General Packet Radio Service (GPRS) is a data network architecture that is designed tointegrate with existing GSM networks and offer packet switched data services access tocorporate networks and the Internet. With the integration of GPRS to GSM, mobileoperators are adding mobile Internet and VPN services to existing voice services byconnecting their GPRS networks to external networks. Thus the profits of operatorsdepend on the security that they enforce to protect their own network from attacksinitiated from the external networks.GPRS Tunneling Protocol (GTP) is the protocol used by GSM and UMTS operators toconvert radio signals from subscribers into data packets. However, GTP does not providefor inherent security which leaves security vulnerabilities in this architecture. Thepurpose of this paper is to assist network architecture designers and networks securityresearchers in evaluation of the potential security risks and solutions in GPRS networks.The next section provides a brief overview of GPRS architecture which will be thegroundwork for the rest of the paper. Section 3 attempts to classify the security servicesthat provide mitigation against various threats. The following sections then list thesecurity threats and their solutions for each security service described in Section 3.Finally, a solution for a new attack that has emerged in GPRS networks called the“Overbilling Attack” is described