Design And Implementation Of A Front-end For WSN Application Systems

Theso-calledWirelessSensorNetworkisadistributednetworkformedbya large number of small sensor nodes (MOTE), which has the ability ofsensing , communicating, and computing, in the target area. Each MOTEconsists of four components: transducer (sensor and AD/DA converter),processor (embedded system—include CPU, storage, embedded OS, andembedded application program), transceiver (radio communication module),and power unit ( battery ,solar battery or other ). Moreover, there are alsosome available optional function units, such as identification module (RFID),positioningmodule(GPS),andpowergenerationunit.The entire network is mainlyconstructed bythe following parts: Networkuser (task management node), which takes in charge of gaining informationfromthenetwork,andmakingvariousresponsestothenetwork;Transmissionmedium (Internet or communications satellite), the bridge and the linkbetween the user and the sensing network; Sink node (receives transmitter),which could transmit the information from the sensor network energy limitednode retransmit to the transmission medium based on its ample energy;Sensing network, which is the core of sensor network. In the sensation area,through the net constructed automatically by massive nodes, the node couldmonitor, sense the information transits to the Sink node, or receive operationcommands from the Sink node, change its active status. Network userincludestheplatform,front,applicationsystemandsoon.Currently, the majority of wireless sensor networks based on theapplication system did not take into account the design of front-end system.Like this, the problems of imbalance and low efficiency appear in someapplication systems. Moreover, WSN application systems are highly specificand can not be effectively reuse. In order to solve these problems, in thispaper, we design a front system which is independent of the application, andsupportsawiderangeofapplications.This system mainly has following functions:1st,statusmonitorThe status monitor mainly has three aspects: Real-time data monitoring, node data monitoring and system message monitoring. The real-time datamonitoring requires to monitor data transmission situation, demonstrate thecurrent processing data quantities, the connection condition, and the processtime (also may examine applies classified and some application dataprocessing situation completely) by the graphic mode. The node datamonitoring uses graphic mode to monitor the data transmission situation ofsome single selected nodes, requires the ability of demonstrating the currentuploading data quantities and the data processing result for that node. Thesystem message monitoring demonstrates the complete or assigned nodes, theapplication system message by tabulating the results, requests to able todemonstrate the serial number, the message type, the content, the processingresult,aswellasthetime.2nd, ConfigurationManagementTheconfigurationmanagement mainlyfocuses on theconfigurationofthefront server and the platform server. It could describe front server's IP, PORT,the description, application ID (may have many same configurations, forconfiguring many applications).In addition, through the configurationmanagement, it also can configure IP, PORT or description for the platformdataandtheorderserver,3rd, OrderManagementIt can add, delete or modify an order frame. Moreover, it also could makea custom-made legitimate order frame which sends operation orders to thenode.4th,DataStatisticsInquiryIt can demonstrate the application data and the order data content, theapplication procedure type, the starts time, the end time, data quantity, nodelabel, processing result, SN, order label, receive node, transmission time, andreplytimebygraphsortabulations.In order to realize above functions, the system has been designed byfollowing6modules:CommanderModule:Itisresponsibleforissuingorderstothelowerlevel,and judges whether succeeds, also save the order to the database after itssuccessful application. The core processing of commander module mainly focuses on transiting orders and constructing order data frames. Once it sendsthe order to the platform, the analysis whether the order was enforced isrequired. If the order was enforced, it needs to save the information into thedatabase, or it needs to make a hint message. The structure of an order frameis mainly consists of frame and order information. By adding order frame toinform the platform that the kind of application which sends the order, theorder information mainly shows sending whatever orders to whichever node.Configuration Manager Module: It manages the platform and the databaseconfiguration. After the launching of this module, the system will search theconfiguration files catalogue first, if the catalogue exists, then loadconfiguration files catalogue, if not, it will create the table of contentsconfiguration files. In the process of creating table of contents configurationfiles, it needs to produce two parts of information, the database configurationmanagement and the platform configuration management. The databaseconfiguration mainly configures the databases where the received data hasbeen stored. This database information contains the name of the databaseserver, the database IP address, as well as access account and password. Theplatform configuration is responsible for disposing the basic information inorder to help communicate between the front system and the platform. Theplatform configuration information mainly includes the port number, theplatform IP address and the description of platform.Receiver Module: it is responsible for receiving the distributed data fromthe platform, stores the data into the original database, or resends to ConverterModule. System opens interception service, if intercepts that platform needsto transmit data, it will receive the data and response to platform, then storesthe data in the original database, after this, it will analyze the data frame, ifanalyze successfully, then transform the data frame, which is the main workof the converter module; otherwise, it will continue to monitor, this data framemay delay the transformation.Register Module: it registers this application to the platform, which meansinforming the platform to transmit the data to IPUS Front. After this modulestarts, it will structure registration order first, and send the structuredregistration order to the platform. In this time, it will start to intercept whether there is a reply of the platform, if there is, analyze the information replied bythe platform, if registers successfully, this module will end, if not, structureregistration order transmission for platform once more. This module isresponsible for the role of noticing the information of the front system to thepre-notification platform, and hence makes it be able to know where thereceived data will be send.Converter Module: it converts the data which the receiver module accepts,analyzes the data, and stored in the database. The data frame form defines inadvance; analyze the data according to the original form, and finally analyzeout all the information of the data.Status Monitor Module: it controls the current of the current data. Throughthe tabulation and the view form, this module works on monitoring the status.It mainly monitors three catalogues: real-time data, node data, systemmessage, and also realizes the historic record inquiry and the statistics of thesethree kinds.Based on the information we stated above, it's clear that the front systemhas the extremely high flexibility and the independence; it could balance thedata load of the entire system, accelerate the processing of the data. As thewireless sensor network application is developing rapidly, the front systemserviceability and the security would gain more attentions, the problem ofhow to design more general and the high secured front system will become ahot issue for applied research. It will have a broad prospect!...