Research Of Several Communication Protocols Based On VMS

VMS(Variable Message Signs) is variable message signs, also known as CMS. Through the text, images, digital signals, such as the synthesis of road geometry information, road traffic information, road traffic information and public service information, such as a variety of information. To facilitate the driver to adjust their driving behavior, to ease traffic congestion, reduce traffic accidents and improve the ability of the highway road network.The national transportation ITS (Intelligent Transportation System) protocol, is the United States of America’s current use of intelligent transportation equipment for the communication protocol standards. The protocol is described in detail in the application of the variable in-formation symbol in the traffic field.After a long time of continuous modification and improvement, it makes the NTCIP agreement has a strong advantage, and therefore in the world has been a certain promotion.GB/T23828-2009 national standard is promulgated in 2009on the implem-entation of the agreement on the symbol of a variable information. Due to the complex geographical environment and cultural differences, resulting in if you want a development and promotion of a unified national intelligent transport protocol standard, it needs a period of development, the required price will be very expensive, and therefore can not be achieved overnight. So GB/T 23828-2009 just on the function of intelligent transportation system (ITS) put forward the basic requirements, and provides a standard testing and acceptance, and acceptance of the basic methods and acceptance criteria, and no to the basic parameters of the provisions. However, with the development of intelligent transportation in our country, a detailed and comprehensive development of intelligent transport protocol standards will be essential, and the NTCIP agreement is such an agreement.This thesis first introduces the basic protocol of NTICP and its development in the United States. Secondly, the current national standard GB/T23828-2009 is introduced, and the characteristics of two kinds of different protocols are obtained by comparing with American NTCIP. At last, by pointing out the shortcomings of the current standard GB/T23828-2009 in China, the advantages of NTCIP and its application in intelligent transportation in the future are pointed out.