3G IP Multimedia Subsystem based framework for lawful interception

Issues related to lawful interception, such as invasion of privacy and efficient investigation, are presently at the forefront of social consciousness. Interception technology has to consistently evolve in order to keep pace with new and varied network structures. Thus, standard lawful interception documents that are appropriate for the existing PSTN, 2G and 3G, and packet-based communication are being proposed. In particular, newly arising services based on IP Multimedia Subsystems (IMSs) that support multimedia streaming, data transmission, and voice over IP, make lawful interception even more imperative. In this paper, we propose an architecture for IMS/Session Initiation Protocol based Lawful Interception (LI) in wireless 3G networks. We also propose LI techniques that are differentiated according to the IMS characteristics where content service providers are separated from network providers. Using the standards of dynamic triggering technologies for commissioning the authority to intercept among multiple network providers as a basis, we analyze IMS architecture and service operation methods. We then propose an LI architecture that is appropriate for IMS services. In addition, we present the results of a quality of service performance analysis conducted on our proposed interception architecture for various numbers of IMS users.