Serbian Institute for Telecommunications and Electronics

Belgrade, Serbia

Serbian Institute for Telecommunications and Electronics

Belgrade, Serbia

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Mileusnic M.,Serbian Institute for Telecommunications and Electronics | Suh T.,Serbian Institute for Telecommunications and Electronics | Lebl A.,Serbian Institute for Telecommunications and Electronics | Mitic D.,Serbian Institute for Telecommunications and Electronics | Markov Z.,Serbian Institute for Telecommunications and Electronics
Acta Polytechnica Hungarica | Year: 2014

In this paper we present how computer simulation can be used to estimate the mean output power and the probability cumulative distribution function of one base station output power in GSM. The basis of the method is adding the simulation of random distance between the mobile station (MS) and base transceiver station (BTS) to the known method of telephone traffic simulation. The simulation is a suitable method for the estimation of base station output power, especially in the case when it is not easy to calculate the output power's dependence on these factors. A couple of numerical examples present the results of these simulations.


Suh T.,Serbian Institute for Telecommunications and Electronics | Mitic D.,Serbian Institute for Telecommunications and Electronics | Lebl-Antonic D.,Vojvode Stepe 450 | Lebl A.,Serbian Institute for Telecommunications and Electronics
Acta Polytechnica Hungarica | Year: 2014

In this paper we present the mathematical analysis of engagement of technicians in the teaching (educational) process on the faculty. The technicians receive the requests from professors and assistants. In the case that all technicians are busy in the moment of generating a new request, some of the assistants take over processing of the request. We analyse the probability of unwanted states, i.e. the states when it was necessary to engage the assistants on processing the request, which could have been processed by the technicians, if they had been free. The number of engaged technicians is determined in such a way that the probability of these unwanted states is satisfactorily small, i.e. that these states take available assistants' time in reasonable limits.


Sandic-Stankovic D.,Serbian Institute for Telecommunications and Electronics | Kukolj D.,University of Novi Sad | Le Callet P.,Ecole Polytechnique - Palaiseau
Journal of Electrical Engineering | Year: 2016

The Depth-Image-Based-Rendering (DIBR) algorithms used for 3D video applications introduce geometric distortions affecting the edge coherency in the synthesized images. In order to better deal with specific geometric distortions in the DIBR synthesized images, we propose full-reference metric based on multi-scale pyramid decompositions using morphological filters. The non-linear morphological filters used in multi-scale image decompositions maintain important geometric information such as edges across different resolution levels. We show that PSNR has particularly good agreement with human judgment when it is calculated between detailed images at higher scales of morphological pyramids. Consequently, we propose reduced morphological pyramid peak signal-to-noise ratio metric (MP-PSNR), taking into account only mean squared errors between pyramids' images at higher scales. Proposed computationally efficient metric achieves significantly higher correlation with human judgment compared to the state-of-the-art image quality assessment metrics and compared to the tested metric dedicated to synthesis-related artifacts. © 2016 Faculty of Electrical Engineering and Information Technology, Slovak University of Technology 2016.


Mitic D.,Serbian Institute for Telecommunications and Electronics | Lebl A.,Serbian Institute for Telecommunications and Electronics | Markov Z.,Serbian Institute for Telecommunications and Electronics
Acta Polytechnica Hungarica | Year: 2012

The bandwidth of signaling channel with bursty errors can be larger or smaller than the bandwidth of channels with random errors. In this paper, we give the answer to the question: Is it possible in an easy way to determine the relationship between the bandwidths of these two models? First, we define the method that determines the bandwidth of the signaling CCS No7 channel under the influence of random errors, and then the method that determines the bandwidth of the signaling CCS No7 channel under the influence of bursty errors. The paper also gives the procedure, which easily compares the channel bandwidth for these two types of errors.


Sandic-Stankovic D.,Serbian Institute for Telecommunications and Electronics
17th DSP 2011 International Conference on Digital Signal Processing, Proceedings | Year: 2011

The performances of morphological wavelets for 3D volume image decorrelation in lossless image compression are presented. Nonlinear morphological wavelets used in non-redundant multiresolution signal decomposition schemes with perfect reconstruction are very fast for implementation as only integer arithmetic is used. The lifting schemes implementing morphological wavelet transforms avoid quantizers which is attractive property for lossless data compression. The performances of both separable and non-separable 3D morphological wavelet transforms using lifting scheme is evaluated. The computation time of 3D decomposition implemented by morphological wavelets is 3 times shorter than the decomposition time with 5/3 wavelet filters used in JPEG2000 standard with similar decorrelation efficiency for lossless compression. © 2011 IEEE.


Stanic M.,Serbian Institute for Telecommunications and Electronics | Lebl A.,Serbian Institute for Telecommunications and Electronics | Mitic D.,Serbian Institute for Telecommunications and Electronics | Markov Z.,Serbian Institute for Telecommunications and Electronics
Przeglad Elektrotechniczny | Year: 2013

We describe the operation of ISDN or IP faulty link detector in mixed telephone network of Electric Power Utility. Basic principle of this detector is increased seizing of Power Line Carrier link that is parallel to ISDN or IP link. Main indicators of detector efficiency: the probability of detection of false failure, the probability of detection miss and mean time to failure detection are calculated, verified by computer simulation and discussed.


Matic V.,Serbian Institute for Telecommunications and Electronics | Lebl A.,Serbian Institute for Telecommunications and Electronics | Mitic D.,Serbian Institute for Telecommunications and Electronics | Dukic M.,Serbian Institute for Telecommunications and Electronics
Przeglad Elektrotechniczny | Year: 2012

In this paper we present that Post Dialling Delay in one telephone network depends on the service discipline in particular network nodes. It is indicated that deviation of PDD from its mean value decreases as the number of nodes included in one established connection increases. The consequence of this fact is that the condition of serving 95% of connections is more stringent in the connections with small number of network nodes included in the connection, while the condition dealing with the mean value of PDD is more stringent in the connections with great number of nodes.


Suh T.,Serbian Institute for Telecommunications and Electronics | Markov Z.,Serbian Institute for Telecommunications and Electronics | Lebl A.,Serbian Institute for Telecommunications and Electronics | Mitic D.,Serbian Institute for Telecommunications and Electronics
Przeglad Elektrotechniczny | Year: 2012

In this paper we present detector of faulty links in non-hierarchical telephone network with alternate call routing, as, for, example, in telephone networks of Electric Power Utility. The operation principle of the detector is traffic measurement on links. The main detector properties are determined: alarm detection, failure detection credibility and the detection time. The last two of three mentioned properties are inversely proportional.


Sandic-Stankovic D.,Serbian Institute for Telecommunications and Electronics | Kukolj D.,University of Novi Sad | Le Callet P.,Ecole Polytechnique - Palaiseau
Eurasip Journal on Image and Video Processing | Year: 2016

The depth-image-based rendering (DIBR) algorithms used for 3D video applications introduce new types of artifacts mostly located around the disoccluded regions. As the DIBR algorithms involve geometric transformations, most of them introduce non-uniform geometric distortions affecting the edge coherency in the synthesized images. Such distortions are not handled efficiently by the common image quality assessment metrics which are primarily designed for other types of distortions. In order to better deal with specific geometric distortions in the DIBR-synthesized images, we propose a full-reference metric based on multi-scale image decomposition applying morphological filters. Using non-linear morphological filters in multi-scale image decomposition, important geometric information such as edges is maintained across different resolution levels. Edge distortion between the multi-scale representation subbands of the reference image and the DIBR-synthesized image is measured precisely using mean squared error. In this way, areas around edges that are prone to synthesis artifacts are emphasized in the metric score. Two versions of morphological multiscale metric have been explored: (a) Morphological Pyramid Peak Signal-to-Noise Ratio metric (MP-PSNR) based on morphological pyramid decomposition, and (b) Morphological Wavelet Peak Signal-to-Noise Ratio metric (MW-PSNR) based on morphological wavelet decomposition. The performances of the proposed metrics have been tested using two databases which contain DIBR-synthesized images: the IRCCyN/IVC DIBR image database and MCL-3D stereoscopic image database. Proposed metrics achieve significantly higher correlation with human judgment compared to the state-of-the-art image quality metrics and compared to the tested metric dedicated to synthesis-related artifacts. The proposed metrics are computationally efficient given that the morphological operators involve only integer numbers and simple computations like min, max, and sum as well as simple calculation of MSE. MP-PSNR has slightly better performances than MW-PSNR. It has very good agreement with human judgment, Pearson’s 0.894, Spearman 0.77 when it is tested on the MCL-3D stereoscopic image database. We have demonstrated that PSNR has particularly good agreement with human judgment when it is calculated between images at higher scales of morphological multi-scale representations. Consequently, simplified and in essence reduced versions of multi-scale metrics are proposed, taking into account only detailed images at higher decomposition scales. The reduced version of MP-PSNR has very good agreement with human judgment, Pearson’s 0.904, Spearman 0.863 using IRCCyN/IVC DIBR image database. © 2016, The Author(s).


Mitic D.,Serbian Institute for Telecommunications and Electronics | Lebl A.,Serbian Institute for Telecommunications and Electronics | Markov Z.,Serbian Institute for Telecommunications and Electronics
AEU - International Journal of Electronics and Communications | Year: 2015

In this paper we proved that calculation of base station output power depending on traffic nearly always gives smaller values than it is in reality, if Erlang model of the channel group is applied. It is proved that increasing of power is caused by the influence of intra-cell connections. The smaller values of power are also obtained when Erlang model is compared to the case of limited number of users, but the difference in this case is not great. The results of calculation are verified by the comparison to the results of simulation. © 2015 Elsevier GmbH. All rights reserved.

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