Earlier cell phones operating without a cellular network, the so-called 0G generation, such as Mobile Telephone Service, date back to 1946. In anticipation of the mid to late 1980s, most cell phones were sufficiently big that they were time and again permanently installed in vehicles as car phones. In the midst of the advance of miniaturization, at this time the vast majority of cell phones are handheld.
Features of a cell phone
In addition to the usual voice function of a telephone, a cell phone can hold up many additional services such as SMS for text messaging, packet switching for access to the Internet, and MMS for transferring and receiving photos and video. A number of the world's largest cell phone manufacturers consist of
Panasonic (Matsushita Electric)
and a lot more.....
There are in addition specialist communications systems related to, but separate from cell phones, such as Professional Mobile Radio. Mobile phones are also distinct from cordless telephones, which in general operate only within a limited range of a specific base station. Technically, the term cell phone includes such devices as satellite phones and pre-cellular mobile phones such as those operating via MTS that do not have a cellular network, while the related term cell(ular) phone does not. In actual fact, the two terms are used almost interchangeably, with the favored term varying by location.
Technology on which cell phone works
Cell phones and the network they function under vary a lot from provider to provider, and even from nation to nation. On the other hand, all of them communicate through electromagnetic radio waves with a cell site or base station, the antennas of which are by and large mounted on a tower, pole, or building. The cell phones have a low power transceiver so as to transmit voice and data to the nearby cell sites, usually 5 to 8 miles away.
When the cellular phone or data device is turned on, it registers with the mobile telephone exchange, or switch, with its only one of its kind identifiers, and will then be alerted by the mobile switch as soon as there is an incoming telephone call. The handset continuously listens for the strongest signal being received from the neighboring base stations. As the user moves in the region of the network, the mobile device will hand off to new cell sites.
Cell sites have comparatively low power (habitually only one or two Watts) radio transmitters, which broadcast their being there and relay communications involving the mobile handsets and the switch. The switch in turn connects the call to a different subscriber of the same wireless service provider or to the public telephone network, which includes the networks of other wireless carriers. The conversation between the handset and the cell site is a stream of digital data that includes digitized audio (except for the first generation analog networks).
The technology or the know-how that achieves this depends on the system that the cell phone operator has adopted. A number of technologies include AMPS for analog, and TDMA, CDMA, GSM, GPRS, EV-DO, and UMTS for digital communications.
Barbara Rittner is a wireless communications technology expert. She frequently regsiters her views on http://phones.blogtastic.com