UMTS (Universal Mobile Telecommunications System) is a third generation telecommunications system based on WCDMA. UMTS (Universal Mobile Telecommunications System) will offer a set of consistent service to the computer and mobile phone users wherever they are in the world. Based on the communications standard GSM (Global System for Mobile communications), UMTS, supported by major standards bodies and manufacturers, is the planned standard for mobile phone users around the world in 2002. Higher bandwidth of UMTS also promises new services, such as video conferencing and promises to realize the Virtual Home Environment (Vhe) where roaming users can have the same services that users are accustomed when at home or at work, through a combination of terrestrial and satellite connections transparent . Provides an introduction to cellular networks and digital communication interface includes air, the radio access network and core network Describe the Release '99 specifications clearly and effectively Discusses UMTS services and future services beyond 3G features a lot of problems and solutions in order to aid understanding Ideal for Academic and students of telecommunications, electronics and computer science courses, research and development engineers working in mobile / wireless communication and Cellular operators and technical consultants.