Tools for planning and designing data

The planning, design, and management of a large telecommunications network is a complex process involving many aspects of the network's cost and performance. Throughput capability, reliability, response time performance, and cost must all be considered in evaluating alternatives. For a large network, obtaining an accurate analysis of anyone of these aspects is a formidable task involving cumbersome calculation and many decisions. The problem of obtaining an accurate analysis of the entire system is magnified by the fact that these individual factors interact strongly with one another. Thus, in order to design a "good" network, or verify that an existing network is operating properly, one must not only be able to solve each of the above problems, but also be able to evaluate the solution of each one in the context of solutions to the others. Computer programs, if they are carefully designed and properly used, can be pO'werful tools in the planning and management process. While one cannot reasonably expect that such programs will solve all problems or even that they will solve anyone problem perfectly, such programs can take a large burden off the analyst by providing accurate and reliable answers to subproblems which can then be used to answer global questions about the overall network. Thus, these programs are used by the qualified analyst as tools. If the man-machine interface is good, the analyst and the computer together can solve problems that neither could solve as well separately and each works on the aspects of the overall problem which he can handle best. The analyst decomposes the overall problem into subproblems and couches his questions to the computer in such a way as to reflect the peculiarities of each particular network and the relative importance of each design criterion, which also varies from system to system. The machine answers specific questions in the context posed and enables the analyst to consider many more alternatives than he would otherwise have the time or inclination to approach using hand analysis alone. This paper functionally describes programs which can be used as design and analysis tools, and the uses they can be put to. Examples of the benefits obtainable through the use of such tools in the design and analysis of actual networks are presented. Although much of the material presented can be applied to the design and analysis of all types of networks,