On the evolution of mobile network protocols towards the support of multimedia teleservices

Starting from the idea that "multimedia" mainly means the integrated manipulation of information, and hence the independent handling of each separate information is not a sufficient result, an enhanced architecture for the UMTS system, involving the low levels (physical, MAC, DDL, and network) of the protocol stack, is proposed for the transport of wireless multimedia. To achieve the best performance from the designed architecture, a synchronisation sub-layer is introduced at the network level, with the main aim of assuring over the air interface "rough" inter-stream synchronisation, used as a first step before a "fine" end-to-end synchronisation is performed by the highest protocol levels. A detailed description of the new functions for each level, their basic algorithms, their location in the protocol stack, as well as the signalling exchange among the modules implementing them and between network and user sides are given.