USING SENSITIVITY FUNCTION FOR CONGESTION CONTROL IN TELECOMMUNICATION NETWORK

Abstract

The scheme of control of congestion with the use of feedback on the sign of the sensitivity function of productivity of the telecommunication network is considered. The performance sensitivity sign (target function) provides the optimal direction for adjusting the speed of the data source. The most common scheme for controlling binary feedback feedback messages about possible network congestion is to detect and set the congestion bit based on the length of the incoming packet queue. The main advantage of a queue-based scheme is its low complexity: the length of the queue can be controlled by a single counter. However, this method can create large queues in network nodes. Detecting the created mash should be delayed for some time to create the queue. Similarly, the detection of a congestion solution is also delayed by the time required to process the queue. To determine the sensitivity function of the network performance, it is proposed to use a simple neural network model of the dynamic system. The developed optimal control algorithm provides the formation of a control signal in such a way that the output of the system is as close as possible to the pre-established characteristics of the network. The model for the backtroque prediction of the queue state is proposed. The results of the simulation of the performance of the proposed scheme show that the scheme based on sensitivity has better performance compared with the usual scheme of choosing the threshold. A sensitivity-based circuit gives smaller variations in queue size and source speeds. Moreover, fluctuations are not significantly different, even if there are large changes in the service speeds of bottlenecks in the telecommunication network or its fragments.