The Analysis And Hardware Implementation Of ACARS Link Layer Protocol

In the mid-90 s of last century,Civil Aviation Data Communications Corporation of China introduced the United States ARINC company's equipment and technology to set up our own VHF data link communication network.Although Civil Aviation of China has built a special network of VHF data link communications only after the United States and Europe,VHF equipment used by domestic airports and airlines relies heavily on imports from the US and Europe,with high cost and difficult to maintain,seriously hindered civil aviation of China from the scale to the core technology.The basic methods of the ACARS link layer protocol analysis and hardware implementation are studied by this paper.First,study the ACARS link layer protocol according to the ARINC 618 and ARINC 620 specifications,and use the MFC to create the simulated airborne CMU and the simulated ground station DSP respectively on the Visual Studio 2013 platform.The two simulated devices can communicate via TCP / IP to realize the basic functions of ACARS link layer.Then,the basic functions of the ACARS link layer are realized with the hardware devices.That is,the simulated airborne CMU and the simulated ground station DSP are connected with the VHF transceiver through the serial port to form the simulated airborne equipment and the simulated ground station.The two simulated devices work in the ACARS system Frequency to build a real ACARS message receiving and sending environment,in order to achieve the basic functions of ACARS link layer.Domestic airports and airlines are using the imported analog VHF equipment.VHF transceiver which is the digital VHF equipment in this paper is realized by a software radio platform based on FPGA.This technology has laid a certain basis for the future ditigal VHF equipment of our country.The test experiment shows that the simulated ground station and the simulated airborne equipment can communicate normally at the operating frequency of ACARS system.The simulated ground station can send the SQ message and respond to the downlink ACARS message sent by the aircraft.The test experiment realize the basic function of ACARS link layer.