UMTS - WCDMA-3G

3G wireless service has been designed to provide high data speeds, always-on data access, and greater voice capacity. Listed below are a few notable points −

• The high data speeds, measured in Mbps, enable full motion video, high-speed internet access and video-conferencing.

• 3G technology standards include UMTS, based on WCDMA technology (quite often the two terms are used interchangeably) and CDMA2000, which is the outgrowth of the earlier CDMA 2G technology.

• UMTS standard is generally preferred by countries that use GSM network. CDMA2000 has various types, including 1xRTT, 1xEV-DO and 1xEV-DV. The data rates they offer range from 144 kbps to more than 2 mbps.

Sub-systems of 3G Network

A GSM system is basically designed as a combination of three major subsystems −

• Network Subsystem (NSS): MSC/VLR, HLR, AuC, SMSC, EIR, MGW. Common for both 2G & 3G Network.
• UTRAN: RNC & RBS.
• Operation and maintenance Support Subsystem (OSS).

There are three dominant interfaces, namely,

• IuCS: Between RNC and MSC for speech & Circuit data;
• IuPS: Between RNC & SGSN for packet data;
• Uu interface: Between the RNC and MS.