Research on the session control technologies in 3GPP UMTS networks

In this paper, it is pointed out that the next generation services should be composed of sessions which allow a subscriber to join in a communication scenario partly or entirely, for example a MS can join the audio part of a multimedia communication, or allow a subscriber to join different communication scenarios, or allow different subscribers to share the same session. From this point of view, we discuss the session-based call control approach used in UMTS, and address some challenges of the current scheme in the R5 network, then give some recommendations for improvements.