cellular network. Used primarily across the Atlantic, Russia and Asia, the analog network of first generation had weak security mechanisms enabling the hacking of telephone lines.
- TACS (Total Access Communication System) is the European version of AMPS model. Using the 900 MHz frequency band, this system was particularly widely used in England, then in Asia (Hong Kong and Japan).
- ETACS- (Extended Total Access Communication System) is an enhanced version of TACS standard developed in the United Kingdom using a larger number of communication channels.
The first generation of cellular networks were made obsolete with the emergence of a second generation fully digital.
The second generation of mobile networks (denoted 2G) Was a break with the first generation of cell phones through the switchover from analogue to digital.
The main 2G mobile telephony standards are:
- GSM (Global System for Mobile communications), The most widely used standard in Europe at the end of the twentieth century, supported the United States. This standard uses the 900 MHz band and 1800 MHz in Europe. United States by cons, the frequency bands used are 850 MHz and 1900 MHz. So-called tri-band, mobile phones that can operate in Europe and the United States.
- CDMA (Code Division Multiple Access) Using a spread spectrum technique for broadcasting a radio signal over a wide frequency range.
- TDMA (Time Division Multiple Access), Using a temporal communication channels cutting technique to increase the volume of data transmitted simultaneously. TDMA is used primarily in the Americas, New Zealand and Asia Pacific.
Thanks to 2G networks, it is possible to transmit voice and digital data of small volume, including text messages (SMS, for Short Message Service) Or multimedia messages (MMS, for Multimedia Message Service). The GSM standard allows a maximum throughput of 9.6 kbps.
Extensions of the GSM standard has been developed to improve the flow. This is the case of the standard GPRS (General Packet Radio System), Which provides theoretical speeds of the order of 114 kbit / s, closer to 40 kbit / s in the reality. This technology does not fall within the scope of the term "3G" was christened 2.5G
Standard EDGE (Enhanced Data Rates for Global Evolution, presented as
2.75G quadruple the throughput improvements GPRS announcing a theoretical speed of 384 Kbps, thus opening the door to multimedia applications. Actually EDGE achieves maximum theoretical speeds of 473 kbit / s, but it was limited to conform to IMT-2000 specifications (International Mobile Telecommunications-2000) Of the ITU ( International Telecommunications Union).
IMT-2000 specifications (International Mobile Telecommunications for the year 2000) Of the International Union of Communications (ITU) define the characteristics of the 3G (Third generation mobile phone). These features include the following:
- a high transmission rate:
- 144 Kbps with total coverage for mobile use,
- 384 Kbps with medium coverage for pedestrian use,
- 2 Mbps with a reduced coverage area for stationary use.
- worldwide compatibility,
- compatible mobile 3rd generation with the second-generation networks,
3G proposes to achieve data rates exceeding 144 kbit / s, opening the door to multimedia uses such as video transmission, video conferencing or access to broadband internet. 3G networks use different frequency bands of the previous networks: 1885-2025 MHz and 2110-2200 MHz.
The main 3G standard used in Europe is called UMTS (Universal Mobile Telecommunications System) Using a coding W-CDMA (Wideband Code Division Multiple Access). UMTS uses the 5 MHz frequency band for the transfer of voice and data with data rates ranging from 384 kbps to 2 Mbps. Technology HSDPA (High-Speed Downlink Packet Access) Is a third generation mobile telephony protocol called "3.5G" to achieve the order of rates from 8 10 Mbit / s. HSDPA uses the frequency band of 5 GHz and uses the W-CDMA coding.
4G4G is the next generation of PBX, being expanded around the world, including in France where it is currently available only in a few large cities. So that within the 3G network, Internet data and telephone conversations were separated, then the rate to be shared between connected users, 4G brings together all of this data. This ensures a better data transfer.
Flow rates range from 100Mb / s to 1Gb / s. The 4G wireless network can therefore offer a much higher rate than the current optical fiber, at least in theory because in practice it is for now "than" from tens of Mb / s, that bandwidth is shared between users of the network in the same area.
In France, the 4G standard used is the LTE (Long Term Evolution) and uses the frequency bands of 2600 MHz and 800 MHz.
As with the transition from 2G to 3G, mobile devices must be adapted to the new generation 4G, which is already the case for many products that were put on the market recently. Indeed, whether mobile or smartphone key, their adaptation to new IPv6 protocols provided by the 4G connection is required. In turn, operators are gradually beginning to offer tailored packages.
(Thanks to liveboox52 for adding paragraph 4G.)
|GSM||2G||Allows transfer of voice or digital data of small volume.||9.6 kpbs||9.6 kpbs|
|GPRS||2.5G||Allows transfer of voice or digital data moderate volume.||21.4 to 171.2 kbps||48 kpbs|
|EDGE||2.75G||Allows simultaneous transfer of voice and digital data.||43.2 to 345.6 kbps||171 kbps|
|UMTS||3G||Allows simultaneous transfer of voice and digital data at high speed.||0144-2 Mbps||384 Kbps|
|LTE||4G||Allows simultaneous transfer of voice and digital data at high speed.||10-300 Mbps||5-75 Mbps|
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