Information Query Method Based On P2P Regional Index Mechanism In Internet Of Things

In Internet of Things (IoTs), information has following characteristics: largequantity, heterogeneity, distributed storage, time sensitivity, frequent updating andhighly security requirement. The existing information query systems mainly adoptcentralized client/server (C/S) mode and need to convert items code into domain maneformat for information inquiry. So they will cause problems such as query processingtrivial, large query delay, the bottleneck the root sever and failure to adapt to dynamicnetwork environments.To solve the above problems, this thesis proposes using the peer to peer (P2P)mode instead of the C/S mode with a query mechanism based on hybrid P2P querymodel. The information servers or databases storing item information and providinginformation service in IoTs, are treated as data nodes of the P2P network. Thismethod removes the process of converting code to domain name by using items codeto query information directly instead, which simplifies the query process. These nodesin P2P network are divided into ordinary nodes and super nodes. For the super nodes,a query routing algorithm based on the time to live (TTL) of query message is used todetermine the search range, which can forward the query messages quickly.The proposed information query method is studied through the NS2simulationin terms of system query throughput, average query response time and average querysuccess rate against node scales and traffic loads. Simulation results show that, withthe expansion of network nodes, the algorithm can keep high query success rate andincreasing system query throughput, while the corresponding average query responsetime grows slowly. So the query algorithm is suitable for high traffic loadenvironments.