Abstract: Compass and GPS positioning technology arc popularly used in the vehicle management systems. The position reporting message is the most frectuent message submitted from vehicles to the monitoring platform,which includes the states of vehicles. In order to improve the efficiency of data transmission and save operating costs, this paper extended the national standard communication protocol JT/T 808-2011. To the single position reporting message,a more effective reporting and handling mechanism has been presented, which would reduce the message length about 40%. For the bulk location data reporting, we optimized the standard LZW algorithm to improve data compression performance. The experimental results on the simulation data and real operating data show that combining the a new location reporting protocol and compression algorithm can reduce about 35% of the data flow.

Key words: COMPASS navigation satellite system, Data transmission, Data compression