An approximation for computing reduction in bandwidth requirements using intelligent multiplexers

This paper stochastically models a single-node telecommunications system both with and without the use of intelligent multiplexing. Intelligent multiplexers take advantage of the idle periods or silences that occur during the course of speech transmissions to merge (or multiplex) packetized talkspurts from more than one source onto a single channel. This allows for a more efficient use of available bandwidth, thereby reducing the amount of bandwidth required to carry a particular traffic load. Digitizing speech into packets of equal size also allows for compression, further reducing bandwidth needs. By comparing the models for systems both with and without multiplexing, we are able to determine the reduction in bandwidth which may be expected for a particular grade of service (measured by blocking probabilities). A bivariate continuous time Markov chain model for a multiplexer is presented. An approximation is introduced to calculate limiting blocking probabilities much more quickly and for larger systems than is possible by solving a set of linear equations for the bivariate model. The accuracy of the approximation is explored through comparison with the bivariate model; the approximation provides a somewhat conservative estimate of blocking, but is close enough to be used as a tool for the range of relevant values. The approximation is then used to compare blocking probabilities for three different levels of speech activity. Results are shown in tabular form.... Telecommunications, Model, Stochastic telecommunications modelhttp://archive.org/details/approximationfor00hensLieutenant Commander, United States NavyApproved for public release; distribution is unlimited

Enterprise Command and Control requirements and common architecture on U.S. Navy surface combatants

Across the U.S. Navy, each new ship class implements a new command and control (C2) system design, leading to separate design and development efforts, training pipelines, support requirements, and upgrade activities. This project serves as an initial step in determining whether the Navy can consolidate C2 systems by defining a common C2 system architecture and requirements that can be applied across all surface combatants for the Surface Warfare and Maritime Interception Operations missions. The project applied a systems engineering process consisting of a needs analysis, functional analysis, and modeling and cost analysis. The needs analysis defined key user objectives and needs and identified threats to Navy platforms. The functional analysis included the core tasks of requirements definition and enterprise architecture. The modeling and cost analysis task verified the C2 system architecture and evaluated possible training course hour savings. The project found that the definition of a common set of C2 system requirements and system architecture is feasible and does provide possible life cycle cost savings to the Navy. In order to fully evaluate a proposed common C2 system, further work will be required, expanding the analysis to other missions and assessing the cost impacts of a common C2 systemhttp://archive.org/details/enterprisecomman109456939N