faster communications with their contacts which means efficient use of radio resources. Conferencing: IMS enables network operators to combine web, audio, and video in conferencing solutions. It will allow users to view presentation materials while listening to the audio of a conference, hold simultaneous private text conversations, all while a conference moderator controls addition, deletion and mute status of participants. Location based Services: IMS location servers overcome some of the limitations of the current LBS technologies. The access network sends positioning information to the server; it captures location data, creating the opportunity to devise new services and revenue opportunities. For example, automated subscription services can be developed to provide updates on local areas when a user moves into them such as the number of local taxi firms, information on restaurants, key sites, and cinemas. The informa- tion can be complemented by promotions such as lower cost entry to museums. In addition, the server needs to be compliant with European and US emergency location mandates and requirements [11]. FMC: IMS will ease the process towards Fixed Mobile Convergence. The mobility management feature will allow users with dual mode (for e.g., DSL/WiMAX) devices to access the same telephony features and functionality regardless of whether they are in DSL network or in a WiMAX environment. 9.10 Challenges IMS is considered by a vast majority of the telecom industry as the platform for delivering real-time multimedia services over multiple access technologies. Despite the wide acceptance for its basic archi- tecture there are still many challenges in adapting IMS SO that it can become the converged architecture for NGMN. We will look into several challenges currently faced by the IMS industry in this section. 9.10.1 Architectural Alignment Though there is alignment around the basic IMS architecture, IMS still needs to undergo adaptations to suit the specific behaviors of individual networks. These unique requ