The Design And Implementation Of The Coap Protocol-Based Sensor Resources Search System

With the popularity of CoAP protocol-based wireless sensor networks, more and more sensor resources will be opened to users. However, how users can quickly find a particular sensor, how to quickly find all sensors of a certain type, how to quickly find all sensors in one place, etc. will become increasingly prominent. The purpose of this paper is to design and implement a search engine for CoAP protocol-based sensor resources, and it will greatly facilitate the work of the user to find the sensor resources and associated development.In this paper, the search engine consists of four functional modules, web crawler module, indexing module, keyword search module and user interface module. Web crawler module will call the CoAP client to communicate with the CoAP server, which lies in the sensor node, and once obtaining the sensor resources, it will integrate resources and store them as files in XML forma; Indexing module is to build the inverted index file based on the sensor resources the Web crawler obtains, thus improving the efficiency of keyword query process. Keyword search module then query the keywords, which the user interface module passes over, according to the inverted index files, and return the query results to the user interface module. The user interface module, on one hand to get user input keywords, and pass the filtered keyword to the keyword search module, on the other hand to get the results of keyword search module, and then returned the generated summary information of the results to the user. Users then can view the detailed search results further, or can do the associated secondary development work.Finally, this paper do the related test validation work to verify the effectiveness of the search engine, including the construction of the search engine platform, the build of physical sensor network and virtual sensor network, and preparation of the test cases, and so on. The results show that the search engine can effectively search for the sensors resources both in IPv6and IPv4network environments and can greatly facilitate the users to find the sensor resources in a short time.