A Method Of Data Subscription And Distribution Based On WSN

With the developing of economic and the improving of scientific technology and living standard, automated construction of public utilities, as an effective way of management which is able to reduce operating costs and enhance, has become an inevitable trend of Social Development. WSN(Wireless Sensor Network) consists of a mass of sensor nodes ,which can sense independently, process data and transmission of information, it can be applied to environmental monitoring, flood forecasting, urban traffic management, inventory and logistics management and other fields. As an emerging technology, people are generally optimistic about its application on the automated construction of public utilities.At present, research on Wireless Sensor Network includes Node localization, time synchronization, network information processing, case detection and routing algorithm and so on. But existing technologies are far from our urgent needs, so some people in this industry proposed innovative research plan of Wireless Sensor Network, and from application view, decomposed seven subjects: Question 1: developing node platform; Question 2: developing the core protocol of self-organizing and self-configuration; Question 3: designing energy efficient communication protocol; Question 4: research of Wireless Sensor Network and Internet connectivity technology; Question 5: developing Wireless Sensor Network data management system; Question 6: research of application system; Question 7:Set up large-scale experimental platform. In this paper, we are concerned on Question 5, we also pay attention to Question 4 and Question 6 during the research.During the combine process of development for Utility automation and Wireless Sensor Network technology, a problem that universality of Utility automation result to development which based on Wireless Sensor Network has a variety of forms exists. To developers, each new development of the field accompanied by a series of requirements and design changes, except for need to consider the matching of hardware equipment, and consider to redesign and develop the software. Based on the above questions, this paper attempts how to control the communications protocol to manage different data fields flexibly in the WSN data management system, so it can resolve the Obstacles bought by the difference of industry data during the developing about WSN system.Taking into account the wireless network technology in the field of public utility applications in different sectors, this paper presents a data subscription and distribution method which stores the communication protocol mapping rules in the database table. We choose XML language to describe Mapping rules because of XML language has the scalability, flexibility and descriptive. It makes the sequence of XML language can be processed by any platform, any programming language, any application of treatment systems, so as to solve the enormous difference on communication protocol which is caused by the difference on business data.The method implementation is divided into three modules: module of collecting data conversion, mapping rules management module, resolve XML interface module. Module of collecting data conversion is responsible for validation, analysis, forming XML sequence file about collecting data; mapping rules management module manages data mapping rules, you can query, add, delete and edit the collected data mapping rules; analytic interface XML interface module provides interface to analysis of communications data frame described by available sequence of XML language.Combination of data subscription and data distribution methods, the paper implementation of a wireless network data management system, which is divided into four modules, namely: listening modules, distribution modules, control modules, wireless sensor network management module. Information exchange between modules when the communication data frame uses sequence of XML .Inter-module communication uses Socket technology.Listening module features include: filtering data frame, the maintenance of routing information, and mechanism for cache and re-send. Here to filter data frames is based on the source of the data frame. The maintenance of the routing module is to save the address information of the node which joins the system first to the database table. This information would provide interactive routing information reference when information when information exchange happens between the wireless network and the data management systems .Listening module will save the data frame buffer on the database to be re-sent if it was failure when sending data frames to distribution module.Distribution modules include: the maintenance of the data subscription, data frame forward, re-issued data cache. When the distribution modules receive a write-off application, the distribution module will delete the application data sheet register information about the application, as well as data subscription Records. Forward data frames, the distribution modules first analysis data frame by data mapping rules, and then transmit it to the appropriate terminal, if it sends fail, it would save the data frame to database for re-send.Control module in the entire wireless network data management system is to send commands and time synchronization to the base stations to coordinate the whole work in system. The most important function of WSN management module is to custom data frame format, at the same time provide access to the information of wireless sensor network nodes and base stations.Although the entire wireless network data management system is not perfect in function, in some aspects of security and reliability are also missing, but already can provide basic data management functions. Using data distribution and subscription method in this system enable the system up to a certain extent with the general applicability to the wireless sensor network data management and can complete data management in a variety of industries.