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Call-level Analysis of a Two-Link Multirate Loss Model based on a Convolution Algorithm

Sagkriotis S. G., Pantelis S. K., Moscholios I. D., Vassilakis V. G.

Journal of Telecommunications and Information Technology

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2018

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nr 1

3--10

EN

We consider a two-link system that accommodates Poisson arriving calls from different service-classes and propose a multirate teletraffic loss model for its analysis. Each link has two thresholds, which refer to the number of in-service calls in the link. The lowest threshold, named support threshold, defines up to which point the link can support calls offloaded from the other link. The highest threshold, named offloading threshold, defines the point where the link starts offloading calls to the other link. The adopted bandwidth sharing policy is the complete sharing policy, in which a call can be accepted in a link if there exist enough available bandwidth units. The model does not have a product form solution for the steady state probabilities. However, we propose approximate formulas, based on a convolution algorithm, for the calculation of call blocking probabilities. The accuracy of the formulas is verified through simulation and found to be quite satisfactory.

2

Derivatives of Blocking Probabilities in Multirate Access Tree Networks

Moscholios I. D., Vardakas J. S., Logothetis M. D., Boucouvalas A. C.

Advances in Electronics and Telecommunications

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2013

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Vol. 3, no. 5

38--48

EN

We consider a multirate access tree network accommodating service-classes of Poisson traffic, and focus on the determination of derivatives of Call Blocking Probabilities (CBP) with respect to offered traffic-load of any service-class. Based on the derivatives, we further show how we can successfully approximate CBP for small variations of offered traffic-load.

3

Retry Loss Models Supporting Elastic Traffic

Moscholios I. D., Vasilakis V. G., Vardakas J. S., Logothetis M. D.

Advances in Electronics and Telecommunications

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2011

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Vol. 2, no. 3

8--13

EN

We consider a single-link loss system of fixed capacity, which accommodates K service-classes of Poisson traffic with elastic bandwidth-per-call requirements. When a new call cannot be accepted in the system with its peak-bandwidth requirement, it can retry one or more times (single and multi-retry loss model, respectively) to be connected in the system with reduced bandwidth requirement and increased service time, exponentially distributed. Furthermore, if its last bandwidth requirement is still higher than the available link bandwidth, it can be accepted in the system by compressing not only the bandwidth of all inservice calls (of all service-classes) but also its last bandwidth requirement. The proposed model does not have a product form solution and therefore we propose an approximate recursive formula for the calculation of the link occupancy distribution and consequently call blocking probabilities. The accuracy of the proposed formula is verified by simulation and is found to be quite satisfactory.