Operative Distribution of Satellite Repeater Radio Resource in Terms of Non-Stationary Ingress Flow with Account of Time Lagged Control
Keywords:
Satellite Repeater, Radio Resource, Satellite Terminal, Interrupted Poisson Process, Modulated Markov Process, Nonlinear Programming, Time Lagged Control, Voice TrafficAbstract
Purpose: Vast satellite-serviced area and subscriber base of satellite repeaters on the one hand and fundamental limitedness of their frequency-energetic resource (radio resource) on the other hand require operative radio resource redistribution between active and passive radio routes to enhance their operation efficiency. The goal of this research is development of a method to control distribution (reservation) of a satellite repeater resource under traffic variance provided by diverse satellite terminals, development of a mathematical model of a non-stationary traffic service process which allows optimizing control of a chosen efficiency factor. Methods: modulated Markov processes, tele-traffic theory, non-linear programming. Results: There have been formulated task of operative distribution (reservation) of satellite repeater radio resource in a form of non-linear programming problem; there has been given an example of its solution during service of a non-stationary message stream which is formed by a group of voice subscribers. Modulated Markov process and its particular case – so called interrupted Poisson process – has been used as a model of a non-stationary message stream formed by voice subscribers taking into account signal suppression in pauses. The essence of this control method is flexible connection of an additional reserve after achievement of a particular limit by message queue in input of satellite terminal. The novelty of the approach implies that the best limit value for each satellite terminal is defined either by statistical characteristic of input stream or by control signals lag factor in satellite radio-frequency line. To solve the given optimization problem of nonlinear programming there has been developed a mathematical model of service of modulated Markov process with time lag during connection of additional channels in a form of three dimensional Markov chain. In order to achieve this goal there has been accepted as restrictions an assumption about exponential rules of duration distribution of active periods and pauses, time lag of connection of additional resources, duration time of certain message transmission and an interval time between them. Removal of one or more of these restrictions is possible by widening of state space and dimensions of the model accordingly. There has been developed an algorithm for this problem solution and there has been given an example for the case when ingress flow is formed only by one subscriber and it is described by interrupted Poisson process. Practical importance: The developed method of operative distribution of satellite repeater radio resource with account of dynamics of heterogeneous network traffic will significantly increase capacity of the domestic satellite networks which include a lot of local satellite terminals (the simplest example indicates from 15 to 40 %).