Dejan Vukobratovic

Dr. Dejan Vukobratovic

Faculty of Technical Sciences, University of Novi Sad, Novi Sad, Serbia

Research Focus & Metrics

Academic Career Length

22Years (2005-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

View All Publications
22 October 2012 in IEEE Communications Letters
Verified
Journal Article
Closed access
CSCedomir Stefanovic
Cedomir Stefanovic
PPPetar Popovski
Petar Popovski
Dejan VukobratovicDejan Vukobratovic
Dejan Vukobratovic
We propose a novel distributed random access scheme for wireless networks based on slotted ALOHA, motivated by the analogies between successive interference cancellation and iterative belief-propagation decoding on erasure channels. The proposed scheme assumes that each user independently accesses the wireless link in each slot with a predefined probability, resulting in a distribution of user transmissions over slots. The operation bears analogy with rateless codes, both in terms of probability distributions as well as to the fact that the ALOHA frame becomes fluid and adapted to the current contention process. Our aim is to optimize the slot access probability in order to achieve rateless-like distributions, focusing both on the maximization of the resolution probability of user transmissions and the throughput of the scheme.

9 October 2009 in IEEE Transactions on Communications
Verified
Journal Article
Closed access
DSDino Sejdinovic
Dino Sejdinovic
Dejan VukobratovicDejan Vukobratovic
Dejan Vukobratovic
ADAngela Doufexi
Angela Doufexi
VSVojin Senk
Vojin Senk
RPRobert J. Piechocki
Robert J. Piechocki
A novel approach to provide unequal error protection (UEP) using rateless codes over erasure channels, named Expanding Window Fountain (EWF) codes, is developed and discussed. EWF codes use a windowing technique rather than a weighted (non-uniform) selection of input symbols to achieve UEP property. The windowing approach introduces additional parameters in the UEP rateless code design, making it more general and flexible than the weighted approach. Furthermore, the windowing approach provides better performance of UEP scheme, which is confirmed both theoretically and experimentally.

13 October 2017 in IEEE Communications Magazine
Verified
Journal Article
Open access
MCMirsad Cosovic
Mirsad Cosovic
ATAchilleas Tsitsimelis
Achilleas Tsitsimelis
Dejan VukobratovicDejan Vukobratovic
Dejan Vukobratovic
JMJavier Matamoros
Javier Matamoros
CACarles Anton-Haro
Carles Anton-Haro
With the transition toward 5G, mobile cellular networks are evolving into a powerful platform for ubiquitous large-scale information acquisition, communication, storage, and processing. 5G will provide suitable services for mission-critical and real-time applications such as the ones envisioned in future smart grids. In this work, we show how the emerging 5G mobile cellular network, with its evolution of machine-type communications and the concept of mobile edge computing, provides an adequate environment for distributed monitoring and control tasks in smart grids. In particular, we present in detail how smart grids could benefit from advanced distributed state estimation methods placed within the 5G environment. We present an overview of emerging distributed state estimation solutions, focusing on those based on distributed optimization and probabilistic graphical models, and investigate their integration as part of the future 5G smart grid services.

11 September 2009 in IEEE Transactions on Multimedia
Verified
Journal Article
Closed access
Dejan VukobratovicDejan Vukobratovic
Dejan Vukobratovic
VSVladimir Stankovic
Vladimir Stankovic
DSDino Sejdinovic
Dino Sejdinovic
LSLina Stankovic
Lina Stankovic
ZXZixiang Xiong
Zixiang Xiong
Fountain codes were introduced as an efficient and universal forward error correction (FEC) solution for data multicast over lossy packet networks. They have recently been proposed for large scale multimedia content delivery in practical multimedia distribution systems. However, standard fountain codes, such as LT or Raptor codes, are not designed to meet unequal error protection (UEP) requirements typical in real-time scalable video multicast applications. In this paper, we propose recently introduced UEP expanding window fountain (EWF) codes as a flexible and efficient solution for real-time scalable video multicast. We demonstrate that the design flexibility and UEP performance make EWF codes ideally suited for this scenario, i.e., EWF codes offer a number of design parameters to be ldquotunedrdquo at the server side to meet the different reception criteria of heterogeneous receivers. The performance analysis using both analytical results and simulation experiments of H.264 scalable video coding (SVC) multicast to heterogeneous receiver classes confirms the flexibility and efficiency of the proposed EWF-based FEC solution.

13 April 2021 in IEEE Access
Verified
Journal Article
Open access
MSMiloš Savić
Miloš Savić
MLMilan Lukic
Milan Lukic
DDDragan Danilovic
Dragan Danilovic
ZBZarko Bodroski
Zarko Bodroski
DBDragana Bajovic
Dragana Bajovic
DJDusan Jakovetic
Dusan Jakovetic
The number of connected Internet of Things (IoT) devices within cyber-physical infrastructure systems grows at an increasing rate. This poses significant device management and security challenges to current IoT networks. Among several approaches to cope with these challenges, data-based methods rooted in deep learning (DL) are receiving an increased interest. In this paper, motivated by the upcoming surge of 5G IoT connectivity in industrial environments, we propose to integrate a DL-based anomaly detection (AD) as a service into the 3GPP mobile cellular IoT architecture. The proposed architecture embeds autoencoder based anomaly detection modules both at the IoT devices (ADM-EDGE) and in the mobile core network (ADM-FOG), thereby balancing between the system responsiveness and accuracy. We design, integrate, demonstrate and evaluate a testbed that implements the above service in a real-world deployment integrated within the 3GPP Narrow-Band IoT (NB-IoT) mobile operator network.

19 December 2014 in IEEE Journal on Selected Areas in Communications
Verified
Journal Article
Open access
ATAndrea Tassi
Andrea Tassi
ICIoannis Chatzigeorgiou
Ioannis Chatzigeorgiou
Dejan VukobratovicDejan Vukobratovic
Dejan Vukobratovic
The explosive growth of content-on-the-move, such as video streaming to mobile devices, has propelled research on multimedia broadcast and multicast schemes. Multirate transmission strategies have been proposed as a means of delivering layered services to users experiencing different downlink channel conditions. In this paper, we consider point-to-multipoint layered service delivery across a generic cellular system and improve it by applying different random linear network coding approaches. We derive packet error probability expressions and use them as performance metrics in the formulation of resource-allocation frameworks. The aim of these frameworks is both the optimization of the transmission scheme and the minimization of the number of broadcast packets on each downlink channel, while offering service guarantees to a predetermined fraction of users. As a case of study, our proposed frameworks are then adapted to the LTE-A standard and the eMBMS technology. We focus on the delivery of a video service based on the H.264/SVC standard and demonstrate the advantages of layered network coding over multirate transmission. Furthermore, we establish that the choice of both the network coding technique and the resource-allocation method play a critical role on the network footprint, as well as the quality of each received video layer.