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Nedeľa, 22. decembra 2024
3g network
Dátum pridania: 14.08.2007 Oznámkuj: 12345
Autor referátu: Pdanno
 
Jazyk: Angličtina Počet slov: 493
Referát vhodný pre: Gymnázium Počet A4: 1.6
Priemerná známka: 2.99 Rýchle čítanie: 2m 40s
Pomalé čítanie: 4m 0s
 

Begining – 3G network has just arrived to the Slovakia, and we would like to tell you abot this new techology. At first I will summarize evolution of mobile network.

Evolution

  • 0G – Zero generation of wireless phone technology. First commercial mobile network started in 1978 in Finland and it was based on Autoradiopuhelin technology. In 80’s was developed NMT(Nordice Mobile Telephone) standard, which belongs to 1G. This techology has used analog transmission. NMT was used in Scandinavia and eastern Europe.
  • 2G – was not able to transmit data like e-mails or software, but only digital voice call or secondary information like date or time. 2G is divided to two standards – TDMA(Time division multiple access - on this standard is also based GSM) and CDMA(Code-Division Multiple Access).
  • 2.5G – is not official name for mobile generation. It is between 2G and 3G. It still uses 2G infrastructure, but offers more services like GPRS.
  • 3G – The biggest Japanese operator launched first commerce network in October 2001. In Slovakia 3G started in september 2005 by Orange operator and in march 2006 by T-mobile.

Technology in short

3G is based on UMTS standard - Universal Mobile Telecommunication System. T-mobile uses UMTS Frequency Division Duplex which complements with older GSM system. UMTS offers much higher capacity and permeability. For receiving and sending data are used symetric channels, which offers better conditions for multimedia. The theoretical speed of data transmition should be around 1920 Kbps, but now real UMTS speed is only between 200 and 300 Kbps. In future it will rise. The bandwidth is between 1920 - 2170 MHz.

Features

Videotelephony is new feature and I suppose it is a flagship of 3G. Videotelephony means, that you can make a phone call and watch person on the other side in real time. That can make your communication easier and more interesting. When you make videotelephony, you don’t hold the phone near your ear, but in front of face. The video camera, which scans image of your face is placed near display. If you don’t want to be scaned by camera, you can turn it off and you can send only your picture or a caricature. The quality of videotelephony depends on speed and quality of transfer. Better light conditions mean better video quality. The speed of videotelephony is 64 Kbps. 3G is not only about videotelephony, but it offers many features, like watching TV, sending e-mails, writing instant messages(ICQ, MSN) downloadnig music, videoclips... 3G can be used for internet connection. For laptops are used cards like EDGEcards.

What do you need, if you want to be 3G?

3G phone and SIM card (128 kB memory, supports 2G and 3G) To be at places covered by UMTS signal, otherwise you phone will work as GSM phone. The signal is not very spread, because 3G is very young technolgy in Slovakia. Orange has covered Bratislava, Kosice, Banska Bystrica and some other bigger cities. The expansion will be slower, because this technology works on higher bandwidth and it’s needed more transmitters.

 
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