Research On RFID Networks And Route Based On Publish/Subscribe System

With RFID network becoming hot in RFID applications,researchers proposed the middleware-based application framework which has been widely used in many fields, such as logistics,supply chain,retail,food,automatic train identification system and so on.Due to the simplicity of the early RFID applications,few researches paid attention to the structure,while most of the work focused on the RFID data acquisition as well as the manufacturing costs,including:low-cost tags,research and design of the readers, the tag collision,the reader collision,tag in a specific application environments,and the reliability of the data reading.Traditional RFID applications are mainly used in specific fields,and the application modes are mostly based on the data center,that is,labeled object data acquisition through reading equipment,then centralized storage and processing.How to associate RFID data with the existing application systems will be the focus point,thus, the middleware is considered to be a key method and technology in the RFID network.Recently,with its popularizing,RFID is going through the application changes from simplicity to complexity;from simple data-processing to event-oriented processing;from local applications to global applications;from the RFID combined with back-end single application systems to data sharing in a heterogeneous environment,and so on.These changes bring new challenges to the RFID data management and system" architecture,and demand a new generation of RFID application framework which can process data events with the following characteristics: RFID data tense,dynamic and relevant,the data flow and the mass data,redundancy and error,as well as data sharing in heterogeneous network.In order to meet the needs of the new generation of RFID network applications, this paper presents a complex event-oriented processing RFID network architecture for the universal application environment,and makes an intensive investigation about the key theories and methods.The main work includes as follows:(1) Pub/Sub system is combined with the RFID complex event processing,and a hierarchical RFID network structure based on Pub/Sub System is proposed,as well as some key descriptions and definitions about the RFID network are given,including the formal description of the RFID network,matching,routing,and so on.The key components about RFID network - the structure and main function of the broker are also discussed.(2) Considering the load and scalability of the RFID network in conditions of massive data,a hierarchical structure and model of the RFID network based on the complex network and the structuring P2P is put forward.On this basis,for the well-known content-based routing CBCB,considering the relationship between the broker neighbors,a broker traversal routing algorithm in a network of cluster-head broker is proposed,and results show that:the broker traversal algorithm considering the relationship between broker neighbors can effectively reduce communication overhead brought by the traversal in the network of cluster-head broker.(3) For the restrictions of network overhead on cluster-head broker network, considering the dependency of the client subscription,this paper proposes a edge-based precisely cover routing algorithm combined with the source address,and further gives the basic algorithm about cluster-head broker and broker in the cluster,which can reduce the repeated spread of subscribers in the traditional Chord ring coverage route. At the same time,in order to adapt to the dynamic changes of the Chord ring,a data proxy approach is used in Chord ring maintenance.Research shows that:on one hand, these methods can be effective in reducing the number of subscribers spreading in the network;on the other hand,they can also reduce the Chord ring maintenance costs.(4) This paper studies and discusses problems about mobility of intra-cluster and inter-cluster based on the Chord ring,and proposes algorithms which can support the mobility for botfi the intra-cluster and inter-cluster based on the Chord ring,including the subscription route algorithm,subscription to the abolition of the route algorithm and so on.This paper also proves the correctness of the algorithms based on weak efficient routing criteria.Experiments show that in comparing with the standard and delay optimization algorithms in route reconstructing expenses,and network load,the algorithms have better performance when in the situation of mobile clients.