Research on the GPRS remote data compression and transmission technology for structure healthy monitoring

As the demand for structure healthy monitoring of civil engineering continues to grow at an unprecedented pace, the need for real time remote data compression and transmission systems becomes more prominent. In this paper, aiming at the problem of massive data transmission in the safety monitoring systems of the civil engineering applications, the GPRS wireless transmission terminal is designed to remotely send the data collected by multiple monitoring systems. In addition, a LZW (Lempel Ziv Welch) lossless data compression algorithm has been detailed and then utilized to compress the collected data. The results show that the LZW algorithm is capable of compressing the data effectively without losing any important data. The data compression efficiency of the LZW algorithm is about 10%, which is 7% lower than that of the traditional Huffman algorithm. Moreover, the compression and decompression time of the LZW algorithm is approximate 10ms, which is about 100 times faster than the traditional Huffman algorithm. Finally, the optimal data points for the underground oil and gas reservoir safety monitoring system have been determined. The result demonstrate that extracting 1000 data points at each step can effectively balance the sampling intervals and the data volume to be sent.