3G Systems

The International Telecommunication Union (ITU) began studies on the globalization of personal communications in 1986 and identifi ed the long-term spectrum requirements for the future third-generation (3G) mobile wireless telecommunications systems. In 1992, the ITU identifi ed 230 MHz of spectrum in the 2 GHz band to implement the IMT-2000 system on a worldwide basis for satellite andterrestrial components. The aim of IMT-2000 is to provide universal coverage enabling terminals to have seamless roaming across multiple networks. The ITU accepted the overall standardization responsibility of IMT-2000 to defi ne radio interfaces that are applicable in different radio environments including indoor, outdoor, terrestrial, and satellites.

Access and global roaming for a wide range of services. Standards bodies in Europe, Japan, and North America are trying to achieve harmony on key and interrelated issues including radio interfaces, system evolution and backward compatibility, user’s migration and global roaming, and phased introduction of mobile services and capabilities to support terminal mobility. Universal Mobile Telecommunication System (UMTS) studies were carried out by ETSI in parallel with IMT-2000 to harmonize its efforts with ITU. In Japan and North America, standardization efforts for 3G were carried out by the Association of Radio Industries Business (ARIB) and the TIA committee TR45, respectively. Two partnership projects, 3GPP and 3GPP2, are involved in harmonizing 3G efforts in Europe, Japan, and North America.

In Europe, 3G systems are intended to support a substantially wider and enhanced range of services compared to the 2G (GSM) system. These enhancements include multimedia services, access to the Internet, high rate data, and so on. The enhanced services impose additional requirements on the fi xed network functions to support mobility. These requirements are achieved through an evolution path to capitalize on the investments for the 2G system in Europe, Japan, and North America.

In North America, the 3G wireless telecommunication system, cdma2000 was proposed to ITU to meet most of the IMT requirements in the indoor office, indoor to outdoor pedestrian, and vehicular environment. In addition, the cdma2000 satisfi es the requirements for 3G evolution of 2G TIA/EIA 95 family of standards (cdmaOne).

In Japan, evolution of the GSM platform is planned for the IMT (3G) core network due to its fl exibility and widespread use around the world. Smooth migration from GSM to IMT-2000 is possible. The service area of the 3G system overlays with the existing 2G (PDC) system. The 3G system connects and interworks with 2G systems through an interworking function (IWF). An IMT-2000-PDCdual mode terminal as well as the IMT-2000 single mode terminal are deployed.