This article is taken from here and translated directly using microsoft word 2007 since the original article is in french.
1 G
The first generation of mobile telephone (noted 1 G) had a functioning analog and consisted of relatively large appliances. It is mainly the following standards:
· ASDMS (Advanced Mobile Phone System),
appeared in 1976 in the United States, is the first cellular network standard. Used mainly across the Atlantic, Russia and Asia, this first generation analogue network possessed of low security mechanisms making it possible piracy lines. telephone
· TACS (Total Access Communication System)
is the European version of the ASD model. Using the 900 MHz frequency band, this system was especially widely used in England and then in Asia (Hong Kong and Japan).
· ETACS (Extended Total Access Communication System)
is an improved version of the TACS standard developed in the United Kingdom using a number more important channels of communication.
The first generation cellular networks were rendered obsolete with the emergence of a second generation fully digital.
2 G
The second generation of mobile networks (noted 2 G) marked a break with the first generation of cell phones with the transition from analog to digital.
The major 2 G mobile telephony standards are the following:
· GSM (Global System for Mobile communications),
the standard used in Europe at the end of the XXe century, supported in the United States. This standard uses the 900 MHz and 1800 MHz in Europe frequency bands. In the United States, by contrast, the used frequency band is the 1900 MHz band. Thus, called tri-band mobile phones that can operate in Europe and the United States.
· CDMA (Code Division Multiple Access),
using a technique of spread spectrum to broadcast a radio signal over a wide range of frequencies.
· TDMA (time Division Multiple Access),
using a technique of temporal cutting of communication channels, to increase the volume of data transmitted simultaneously. The TDMA technology is mainly used on the American continent, New Zealand and in Asia Pacific.
With 2 G networks, it is possible to transmit voice and digital data of low volume, for example text messages (SMS, for Short Message Service) or multimedia messages (MMS, for multimedia Message Service). The GSM standard allows a maximum flow rate of 9.6 kbps.
Extensions of the GSM standard have been developed to improve the flow. This is the case of the standard GPRS (general Packet Radio system), that allows to obtain theoretical flow of the order of 114 kbit/s, the nearest of 40 kbit/s in reality. This technology not returning not under the name "3 G" has been named 2. 5 G
The standard EDGE (enhanced Data Rates for Global evolution, presented as )
2. 75 G quadruple standard GPRS throughput improvements in announcing a theoretical rate of 384 Kbps, thus opening the door to multimedia applications. In reality the EDGE standard allows to achieve theoretical maximum flow of 473 Kbps, but it was limited to conform to the ITU IMT-2000 (International Mobile Telecommunications -2000) specifications ( International telecommunications Union).
2. 75 G quadruple standard GPRS throughput improvements in announcing a theoretical rate of 384 Kbps, thus opening the door to multimedia applications. In reality the EDGE standard allows to achieve theoretical maximum flow of 473 Kbps, but it was limited to conform to the ITU IMT-2000 (International Mobile Telecommunications -2000) specifications ( International telecommunications Union).
3 G
IMT-2000 specification (International Mobile Telecommunications for the year 2000) of the International Union of Communications (ITU), define the characteristics of the 3 G third-generation mobile telephony). These characteristics include the following:
· high-speed transmission:
· 144 Kbps with total for mobile use coverage
· 384 Kbps with coverage mean for pedestrian, use
· 2 Mbps with a zone of cover reduced for use fixed.
· world, compatibility
· compatibility of mobile services of 3rd generation with second generation networks
3 G offers to reach higher than 144 kbit/s rates, thus opening the door to multimedia applications such as video transmission, the visio-Conference or internet access broadband. 3 G networks use strips of different frequencies of previous networks: 1885-2025 MHz and 2110-2200 MHz.
The main standard 3 G used in Europe is called UMTS (Universal Mobile telecommunications system), using a coding W-cdma (wideband Code Division Multiple Access). The UMTS technology uses the frequency band 5 MHz for the transfer of voice and data with speeds ranging from 384 kbps to 2 Mbps. Technology HSDPA (high speed downlink Packet Access) is a third generation mobile telephony protocol called "3. 5 G" to achieve speeds of the order of 8 to 10 Mbps. HSDPA technology uses the 5 GHz frequency band and uses W-CDMA coding.
Summary table
Standard | Generation | Frequency band | Flow | |
2 G | Allows the transfer of voice or digital data of low volume. | 9.6 kpbs | 9.6 kpbs | |
GPRS | 2. 5 G | Allows the transfer of voice or digital data on moderate volume. | 21, 4-171, 2 kpbs | 48 kpbs |
EDGE | 2. 75 G | Allows simultaneous transfer of voice and digital data. | 43, 2-345, 6 kbps | 171 kbps |
UMTS | 3 G | Allows simultaneous transfer of voice and digital data throughput. | 0-144-2 Mbps | 384 Kbps |
