Research & Design On High Speed Fault-Safety Lan

With the enhancement of train' s running speed and density in hign speed railway, the traditional method on delivering the railway safety information can' t satisfy the demand of train' s safety running. High speed fault-safety LAN using optical fribe communication technology, network technology and computer technology, it' s a important transformation. If Adopting optical fribe special network, it can supply high quality channels ; insure real time character and big capacitance with information delivering, possessing strong anti-jamming capacity; suitable for high speed railway' s long distance station structure;decreasing cable investment;in the mean time , syncretizing data communication and computer technology, resolving the question of abundance information' s dealing. It adapts to the development of railway signal communication' s modernization .The paper' s main content includes of 125Mbps high speed fault-safety LAN' s network framework, the design of data link control protocol and the research of network' s performance. High speed fault-safety LAN' s network framework is introduced mainly From LAN' s topology and transfer medium. By comparing all kinds of topology' s characterstic, combining the demand of optical fribe' s transfer medium, then according double loop framework and double redundant structure' comparison on reliability safeness, it can put forward the better structure which is double redundant structure, also supply the structure' s drawing of point;following it ,the paper mainly talks about the LAN' s access control protocol, after comparing some LAN technology , and according the network' s especially requirement, the system adopts special communication control protocol, at the same time offer the software' s standard of protocol' s program;otherwise,the paper provides the measures on the system' s safeness , real time character, high reliability and maintenance;at last, using queuing theory analyses the network' s performance.