Research In Application Of Reliable Multicast For Electrical Railway Real-Time Monitoring System

As the great development and innovation of the railway, as the favoring process of the sixth speed increasing, the supervisory control and data Acquisition system of the electrical railway is developed to the large system and controled by network. Higher requests on the real-time attribute,reliability and security are sued by the new SCADA distributed system. Currently, with the widely use of the App: one point to many or many points to many, more and more attentions are centralized in multicast. But because endeavour service is supplied by IP multicast only and transmitting data unfailingly can not be ensured, it is suggested that doing research on reliable muliticast mechanism and enhancing the reliability when using IP multicast became an important aspect of multicast protocol study.As the difference for reliability requirements is large in different using conditions, a wide-open research phase is still been in by the research of reliable multicast protocol,there isn't a protocol can be set as the universal protocol for every network application.The reliable multicast protocols published recently are emphasized reliable transmission mostly, and real-time transmitting is considered little,so the new distributed system couldn't be satisfied.The structure and the feature of the real-time monitoring system's network were analyzed, so multicast as the main communication way of the real-time monitoring system is put forward here. The realization and its error control mechanism of some classic reliable multicast protocols were studied, error control mechanism of reliable multicast which adapted to different network and application was derived.Contrapose the characteristic of the electrical railway real-time monitoring system, an reliable multicast protocol which based on real-time:RTBRMP is designed by this passage, the reliability and real time ability of data transmitting in control center when using multicast can be ensured.At last, overpass the simulation, RTBRMP and other two reliable multicast protocol are compared contrapose some guide line of reliability in a simulation circumstance which is similar to the electrical railway real-time monitoring system. It is concluded that RTBRMP has advantages when using multicast.