Live video streaming over packet networks and wireless channels

The transmission of live video over noisy channels requires very low end-to-end delay. Although automatic repeat request ensures lossless transmission, its usefulness to live video streaming is restricted to short connections because of the unbounded retransmission latency. An alternative is to use forward error correction (FEC). Since finding an optimal error protection strategy can be time expensive, FEC systems are commonly designed for the worst case condition of the channel, which limits the end-to-end performance. We study the suitability of two scalable FEC-based systems to the transmission of live video over packet networks. The first one uses Reed-Solomon codes and is appropriate for the Internet. The second one uses a product channel code and is appropriate for wireless channels. We show how fast and robust transmission can be achieved by exploiting a parametric model for the distortion-rate curve of the source coder and by using fast joint source-channel allocation algorithms. Experimental results for the 3D set partitioning in hierarchical tree video coder show that the systems have good reconstruction quality even in severe channel conditions. Finally, we compare the performance of the systems to the state-of-the-art for video transmission over the Internet. 1

Network streaming and compression for mixed reality tele-immersion

Bulterman, D.C.A. [Promotor]Cesar, P.S. [Copromotor

Modélisation et distribution adaptatives de grandes scènes naturelles

Cette thèse traite de la modélisation et la diffusion de grandes scènes 3D naturelles. Nous visons à fournir des techniques pour permettre à des utilisateurs de naviguer à distance dans une scène 3D naturelle, tout en assurant la cohérence botanique et l'interactivité. Tout d'abord, nous fournissons une technique de compression multi-résolution, fondée sur la normalisation, l'instanciation, la décorrélation, et sur le codage entropique des informations géometriques pour des modèles de plantes. Ensuite, nous étudions la transmission efficace de ces objets 3D. L'algorithme de paquétisation proposé fonctionne pour la plupart des représentations multi-résolution d'objet 3D. Nous validons les techniques de paquétisation par des expériences sur un WAN (Wide Area Network), avec et sans contrôle de congestion (Datagram Congestion Control Protocol). Enfin, nous abordons les questions du streaming au niveau de la scène. Nous optimisons le traitement des requêtes du côté serveur en fournissant une structure de données adaptée et nous préparons le terrain pour nos travaux futurs sur l'évolutivité et le déploiement de systèmes distribués de streaming 3D. ABSTRACT : This thesis deals with the modeling and the interactive streaming of large natural 3D scenes. We aim at providing techniques to allow the remote walkthrough of users in a natural 3D scene ensuring botanical coherency and interactivity.First, we provide a compact and progressive representation for botanically realistic plant models. The topological structure and the geometry of the plants are represented by generalized cylinders. We provide a multi-resolution compression scheme, based on standardization and instantiation, on difference-based decorrelation, and on entropy coding. Then, we study efficient transmission of these 3D objects. The proposed packetization scheme works for any multi-resolution 3D representation. We validate our packetization schemes with extensive experiments over a WAN (Wide Area Network), with and without congestion control (Datagram Congestion Control Protocol). Finally, we address issues on streaming at the scene-level. We optimize the viewpoint culling requests on server-side by providing an adapted datastructure and we prepare the ground for our further work on scalability and deployment of distributed 3D streaming systems

Adaptive Modeling and Distribution of Large Natural Scenes

This thesis deals with the modeling and the interactive streaming of large natural 3D scenes. We aim at providing techniques to allow the remote walkthrough of users in a natural 3D scene ensuring botanical coherency and interactivity.First, we provide a compact and progressive representation for botanically realistic plant models. The topological structure and the geometry of the plants are represented by generalized cylinders. We provide a multi-resolution compression scheme, based on standardization and instantiation, on difference-based decorrelation, and on entropy coding. Then, we study efficient transmission of these 3D objects. The proposed packetization scheme works for any multi-resolution 3D representation. We validate our packetization schemes with extensive experiments over a WAN (Wide Area Network), with and without congestion control (Datagram Congestion Control Protocol). Finally, we address issues on streaming at the scene-level. We optimize the viewpoint culling requests on server-side by providing an adapted datastructure and we prepare the ground for our further work on scalability and deployment of distributed 3D streaming systems

Streaming of High-resolution Progressive Meshes Over The Internet

Ph.DDOCTOR OF PHILOSOPH

The improvement of 5G massive MIMO antenna array port-to-port isolation

Abstract. In this thesis, the phenomenon of mutual coupling in 5G mMIMO base station antenna array is studied and a solution to improve port-to-port isolation is proposed. Mutual coupling occurs when antennas are placed close to each other in modern base station antenna arrays. Basically, it causes other antennas to absorb part of the antenna’s radiated energy or rescatter a portion of the incident energy in various directions, allowing them to act as secondary transmitters. The absorbed energy by other antenna changes an array radiation pattern, array manifold and radiators input impedance changed. This is not a desirable phenomenon because the other antennas’ absorbed energy is not radiated as designed and change in input impedance causes mismatches. So,mutual coupling lowers antenna array efficiency and performance in transmitter and receiver. The initial antenna array design in this work is Nokia’s own model, operating in the frequency band of 3.3–3.8 GHz. It is already in the production and deployment phase to the field for customers. The aim of the work was to improve port-to-port isolation from -18.74 dB to -30 dB while maintaining all other design parameters for matching and radiation properties. To do this, antenna mutual coupling is studied and simulated in the original design with the electromagnetic simulation tool Ansys HFSS. The simulation cases are divided into smaller models, based on how coupling occurs in the design. Root causes for restricting the isolation performance are observed and a proposed method for improved port-to-port isolation is illustrated. To verify the correct radiation performance for the proposed method, radiation results are post-processed with MATLAB. Finally, the results are analysed based on the base station antenna standards and compared to the initial design. This thesis provided a 2.84 dB for port-to-port isolation improvement while meeting all other design specifications.Portista porttiin välisen isolaation parantaminen 5G mMIMO antenniryhmässä . Tiivistelmä. Tässä diplomityössä tutkitaan antennien välistä keskinäistä kytkeytymistä 5G mMIMO tukiasema-antenniryhmässä ja esitellään ratkaisu portista porttiin välisen isolaation parantamiseksi. Antennien välinen keskinäinen kytkeytyminen tapahtuu, kun ne ovat lähellä toisiaan moderneissa tukiasema-antenniryhmissä. Sen takia toiset antennit absorboivat osan yhden antennin lähettämästä energiasta tai uudelleen sirottavat sen useisiin suuntiin aiheuttaen niiden toimimisen sekundäärisinä lähettiminä. Toisten antennien absorboima energia muuttaa niiden säteilykuvioita, jännitteitä ja tuloimpedanssia. Tämä ei ole toivottu ilmiö, koska toisten antennien absorboima energia ei ole lähetetty alkuperäisestä säteilijästä kuten on suunniteltu, ja tuloimpedanssin muutos aiheuttaa antenneihin epäsovitusta. Antennien välinen kytkeytyminen siis huonontaa antenniryhmän tehokkuutta ja suorituskykyä sekä lähettimessä että vastaanottimessa. Työn alkuperäinen antenniryhmämalli on Nokian kehittämä ja toimii 3.3–3.8 GHz taajuuskaistalla. Se on jo tuotanto- ja käyttöönottovaiheessa kentällä asiakkaille. Tämän työn tavoite on parantaa portista porttiin välistä isolaatiota -18.74 dB:stä -30 dB:iinsäilyttäen samalla kaikki muut suunnitteluparametrit sovitukselle ja säteilyominaisuuksille. Tämän saavuttamiseksi antennien keskinäistä kytkentää tutkitaan ja simuloidaan alkuperäisessä mallissa sähkömagneettisella simulointityökalulla, Ansys HFSS:llä. Simulaatiotapaukset on jaettu pienempiin osiin sen mukaan, miten antennien välinen keskinäiskytkentä tapahtuu alkuperäisessä mallissa. Isolaation suorituskyvyn rajoittamisen juurisyyt esitellään ja ehdotettu menetelmä porttien välisen eristyksen parantamiseksi mallinnetaan ja simuloidaan. Ehdotetun menetelmän säteilyominaisuuksien tarkistamiseksi tulokset jälkikäsitellään MATLAB ohjelmistolla. Lopuksi säteilytuloksia analysoidaan tukiaseman antennistandardien perusteella ja verrataan alkuperäiseen malliin. Tässä työssä saavutetaan 2.84 dB:n parannus portista porttiin isolaatioon samalla saavuttaen kaikki muut suunnitteluspesifikaatiot

Ubiquitous Scalable Graphics: An End-to-End Framework using Wavelets

Advances in ubiquitous displays and wireless communications have fueled the emergence of exciting mobile graphics applications including 3D virtual product catalogs, 3D maps, security monitoring systems and mobile games. Current trends that use cameras to capture geometry, material reflectance and other graphics elements means that very high resolution inputs is accessible to render extremely photorealistic scenes. However, captured graphics content can be many gigabytes in size, and must be simplified before they can be used on small mobile devices, which have limited resources, such as memory, screen size and battery energy. Scaling and converting graphics content to a suitable rendering format involves running several software tools, and selecting the best resolution for target mobile device is often done by trial and error, which all takes time. Wireless errors can also affect transmitted content and aggressive compression is needed for low-bandwidth wireless networks. Most rendering algorithms are currently optimized for visual realism and speed, but are not resource or energy efficient on mobile device. This dissertation focuses on the improvement of rendering performance by reducing the impacts of these problems with UbiWave, an end-to-end Framework to enable real time mobile access to high resolution graphics using wavelets. The framework tackles the issues including simplification, transmission, and resource efficient rendering of graphics content on mobile device based on wavelets by utilizing 1) a Perceptual Error Metric (PoI) for automatically computing the best resolution of graphics content for a given mobile display to eliminate guesswork and save resources, 2) Unequal Error Protection (UEP) to improve the resilience to wireless errors, 3) an Energy-efficient Adaptive Real-time Rendering (EARR) heuristic to balance energy consumption, rendering speed and image quality and 4) an Energy-efficient Streaming Technique. The results facilitate a new class of mobile graphics application which can gracefully adapt the lowest acceptable rendering resolution to the wireless network conditions and the availability of resources and battery energy on mobile device adaptively

Appearance Preserving Rendering of Out-of-Core Polygon and NURBS Models

In Computer Aided Design (CAD) trimmed NURBS surfaces are widely used due to their flexibility. For rendering and simulation however, piecewise linear representations of these objects are required. A relatively new field in CAD is the analysis of long-term strain tests. After such a test the object is scanned with a 3d laser scanner for further processing on a PC. In all these areas of CAD the number of primitives as well as their complexity has grown constantly in the recent years. This growth is exceeding the increase of processor speed and memory size by far and posing the need for fast out-of-core algorithms. This thesis describes a processing pipeline from the input data in the form of triangular or trimmed NURBS models until the interactive rendering of these models at high visual quality. After discussing the motivation for this work and introducing basic concepts on complex polygon and NURBS models, the second part of this thesis starts with a review of existing simplification and tessellation algorithms. Additionally, an improved stitching algorithm to generate a consistent model after tessellation of a trimmed NURBS model is presented. Since surfaces need to be modified interactively during the design phase, a novel trimmed NURBS rendering algorithm is presented. This algorithm removes the bottleneck of generating and transmitting a new tessellation to the graphics card after each modification of a surface by evaluating and trimming the surface on the GPU. To achieve high visual quality, the appearance of a surface can be preserved using texture mapping. Therefore, a texture mapping algorithm for trimmed NURBS surfaces is presented. To reduce the memory requirements for the textures, the algorithm is modified to generate compressed normal maps to preserve the shading of the original surface. Since texturing is only possible, when a parametric mapping of the surface - requiring additional memory - is available, a new simplification and tessellation error measure is introduced that preserves the appearance of the original surface by controlling the deviation of normal vectors. The preservation of normals and possibly other surface attributes allows interactive visualization for quality control applications (e.g. isophotes and reflection lines). In the last part out-of-core techniques for processing and rendering of gigabyte-sized polygonal and trimmed NURBS models are presented. Then the modifications necessary to support streaming of simplified geometry from a central server are discussed and finally and LOD selection algorithm to support interactive rendering of hard and soft shadows is described