A control architecture for a multidiscipline switch

To carry the tomorrow's interactive multimedia services the underlying transport network must be able to support a large variety of connections. These connections may set most varying bit rate, delay, error rate, etc. requirements for the transport system. A number of networking concepts have been piloted, but none of them has gained ultimate acceptance. ATM technology has been the most popular one, but it has been reported to have certain shortcomings and, therefore, other transport concepts have also been considered. It can be envisaged that heterogeneous transport solutions will be used for delivering future multimedia services. This inevitably leads to the situation that bit streams are carried over multiple networks which implement different transport technologies. Thus network elements, such as switches, should be able to interface to different networks and support switching of dissimilar data units. As a solution to the emerging problem, this paper introduces the concept of multidiscipline switching which combines two or more transmission technologies into a compact fabric. In order to support different networks and services carried on them, a sophisticated service and control architecture is needed. Reported experiments on distributed switching, combined with separation of fabric control from connection and service control, have given encouraging directions to tackle with the implementation problem. As an example, a switching solution combining time-slot, cell and packet switching is presented.