Overflows of Elastic Traffic

This article presents the results of a study on hierarchical multiservice traffic overflow systems. The systems under investigation were composed of a number of primary resources and one alternative resource. Traffic in the considered systems was generated with the assumption that there was a finite number of traffic sources in individual classes. Further assumption was that offered traffic is elastic traffic for which – with an increase of the load of the system – a change in the volume of allocated resources is possible followed by concurrent extension of their service time. The article includes the results that present the blocking probability in the sample elastic traffic overflow systems. The study focuses on a determination of the influence of the traffic intensity, volume of resources, degree of compression, resource with compression (primary resources, alternative resources) and the cardinality of traffic sources on values of the blocking probability in individual call classes and on the number of calls that overflow to the alternative resource.

Modelling of Cellular Networks with Traffic Overflow

The paper proposes a new method for modelling multiservice cellular networks with traffic overflow. The proposed method employs a model of Erlang’s Ideal Grading (EIG) with multiservice traffic and differentiated availability. The fundamental advantage of the proposed method, as compared to other relevant methods, is a major simplification in modelling systems with traffic overflow that results from the elimination of the necessity of a determination of the parameters of overflow traffic, that is, the average value and the variance. According to the proposed method, calculations in the overflow system can be reduced to calculations in a system composed of one grading only. The paper presents the method for determining availability in such a grading that models a system with traffic overflow. The results of analytical calculations were compared with the results of simulation experiments. The results of the research study confirm high accuracy of the proposed method.