MPEG-DASH

Traffic monitoring reduces congestion, improves safety, and supports environmental sustainability. Real-time flow tracking, anomaly detection, and efficient management are key. Convolutional Neural Networks (CNNs) have become integral due to their compact size and easy deployment. However, their effectiveness depends heavily on the quality of the input data, especially image resolution. With highresolution cameras, especially 4K, balancing image quality, detection accuracy, and system efficiency is critical. We propose the Multi-Resolution Traffic Monitoring Dataset (MRTMD), which captures transport scenes at resolutions ranging from 2160p to 360p. This dataset serves as a benchmark for standard object detection models, enabling the development of more efficient and cost-effective traffic monitoring solutions. MRTMD will be freely available on GitHub, offering a valuable resource for researchers and practitioners. We evaluate leading object detection models-YOLOv9, YOLOv8, YOLOv7, Faster R-CNN, FCOS, SSD, and RT-DETR-across varied resolutions. Our analysis focuses on mean Average Precision (mAP), recall, and processing time. We also assess the accuracy of Number Plate Recognition (NPR) for tasks that require fine-grained detail extraction. Our findings show that detection performance typically varies within ±0.01 to ±0.03 in mAP and recall across resolutions, suggesting higher resolutions are not always advantageous. However, they remain crucial for tasks like NPR. The multi-resolution dataset enables a comprehensive evaluation of the trade-off between image quality and task performance. Ultimately, our analysis highlights the importance of resolution selection in large-scale deployments, informing system designers and policymakers. This dataset is a vital tool for balancing performance, cost, and practical constraints in real-world traffic monitoring. INDEX TERMS Dataset vehicle detection, high resolution image dataset, number plate recognition, computer vision.

Encoding and transcoding videos into multiple codecs and representations is a significant challenge that requires seconds or even days on high-performance computers depending on many technical characteristics, such as video complexity or encoding parameters. Cloud computing offering on-demand computing resources optimized to meet the needs of customers and their budgets is a promising technology for accelerating dynamic transcoding workloads. In this work, we propose OTEC, a novel multi-objective optimization method based on the mixed-integer linear programming model to optimize the computing instance selection for transcoding processes. OTEC determines the type and number of cloud and fog resource instances for video encoding and transcoding tasks with optimized computation cost and time. We evaluated OTEC on AWS EC2 and Exoscale instances for various administrator priorities, the number of encoded video segments, and segment transcoding times. The results show that OTEC can achieve appropriate resource selections and satisfy the administrator's priorities in terms of time and cost minimization.

Cilj je ovog rada analizirati financijski uspjeh i stabilizaciju poslovanja globalne streaming platforme Netflix. Netflix je globalna streaming platforma za proizvodnju i distribuciju medijskog sadržaja koja pripada "novoj" medijskoj industriji nastaloj na temeljima razvoja digitalne tehnologije. Razvojem interneta i konvergencijom sustava distribucije medijskog sadržaja, pozicionirao se kao nasljednik kabelske televizije. Promjene navika konzumacije medijskih sadržaja Generacije Z omogućile su nastanak i razvoj različitih streaming servisa, a time i Netflixa. Model posjedovanja zamijenjen je plaćanjem pretplate što je omogućilo rast prihoda iznad stope rasta troškova proizvodnje. Netflix je trenutno najveća globalna streaming platforma prema ostvarenim prihodima i neto dobiti.

U ovom radu raspravljamo o tome kako je, sa razvojem tehnologije, naglo porasla potreba za multimedijalnim uslugama i komunikacijama. Danas se pokušava održati ista infrastruktura, ali i poboljšati različite aplikacije koje su odgovorne za prenos glasa.
Međutim, fenomen koji se zove VoIP i dalje zauzima samo mali deo udela u svim komunikacijama. Možemo reći da budućnost VoIP-a leži u mogućnostima novih i naprednijih aplikacija, gde je glas samo jedna od informacija u aplikaciji. Korišćenje VoIP-a smanjuje troškove, ali se i dalje mora postaviti pitanje kvaliteta veze koja se može uspostaviti.

In this paper, we are discussing how, with the development of technology, the need for multimedia services and communications has increased rapidly. Today, attempts are being made to maintain the same infrastructure, but also to improve various applications that are responsible for voice transmission.
However, the phenomenon called VoIP still occupies only a small part of the share in all communications. We can say that the future of VoIP lies in the possibilities of new and more advanced applications, where voice is only one of the information in the application. The use of VoIP reduces costs, but the question of the quality of the connection that can be established must still be raised.

3D video is a new form of video featuring omniview and immersive properties that are beneficial to many applications like telediagnosis, remote physiotherapy and elearning. In these applications, the data are always multi-modal and highly synchronized. For 2D video streaming, the MPEG group standardized Dynamic Adaptive Streaming over HTTP (DASH) with major transport formats, MPEG-2 TS and ISO Base Media File, including video, audio and subtitle formats. This paper presents OmniViewer, a multi-modal 3D streaming system based DASH, enhancing the versatility of the existing DASH standard and delivery infrastructure such as HTTP servers. Besides 3D video, OmniViewer supports multi-modal media in the DASH content for real-time media-synchronized interactive services. OmniViewer provides a complete multi-modal 3D video streaming solution from recording to rendering through DASH, which fills the gap between monoscopic 3D systems and 3D streaming systems.

To open up new possibilities to assess the multimodal perceptual quality of omnidirectional media formats, we proposed a novel open source 360 audiovisual (AV) quality dataset. The dataset consists of high-quality 360 video clips in equirectangular (ERP) format and higher-order ambisonic (4 th order) along with the subjective scores. Three subjective quality experiments were conducted for audio, video, and AV with the procedures detailed in this paper. Using the data from subjective tests, we demonstrated that this dataset can be used to quantify perceived audio, video, and audiovisual quality. The diversity and discriminability of subjective scores were also analyzed. Finally, we investigated how our dataset correlates with various objective quality metrics of audio and video. Evidence from the results of this study implies that the proposed dataset can benefit future studies on multimodal quality evaluation of 360 content.

U ovom radu dat je pregled servisa plaćene televizije (PAY TV) u okviru digitalne zemaljske televizije u Evropi. Najpre su za sve evropske zemlje date karakteristike "slobodne" (free-to-air) zemaljske TV koje uključuju: broj zauzetih multipleksa, standard za DTV (DVB-T i DVB-T2), standard za video-kompresiju i broj SDTV i HDTV kanala u multipleksima. Zatim je dat pregled osnovnih karakteristika za PAY TV, kao i osnovne tehničke specifikacije koje koriste provajderi za emitovanje PAY TV. Grafički je prikazano poređenje broja SDTV i HDTV kanala koji se emituju u free-to-air i PAY TV sistemima kao zastupljenost DVB-T i DVB-T2 standarda za sve evropske zemlje.

Video streaming applications currently dominate Internet traffic. Particularly, HTTP Adaptive Streaming (HAS) has emerged as the dominant standard for streaming videos over the best-effort Internet, thanks to its capability of matching the video quality to the available network resources. In HAS, the video client is equipped with a heuristic that dynamically decides the most suitable quality to stream the content, based on information such as the perceived network bandwidth or the video player buffer status. The goal of this heuristic is to optimize the quality as perceived by the user, the so-called Quality of Experience (QoE). Despite the many advantages brought by the adaptive streaming principle, optimizing users' QoE is far from trivial. Current heuristics are still suboptimal when sudden bandwidth drops occur, especially in wireless environments, thus leading to freezes in the video playout, the main factor influencing users' QoE. This issue is aggravated in case of live events, where the player buffer has to be kept as small as possible in order to reduce the playout delay between the user and the live signal. In light of the above, in recent years, several works have been proposed with the aim of extending the classical purely client-based structure of adaptive video streaming, in order to fully optimize users' QoE. In this paper, a survey is presented of research works on this topic together with a classification based on where the optimization takes place. This classification goes beyond client-based heuristics to investigate the usage of server-and network-assisted architectures and of new application and transport layer protocols. In addition, we outline the major challenges currently arising in the field of multimedia delivery, which are going to be of extreme relevance in future years.

Adapting and tiling the streaming of virtual reality (VR) video content has the potential to reduce the ultra-high bandwidth requirements of this type of multimedia services. Towards that goal, the optimization of a number of aspects is currently actively being researched. Novel rate adaptation heuristics, sophisticated viewport prediction algorithms and streaming protocol optimizations have proven their value to improve certain aspect of the VR streaming chain. However, the interplay between all these different optimizations as well as their tradeoff has not yet been explored in an experimental playground. The purpose of this demonstrator is to provide a full end-to-end adaptive tile-based VR video streaming system where each of the optimization aspects can be tuned with and their effect illustrated on-site.

U radu je prikazan jedan model za povezivanje više televizijskih studija i uključenja ekipe sa terena korišećnjem različitih protokola. Ovaj model je implementiran na Fakultetu tehničkih nauka u Kosovskoj Mitrovici. Strimovanje se vrši na serveru koji se nalazi u televiziji na kome je instalirana Wowza platforma i koja sadrži aplikacije za svaki studio sa kojim se vrši razmena i sa ekipom sa terena. Za strimovanje sa terena koristi se mobilni telefon gde se strimovanje obavlja pomoću 3G/4G mreže. Obzirom na to da je korisćenje mobilnih telefona veliko i da se koriste za razne vrste poslova, tako je i gledanje televizije na mobilnim telefonom postao neizbežni trend, sve više postoje aplikacije i softverska rešenja koje taj proces olakšavaju. Kako se prenos oslanja na internet vezu, strim je transkodovan u tri različite rezolucije i pri različitim bitskim protocima. U radu je prikazana ostvarena konekcija i analizirani paketi za sve tri rezolucije, odnosno grafički je prikazan broj paketa u jednoj sekundi za posmatrani određeni interval, kao i broj izgubljenih paketa.

BPL – Broadband over powerlines tehnologija (PBL) potencijalna je tehnologija koja može omogućiti širokopojasni pristup internetu svakom kućanstvu koje koristi komercijalnu elektroenergetsku mrežu. Također, PBL tehnologiju moguće je upotrijebiti u širenju pristupa širokopojasnom internetu u ruralnim krajevima gdje je gradnja telekomunikacijske infrastrukture ekonomski neisplativa ili otežana zbog geografske konfiguracije. U radu je dan pregled BPL tehnologije i problema BPL-a s kojima se inženjeri suočavaju u praksi (premošćivanje spojeva između visokonaponske, srednjenaponske i niskonaponske mreže, elektromagnetska kompatibilnost) te je navedena mogućnost širenja širokopojasnog interneta u ruralnim krajevima Ličko-senjske županje. Kao rezultat primjene BPL tehnologije treba proizaći i vizija digitalnog gazdinstva (digital farm, digital village), kao osnova uspješnog razvitka ruralnih područja. Prikazana su i mjerenja u simuliranim uvjetima temeljem korištenja kućnih PLC uređaja koj...

RezIMe: Sve više ljudi ima svakodnevni pristup multimedijalnom sadržaju (video materijalima, audio sadržajima, televiziji, podacima itd.) na različitim mrežama, koristeći različite uređaje, kao što su kompjuteri, prenosivi medijski plejeri, televizori, pametni telefoni ili čak mobilni telefoni. Ljudi sa svih krajeva sveta trenutno koriste Internet za slušanje radija, gledanje filmova i televizijskih emisija na zahtev. Poslednjih godina su aplikacije za prenos audiovizuelnog sadržaja putem striminga postale veoma popularne i veliki potrošač Internet protoka. Velike su šanse da se ovaj trend nastavi iz nekoliko razloga. Prvo, cena skladištenja podataka nastavlja ubrzano da opada, što čini ekonomski olakšano skladištiti velike multimedijalne fajlove. Drugo, poboljšanja u samoj infrastrukturi Interneta, široko rasprostranjena dostupnost konekcija sa velikim brzinama, tehnička distribucija sadržaja i protokoli za kvalitet servisa (QoS) će mnogo olakšati distribuciju audiovizuelnog sadržaja kao što su video na zahtev i žive prenose. Treći razlog je sposobnost terminala da ispune zahteve koji postoje za isporuku visokokvalitetnih audio/video materijala koji nude personalizovanu uslugu. KLJUČNE REČI: Multimediji, mutimedijalne komunikacije, mrežni prenos zvuka, VOIP. ABSTRACT: More and more people have daily access to multimedia content (video materials, audio content, television, data, etc.) on different networks, using a variety of devices, such as computers, portable media players, TVs, smart phones or even mobile phones. People from all over the world now use the Internet to listen to the radio, watching movies and television shows on demand. In recent years, applications for transmission of audiovisual content via streaming has become very popular and a great consumer of Internet bandwidth. There are great chances that this trend continues for several reasons. First, the price of data storage continues to decline rapidly, which makes it economically easier to store large multimedia files. Second, improvements in the infrastructure of the Internet, the widespread availability of high speed connections, technical content distribution and protocols for quality of service (QoS) would greatly facilitate the distribution of audiovisual content such as video on demand and live transmissions. The third reason is the ability of the terminal to meet the requirements that exist for the delivery of high quality audio/video materials that offer personalized service.

Nowadays, media content can be delivered via diverse broadband and broadcast technologies. Although these different technologies have somehow become rivals, their coordinated usage and convergence, by leveraging of their strengths and complementary characteristics, can bring many benefits to both operators and customers. For example, broadcast TV content can be augmented by on-demand broadband media content to provide enriched and personalized services, such as multi-view TV, audio language selection and inclusion of real-time web feeds. A piece of evidence is the recent Hybrid Broadcast Broadband TV (HbbTV) standard, which aims at harmonizing the delivery and consumption of (hybrid) broadcast and broadband TV content. A key challenge in these emerging scenarios is the synchronization between the involved media streams, which can be originated by the same or different sources, and delivered via the same or different technologies. To enable synchronized (hybrid) media delivery services, some mechanisms providing timelines at the source side are necessary to accurately time align the involved media streams at the receiver-side. This paper provides a comprehensive review of how clock references (timing) and timestamps (time) are conveyed and interpreted when using the most widespread delivery technologies, such as DVB, RTP/RTCP and MPEG standards (e.g., MPEG-2, MPEG-4, MPEG-DASH and MMT). It is particularly focused on the format, resolution, frequency and the position within the bitstream of the fields conveying timing information, as well as on the involved components and packetization aspects. Finally, it provides a survey of proofs of concepts making use of these synchronization related mechanisms. This complete and thorough source of information can be very useful for scholars and practitioners interested in media services with synchronization demands.

The rapid adoption of MPEG-DASH is testament to its core design principles that enable the client to make the informed decision relating to media encoding representations, based on network conditions, device type and preferences. Typically, the focus has mostly been on the different video quality representations rather than audio. However, for device types with small screens, the relative bandwidth budget difference allocated to the two streams may not be that large. This is especially the case if high quality audio is used, and in this scenario, we argue that increased focus should be given to the bit rate representations for audio. Arising from this, we have designed and implemented a subjective experiment to evaluate and analyse the possible effect of using different audio quality levels. In particular, we investigate the possibility of providing reduced audio quality so as to free up bandwidth for video under certain conditions. Thus, the experiment was implemented for live music concert scenarios transmitted over mobile networks, and we suggest that the results will be of significant interest to DASH content creators when considering bandwidth tradeoff between audio and video.

Internet današnjice sastoji se od preko 50.000 mreža koje su pod kontrolom privatnih lica. Zajedno ove mreže pružaju mogućnost globalnog povezivanja. Da bi povezanost u današnjem svetu u startu bila moguća, ove mreže moraju međusobno da komuniciraju. Upravo tu dolazimo do pojma Internet exchange point (IXP), preko kojeg dobijamo tehničke mogućnosti da se mreže povezu i razmene podatke. U ovom radu pokazaćemo merenja koja dokazuju kako IXP imaju pozitivan efekat na performansu mreže. Takođe, objasnićemo korake startovanja jednog IXP-a.

Omnidirectional video is becoming increasingly popular among viewers, but its delivery requires considerable amount of network bandwidth. Today's streaming services are transmitting the full spatial angle of omnidirectional videos, although most of the transmitted content is not utilized. Due to both limited bandwidth availability and its dynamic fluctuations, adaptive delivery solutions play a key role in supporting high user quality streaming of omnidirectional videos. This paper describes research which extends the MPEG-DASH Spatial Relationship Description by adding scalable video encoding to spatial tiling. It proposes a novel tile-layering based gaze adaptation algorithm for omnidirectional video delivery and employs it in conjunction with multiple tiling schemes. The benefits of the proposed algorithm with diverse tiling schemes are evaluated objectively in terms of bandwidth savings and adaptation latency. The results show a reduction of network bandwidth requirements to about 30% of the original bandwidth value with a low processing latency of 70.87 ms.

We present an end-to-end system for streaming Cinematic Virtual Reality (VR) content (also called 360 or omnidirectional content). Content is captured and ingested at a resolution of 16K at 25Hz and streamed towards untethered mobile VR devices. Besides the usual navigation interactions such as panning and tilting o ered by common VR systems, we also provide a zooming interactivity. is allows the VR client to fetch high quality pixels captured at a spatial resolution of 16K that greatly increase perceived quality compared to a 4K VR streaming solution. Since current client devices are not capable of receiving and decoding a 16K video, several optimizations are provided to only stream the required pixels for the current viewport of the user, while meeting strict latency and bandwidth requirements for a qualitative VR immersive experience. CCS CONCEPTS •Computing methodologies →Virtual reality;

Rapid advances in compression and transmission technologies enabled multi-view video streaming over the Internet through state-of-the-art MPEG standards such as dynamic adaptive streaming over HTTP (DASH) and high-efficiency video coding. Yet, standards for subjective and objective measurement of quality of experience (QoE) are lagging in the area. The MPEG-DASH system requires constant bitrate (CBR) coding and an efficient rate control strategy in order to increase QoE. Multi-view video plus depth format is preferable due to high compression gain but quality of intermediate view is crucial, strictly depending on performance of inter/intra-view rate allocation as well as rendering algorithms. We propose to find optimal ratio for interview rate allocation in CBR using our previously developed objective QoE measures using depth maps and structural similarities. To assess small differences and discriminate similar quality levels, a new subjective assessment methodology is also proposed as a multiple stimuli plus simultaneous presentation for paired comparison. The results show that the unequal rate allocation is superior to the equal rate allocation in terms of objective QoE as 0.012-0.04 (which translates into a bit rate saving of 15-24%) and subjective QoE as 0.3-0.5. Furthermore, a very high correlation is achieved between the new QoE measures and paired comparison results.

The rapid adoption of MPEG-DASH is testament to its core design principles that enable the client to make the informed decision relating to media encoding representations, based on network conditions, device type and preferences. Typically, the focus has mostly been on the different video quality representations rather than audio. However, for device types with small screens, the relative bandwidth budget difference allocated to the two streams may not be that large. This is especially the case if high quality audio is used, and in this scenario, we argue that increased focus should be given to the bit rate representations for audio. Arising from this, we have designed and implemented a subjective experiment to evaluate and analyse the possible effect of using different audio quality levels. In particular, we investigate the possibility of providing reduced audio quality so as to free up bandwidth for video under certain conditions. Thus, the experiment was implemented for live music concert scenarios transmitted over mobile networks, and we suggest that the results will be of significant interest to DASH content creators when considering bandwidth tradeoff between audio and video.

Owing to increasing consumption of video streams and demand for higher quality content and more advanced displays, future telecommunication networks are expected to outperform current networks in terms of key performance indicators (KPIs). Currently, content delivery networks (CDNs) are used to enhance media availability and delivery performance across the Internet in a cost-effective manner. The proliferation of CDN vendors and business models allows the content provider (CP) to use multiple CDN providers simultaneously. However, extreme concurrency dynamics can affect CDN capacity, causing performance degradation and outages, while overestimated demand affects costs. 5G standardization communities envision advanced network functions executing video analytics to enhance or boost media services. Network accelerators are required to enforce CDN resilience and efficient utilization of CDN assets. In this regard, this study investigates a cost-effective service to dynamically select the CDN for each session and video segment at the Media Server, without any modification to the video streaming pipeline being required. This service performs time series forecasts by employing a Long Short-Term Memory (LSTM) network to process real time measurements coming from connected video players. This service also ensures reliable and cost-effective content delivery through proactive selection of the CDN that fits with performance and business constraints. To this end, the proposed service predicts the number of players that can be served by each CDN at each time; then, it switches the required players between CDNs to keep the (Quality of Service) QoS rates or to reduce the CP's operational expenditure (OPEX). The proposed solution is evaluated by a real server, CDNs, and players and delivering dynamic adaptive streaming over HTTP (MPEG-DASH), where clients are notified to switch to another CDN through a standard MPEG-DASH media presentation description (MPD) update mechanism.

televizija / televisionPredmet istraživanja prikazanog u ovoj doktorskoj tezi je emitovanje TV programa preko digitalnih sistema za prenos televizijskog signala putem zemaljskih predajnika druge generacije DVB-T2 (Digital Video Broadcasting- Terrestrial), koji se koristi u Evropi. DVBT2 je savremeni sistem koji omogućava da se u multipleksu RF kanala opsega 8 MHz emituje 15-18 programa standardne definicije, SD (Standard definition), ali samo 4-6 programa visoke definicije, HD (High Definition), koji imaju mnogo veće bitske protoke. Poboljšanje kvaliteta nastaviće se kroz formate HD i 3D programa druge generacije, do formata ultra visokih definicija, UHD (Ultra High Definition) u budućnosti. Nove formate će karakterisati sve veći izvorni tok. Bez obzira na primenu efikasnih tehnika komprimovanja, kao što je HEVC (High Efficiency Video Coding), protok komprimovanog video signala će biti sve veći, a u multipleks jednog RF kanala će moći da se smesti sve manje TV programa. Istraživanje...

The rapid adoption of MPEG-DASH is testament to its core design principles that enable the client to make the informed decision relating to media encoding representations, based on network conditions, device type and preferences. Typically, the focus has mostly been on the different video quality representations rather than audio. However, for device types with small screens, the relative bandwidth budget difference allocated to the two streams may not be that large. This is especially the case if high quality audio is used, and in this scenario, we argue that increased focus should be given to the bit rate representations for audio. Arising from this, we have designed and implemented a subjective experiment to evaluate and analyse the possible effect of using different audio quality levels. In particular, we investigate the possibility of providing reduced audio quality so as to free up bandwidth for video under certain conditions. Thus, the experiment was implemented for live music concert scenarios transmitted over mobile networks, and we suggest that the results will be of significant interest to DASH content creators when considering bandwidth tradeoff between audio and video.

Continuous improvements to the state of the art have made it easier to create, send and receive vast quantities of video over the Internet. Catalysed by these developments, video is now the largest, and fastest growing type of traffic on modern IP networks. In 2015, video was responsible for 70% of all traffic on the Internet, with an compound annual growth rate of 27%. On the other hand, concerns about the growing energy consumption of ICT in general, continue to rise. It is not surprising that there is a significant energy cost associated with these extensive video usage patterns. In this thesis, I examine the energy consumption of typical video configurations during decoding (playback) and encoding through empirical measurements on an experimental test-bed. I then make extrapolations to a global scale to show the opportunity for significant energy savings, achievable by simple modifications to these video configurations. Based on insights gained from these measurements, I propose...

U ovom radu dat je pregled servisa plaćene televizije (PAY TV) u okviru digitalne zemaljske televizije u Evropi. Najpre su za sve evropske zemlje date karakteristike "slobodne" (free-to-air) zemaljske TV koje uključuju: broj zauzetih multipleksa, standard za DTV (DVB-T i DVB-T2), standard za video-kompresiju i broj SDTV i HDTV kanala u multipleksima. Zatim je dat pregled osnovnih karakteristika za PAY TV, kao i osnovne tehničke specifikacije koje koriste provajderi za emitovanje PAY TV. Grafički je prikazano poređenje broja SDTV i HDTV kanala koji se emituju u free-to-air i PAY TV sistemima kao zastupljenost DVB-T i DVB-T2 standarda za sve evropske zemlje.

Omnidirectional video is becoming increasingly popular among viewers, but its delivery requires considerable amount of network bandwidth. Today's streaming services are transmitting the full spatial angle of omnidirectional videos, although most of the transmitted content is not utilized. Due to both limited bandwidth availability and its dynamic fluctuations, adaptive delivery solutions play a key role in supporting high user quality streaming of omnidirectional videos. This paper describes research which extends the MPEG-DASH Spatial Relationship Description by adding scalable video encoding to spatial tiling. It proposes a novel tile-layering based gaze adaptation algorithm for omnidirectional video delivery and employs it in conjunction with multiple tiling schemes. The benefits of the proposed algorithm with diverse tiling schemes are evaluated objectively in terms of bandwidth savings and adaptation latency. The results show a reduction of network bandwidth requirements to about 30% of the original bandwidth value with a low processing latency of 70.87 ms.

The rapid adoption of MPEG-DASH is testament to its core design principles that enable the client to make the informed decision relating to media encoding representations, based on network conditions, device type and preferences. Typically, the focus has mostly been on the different video quality representations rather than audio. However, for device types with small screens, the relative bandwidth budget difference allocated to the two streams may not be that large. This is especially the case if high quality audio is used, and in this scenario, we argue that increased focus should be given to the bit rate representations for audio. Arising from this, we have designed and implemented a subjective experiment to evaluate and analyse the possible effect of using different audio quality levels. In particular, we investigate the possibility of providing reduced audio quality so as to free up bandwidth for video under certain conditions. Thus, the experiment was implemented for live music concert scenarios transmitted over mobile networks, and we suggest that the results will be of significant interest to DASH content creators when considering bandwidth tradeoff between audio and video.

Brojni su uređaji koji rade na različitim platformama i sa različitim programima. Zato dolazi do potrebe da se razvija softver koji je sposoban da komunicira sa različitim aplikacijama napisanim u različitim programskim jezicima i na različitim platformama. Najbolji način da se to primeni je kreiranje veb servisa koji se zasniva na servisno orijentisanoj arhitekturi. Taj servis će komunicirati sa ostalim aplikacijama preko SOAP poruka koje su zasnovane na XML-u. Kao tehnologiju za razvoj veb servisa je korišćen Microsoft WCF (Windows Communication Foundation). Klijentske aplikacije koje taj servis opslužuje u ovom softverskom sistemu su .NET Rich Client aplikacija i Java Android aplikacija. Dakle dve aplikacije koje su pisane u različitim programskim jezicima i obe su zasnovane na drugačijim platformama. KLJUČNE REČI: SOA, WCF, Android, Cloud, interoperabilnost, veb servis ABSTRACT: There are many devices that run on different platforms and with different computer programs. Therefore there is a need to develop software which has ability to communicate with different applications written in different programming languages and run on different platforms. The best way to do that is to create a web application service which is based on serviceoriented architecture. This service will communicate with other applications via SOAP-based XML messages. Technology used for developing Web services is WCF (Windows Communication Foundation). Client applications that this service is serving in this software system are .NET Rich Client applications and Java Android applications. Those are two applications that are written in different programming languages, and both are based on different platforms.

U ovom diplomskog rada analizirani su izazovi višeplatformskog razvoja mobilnih aplikacija za iOS i Android platforme s posebnim osvrtom na tehnologiju React Native. Opisani su načini pretvorbe programskog koda, mikrousluge, rad s korisničkim računima, korištenje socketa i lokalno skladištenje podataka pri nedostatku mreže. U praktičnom dijelu rada izrađena je višeplatformska mobilna aplikacija za pretragu i prijavu na događaje uz zahtjev za sinkronizacijom u stvarnom vremenu Ticketnator. Aplikacija je ostvarena korištenjem programskog okvira React Native i razvojnog okruženja Visual Studio Code. Za potrebe sustava na strani poslužitelja koristi se platforma Firebase kao baza podataka, sustav za autentikaciju i korištenje aplikacije u nedostatku internetske veze. Za lokalno skladištenje podataka koristi se spremnik stanja Redux. Ispitivanjem aplikacije pokazano je da aplikacija zadovoljava sve funkcionalne i nefunkcionalne zahtjeve s naglaskom na sinkronizacijske i vremenske zahtjev...

The rapid adoption of MPEG-DASH is testament to its core design principles that enable the client to make the informed decision relating to media encoding representations, based on network conditions, device type and preferences. Typically, the focus has mostly been on the different video quality representations rather than audio. However, for device types with small screens, the relative bandwidth budget difference allocated to the two streams may not be that large. This is especially the case if high quality audio is used, and in this scenario, we argue that increased focus should be given to the bit rate representations for audio. Arising from this, we have designed and implemented a subjective experiment to evaluate and analyse the possible effect of using different audio quality levels. In particular, we investigate the possibility of providing reduced audio quality so as to free up bandwidth for video under certain conditions. Thus, the experiment was implemented for live music concert scenarios transmitted over mobile networks, and we suggest that the results will be of significant interest to DASH content creators when considering bandwidth tradeoff between audio and video.

televizija / televisionPredmet istraživanja prikazanog u ovoj doktorskoj tezi je emitovanje TV programa preko digitalnih sistema za prenos televizijskog signala putem zemaljskih predajnika druge generacije DVB-T2 (Digital Video Broadcasting- Terrestrial), koji se koristi u Evropi. DVBT2 je savremeni sistem koji omogućava da se u multipleksu RF kanala opsega 8 MHz emituje 15-18 programa standardne definicije, SD (Standard definition), ali samo 4-6 programa visoke definicije, HD (High Definition), koji imaju mnogo veće bitske protoke. Poboljšanje kvaliteta nastaviće se kroz formate HD i 3D programa druge generacije, do formata ultra visokih definicija, UHD (Ultra High Definition) u budućnosti. Nove formate će karakterisati sve veći izvorni tok. Bez obzira na primenu efikasnih tehnika komprimovanja, kao što je HEVC (High Efficiency Video Coding), protok komprimovanog video signala će biti sve veći, a u multipleks jednog RF kanala će moći da se smesti sve manje TV programa. Istraživanje...

Marketing putem Web stranica omogućuje jedinstvenu mogućnost stalnog prikupljanja podataka o ponašanju posjetitelja tih web stranica. Naime, za svaku je tvrtku, odnosno poslovni sustav od izuzetne važnosti prikupiti što više korisnih informacija i detalja o korisnicima svojih proizvoda i usluga. Činjenica je da se trendovi u svijetu sve dinamičnije mijenjaju i da ih je sve teže pratiti. U skladu sa time, jednom kreirane web stranice ne predstavljaju završen zadatak. Njihovo dotjerivanje, reorganiziranje mora biti stalan proces i to po mogućnostima u skladu sa dinamikom promjena na tržištu potražnje. No, to često i nije tako trivijalno izvedivo. Kroz daljnji tijek ovoga rada predstavit će se model permanentnog sustavnog praćenja, analiziranja i reorganiziranja web čvora, «upravljivo» prema ponašanju, odnosno aktivnostima korisnika web stranica. Da bi se to postiglo potrebno je imati jasan uvidu u sve clemente web stranica i njihove karakteristike. Kako bi se moglo pratiti, analizirat...

Owing to increasing consumption of video streams and demand for higher quality content and more advanced displays, future telecommunication networks are expected to outperform current networks in terms of key performance indicators (KPIs). Currently, content delivery networks (CDNs) are used to enhance media availability and delivery performance across the Internet in a cost-effective manner. The proliferation of CDN vendors and business models allows the content provider (CP) to use multiple CDN providers simultaneously. However, extreme concurrency dynamics can affect CDN capacity, causing performance degradation and outages, while overestimated demand affects costs. 5G standardization communities envision advanced network functions executing video analytics to enhance or boost media services. Network accelerators are required to enforce CDN resilience and efficient utilization of CDN assets. In this regard, this study investigates a cost-effective service to dynamically select the CDN for each session and video segment at the Media Server, without any modification to the video streaming pipeline being required. This service performs time series forecasts by employing a Long Short-Term Memory (LSTM) network to process real time measurements coming from connected video players. This service also ensures reliable and cost-effective content delivery through proactive selection of the CDN that fits with performance and business constraints. To this end, the proposed service predicts the number of players that can be served by each CDN at each time; then, it switches the required players between CDNs to keep the (Quality of Service) QoS rates or to reduce the CP's operational expenditure (OPEX). The proposed solution is evaluated by a real server, CDNs, and players and delivering dynamic adaptive streaming over HTTP (MPEG-DASH), where clients are notified to switch to another CDN through a standard MPEG-DASH media presentation description (MPD) update mechanism.

The rapid adoption of MPEG-DASH is testament to its core design principles that enable the client to make the informed decision relating to media encoding representations, based on network conditions, device type and preferences. Typically, the focus has mostly been on the different video quality representations rather than audio. However, for device types with small screens, the relative bandwidth budget difference allocated to the two streams may not be that large. This is especially the case if high quality audio is used, and in this scenario, we argue that increased focus should be given to the bit rate representations for audio. Arising from this, we have designed and implemented a subjective experiment to evaluate and analyse the possible effect of using different audio quality levels. In particular, we investigate the possibility of providing reduced audio quality so as to free up bandwidth for video under certain conditions. Thus, the experiment was implemented for live music concert scenarios transmitted over mobile networks, and we suggest that the results will be of significant interest to DASH content creators when considering bandwidth tradeoff between audio and video.

Razvijene poštanske uprave su godinama investirale u nove tehnologije prvenstveno insistirajući na povećanju produktivnosti i na smanjenju cene koštanja poštanskog procesa. U takvom pristupu videle su način za suprostavljenje narastajućoj konkurenciji u ovoj oblasti. Kao posledica tehnoloških dostignuća i novih komunikacionih obrazaca, poštanske usluge su se značajno promenile u poslednjih deset godina, pa se u budućnosti u tehnološkim rešenjima očekuje prvenstveno stavljanje naglaska na dostizanje određenog nivoa prilagodljivosti. Sa automatizacija prerade koja je bila sedište razmatranja, akcenat se prebacuje na promene obima pošiljaka i potreba klijenata, mešanje usluga i promene u regulativi. U radu je pokazano kako nove tehnologije zasnovane na elektronskim komunikacijama ne moraju predstavljati samo pretnju tradicionalnom fizičkom protoku informacija, već se mogu iskoristiti i za dalji razvoj poštanskih operatora. Takođe, objašnjen je načina korišćenja metoda višekriterijumske analizi prilikom formiranja stava o opredeljenju klijenata o tome uslugu kog operatora će zahtevati ili koju uslugu će klasifikovati kao nešto što može zadovoljiti njegove potrebe. U mogućnosti raspolaganja ovakvim podacima koji će se kombinovati sa novim tehnološkim rešenjima autori vidi način za opstanak na ovom veoma perspektivnom tržištu.

Sadržaj -U ovom radu izvršena je analiza aktuelnih steganografskih tehnika i metoda, i ukazano je na prednosti i nedostatke postojećih tehnika koje se koriste u steganografiji. Kao primjeri za datoteke sa slikama upotrebljen je JPEG, a za audio datoteke MP3 format. Primjenom određenih steganografskih tehnika na originalnu datoteku dobija se steganografski obrađen nosač podataka koji se naziva stego-datoteka. U zavisnosti od količine utisnutog otvorenog teksta u određenoj stego-datoteci moguće su određene varijacije koje se manifestuju kroz razlike u veličini i kvalitetu u odnosu na originalnu datoteku. Tehnike koje se koriste su: ubacivanje, zamjena i generisanje. Ključne riječisteganografija, steganoanaliza, stego-datoteka, kapacitet, bit, piksel. KRIVANJE podataka iz bezbjedonosnih razloga danas je uobičajena pojava u svim organizacijama čije se poslovanje bazira na zaštićenom prenosu podataka. Skriti informaciju znači ne dozvoliti da informacija bude čitljiva trećim licima. Poslovni sistemi koji funkcionišu preko računarske mreže povećavaju međuzavisnost između informacija i komunikacionog kanala, te na taj način postaju meta mnogih zlonamjernih korisnika. To svakako dovodi do potrebe zaštite podataka u poslovnom okruženju. Za rješenje problema, pored primjene određenih kriptografskih algoritama kao što su RSA, DES, AES i sl., moguća je i upotreba steganografskih metoda koje omogućavaju prikrivanje podataka iza bezazlenih objekata u slikama, audio, video snimcima, ali na taj način da originalni nosilac podatka ostane vjerodostojan. U današnjem poslovanju postoji povećana zabrinutost zbog velikog broja zloupotrebe računarskih sistema, pa je zbog toga upotreba kriptološke zaštite u stalnom porastu. Na žalost, većina kriptoloških tehnika postale su ranjive na napade koji se izvode od strane hakera. To se takođe odnosi i na napredne šifarske metode. Cilj svake kripto-metode je da pronađe najbrži i najpovoljniji način da prenesena informacija bude sačuvana. Jedna od takvih metoda koje se danas koriste zasniva se na upotrebi steganografije. Steganografija je nauka koja se bavi sakrivanjem informacija u drugim podacima, tako da je i samo postojanje šifrata sakriveno u nosiocu podatka. Riječ steganografija je kovanica od dvije riječi grčkog porijekla, στεγανοσ (steganos) i γραφο (grafo), što u prevodu znači pisati skriveno. Cilj steganografije je da prenese informacije od pošiljaoca do primaoca tako što se podatak utisne u nosioca podatka, koji mora da bude čitljiv i razumljiv za odredište. Za razliku od kriptografije gdje je neprijatelju omogućeno da presretne poruku, da je pokuša promijeniti, odnosno, narušiti njen integritet, steganografija je nauka i umjetnost razmjene osjetljivih ili privatnih podataka koja skriva postojanje komunikacije. Čak, iako neprijatelj prepozna da se prenosi neka informacija, cilj je da se steganografska poruka sakrije 1

360-degree video streaming for high-quality virtual reality (VR) is challenging for current wireless systems because of the huge bandwidth it requires. However, millimeter wave (mmWave) communications in the 60 GHz band has gained considerable interest from the industry and academia because it promises gigabit wireless connectivity in the huge unlicensed bandwidth (i.e., up to 7 GHz). This massive unlicensed bandwidth offers great potential for addressing the demand for 360-degree video streaming. This paper investigates the problem of 360-degree video streaming for mobile VR using the SHVC, the scalable of High-Efficiency Video Coding (HEVC) standard and PC offloading over 60 GHz networks. We present a conceptual architecture based on advanced tiled-SHVC and mmWave communications. This architecture comprises two main parts. (1) Tile-based SHVC for 360-degree video streaming and optimizing parallel decoding. (2) Personal Computer (PC) offloading mechanism for transmitting uncompress...

Cilj komunikacijskih mreža je da se prenese informacija od izvorišnog čvora do nekog čvora koji je označen kao prijemnik. U skladu s tim, osnovno pitanje koje se postavlja kod dizajna mreža je kako povećati količinu podataka koja se prenosi. Jedan od načina koji se koristi u ovu svrhu je mrežno kodiranje. Osnovna ideja mrežnog kodiranja je da se povećaju mogućnosti mrežnih čvorova, koji su posrednici u prenosu podataka, tako što im se omogućava da kombinuju pakete koji dolaze sa različitih izvora te da zatim takve kombinacije prosljeđuju dalje. Na ovaj način efikasnije se mogu iskoristiti karakteristike bežičnog medija, te uz pravilno korištenje može se doći do značajnog pomaka u propusnosti bežičnih mreža. U ovom radu predstavit ćemo osnovne karakteristike mrežnog kodiranja, te koje sve pogodnosti ono omogućava u mreži, tj. koje karakteristike mreže su poboljšane korištenjem ovog kodiranja. Također ćemo predstaviti različite šeme koje se koriste prilikom kodiranja paketa. Prilikom ...

U radu je prikazan jedan model za povezivanje više televizijskih studija i uključenja ekipe sa terena korišećnjem različitih protokola. Ovaj model je implementiran na Fakultetu tehničkih nauka u Kosovskoj Mitrovici. Strimovanje se vrši na serveru koji se nalazi u televiziji na kome je instalirana Wowza platforma i koja sadrži aplikacije za svaki studio sa kojim se vrši razmena i sa ekipom sa terena. Za strimovanje sa terena koristi se mobilni telefon gde se strimovanje obavlja pomoću 3G/4G mreže. Obzirom na to da je korisćenje mobilnih telefona veliko i da se koriste za razne vrste poslova, tako je i gledanje televizije na mobilnim telefonom postao neizbežni trend, sve više postoje aplikacije i softverska rešenja koje taj proces olakšavaju. Kako se prenos oslanja na internet vezu, strim je transkodovan u tri različite rezolucije i pri različitim bitskim protocima. U radu je prikazana ostvarena konekcija i analizirani paketi za sve tri rezolucije, odnosno grafički je prikazan broj paketa u jednoj sekundi za posmatrani određeni interval, kao i broj izgubljenih paketa.

A standard called MPEG Dynamic Adaptive Streaming over HTTP (MPEG DASH) ensures the interoperability between different streaming services and the highest possible video quality in changing network conditions. The solutions described in the available literature that focus on video segmentation are mostly proprietary, use a high amount of computational power, lack the methodology, model notation, information needed for reproduction, or do not consider the spatial and temporal activity of video sequences. This paper presents a new model for selecting optimal parameters and number of representations for video encoding and segmentation, based on a measure of the spatial and temporal activity of the video content. The model was developed for the H.264 encoder, using Structural Similarity Index Measure (SSIM) objective metrics as well as Spatial Information (SI) and Temporal Information (TI) as measures of video spatial and temporal activity. The methodology that we used to develop the mat...

Long lasting Ethernet standards have grown beyond traditional LAN networks through MAN to WAN environment, where it has become the technology which many providers use for developing convergent networks that transport new generation services, such as triple-play widely deployed everywhere – from airports and hotels to large cruise ships. The question of network suitability for providing various communication services has to be considered in practice, especially in case of large ships, as the content of traffic is very diverse with exceptionally variable intensity. Under such specific circumstances for ships theoretical models cannot be directly applied. Rather, network design and implementation depend on practical preliminary test results and analysis. To this end, the out-of-service simulation of either network or user equipment was done according to the RFC 2544 recommendation by means of a smart test device that generates the appropriate test traffic over the Ethernet link from a ...

Sadržaj-Kvalitetu geopodataka koji se koriste u kompanijskim Geografskim Informacionim Sistemima se pridaje sve veći značaj. Mobilne GIS aplikacije sa mogućnošću očitavanja GPS lokacije omogućavaju premeštanje procesa unosa i ažuriranja geopodataka iz centrale kompanije na teren. Za potrebe postojećeg GinisED sistema za evidenciju elektrodistributivne mreže započet je razvoj mobilne GIS aplikacije GinisED Mobile. U ovom radu opisan je naš predlog arhitekture mobilne GIS aplikacije i definicija procesa koji je potrebno ispoštovati pri radu na terenu.