Design of long-distance and high-speed data transmission system based on long range Ethernet technique

Nowadays, long-distance data transmission is one of the key features for remote sensing systems such as seismic exploration. In these kinds of systems, ordinary twisted pair is more suitable than fiber optics because of working environments or limited costs. But there are two limitations as long distance and data transmission speed which are not easy to be improved in these systems. We designed and realized a high-speed data transmission system (thereinafter referred to as LHS) based on long range Ethernet technique and self-defined protocol with the help of FPGA hardware real-time processing. In this system, we only use the lowest level of physical transmission protocol in OSI reference model just for the high real-time performance. Vanishing of TCP/IP protocol which is widely used in normal Ethernet system simplifies the design and realization of transmission system greatly. Applying a DSP-based pre-emphasis and equalization to its transmitted data, this system can drive CAT-6 twisted pair lines with length of 220 meters at 100Mbps data speed. Furthermore, this system is real-time, stable and low-cost. The scheme proposed here can be used in related remote sensing systems.