SUMMARY
Context. Article is devoted to development of a method of definition of probability-time characteristics of layer of services andapplications servers of IMS. It is shown that constantly growing a variety of services which IMS, and increase in demand for themamong users is capable to provide and also the fact that with development of telecommunications the increasing attention is paid toquality of providing services – QoS, the problem of assessment of quality of providing services causes relevance of development of amethod of definition of probability-time characteristics of layer of services and applications servers of IMS.Objective. Develop a method of definition of probability-time characteristics of layer of services and applications servers of IMStaking into account different types of services which IMS is capable to provide.Method. It is considered architecture of IMS. The main attention is paid to the layer of services and applications servers. For developmentof a method of definition of probability-time characteristics of layer of services and applications servers of IMS it is offeredto use approaches of the queuing theory and the tensor analysis of networks. The offered method represents the sequence ofstages which execution allows to define structural blocks of layers of services and applications servers of IMS which are responsiblefor providing services of different types; present call session control function and the layer of services and applications servers in theform of separate laid on network – initial queuing network; for use of a planimetric method to enter the imagined branch which createsthe closed circuit; enter planimetric intensity and define their directions; define a transition matrix from initial network to primitivenetwork; present the invariant equation for initial network; define planimetric intensity and on their basis to calculate intensity ofreceipt of requests for services and loadings of servers in initial network. As a result – to receive expressions for calculation of probability-time characteristics of layer of services and applications servers.Results. The method of definition of probability-time characteristics of layer of services and applications servers of IMS on thebasis of approaches of the queuing theory and tensor analysis of networks which allows to consider different types of services whichIMS is capable to provide is offered.Conclusions. The method of definition of probability-time characteristics of layer of services and applications servers of IMSwill allow designers IMS to calculate probability-time characteristics at early stages of the project that will allow to define the necessarynetwork resources for ensuring required value of quality of providing services of different types. Further, at development of theoffered method, at a research of layer of services and applications servers of IMS for the purpose of definition of probability-timecharacteristics accounting of self-similarity of a flow of requests for services and restrictions of a buffer memory of servers is reasonable.