Research And Design Of The NOTAM Distribution Service

With the prosperity and development of global civil aviation industry, ATM(Air Traffic Management) is continuously growing. Transition from AIS(Aeronautical Information Service) to AIM(Aeronautical Information Management) which is proposed by EUROCONTROL is gradually accepted by other nations. Core of AIM is to build Flight information service environment which is cathedrals of digital-centered, networks-based, real time, safe and sharing. As important part of flight information, NOTAM is necessary message for all people related with flight and its accuracy, timeliness and efficiency matters a lot to ATM. Our main research content and innovations are as follows:Firstly, we analyzed the merits and defects of current data distribution services module and situations they suit, combined with the characteristics of NOTAM services such as clear destination and could be subscribed according to demand, we proposed a module of flight information distribution services based on publish/ subscribe. In the light of detailed content of NOTAM, we designed publish/subscribe module according to theme. Modeling and analyses of this module using Petri net verified its correctness and stability.Secondly, after deep study on DDS(Data Distribution Service) standard and QoS(Quality of Services) strategy, we designed a middleware which is capable of realizing agent function of the publish/subscribe module. Detail design includes architecture, data structure and procedure of NOTAM distribution services. Modeling with CPN Tools dynamically demonstrated how middleware works in process of publication and subscribe services, and proved its correctness at the same time.Thirdly, we did not take data routing in consideration at the beginning, so by taking advantage of preponderance of multicast at application layer, we proposed routing protocol for NOTAM distribution. This protocol aims at distributing in high efficient way by constructing a multicast tree of which the source node is a publisher. Modeling scene of publish/subscribe NOTAM and analyses of results verified feasibility and efficiency of protocol.Finally, in order to handle the problem of generating multicast tree, we proposed a new minimum delay multicast tree module and use genetic algorithm to get its solution. Simulation results show that new module could generate correct multicast tree in much easier and faster way.