Implementation Of Real-time Protocol In Train Communication Network

In 1999, IEC/TC9/WG22 formally specified Train Communication Network (TCN) standard IEC61375 as international standard. Train Communication Network (TCN) has been applied in a worldwide scope currently. Domestic researches on TCN devices are gradually advanced, but the counterparts on Real-time protocol (RTP) are in a respectively low level with several flaws in their procedures. Therefore having studied TCN standard, a general Real-time protocol stack is designed and implemented with OSI reference model.The foundation of RTP stack contains four modules:core protocol module, device interface module, system simulation module and user interface module. The implementation of core protocol module in RTP stack complies with particular layers in TCN standard:Multifunction Vehicle Bus (MVB) and Wired Train Bus (WTB) link layer function; Network routing function and routing directories; Transport control block and transport state transfer mechanism; Session control block and message callback mechanism; Process variable service and message service application interfaces. Special device structure is designed in device interface module. Specific operating system function is defined in system simulation module. User interface module provides foundation for further train network management service.RTP stack optimizes device link layer and network routing structure, reinforcing its reliability and real-time feature. Furthermore, trends of TCN development in the future are fully considered in design. Device interface module effectively manages bus devices, supporting extensions of bus type. System simulation module enables stack with adaptation capability to various system environment, easy for transportation. RTP stack went through multiple tests in testing platform, indicating its good performance.