As we indicated in Chapter 1, "Introduction," the European Telecommunications Standards Institute (ETSI)/ Special Mobile Group (SMG) developed two standards for International Mobile Telecommunication in the year 2000 (IMT-2000). One of them is the Universal Mobile Telecommunications System (UMTS) Wideband Code Division Multiple Access (W-CDMA), which is based upon a direct-sequence CDMA (DS-CDMA) technology and operates in the frequency division duplex (FDD) mode. The other is the UMTS TDD system, which is based on time-division CDMA (TD-CDMA) principles. The purpose of this chapter is to present an overview of the W-CDMA UMTS system as specified in the ETSI standards documents [1]-[40].

The chapter is organized as follows. We begin with a synopsis of the UMTS system features and follow it up with the third-generation (3G) wireless network architecture. The UMTS uses a layered protocol architecture at different interface points, each layer performing a set of specific functions. We present an overview of the radio interface protocol stack. The next few sections describe each of the constituent protocols of this stack, namely the physical layer, the medium access control, radio link control, the packet data convergence protocol, the broadcast multicast protocol, and the radio resource control protocol. Topics, such as the synchronization procedure, power controls, and handovers, are also described. The material of this chapter has been drawn from a series of standards documents. In many instances, our descriptions have been necessarily brief and comprehensive. However, we have included relevant references at...