Research For The Key Technology In The Dissemination Of The Service Data Based On The Opportunistic Routing Algorithm

TIS(Transport Information Service) plays an important part in ITS(Information Transportation System), shoulders the responsibility to provide travelers information about traveling timely,accurately, and considerately. TIS includes many characteristics, for example, it donnot has the unique pattern to receive service requirements, provide the service answers back, show the answer information to the travelers and it represents intellectualized characteristics. So, the network of TIS is hybrid. Under that model, VANET(Vehicular Ad-hoc NETwork) plays the base role. To face many problems such as the different construction of the subnets, different node density and fast-changing network topology, it is important to design a great data dissemination algorithm.The paper analyzed the working processes and the construction of the TIS, showed the challenges for the TIS, and leaded to the importance of studying the data dissemination algorithm. It showed the differences between VANET and MANET, proposed to design the algorithm utilizing the theory of opportunistic network. It studied the concept of opportunistic network and the way the information blows in the network, analyzed the algorithms and classified them, made descriptions about the typical algorithms and compare them.The algorithm proposed in this paper includes the working processes of the service discovery and the service combination and the working context for the module. The paper proposed a two-hop algorithm called OSDD and simulated it. The paper analyzed the simulating software in the region of traffic and wireless network and simulated OSDD, and recorded the results. The results illustrated that OSDD performed well in decreasing the package ratio and the network drop rate.