<title>Fiber network telecommunication information system design using modern design methodologies</title>

Abstract

The work represents the conceptual model of link objects and the corresponding system of parameters describing their state. Telecommunication information system design stages are investigated on the basis of the obtained model. TIS architecture suggested in the work brings about the concept ofunited telecommunication information space.Modem development and prevalence of fiber transmission system have determined a range of problems concerning design, support and monitoring of link objects'6 . Fiber Network (FN) is a complex system object that includes a large number of elements, each characterized by a set of particular parameters3 which need to be properly controlled. At this level it's efficient to use RAD-technologies (Rapid Application Development) of visual design which make it possible to reduce economic costs and usage of other resources. To bring about such RAD-technologies it's necessary to develop and create visual components bases which would enable the building of different telecommunication systems. In this sense it is necessary to create information models of link objects with different levels of sophistication which enable further creation of information telecommunication system of a new quality -systems with the elements of knowledge bases and ability to evolutionary development. Another problem, widely covered in foreign and Russian literature6' ,is the development of complex system of FN-state monitoring and forecasting. One of the promising ways of solving monitoring problems is the application of hierarchical approach to build the system of parameters determining the state of telecommunication systems at different levels of their consideration (micro-, mezo-and macrolevels). The goal of the research is the application of structural approach and usage of CASE-technologies to develop and create automated FN information telecommunication system designing and monitoring. DEVELOPMENT OF FN CONCEPTUAL AND DATALOGICAL MODELSSubject area analysis12 has revealed that notionally FN can be considered a data communications network where fiber is used as a signal transmission environment. This allows to introduce such information substance as "Transmission Network" (TN). As a result of link object or the substance "Transmission Network" decomposition TIS conceptual model can be represented as a three-level hierarchical system, TIS structural scheme portrayed in Figure 1 . According to paper'3 at the first level of decomposition (macrolevel A) the substance "Transmission Network" is depicted as total bination of two subsystems: "Net Node" and "Connection". "Net Node" subsystem is a set of technical instruments providing the formation of standard physical transfer circuits. Within the model the substance "Connection" corresponds to the transmission line which has one signal transmission medium and connects net nodes. The decomposition of Amacrolevel subsystems results in the formation of B-mezolevel which consists of atomic (non-decomposed) attribute "Bandwidth" and three complex attributes or substances "Com...