15 research outputs found
On Transmission System Design for Wireless Broadcasting
This thesis considers aspects related to the design and standardisation of transmission systems for wireless broadcasting, comprising terrestrial and mobile reception. The purpose is to identify which factors influence the technical decisions and what issues could be better considered in the design process in order to assess different use cases, service scenarios and end-user quality. Further, the necessity of cross-layer optimisation for efficient data transmission is emphasised and means to take this into consideration are suggested. The work is mainly related terrestrial and mobile digital video broadcasting systems but many of the findings can be generalised also to other transmission systems and design processes.
The work has led to three main conclusions. First, it is discovered that there are no sufficiently accurate error criteria for measuring the subjective perceived audiovisual quality that could be utilised in transmission system design. Means for designing new error criteria for mobile TV (television) services are suggested and similar work related to other services is recommended.
Second, it is suggested that in addition to commercial requirements there should be technical requirements setting the frame work for the design process of a new transmission system. The technical requirements should include the assessed reception conditions, technical quality of service and service functionalities. Reception conditions comprise radio channel models, receiver types and antenna types. Technical quality of service consists of bandwidth, timeliness and reliability. Of these, the thesis focuses on radio channel models and errorcriteria (reliability) as two of the most important design challenges and provides means to optimise transmission parameters based on these.
Third, the thesis argues that the most favourable development for wireless broadcasting would be a single system suitable for all scenarios of wireless broadcasting. It is claimed that there are no major technical obstacles to achieve this and that the recently published second generation digital terrestrial television broadcasting system provides a good basis. The challenges and opportunities of a universal wireless broadcasting system are discussed mainly from technical but briefly also from commercial and regulatory aspectSiirretty Doriast
COST EFFICIENT PROVISIONING OF MASS MOBILE MULTIMEDIA SERVICES IN HYBRID CELLULAR AND BROADCASTING SYSTEMS
Uno de los retos a los que se enfrenta la industria de las comunicaciones móviles e inalámbricas es proporcionar servicios multimedia masivos a bajo coste, haciéndolos asequibles para los usuarios y rentables a los operadores. El servicio más representativo es el de TV móvil, el cual se espera que sea una aplicación clave en las futuras redes móviles. Actualmente las redes celulares no pueden soportar un consumo a gran escala de este tipo de servicios, y las nuevas redes de radiodifusión móvil son muy costosas de desplegar debido a la gran inversión en infraestructura de red necesaria para proporcionar niveles aceptables de cobertura.
Esta tesis doctoral aborda el problema de la provisión eficiente de servicios multimedia masivos a dispositivos móviles y portables utilizando la infraestructura de radiodifusión y celular existente. La tesis contempla las tecnologías comerciales de última generación para la radiodifusión móvil (DVB-H) y para las redes celulares (redes 3G+ con HSDPA y MBMS), aunque se centra principalmente en DVB-H. El principal paradigma propuesto para proporcionar servicios multimedia masivos a bajo coste es evitar el despliegue de una red DVB-H con alta capacidad y cobertura desde el inicio. En su lugar se propone realizar un despliegue progresivo de la infraestructura DVB-H siguiendo la demanda de los usuarios. Bajo este contexto, la red celular es fundamental para evitar sobre-dimensionar la red DVB-H en capacidad y también en áreas con una baja densidad de usuarios hasta que el despliegue de un transmisor o un repetidor DVB-H sea necesario. Como principal solución tecnológica la tesis propone realizar una codificación multi-burst en DVB-H utilizando códigos Raptor. El objetivo es explotar la diversidad temporal del canal móvil para aumentar la robustez de la señal y, por tanto, el nivel de cobertura, a costa de incrementar la latencia de la red.Gómez Barquero, D. (2009). COST EFFICIENT PROVISIONING OF MASS MOBILE MULTIMEDIA SERVICES IN HYBRID CELLULAR AND BROADCASTING SYSTEMS [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/6881Palanci
Design and Analysis of Forward Error Control Coding and Signaling for Guaranteeing QoS in Wireless Broadcast Systems
Broadcasting systems are networks where the transmission is received by several terminals. Generally broadcast receivers are passive devices in the network, meaning that they do not interact with the transmitter. Providing a certain Quality of Service (QoS) for the receivers in heterogeneous reception environment with no feedback is not an easy task. Forward error control coding can be used for protection against transmission errors to enhance the QoS for broadcast services. For good performance in terrestrial wireless networks, diversity should be utilized. The diversity is utilized by application of interleaving together with the forward error correction codes. In this dissertation the design and analysis of forward error control and control signalling for providing QoS in wireless broadcasting systems are studied.
Control signaling is used in broadcasting networks to give the receiver necessary information on how to connect to the network itself and how to receive the services that are being transmitted. Usually control signalling is considered to be transmitted through a dedicated path in the systems. Therefore, the relationship of the signaling and service data paths should be considered early in the design phase. Modeling and simulations are used in the case studies of this dissertation to study this relationship.
This dissertation begins with a survey on the broadcasting environment and mechanisms for providing QoS therein. Then case studies present analysis and design of such mechanisms in real systems. The mechanisms for providing QoS considering signaling and service data paths and their relationship at the DVB-H link layer are analyzed as the first case study. In particular the performance of different service data decoding mechanisms and optimal signaling transmission parameter selection are presented. The second case study investigates the design of signaling and service data paths for the more modern DVB-T2 physical layer. Furthermore, by comparing the performances of the signaling and service data paths by simulations, configuration guidelines for the DVB-T2 physical layer signaling are given. The presented guidelines can prove useful when configuring DVB-T2 transmission networks. Finally, recommendations for the design of data and signalling paths are given based on findings from the case studies. The requirements for the signaling design should be derived from the requirements for the main services. Generally, these requirements for signaling should be more demanding as the signaling is the enabler for service reception.Siirretty Doriast
A Multi-Burst Sliding Encoding for Mobile Satellite TV Broadcasting
Protection of data against long fading time is one of the greatest challenges posed by a satellite delivery system offering multimedia services to mobile devices like DVB-SH. To deal with this challenge several enhancements and modifications of the existing terrestrial mobile TV (DVB-H) physical and link layers are being considered. These solutions provide the required protection depth but they don't take into account the specificity of mobile handheld devices such as power consumption, memory constraints and chipsets implementation costs. In this report, we propose an innovative algorithm (called Multi Burst Sliding Encoding or MBSE) that extends the DVB-H intra-burst (MPE-FEC) protection to an inter-burst protection so that complete burst losses could be recovered while taking into account the specificity of mobile handheld devices. Based on a clever organisation of the data, our algorithm allows to provide protection against long term fading while still using RS code implemented in DVB-H chipsets. We evaluate the performance of MBSE by both theoretical analysis as well as intensive simulations and experiments. The results also show good performance in terms of protection, battery and memory saving. The MBSE is now under standardisation and it is considered by the DVB Forum as the main solution for the DVB-SH class terminals
Transmission of Mobile Multimedia Services in DVB-SH Networks
[ES] La presente Tesina estudia la transmisión de contenidos y servicios multimedia a través de redes
de difusión basadas en el sistema DVB-SH (Digital Video Broadcasting ¿ Satellite Services to Handheld
Devices), el cual permitirá conseguir una cobertura nacional en toda Europa de servicios de TV móvil y cuya
puesta en funcionamiento está prevista para el 2008. DVB-SH es una evolución tecnológica del estándar
europeo de TDT móvil DVB-H (Digital Video Broadcasting - Handhelds). Sus principales características
son una arquitectura híbrida terrestre-satelital y la transmisión en banda S en torno a los 2 GHz. la cual está
disponible en Europa para este tipo de servicios. Además, debido a las peculiaridades de la recepción vía
satélite, DVB-SH incorpora nuevos mecanismos de protección entre los que destacan un entrelazador de
larga duración de nivel físico y un nuevo esquema de codificación de nivel de enlace. Debido a que en la
actualidad el sistema DVB-SH todavía se encuentra en una fase muy temprana de validación, el trabajo
realizado en esta tesina está encaminado a evaluar los nuevos mecanismos de nivel de enlace DVB-SH a
partir de trazas de errores DVB-H. Se analizará la calidad de usuario para diferentes mecanismos de
protección y finalmente se identificarán aquellos esquemas y configuraciones más adecuados para las
situaciones de recepción más importantes[EN] This Master's thesis studies the transmission of multimedia digital contents in broadcasting
networks based in the DVB-SH (Digital Video Broadcasting ¿ Satellite Services to Handheld Devices)
standard. This standard will make possible a network capable of providing mobile TV services in all Europe,
which is due at 2008. DVB-SH is the technological evolution of the European mobile DTT standard DVB-H
(Digital Video Broadcasting - Handhelds). Its main characteristics are a hybrid terrestrial ¿ satellite
architecture and the transmission at 2 GHz in the S-band, which is at disposal in Europe for this kind of
services. Because of the peculiarities of satellite reception, DVB-SH incorporates new protection
mechanisms. Among these mechanisms, a long duration interleaver and a new link layer codification scheme
stand out. However, DVB-SH technology is still in an early phase of validation. Because of this, the work
fulfilled in this Master's thesis is aimed at evaluating these codification schemes by means of DVB-H error
traces. The user experience quality will be analyzed for different protection mechanisms and the schemes and
configurations with better performance will be highlighted.Gozálvez Serrano, D. (2007). Transmission of Mobile Multimedia Services in DVB-SH Networks. http://hdl.handle.net/10251/12620Archivo delegad
Evaluation of unidirectional background push content download services for the delivery of television programs
Este trabajo de tesis presenta los servicios de descarga de contenido en modo push como un
mecanismo eficiente para el envío de contenido de televisión pre-producido sobre redes de
difusión. Hoy en día, los operadores de red dedican una cantidad considerable de recursos
de red a la entrega en vivo de contenido televisivo, tanto sobre redes de difusión como
sobre conexiones unidireccionales. Esta oferta de servicios responde únicamente a
requisitos comerciales: disponer de los contenidos televisivos en cualquier momento y
lugar. Sin embargo, desde un punto de vista estrictamente académico, el envío en vivo es
únicamente un requerimiento para el contenido en vivo, no para contenidos que ya han sido
producidos con anterioridad a su emisión. Más aún, la difusión es solo eficiente cuando el
contenido es suficientemente popular.
Los servicios bajo estudio en esta tesis utilizan capacidad residual en redes de difusión para
enviar contenido pre-producido para que se almacene en los equipos de usuario. La
propuesta se justifica únicamente por su eficiencia. Por un lado, genera valor de recursos de
red que no se aprovecharían de otra manera. Por otro lado, realiza la entrega de contenidos
pre-producidos y populares de la manera más eficiente: sobre servicios de descarga de
contenidos en difusión.
Los resultados incluyen modelos para la popularidad y la duración de contenidos, valiosos
para cualquier trabajo de investigación basados en la entrega de contenidos televisivos.
Además, la tesis evalúa la capacidad residual disponible en redes de difusión, por medio de
estudios empíricos. Después, estos resultados son utilizados en simulaciones que evalúan
las prestaciones de los servicios propuestos en escenarios diferentes y para aplicaciones
diferentes. La evaluación demuestra que este tipo de servicios son un recurso muy útil para
la entrega de contenido televisivo.This thesis dissertation presents background push Content Download Services as an
efficient mechanism to deliver pre-produced television content through existing broadcast
networks. Nowadays, network operators dedicate a considerable amount of network
resources to live streaming live, through both broadcast and unicast connections. This
service offering responds solely to commercial requirements: Content must be available
anytime and anywhere. However, from a strictly academic point of view, live streaming is
only a requirement for live content and not for pre-produced content. Moreover,
broadcasting is only efficient when the content is sufficiently popular.
The services under study in this thesis use residual capacity in broadcast networks to push
popular, pre-produced content to storage capacity in customer premises equipment. The
proposal responds only to efficiency requirements. On one hand, it creates value from
network resources otherwise unused. On the other hand, it delivers popular pre-produced
content in the most efficient way: through broadcast download services.
The results include models for the popularity and the duration of television content,
valuable for any research work dealing with file-based delivery of television content. Later,
the thesis evaluates the residual capacity available in broadcast networks through empirical
studies. These results are used in simulations to evaluate the performance of background
push content download services in different scenarios and for different applications. The
evaluation proves that this kind of services can become a great asset for the delivery of
television contentFraile Gil, F. (2013). Evaluation of unidirectional background push content download services for the delivery of television programs [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/31656TESI
Soluções de broadcast para redes 4G
Mestrado em Engenharia Electrónica e de TelecomunicaçõesA primeira difusão de conteúdos video e audio teve um forte impacto no quotidiano da população que assistiu a uma revolução nos modelos de transmissão de informação e de entretenimento. A evolução desde então foi significativa, e já na era digital, encontramo-nos face a uma nova sub-elevação da metodologia e do conceito subjacentes à transmissão de conteudos multimédia. O mundo actual apresenta, contudo, diferentes requisitos, de entre os quais se destacam a procura pela alta definição e mobilidade. A mobilidade tem sido um particular foco de atenção por parte dos operadores que exploram agora modelos para entregar uma vasta gama de serviços que sejam atractivos para os utilizadores.
Esta dissertação apresenta um sumário das tecnologias emergentes de broadcast que se distinguem nas várias partes do mundo com a sua particular incidência geográfica, características e cenários de aplicação. É ainda apresentada uma arquitectura 4G abordando assuntos inerentes à mobilidade e qualidade de serviço com particular incidência nos aspectos relacionados com a integração de uma tecnologia de broadcast particular.
Para avaliação da arquitectura proposta foram efectuados estudos com base num equipamento de broadcast na sua versão comercial, permitindo desta forma obter uma análise que ilustra o que os operadores podem esperar do estado actual dos dispositivos. Os resultados permitiram retirar ilações sobre o comportamento de um equipamento considerado como um produto final a disponibilizar aos operadores, quando integrado num ambiente 4G com suporte de mobilidade e QoS. Nomeadamente é discutida a sua aplicabildiade tendo em linha de conta as desvantagens introduzidas pelas características inerentes à própria tecnologia.Broadcast of video and audio through analogical television completely changed the paradigm of information and entertainment divulgation. Today, in the “digital era”, the Analogue Switch Off revolution is being held. Manufacturers and operators already show concerns regarding the support of mobility, quality of experience and of service. Delivering competitive High Definition contents and providing solutions for the average “on-the-move” user are two of the most important issues to be dealt by the service providers, which are also within the analysis scope of this work.
This dissertation presents an overview on the most relevant broadcast technologies which are assumed to be of relative acceptance in their respective target market. It presents their main characteristics and applicability.
4G architectural concepts are also analyzed, closely dealing with mobility and quality of service provisioning, with particular focus on the seamless integration of broadcast technologies.
As a mean to evaluate the feasibility of integrating broadcast technologies with 4G architectures, a performance evaluation study was performed using commercial equipment. In this way a several set of considerations constructed illustrating the features and functionalities which operators can expect or disregard from professional commercial broadcasting devices. Results allow the withdrawing of conclusions concerning the integration of a final broadcasting solution when incorporated within a 4G environment with QoS and mobility support. Its applicability is evaluated having in mind the performance drawbacks introduced by the specific technology, and generalized towards the gathering of more general conclusions which consider the main characteristics of the commercial broadcasting devices