Research On The Key Technologies In Satellite MPLS Networks

Multi-Protocol Label Switching which has provided a perfect framework for the joint optimaization between IP and satellite becomes an important candinate for the construction of next generation satellite network. Even so, statelite communication has some special features that quit different from terrestrial network, such as bad link quality, lack of bandwith provision and limited processing capacity. What negtieve effects would be introduced by those features and how could we build an optimized system in such enciroment is an important problem that must be resolved.In this dissertation, we firstly proposed a framework of satellite MPLS network. Some practical design and selection are promoted, such as networking scheme, protocol structure, data transmission method, signaling plan and QoS mechanism, which make up of the basic research environment of this dissertation.Since a reliable conservation of resources is essential for the operation of MPLS system, then we foused on the performance degradation caused by high bit error rate and rain attenation on Ka band radio link.In order to counteract with bit errors, we investigated the design of MPLS lablel and its validation mechanism. Theoretic analysis was executed to evaluate the influence on the TCP bearing performance of the LSP in the satellite MPLS network that caused by the label error. The simulation results show that our mathematical model could accurately calculate the throughput loss of TCP session on the LSP. And furthermore, the proposed label validation mechanism which is based on parity check had also been proven to be simple and effective.Rain attenuation on Ka-band radio link is another problem to the operation of satellite MPLS network. To deal with this issue, we firstly constructed a scheme to generate rain attenuation series that used for the simulation, and then proposed a novel method of LSP's protection and restoration that not only executes the linear prediticion to detect LSP failure but also uses the geographic information to select the backup site. The simulation results show that our scheme which is an important supplement to physical layer's solutions could effectively resolve the link interruption caused by rain.At last, we turned to the resources allocation problem which is critical to the QoS support of satellite MPLS network. In order to avoid call interruption, we divided the traffic into two categories, such as delay-sensitive traffic and delay–tolerable traffic. If there is a resources preemption occured between traffics, system would actively do traffic shaping on delay–tolerable traffic and release bandwidth for the delay-sensitive one. The numerical experiments show that our method could redue the traffic's bandwidth requirement, and therefore allivate the QoS degration caused by the traffic interruption.