Node B Structure  Circuit Switched-Core Network consisting of MSC Server and MGW and is common for both GSM & WCDMA.  Packet Core Network consisting of SGSN & GGSN and is common for both GSM & WCDMA networks.  Radio Network shall be separate for both GSM & WCDMA.  Radio Network-GSM: BSC, BTS and WCDMA: RNC, Node B  The Node B is the function within the UMTS network that provides the physical radio link between the UE (User Equipment) and the network.  Analogies can be drawn between the function of a Node B and those of a BTS.  In contrast with GSM base stations, Node B uses WCDMA as the air interface technology.  Node B contains radio frequency transmitter(s) and the receiver(s) used to communicate directly with mobile devices, which move freely around it.  Nodes Bs have minimum functionality, and are controlled by an RNC (Radio Network Controller).  New Radio Access network needed mainly due to new radio access technology  Core Network (CN) is based on GSM/GPRS  Radio Network Controller (RNC) corresponds roughly to the Base Station Controller (BSC) in GSM  Node B corresponds roughly to the Base Station in GSM  In the FDD mode the uplink and down link uses separate frequency bands.  The carrier has a bandwidth of 5 MHz.  The UTRAN chip rate is 3.84 Mcps.  The spreading factor can vary BETWEEN 4 TO 512.