Summary: One of the most important properties of telecommunication networks to ensure their effective functioning is survivability. To ensure the survivability of telecommunication networks it’s required to solve a number of scientific and engineering problems at all stages of their life cycle – design, modernization or improvement, operation. Questions of ensurance of survivability of telecommunication networks are becoming more actual due to the intensive development of telecommunications in the past decade. The synthesis problems of survivability systems, evaluation, ensurance and improvement of structural survivability of the systems, as determined by the needs of practice acquired particular actuality today. The aim of this work is to develop a method of ensurance of structural survivability of telecommunication network (TCN), which implements the streaming approach using the proposed index of structural survivability TCN defined lower boundary of structural survivability, providing a guaranteed stable functioning TCN, the achievement of the desired value which is performed by the introduction of structural redundancy (as the property of survivability possess only redundant systems) using the optimization procedure of the sections branches reservation, the choice of which is determined on the basis of maximizing the effectiveness of each stage of the reservation. The optimization of value of the structural survivability of TCN is to achieve its maximum value at the existing restrictions. The method to ensure structural survivability TCN, based on the formation of sets of admissible routes for each service requirements, for which are formed the sets of admissible sections is developed. Are determined the probable values of unaffecting each section, and for each set of sections, which are formed on the basis of the lower boundary of the structural survivability TCN obtained as an average value of probable unaffecting sections. The paper proposes a developed the method of the ensurance of structural survivability of TCN, which is designed for procedural model, which includes the execution of the sequence of steps: 1) formation of the source data, 2) the evaluation of the structural survivability of TCN, 3) the ensurance structural survivability of TCN, 4) the development of solutions for the structural survivability of TCN. For each stage, are formulated the objectives and are determined ways to decide them. For stage 1) the list and the method to present the initial data are determined; for stage 2) are determined ways of forming sets of admissible routes and obtaining for them sets of 166 International Journal "Information Technologies & Knowledge" Volume 8, Number 2, 2014 admissible sections, for which are given methods for calculating the probabilities of unaffecting of each sections and the probabilities of unaffecting of all admissible sections which separate points s and t ( s,t n = 1, , s ≠ t, n – number of network points), is formulated a condition for the lower bound of the required structural survivability of TCN. In stage 3) optimization problem is formulated to ensure the required value of the lower limit of the structural survivability of TCN as a mathematical programming problem, is shown the feasibility of using the gradient method to solve it, a method of calculating the efficiency of each step of the optimization process. Stage 4) is final. At this stage is drawn the conclusion that the obtained solution of the optimization problem to introduce structural redundancy with in sets of limits or provides the required value of the index of structural survivability TCN or provides the procedure of recommendations on: changing the value of the matrix elements of the probability of unaffecting branches of the network which is computed value by solving the problem; the change of classes (priorities) and the "weights" of certain requirements; limiting values of network requirements, the change of defined limit values, the lower boundary of the structural survivability TCN. The proposed method can be used in the case where the sets of admissible routes and admissible sections are the sets of all possible routes and all possible sections in the TCN. An example of implementation of the proposed method to ensure structural survivability of the telecommunications network is made.

Ключевые слова: структурная живучесть, сеть, резервирование, путь, сечение, показатель живучести.

Ключевые слова классификации ACM: С.2. Computer-communication networks, H. Information Systems - H.1 Models and Principles, K. Computing Milieux - K.6 Management of computing and information system.

Link:

МЕТОД ОБЕСПЕЧЕНИЯ СТРУКТУРНОЙ ЖИВУЧЕСТИ ТЕЛЕКОММУНИКАЦИОННОЙ СЕТИ (The Method of the Ensurance of Structural Survivability of Telecommunication Network)

Нина Князева

http://www.foibg.com/ijitk/ijitk-vol08/ijitk08-02-p08.pdf