【文章內(nèi)容簡介】 ation acceleration rate. Test results show that the mass of the Typethree sleeper is larger, so its track structure possesses much higher stiffness than the New Typetwo sleeper track structure. In the wheelset falling test, the typethree sleeper track structure offers smaller vibration acceleration rates of rails and sleepers and much lower vibration frequencies, as pared with the New Typetwo sleeper track structure. However, the wheelrail impact forces of the track structures with two types of sleepers are basically the same, Field tests show that the Typethree sleeper track structure is more stable. According to the test results, to enhance the track stability and prolong the track maintenance cycle, it is better to adopt Typethree sleepers and 60kg/m rails on the lines where trains where trains run at the speeds 160 km/h. The optimized schedule of the traction system can be integrated to the existing traction control system. BASIC MODEL OF SYSTEM AND RECTIFIERS For a mass transit system, in order to increase the energy efficiency of the power supply system, regenerative braking is employed together with the rheostat braking. During regenerative braking, the power is either absorbed by nearby trains or returned to the power system through converters in the nearby substations. For a given train running from the current station to the distinction station, ignoring those temporary stops, we assume the speed profile of trains can be represented by several key parameters including the starting time, motoring time, coasting time, braking time and running time [XS, XA, XC, XD, r] as illustrated in ， where suffix S denotes starting, A denotes motoring, C denotes coasting and D denotes braking. For long distance run, such as intercity railway system, the motoring and coasting operation modes may repeat more than one time to cover long distance. There is an ever increasing demand for the onboard Inter access from the passenger train. As deploying the broadband wireless along the railway is one of the resolutions for the proposes of Inter services on the passenger train, it is the hot research spot at present. Aiming at this direction, this paper proposes a work topology for the railway broadband wireless link, mesh nodes invalid risk degree and influence factor, and a lyaly minimum spanning tree algorithm. And then, the performance of robust of the banyantree topology is analyzed. Based on the banyantree topology, this paper presents a design of mulitportal bus structure and amultiradio Mesh node structure for the railway wireless mesh work, using the microcell deployment method and the mixed channel multiplexing method. And then the performance of latency and throughput of the work system are analyzed. Finally, an illustrative implementation scheme is designed for a railway section with a length of 300km. Based on the theoretical analysis and illustrative implementation proposal, the paper that the banyantree topology is the suitable for the implemention of railway broadband wireless overlay with low latency, hig