A recursive, explicit and fair method to efficiently and fairly adjust TCP windows in satellite networks

摘要

As originally specified, TCP did not perform well over satellite network systems, systems known with their rapidly time-varying network topologies. This paper addresses some vexing attributes that impair TCP performance in LEO satellite networks. The paper proposes a scheme that allows satellite systems to automatically adapt to the number of active TCP flows, the free buffer size and the bandwidth-delay product of the network. The proposed scheme controls the efficiency of the system by matching the aggregate traffic rate to the sum of the link capacity and total buffer size. This attribute helps to adjust TCP's aggressiveness and to prevent persistent queues from forming. The system min-max fairness is achieved by allocating bandwidth among individual flows in proportion with their RTTs. Simulation results elucidate that the proposed scheme substantially improves the system fairness, reduces the number of packet drops and makes better utilization of the bottleneck link. The results demonstrate also that the proposed scheme works properly in more complicated environments where connections traverse multiple bottlenecks and the available bandwidth may change over data transmission time.