In the world the mobile telephone connections are known from 20. gs. 80. middle years.
In Latvia the era of the mobile connections began in 1992. year, when in Latvia territory began to operate first the >>>sniedzejs<<< of favours of such kind Latvia mobile telephone. In its time there were accessible connections in the 1G NMT standard, what operated in 450 Mhz frequency. This network was unlocked in a 2002. year end. In 1995. year LMT inculcated GSM. In 1997. year began to operate a second operator – Baltkom GSM, which already from the beginning operated in the
GSM standard of the mobile connections.
The most popular standard of the mobile telephones in the world (and in Latvia) is GSM(Global System for Mobile communications).
The mobile telephone is wireless device voice and datu transmission in large distances. It is one from the kinds of wireless telephones. It leans on communications between a telephone and base station, which mutual finds relativi near (GSM not farther for 35km). That provide connections in a more spacious territory, utillizes a few bases the stations, what provides coverage in its >>>apkartne<<< (in a cage). From this reason, in a few speeches sometimes call the mobile telephones for the telephones of cages (English cell phone).
The mobile telephone is from such components:
*Radio (transmitter, receiver and aerial),
*Processor of signals (multiple access function -that a few users can operate in one frequency), forward error correction (additional dati, that in a second end it can correct notiekta size sending errors),
*Kodeks (analognumber and numberanalogy transformers (sound)), sound strengtheners, microphone and loud speaker,
*Battery (from where take electricity so all start going)
*Screen and buttons
*The central processor (user intefeiss screen and buttons, processor of signals guidance, also telephone connection with a computer)
In beginning with the mobile telephone it can only piezvanit and to get bells.
So still there is the main function. Later came klat can send and to get short
text statements (alike as in the system of pagers). In the GSM networks call them for
reports (SMS). Yet, the determinant of numbers has come klat the mobile telephones,
what shows a >>>zvanitaja<<< of the entering bell number. Availability of this function depends from an operator. (it is ordinary accessible).
It can connect many mobile telephones with a computer. This it can utillize:
*USB cable, a few variants are here possible:
*USB – copula port transition – from telephone >>>skatupunkta<<< does not differ from a copula cable connection, the unique difference is it, that in a computer a cable is stuck by USB port. Computer operating system this device identify as velvienu copula port,
*The infra-red port (IR). Here also there are two possibilities,
*Copula port emulation (Loose IRCOMM) – such same possibilities, as with a copula port cable, wires are not necessary only (but it is necessary a direct visibility),
*Loose – a more spacious support of protocols, from which most considerable there is IROBEX (OBEX through infra-red
*Bluetooth – a few protocols, from which diffused there are copula port emulation
and OBEX, are ordinary accessible here. Other protocols are possible also.
The infra-red connection and Bluetooth it can utillize also that send datu of small amounts between two by one technologies supporting telephones. This was foreseen to utillize a telephone sending (that, giving what, telephone number, it is not jâpârraksta with a hand) of numbers, but it can utillize this also sending of files. This possibility almost always bazejas on OBEX protocol.