A Resource Management Scheme for Satellite Networks with Dynamic Bandwidth Allocation Procedures

Current satellite systems operate according to circuit switching transfer modes. To improve flexibility and efficiency, several kinds of packet switching systems have been proposed. However, it appears that full packet switches are still too complex and expensive to be implemented on board the satellites, in the mid-term. For the time being, a compromise has been found in satellite networks with Dynamic Bandwidth Allocation Capabilities (DBAC). Such systems are based on classical circuit switches, but the DBAC payload allows changing dynamically the capacity of each connection, without the need of tearing-down and setting-up again the connection itself. In this paper we consider a DBAC satellite system and define algorithms to allocate the bandwidth in such a way as to provide performance guarantees and to exploit efficiently the system resources. We assume that the overall traffic is divided into high priority (HP) traffic and low priority (LP) traffic. A given amount of resources is assigned to the HP traffic so as to satisfy pre-defined performance measures. When the HP traffic is not employing all the allocated capacity, the unused capacity is temporarily taken away from the HP traffic and used to carry LP traffic. The HP traffic loading the system is regulated by means of Dual Leaky Buckets (DLBs). We define bandwidth-handling policies, design Connection Admission Control rules and evaluate analytically the system performance.