Coverage optimization and power reduction in SFN using simulated annealing

An approach that predicts the propagation, models the terrestrial receivers and optimizes the performance of single frequency networks (SFN) for digital video broadcasting in terms of the final coverage achieved over any geographical region, enhancing the most populated areas, is proposed in this paper. The effective coverage improvement and thus, the self-interference reduction in the SFN is accomplished by optimizing the internal static delays, sector antenna gain, and both azimuth and elevation orientation for every transmitter within the network using the heuristic simulated annealing (SA) algorithm. Decimation and elevation filtering techniques have been considered and applied to reduce the computational cost of the SA-based approach, including results that demonstrate the improvements achieved. Further representative results for two SFN in different scenarios considering the effect on the final coverage of optimizing any of the transmitter parameters previously outlined or a combination of some of them are reported and discussed in order to show both, the performance of the method and how increasing gradually the complexity of the model for the transmitters leads to more realistic and accurate results.This work was supported by the Spanish Ministry of Science and Innovation under Projects TEC2008-02730 and TEC2012-33321. The work of M. Lanza and Á. L. Gutiérrez was supported by a Pre-Doctoral Grant from the University of Cantabria

Verification Methodology of Fade Characteristics in a DAB+ SFN in Wroclaw

The article presents the methodology for measuringverification of the phenomenon of fades in the DAB+ SFN. Theverification is related to comparing the characteristics of the fadesdetermined theoretically with the occurring fades in the realenvironment of a large city. The conditions favorable for theoccurrence of fading are presented and by selecting theappropriate propagation analysis tool, the places where theoccurrence of fading is most likely were selected. In these places ananalysis of the characteristics of fades was carried out and theconditions for their verification were determined

Verification Methodology of Fade Characteristics in a DAB+ SFN in Wroclaw

The article presents the methodology for measuringverification of the phenomenon of fades in the DAB+ SFN. Theverification is related to comparing the characteristics of the fadesdetermined theoretically with the occurring fades in the realenvironment of a large city. The conditions favorable for theoccurrence of fading are presented and by selecting theappropriate propagation analysis tool, the places where theoccurrence of fading is most likely were selected. In these places ananalysis of the characteristics of fades was carried out and theconditions for their verification were determined

Measurement campaign on transmit delay diversity for mobile DVB-T/H systems

This article is posted here with permission from IEEE - Copyright @ 2010 IEEEThis paper describes the work carried out by Brunel University and Broadreach Systems (UK) to quantify the advantages that can be achieved if Transmit Delay Diversity is applied to systems employing the DVB standard. The techniques investigated can be applied to standard receiver equipment without modification. An extensive and carefully planned field trial was performed during the winter of 2007/2008 in Uxbridge (UK) to validate predictions from theoretical modeling and laboratory simulations. The transmissions were performed in the 730 MHz frequency band with a DVB-T/H transmitter and a mean power of 18.4 dBW. The impact of the transmit antenna separation and the MPE-FEC was also investigated. It is shown that transmit delay diversity significantly improves the quality of reception in fast fading mobile broadcasting application

Improved Spectrum Usage with Multi-RF Channel Aggregation Technologies for the Next-Generation Terrestrial Broadcasting

[EN] Next-generation terrestrial broadcasting targets at enhancing spectral efficiency to overcome the challenges derived from the spectrum shortage as a result of the progressive allocation of frequencies - the so-called Digital Dividend - to satisfy the growing demands for wireless broadband capacity. Advances in both transmission standards and video coding are paramount to enable the progressive roll-out of high video quality services such as HDTV (High Definition Televison) or Ultra HDTV. The transition to the second generation European terrestrial standard DVB-T2 and the introduction of MPEG-4/AVC video coding already enables the transmission of 4-5 HDTV services per RF (Radio Frequency) channel. However, the impossibility to allocate higher bit-rate within the remaining spectrum could jeopardize the evolution of the DTT platforms in favour of other high-capacity systems such as the satellite or cable distribution platforms. Next steps are focused on the deployment of the recently released High Efficiency Video Coding (HEVC) standard, which provides more than 50% coding gain with respect to AVC, with the next-generation terrestrial standards. This could ensure the competitiveness of the DTT. This dissertation addresses the use of multi-RF channel aggregation technologies to increase the spectral efficiency of future DTT networks. The core of the Thesis are two technologies: Time Frequency Slicing (TFS) and Channel Bonding (CB). TFS and CB consist in the transmission of the data of a TV service across multiple RF channels instead of using a single channel. CB spreads data of a service over multiple classical RF channels (RF-Mux). TFS spreads the data by time-slicing (slot-by-slot) across multiple RF channels which are sequentially recovered at the receiver by frequency hopping. Transmissions using these features can benefit from capacity and coverage gains. The first one comes from a more efficient statistical multiplexing (StatMux) for Variable Bit Rate (VBR) services due to a StatMux pool over a higher number of services. Furthermore, CB allows increasing service data rate with the number of bonded RF channels and also advantages when combined with SVC (Scalable Video Coding). The coverage gain comes from the increased RF performance due to the reception of the data of a service from different RF channels rather that a single one that could be, eventually, degraded. Robustness against interferences is also improved since the received signal does not depend on a unique potentially interfered RF channel. TFS was firstly introduced as an informative annex in DVB-T2 (not normative) and adopted in DVB-NGH (Next Generation Handheld). TFS and CB are proposed for inclusion in ATSC 3.0. However, they have never been implemented. The investigations carried out in this dissertation employ an information-theoretical approach to obtain their upper bounds, physical layer simulations to evaluate the performance in real systems and the analysis of field measurements that approach realistic conditions of the network deployments. The analysis report coverage gains about 4-5 dB with 4 RF channels and high capacity gains already with 2 RF channels. This dissertation also focuses on implementation aspects. Channel bonding receivers require one tuner per bonded RF channel. The implementation of TFS with a single tuner demands the fulfilment of several timing requirements. However, the use of just two tuners would still allow for a good performance with a cost-effective implementation by the reuse of existing chipsets or the sharing of existing architectures with dual tuner operation such as MIMO (Multiple Input Multiple Output).[ES] La televisión digital terrestre (TDT) de última generación está orientada a una necesaria mejora de la eficiencia espectral con el fin de abordar los desafíos derivados de la escasez de espectro como resultado de la progresiva asignación de frecuencias - el llamado Dividendo Digital - para satisfacer la creciente demanda de capacidad para la banda ancha inalámbrica. Los avances tanto en los estándares de transmisión como de codificación de vídeo son de suma importancia para la progresiva puesta en marcha de servicios de alta calidad como la televisión de Ultra AD (Alta Definición). La transición al estándar europeo de segunda generación DVB-T2 y la introducción de la codificación de vídeo MPEG-4 / AVC ya permite la transmisión de 4-5 servicios de televisión de AD por canal RF (Radiofrecuencia). Sin embargo, la imposibilidad de asignar una mayor tasa de bit sobre el espectro restante podría poner en peligro la evolución de las plataformas de TDT en favor de otros sistemas de alta capacidad tales como el satélite o las distribuidoras de cable. El siguiente paso se centra en el despliegue del reciente estándar HEVC (High Efficiency Video Coding), que ofrece un 50% de ganancia de codificación con respecto a AVC, junto con los estándares terrestres de próxima generación, lo que podría garantizar la competitividad de la TDT en un futuro cercano. Esta tesis aborda el uso de tecnologías de agregación de canales RF que permitan incrementar la eficiencia espectral de las futuras redes. La tesis se centra en torno a dos tecnologías: Time Frequency Slicing (TFS) y Channel Bonding (CB). TFS y CB consisten en la transmisión de los datos de un servicio de televisión a través de múltiples canales RF en lugar de utilizar un solo canal. CB difunde los datos de un servicio a través de varios canales RF convencionales formando un RF-Mux. TFS difunde los datos a través de ranuras temporales en diferentes canales RF. Los datos son recuperados de forma secuencial en el receptor mediante saltos en frecuencia. La implementación de estas técnicas permite obtener ganancias en capacidad y cobertura. La primera de ellas proviene de una multiplexación estadística (StatMux) de servicios de tasa variable (VBR) más eficiente. Además, CB permite aumentar la tasa de pico de un servicio de forma proporcional al número de canales así como ventajas al combinarla con codificación de vídeo escalable. La ganancia en cobertura proviene de un mejor rendimiento RF debido a la recepción de los datos de un servicio desde diferentes canales en lugar uno sólo que podría estar degradado. Del mismo modo, es posible obtener una mayor robustez frente a interferencias ya que la recepción o no de un servicio no depende de si el canal que lo alberga está o no interferido. TFS fue introducido en primer lugar como un anexo informativo en DVB-T2 (no normativo) y posteriormente fue adoptado en DVB-NGH (Next Generation Handheld). TFS y CB han sido propuestos para su inclusión en ATSC 3.0. Aún así, nunca han sido implementados. Las investigaciones llevadas a cabo en esta Tesis emplean diversos enfoques basados en teoría de la información para obtener los límites de ganancia, en simulaciones de capa física para evaluar el rendimiento en sistemas reales y en el análisis de medidas de campo. Estos estudios reportan ganancias en cobertura en torno a 4-5 dB con 4 canales e importantes ganancias en capacidad aún con sólo 2 canales RF. Esta tesis también se centra en los aspectos de implementación. Los receptores para CB requieren un sintonizador por canal RF agregado. La implementación de TFS con un solo sintonizador exige el cumplimiento de varios requisito temporales. Sin embargo, el uso de dos sintonizadores permitiría un buen rendimiento con una implementación más rentable con la reutilización de los actuales chips o su introducción junto con las arquitecturas existentes que operan con un doble sintonizador tales como[CA] La televisió digital terrestre (TDT) d'última generació està orientada a una necessària millora de l'eficiència espectral a fi d'abordar els desafiaments derivats de l'escassetat d'espectre com a resultat de la progressiva assignació de freqüències - l'anomenat Dividend Digital - per a satisfer la creixent demanda de capacitat per a la banda ampla sense fil. Els avanços tant en els estàndards de transmissió com de codificació de vídeo són de la màxima importància per a la progressiva posada en marxa de serveis d'alta qualitat com la televisió d'Ultra AD (Alta Definició). La transició a l'estàndard europeu de segona generació DVB-T2 i la introducció de la codificació de vídeo MPEG-4/AVC ja permet la transmissió de 4-5 serveis de televisió d'AD per canal RF (Radiofreqüència). No obstant això, la impossibilitat d'assignar una major taxa de bit sobre l'espectre restant podria posar en perill l'evolució de les plataformes de TDT en favor d'altres sistemes d'alta capacitat com ara el satèl·lit o les distribuïdores de cable. El següent pas se centra en el desplegament del recent estàndard HEVC (High Efficiency Vídeo Coding), que oferix un 50% de guany de codificació respecte a AVC, junt amb els estàndards terrestres de pròxima generació, la qual cosa podria garantir la competitivitat de la TDT en un futur pròxim. Aquesta tesi aborda l'ús de tecnologies d'agregació de canals RF que permeten incrementar l'eficiència espectral de les futures xarxes. La tesi se centra entorn de dues tecnologies: Time Frequency Slicing (TFS) i Channel Bonding (CB). TFS i CB consistixen en la transmissió de les dades d'un servei de televisió a través de múltiples canals RF en compte d'utilitzar un sol canal. CB difon les dades d'un servei a través d'uns quants canals RF convencionals formant un RF-Mux. TFS difon les dades a través de ranures temporals en diferents canals RF. Les dades són recuperades de forma seqüencial en el receptor per mitjà de salts en freqüència. La implementació d'aquestes tècniques permet obtindre guanys en capacitat i cobertura. La primera d'elles prové d'una multiplexació estadística (StatMux) de serveis de taxa variable (VBR) més eficient. A més, CB permet augmentar la taxa de pic d'un servei de forma proporcional al nombre de canals així com avantatges al combinar-la amb codificació de vídeo escalable. El guany en cobertura prové d'un millor rendiment RF a causa de la recepció de les dades d'un servei des de diferents canals en lloc de només un que podria estar degradat. De la mateixa manera, és possible obtindre una major robustesa enfront d'interferències ja que la recepció o no d'un servei no depén de si el canal que l'allotja està o no interferit. TFS va ser introduït en primer lloc com un annex informatiu en DVB-T2 (no normatiu) i posteriorment va ser adoptat en DVB-NGH (Next Generation Handheld). TFS i CB han sigut proposades per a la seva inclusió en ATSC 3.0. Encara així, mai han sigut implementades. Les investigacions dutes a terme en esta Tesi empren diverses vessants basades en teoria de la informació per a obtindre els límits de guany, en simulacions de capa física per a avaluar el rendiment en sistemes reals i en l'anàlisi de mesures de camp. Aquestos estudis reporten guanys en cobertura entorn als 4-5 dB amb 4 canals i importants guanys en capacitat encara amb només 2 canals RF. Esta tesi també se centra en els aspectes d'implementació. Els receptors per a CB requerixen un sintonitzador per canal RF agregat. La implementació de TFS amb un sol sintonitzador exigix el compliment de diversos requisit temporals. No obstant això, l'ús de dos sintonitzadors permetria un bon rendiment amb una implementació més rendible amb la reutilització dels actuals xips o la seua introducció junt amb les arquitectures existents que operen amb un doble sintonitzador com ara MIMO (Multiple Input Multiple Output).Giménez Gandia, JJ. (2015). Improved Spectrum Usage with Multi-RF Channel Aggregation Technologies for the Next-Generation Terrestrial Broadcasting [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/52520TESI

Energy Savings from Implementing Collaborative Beamforming for a Remote Low Power Wireless Sensor Network

This paper outlines the implementation of collaborative beamforming to a remote low power wireless sensor network and presents its energy saving potential. The directivity procured from the beamforming allows power to be saved, which is distributed over the network. This allows each sensor within the network to have the same prolonged lifetime, and thus create a long lasting reliable network. The associated overhead with collaborative beamforming is in conjunction examined, where Single Frequency Networks (SFN) are taken as reference for synchronisation procedures. Finally, the influences of various network operating parameters on the energy benefit that can be obtained from collaborative beamforming in respect to network sizes are presented

The planning and optimisation of DVB-H radio network

In the DVB-H (Digital Video Broadcasting - Handheld) radio network planning, there are details that lack final consensus in the scientific field. The aim of this doctoral dissertation is to investigate advanced DVB-H radio network planning and optimisation. This dissertation presents the results of measurement techniques, network coverage and quality estimation, technological and economical optimisation, as well as error correction and single frequency network performance. The outcome includes proposed DVB-H radio network planning and optimisation methods that can be applied to the further investigation of detailed parameters in the radio link budget. There are also case studies that show the functionality of the presented methods with typical performance values. Based on comparative investigations, a process chart was created for DVB-H radio network planning and optimisation. The process blocks can be applied in a typical DVB-H network deployment, for the initial high-level phase as well as in the detailed network planning and optimisation phase. Using this process, the most relevant items were selected for in-depth studies. The investigations are presented in the annexed publications. The reminder was revised by comparative literature studies. The structure of the thesis follows the designed process charts. The main focus of this dissertation is the development of DVB-H radio network planning methodologies. One of the goals was to investigate the radio interface measurements, their post-processing and analysis. This can provide a guide to the selection of the appropriate values as a function of the radio channel type. An additional goal is the controlled management of over-sized single frequency network areas through the balancing of elevated SFN interference levels and related SFN gains. The development of a radio path loss simulator is the basis for these studies. The case results are presented as a function of the relevant radio parameter values, transmitter power levels and site antenna heights, both in theoretical and realistic network layouts. In addition to these topics, this document also investigates selected electro-magnetic compatibility, human exposure safety zones and radio coverage estimations. Also the balancing of technical radio parameters and network costs in order to complete the planning process steps is covered

PERFORMANCE EVALUATION OF DVB-T2 BROADCASTING NETWORK: A CASE STUDY OF DAR ES SALAAM, TANZANIA

DVB-T2 is the second generation of the digital terrestrial television broadcasting system which transmits composite (compressed digital audio and video) signal and other data in an MPEG-4 transport stream, using coded orthogonal frequency-division multiplexing (COFDM or OFDM) modulation. DVB-T2 uses multiple MPEG-4 transport streams and have enhanced FEC and higher QAM (256-QAM) constellations. Tanzania switched from analogue to Digital Video Broadcasting Terrestrial second generation (DVB-T2) in 2013, since the official switching there has been complaints from the DVB-T2 users on the coverage and quality of service provided. In this paper we evaluated the DVB-T2 performance and make the recommendations on the ways to optimize the performance. Through measurements it has been observed that, the quality of coverage in some areas (locations) is poor, so to improve the received signal strength coverage and quality we recommend the use of enhanced Yagi-Uda antenna gain which is going to be designed. Keywords: DVB-T2, Received Signal Strength Indicator (RSSI), Bit Error Rate (BER), Carrier to Noise Ratio (CNR), Modulation Error Rate (MER), Polarization, Yagi-Uda antenna