Coba jelasin Bubuka dari Universal Mobile Telecommunications System dalam bahasa sunda dong

Artikel ieu medar téknologi, bisnis, kaguna katut aspék-aspék lianna ngeunaan UMTS, anu ngagunakeun air interface W-CDMA jeung  infrastruktur GSM.

UMTS, ku cara ngagunakeun W-CDMA, ngarojong laju transfer data sagancang 14,0 Mbit/s dina téori (lamun maké HSDPA), sanajan ayeuna para pamaké ieu teknologi bisa ngaharepkeun laju transfer nepi ka 384 kbit/s pikeun héndsét R99, sarta 3.6 Mbit/s pikeun héndsét HSDPA dina konéksi downlink. Laju transfer ieu masih jauh leuwih gancang manan hiji GSM error-corrected circuit switched data channel anu ngan 9,6 kbit/s atawa sababaraha channel anu ngan 9.6 kbit/s dina HSCSD (14.4 kbit/s pikeun CDMAOne). Laju transfer data ieu ogé leuwih gancang manan para pasaing téknologi jaringan lianna saperti CDMA2000, PHS atawa WLAN anu nawarkeun aksés ka World Wide Web dina alat télékomunikasi mobil.

Precursors to 3G are  2G mobile telephony systems, such as GSM, IS-95, PDC, PHS and other 2G technologies deployed in different countries. In the case of GSM, there is an evolution path from 2G, called GPRS, also known as 2.5G. GPRS supports a much better data rate (up to a théoretical maximum of 140.8 kbit/s, though typical rates are closer to 56 kbit/s) and is packet switched rather than connection oriented (circuit switched). It is deployed in many places where GSM is used. E-GPRS, or EDGE, is a further evolution of GPRS and is based on more modérn coding schemes.  With EDGE the actual packet data rates can réach around 180 kbit/s (effective). EDGE systems are often referred as "2.75G Systems".

Since 2006, UMTS networks in many countries have been or are in the process of being upgraded with High Speed Downlink Packet Access (HSDPA), sometimes known as 3.5G. Currently, HSDPA enables downlink transfer speeds of up to 7.2 Mbit/s. Work is also progressing on improving the uplink transfer speed with the High-Speed Uplink Packet Access (HSUPA). Longer term, the 3GPP Long Term Evolution project plans to move UMTS to 4G speeds of 100 Mbit/s down and 50 Mbit/s up, using a next generation air interface technology based upon OFDM.

UMTS supports mobile videoconferencing, although experience in Japan and elsewhere has shown that user demand for vidéo calls is not very high.

Other possible uses for UMTS include the downloading of music and vidéo content, as well as live TV.