Management System Of Frequency Coordination And Calculation Method

The application of radio system becomes more and more popular and wide because of the development of the telecommunication technology, including the area of the broadcast, TV, communication etc. Radio stations and signals tower are building all over the world. As everyone knows, the frequency resource is limit; in the situation of lacking of common management and allocation, the station instrument of two neighborhood country usually interfere with each other, just because they are too close. There comes the frequency coordination problem.In frequency coordination procedure, one who starts the coordination procedure must provides frequency and antenna data of their radio station by the way of letter, the other one carries out interfering calculation using these data to check whether their station has actually interfered with other country's station. This calls coordination calculation. If necessary, the two country need to have a meeting, discussing detail items. In this course, the most important document is the letter, which is divided into sending letter and receiving letter. The notice data (including the frequency and antenna) is the important part, which takes part in coordination calculation procedure. Besides the letter, coordination procedure also includes coordination meetings.On the meeting, the two countries reach an agreement about coordination detail and decide the coordination standard. Coordination standard is very important, because the coordination calculation procedure depends on the coordination standard, different standard have different conclusion to the same calculation.The calculation methods of different service types are different. ITU provides each service type with interfering calculation model. For example, propagation model 1448 describes calculation method of earth station service's coordination area. The coordination area of earth station is area in which the sending or receiving signal of the earth station may interfere with other radio systems. The calculation procedure is complex, relates to much radio theory and calculation. We use propagation model 1448 when we complement the system.Determination of coordination area is based on the concept of the permissible interference power at the antenna terminals of a receiving terrestrial station or earth station. The coordination distance, determined for each azimuth around the coordinating earth station, defines the coordination contour that encloses the coordination area. Hence, the core of coordination area calculation is coordination distance for each azimuth.The attenuation required to limit the level of interference between a transmitting terrestrial stations or earth station and a receiving terrestrial station or earth station to the permissible interference power is represented by the minimum required loss. Determination of coordination area requires the calculation of the predicted path loss and its compression with the minimum required loss for every azimuth around the coordinating earth station. The predicted path loss is dependent on several factors including the length and general geometry of the interfering path, antenna directive, and radio climatic etc. The coordination distance is the distance at which these two losses are considered to be equal.The coordination procedure is composed of much interactive of letters and technical document, which also needs complex coordination calculation. These are handled by manual work usually. To improve the efficiency of frequency coordination, this paper design and complement the Management System of Frequency Coordination and Calculation Method based on actual application. The whole papers are made up by seven chapters, which is divided into four parts. The first part includes two chapters, which introduces the background of the subject selection, main work, the problem in system design and corresponding solution. The third chapter is the second part, which pays attention to the principle of system design, the topology structure of system network, and system architecture structure. The next three chapters are the third part, they states the design idea and specific implement of each module in detail. The end of the paper summarizes the shortage of the system, also prospect the future work.The first part is technology related introduction part. This part first introduces the background of frequency coordination and difficult point of coordination management, state the necessity of developing the Management System of Frequency Coordination and Calculation Method, then explain the technology background and difficulty solution of system development and design.The second part is about the system design, which includes whole architecture design and database design of each module. This part first gives the basic principle that the system design obeys, which is security, error-compatible, easy to use, stability principle. This part next states the structure of system architecture and network. The system needs a computer to load the web server and database server. The operator uses the web browser of personal computer to visit the system through radio system intranet. The users also need to install the calculation software, which accepts the station parameter data exported by management system, carries out the coordination calculation, generate the calculation result table and coordination area diagram. The whole system is consisted of management system, calculation system and core management platform. The management system includes station coordination module, coordination meeting module, coordination standard module and query-statistics module, which is in charge of management job of coordination procedure. For example, coordination subject recording, letter recording, station parameter entering, calculation result archiving, coordination standard maintain, meeting document division etc. The calculation system mainly carries out the interfering calculating job. It uses the parameter data from management system and assistant frequency, geography information retrieved from database server deployed by the country to generate calculation result. The core management platform is designed to apply system configure, account management, power allocation job. This part finally describes the database design principle and corresponding ER diagram of each module.The third part mainly describes the detail design and implementation of each module. This part starts with module function, database interface, and implementation description to introduce the design and implementation of each module, also gives the flow graph of implementation. When discussing the calculation module, this part stresses the calculation method and implementation detail of earth station's coordination area. This part finally talks about the interface between management system and calculation system. The data exported by management system includes two parts: station parameter data and coordination standard. These two parts are exported in XML format, which take part in calculation procedure to create the calculation result and coordination area diagram. The calculation result, which is imported in management system for archiving, is also stored in XML format.