The Research On Data Transportation Of Near Field Communication

Near Field Communication is a kind of short-range wireless connectivity technology working at13.56MHz,which derives from Radio Frequency Identification. The transportation technology of NFC refers to a critical question,that is, the theory of anti-collsion algorithm.The theory aims at how to correspond successfully among too many targets at the same time,in other words,it is to solve the problem of how to recognize the most targets effectively in the least time.This paper makes a brief introduction of the frame and basic knowledge of NFC system, and then does thorough research in its key technique from the point of anti-collsion mechanism..A kind of the classical anti-collsion algorithm is the random anti-collsion algorithm represe--nted by ALOHA algorithm,based on which, SA algorithm,FSA algorithm and DFSA algorithm are established.The paper analyzes the function and efficiency of the random anti-collsion algorithm and comes to the conclusion that it is easier carried out but with lower efficiency resulting from lacking of capability of getting rid of randomization in the process of transportation. On detecting collision,slots will be redistributed to start a new round of query resulting in wasting resource.Another kind of the classical anti-collsion algorithm is the certaintity anti-collsion algorithm, represented by BTS algorithm,DBTS algorithm and RIBTS algorithm.The certaintity anti-collsion algorithm, which is based on Binary Tree Search, effectively improves the efficiency.However, with the increase of the targets,it will cause a long delay because of its complex searching process.In this instance,the paper presents a new kind of anti-collsion algorithm with higher efficiency based on bit numbers.The function is that group the targets according to the bit numbers in order to reduce the targets, and then random anti-collsion algorithm or certaintity anti-collsion algorithm will be used to identify each of them. The new algorithm is more efficetive on testing. At the same time,it is helpful to reduce the stack space for RIBTS algorithm.