Research On Modeling Of Communication Control Server And Applications Of CTCS2+ATO Train Control Systems

Intercity rail of Zhujiang Delta District is confronted with a series of demands and challenges because of the particularity of its geographical location, specifically for LAN-based, service-oriented and transit traffic, so China Railway Corporation and the Guangdong Province proposed for the Zhujiang Delta intercity rail an extension with ATO function based on CTCS-2 train control system. Communication control server is an important security subsystem of CTCS2+ATO intercity rail train control system. Communication control server is based on computer technology as the main means to control security doors, and operational plans forwarding capabilities to meet the needs of intercity rail line size, transport operations, traffic safety, improvement of transport efficiency, improvement of working conditions and creating conditions for the modernization of management. This paper conducted n-depth analysis and discussion of the logic processing unit and ISDN server subsystems of communication control server.Firstly, several key Operational scenarios of logic processing unit of communication control server is discussed. Formal methods of hierarchical colored Petri net is applied for key scene modeling of communication control server logic processing unit. The models are including periodic and non-periodic messaging model, GSM-R fault processing sub-model, train registration and launching model, train cancellation model, door and screen door protection and linkage control model, automatic train operation adjustment model. Subsequent laboratory simulation experiments carried out on the model for further verification and analysis. In laboratory simulation experiments and factory acceptance test, CPN-TOOLS is used for analysis of validation of hierarchical colored Petri net models. The results show that with the increase in the re-transmission interval, the model packet loss probability decreases, but the transmission delay will increase. And a recommended re-transmission delay value of from 3.0s to 3.5s is acquired as well. Then simulation testing environment and testing sequences are described particularly for Operational scenarios such as train registration, trains cancellation, door and screen door protection and linkage control, and automatic train operation adjustment.Most CCS scenarios need cooperation of a driver. However, the driver identity recognition rely solely the ID number entered by the driver through DMI. This leads to high security risks. This paper proposes an information hiding algorithm to hide driver’s information into speech signal to ensure the driver’s identification. In the information hiding algorithm implementation, the data quantity of speech signal is large. Therefore, this paper puts forward a bandwidth saving method based on the pitch cycle with little influence on the quality of speech signal.Communication functional module of ISDN server--a sub-system of communication control server, referred to "European Radio European Radio System Function Interface Specifications" is developed using a software method. There are four layers in ISDN server. They are physical layer, data link layer, network layer and transport layer. The advantage of software implementation is departing from hardware stringent requirements. Finally, an expanded and more detailed timing sequence based on"European Radio Interface Specification European Radio system function" is designed for ISDN server. Finally, communication control server independently developed by Communication and Signal Research Institute of China Academy of Railway Science runs through the simulation laboratory testing and factory acceptance test held by Zhujiang Delta Intercity Railway Corporation.