The document describes the 3GPP Release 99 radio access network architecture. It discusses the key network elements of UTRAN including the Node B, RNC, interfaces between network elements like Iub, Iur, Iu. It provides an overview of the reference architecture showing the core network elements and interfaces to the core. It also summarizes protocols used on different interfaces like RANAP, RNSAP, NBAP and their functions. Finally, it discusses concepts like macrodiversity and SRNC relocation in UTRAN.