Optimal Capacity Allocation for Support of ATM Services over SDH Unidirectional Rings

This paper develops an analytical model for the multiplexing of Asynchronous Transfer Mode (ATM) connections onto the Synchronous Digital Hierarchy (SDH) Virtual Containers over an unidirectional self-healing ring. The proposed algorithm can produce a near optimal solution in pseudo-polynomial time and may be used in the ATM management entity for the real time allocation of capacity to ATM connections. (STM) services in real time. On the other hand, the algorithm can also be used at the SDH level to provide a (near) optimal capacity allocation to higher level management functions such as ATM. This paper provides an analytical model for the ATM concentrator. This concentrator is located at the edge of the SDH ring network (according to the CAAS architecture) and will attempt to multiplex as many of ATM connections onto the SDH Virtual Containers as possible. The SDH management, in turn, tries to allocate the shared capacity of the ring to the ATM layer requests so that a particular decision criterion is met. For example, the decision criteria may be to maximise total revenue or to minimise the number of blocked connections. Since the second criterion will have a tendency of favouring lower bandwidth connections, we only consider the first decision criterion in this paper.