Research On Communication Module In Vehicle Position And Navigation System

As a branch of ITS, the vehicle position and navigation system in developed countries has been carried to resolve the serious traffic problem and acquired great achievement. But in China, the research just begins in recent years but it will reach its high tide because of the 2008 Olympics in Beijing.In the conventional vehicle position and navigation system, the wireless communication part is always a scabrous problem. The former transmission techniques, such as broadcasting station, Trunking System, satellite communications, GSM SMS, are not perfect in the application. The fact is that these communication techniques are always limited by so many facts like communication area, expansive cost, complicated technique, transmission delay, data speed, reliability and so on. Thus they can't meet all the requirements of data communication in vehicle position and navigation system. Whereas, a novel communication protocol GPRS is introduced to solve the transmission problem here.This paper is based on the incomparable advantages of the GPRS network. It covers wide and transfers data in high speed; "always online"; allows a non-expensive transmission and a cost related with the amount of data transmitted. The data through the GPRS network is both steady and reliable. These advantages make it fit for the frequent, discontinuous and distributed data flow like in Vehicle position and navigation system.At first, the main performance of several types of GPRS module is compared in this paper and the excellent MC55 is selected as our design point. Serial communication on Windows CE is applied to design the network communication.