Dynamic bandwidth allocation in a circuit-switched satellite network: provision of deterministic and statistical QoS guarantees

摘要

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 considered complex and expensive, when implemented on board the satellites. 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 the changing dynamically of the capacity of each connection, without the need for 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 so as to provide deterministic and statistical QoS guarantees. The traffic sources are regulated by standard dual leaky buckets (DLB). We define bandwidth-handling policies, design connection admission control rules and evaluate analytically the system performance. As expected, the numerical results show a significant increase of the overall utilisation factor of our system, when compared with a plain circuit-switching solution.