etwork is more of an upgrade to the GSM network. The same components of the GSM network provides voice service and the GPRS network handles data. Due to this reason the GSM network providers do not have to start from scratch to deploy GPRS. GPRS triggered the transformation from circuit switched GSM network to packet switched network and hence is con- sidered a technology between 2G and 3G, or commonly referred to as 2.5G. Fundamentals of EMS, NMS and OSS/BSS Packet network Figure 9.3 GPRS network simplified architecture. Some of the benefits of GPRS over circuit switched networks include: Higher speed Instantaneous access to service (always on) New services related to data communication Ease of upgrade and deployment on existing GSM network Can support applications that does not require dedicated connection Compared to GSM there are three new components that are required with GPRS (see Figure 9.3): Terminal Equipment (TE): The existing GSM user equipments will not be capable of handling the enhanced air interface and packet data in GPRS. Hence new terminal equipments are required that can handle packet data of GPRS and voice calls using GSM. Serving GPRS support node (SGSN): It handles mobility management func- tions including routing and hand over. SGSN converts mobile data into IP and is capable of IP address assignment. Gateway GPRS support node (GGSN): It acts as a gateway to connect with external networks like public Internet (IP network) and other GPRS net- works from a different service provider. It can be used to implement security/ firewall in screening subscribers and address mapping. The remaining components in GPRS are similar to GSM with minor software and hardware upgrades. The BSC in GPRS needs installation of hardware com- ponents called packet control unit (PCU) to handle packet data traffic and some software upgrades while components like BTS, HLR, and VLR will only require software upgrades. Communication Networks 9.5 UMTS Network UMTS (Universal Mobile Telecommunications System) is a 3G (thir