3G(Third Generation Mobile Telephony)
3G is an ITU(International Telecommunication Union) specification for the third generation (analog cellular was the first generation, digital PCS the second) of mobile communications technology.3G promises increased bandwidth up to 384 Kbps when a device is stationary or moving at pedestrian speed, 128 Kbps in a car, and 2 Mbps in fixed applications. Implemented in Europe as UMTS and CDMA2000 in North America, its goals are high-quality multimedia and advanced global roaming.
WCDMA(Wideband Code Division Multiple Access)
A 3G technology that increases data transmission rates in GSM systems by using the CDMA air interface instead of TDMA. WCDMA is based on CDMA and is the technology used in UMTS. WCDMA was adopted as a standard by the ITU under the name “IMT-2000 direct spread”. It has been selected for the third generation of mobile telephone systems in Europe, Japan and the United States.
UMTS(Universal Mobile Telecommunications System)
Third generation telecommunications system based on WCDMA-DS. The goal of UMTS is to enable networks that offer true global roaming and can support a wide range of voice, data and multimedia services. A new-generation technology for rapidly moving data and multimedia over wireless devices. The European implementation of the 3G wireless phone system, UMTS provides service in the 2GHz band and offers global roaming and personalized features; designed as an evolutionary system for GSM network operators, multimedia data rates offered by UMTS are: vehicular - 144 kbit/s; pedestrian 384 kbit/s; in-building 2Mb/s.
HSDPA(High-Speed DownlinkPacket Access)
HSDPA is a packet-based data service in WCDMA downlink with data transmission up to 8-10 Mbps (and 20 Mbps for MIMO systems) over a 5MHz bandwidth in WCDMA downlink. The high speeds of HSDPA are achieved through techniques including: 16 Quadrature Amplitude Modulation, variable error coding, and incremental redundancy.
ATM(Asynchronous Transfer Mode)
A network technology protocol based on encoding and transmitting data in relatively small cells/packets of a fixed length. Allows for high-speed transmission of video, audio and data over the same network.
ATM is a connection-oriented switching technique with very high speed and high bandwidth. The CCITT (Consultative Committee International Telephone and Telegraph) is betting on ATM’s many benefits for the future broadband network.
