From the heavy cordless phones of the 1980′s to the smart phones of today, cellular phone technology has undergone a incredible change. But have you ever wondered how you can call to your well wisher in the whole world with the usage of a mobile phone? You also have knowledge about the main features such as WAP and GPRS from the cell phone vendors and service providers. But you must aware of what they really mean?
There are numerous mobile technologies. So next time, when you are going to purchase a phone, you should know what technologies it has.
Generations of mobile communications
In the late 1970s, the first generation (1G) of mobile communications was introduced; it was primarily used for voice transfer. Second generation (2G) systems came into existence in the early 1990s and was further developed to 2.5G, which includes high technologies such as TDMA, GSM and CDMA. These technologies were used for voice and data.
The next generation of mobile communications is 3G which delivers data speeds from 384 kbps to 2 Mbps and over wireless interfaces such as GSM, TDMA and CDMA.
Mobile phone access technologies
Frequency division multiple access (FDMA)
The first-generation analog mobile access method; for each call, FDMA uses separate frequencies. For instance, if there are four stations, each will receive their own frequency. So there is no interference between them. It reduces interference, but limits the number of users.
Time division multiple access (TDMA)
TDMA allocates unique time slots to each user within each channel, thus allowing many users to access the radio frequency without anyone’s interference. Each mobile conversation uses only a particular frequency slot of the time.