Network densification is seen as a necessary trend in the evolution toward 5G networks to cope with future high-traffic demands. In particular, the use of femtocells seems to be the most feasible solution for hotspot areas where high traffic is concentrated. However, femtocell densification will face a number of technical challenges. Among others, the co-tier interference arises as an old acquaintance with a new significance. In point of fact, the interference characteristics and the role of aggressor and victim depend on a large extent on the density scenario, especially when femtocells share the same channel and operate in a Closed Subscriber Group (CSG) mode. In this regard, identification of victim and aggressor femtocells is a prerequisite to design an effective interference management scheme for ultra-dense femtocell networks (UDFNs). This paper implements a new approach for radio resource utilization and management for victim femtocells in an ultra-dense network environment. The proposed semi-clustering of victim-cell (SCVC) approach focuses mainly on users’ status whether critical or non-critical to categorize victim femtocells and their aggressors. After identifying the victim femtocells, the SCVC scheme semi-cluster each victim femtocell based on the status of each user. Then, it smartly allocates the appropriate radio resources in a dynamic manner, which allows ranging from shared use of resources for critical users to the frequency reuse one for non-critical users, thereby ensuring minimum co-tier interference and enhancement of spectrum efficiency. Simulation results show that our approach outperforms one of the prominent related schemes, namely, femtocell cluster based resource allocation (FCRA), in terms of the mean throughput of critical users, the average capacity of victim femtocells, and the percentage of resource utilization by an approximate average gain of 185%, 64%, and 31%, respectively.

Semi-Clustering of Victim-Cells Approach for Interference Management in Ultra-Dense Femtocell Networks

The present Master Thesis analyzes the DVB-H radio Frequency Network Planningproblematic, studying the influence of a propagation model used in the calculation ofnetwork coverage. In this way, the aim of this work is the design of a procedure andalgorithm to adjust a propagation model considering measurement campaigns performed indifferent environments (dense-urban, urban, sub-urban and rural).The methodology relies on the adjustment of the Xia-Bertoni propagation modelparameters using the Least Mean Square (LMS) method, considering the collectedmeasurements and the simulation model parameters obtained from a GeographicInformation System (GIS). Coverage simulations and measurement results are comparedusing a 3-Dimensional city model (terrain and buildings) for different terrain topologies(flat, hills and canyons) and environments.The resulting adjusted model has been tested and compared with other commonmodels (COST231 and Okumura-Hata) using specific metrics, thus proving its validity fordifferent frequencies, environments and terrain topologies. In order to validate theprocedure and designed algorithm, this Master Thesis gathers real data from measurementcampaigns carried out in different cities: Gavle (Sweden), Bucaramanga (Colombia),Valencia (Spain) and Munich (Germany). Besides, this work provides an insight on bestpractices to perform measurement campaigns.The outcome of this work is a useful tool in radio network planning for DVB-Hsystems, which ensures reliable results in all environments and terrain topologies.

On dvb-h radio frequency planning: : adjustment of a propagation model through measurement campaign results

Network densification is one of the imperative mechanisms expected to enable next generation 5G networks to meet the highly foreseen 1000-fold increase in capacity. In this regard, densification of femtocells is a promising concept to meet growing mobile service requirements and for sustainability of users’ Quality of Service (QoS), especially for hotspots. In this context, this paper first investigates the inter-cell interference scenarios within a typical small femtocell cluster and then discusses the challenges facing femtocell densification in terms of co-tier interference. Moreover, the concept of femtocell classification into different classes is demonstrated. Finally, the article presents a case study where an interference and resource management approach for ultra-dense femtocell networks (UDFNs) is introduced. This proposal organizes the users in each femtocell into two categories, where the first category is for critical users only and the second is for non-critical users. A disjoint cluster is then formed for the first category within each femtocell and its aggressor/s. Moreover,﻿ the approach implements a dynamic resource allocation mechanism, based on the status of each user within each femtocell. This mechanism allows ranging from the shared resources for the first category and its aggressor/s, to the frequency reuse one for the second category. The simulation results show that the proposal outperformed one of the prominent related techniques in the literature, namely the X2 with UE support (X2-UEs) for all deployment density scenarios from sparse to ultra-dense. The evaluations were made in regard to the users’ average throughput and the mean capacity of femtocells. The simulation results show that the SCC technique outperformed its counterpart by an average gain of 32.58% for the aforesaid first metric, and an average enhancement of 16.79 Mbps for the later metric compared to only 6.26 Mbps achieved by the X2-UEs.

Deployment Challenges and Co-tier Interference Management Techniques for Ultra-dense Femtocell Networks

Systems and methods are provided for generating a hybrid signal. Digital video is broadcast in a first set of at least one time slot of a plurality of time slots comprising the hybrid signal. Mobile data, formatted for reception at a mobile device, is broadcast in a second set of at least one time slot of the plurality of time slots comprising the hybrid signal. Structured data is broadcast in a transition band between the first set of at least one time slot and the second set of at least one time slot.

Hybrid time-divisional multiplexed modulation

Across the Andean Region the Digital Television (DTT)is already in motion. While most of countries in South America have adopted the Brazilian adaptation of the Japanese DTT standard ISDB-Tb, Colombia selected the second-generation Europan DTT standard DVB-T2, generating unique and completely new coexistence broadcasting scenarios, Firstly, it is the first region in the word in which DVB-T2 and ISDB-Tb coexist. Additionally, DVB-T2 have to coexist with analogue TV NTSC transmissions until the analogue switch-off. This paper provides interference protection ratios based on laboratory measurements and performs coexistence studies in realistic scenarios to illustrate the importance of assessing the protection ratios to achieve an efficient spectrum usage.

/pdf/interference-analysis-for-dvb-t2-network-planning-in-1xtif1sb4d.pdf

Interference Analysis for DVB-T2 Network Planning in Colombia with other Television Broadcasting Technologies

The authors would like to thank the funding received from the Ministerio de Ciencia e Innovacion within the Project number TEC2011-27723-C02-02 and from the Ministerio de Industria, Turismo y Comercio TSI-020100-2011-266 funds. This article had been written in the framework of the CELTIC project CP08-001 COMMUNE. The authors would like to acknowledge the contributions of their colleagues.

Realistic Implementation of X2-based Interface Management for LTE Femtocells

RESUMEN Este articulo presenta y analiza el problema de planificacion de redes de Television Digital Terrestre (TDT) movil basadas en el estandar DVB-H, empleando para ello tanto transmisores sincronizados como gap-fillers, y propone un algoritmo de planificacion basado en la tecnica de optimizacion del Simulated Annealing (SA). El SA es un proceso de optimizacion discreto basado en el metodo de templado (annealing) de la metalurgia. La caracteristica mas importante del SA es que un estado peor puede ser aceptado, y de esta manera se puede “escapar” de un minimo local. A menudo se dice que mientras que es muy facil hacer que el SA funcione, es dificil hacer que funcione bien.El objetivo del algoritmo realizado es minimizar el coste de despliegue de red para un objetivo de cobertura dado, optimizando al mismo tiempo la potencia transmitida por ambos tipos de emisores y el azimut de las antenas transmisoras de los gap-fillers. En el articulo se presenta el ajuste realizado al algoritmo para adaptarlo al problema de optimizacion y los resultados obtenidos, comparandolos con los del algoritmo genetico multiobjetivo, en un escenario real (ciudad de Valencia en Espana). Finalmente, se demuestra que el SA obtiene mejores resultados que el algoritmo genetico.PALABRAS CLAVE: Redes de television digital terrestre movil DVB-H, Planificacion de red, Simulated Annealing  ABSTRACT This article presents and analyzes the problem of DVB-H based mobile TV network planning using synchronized transmitters and gap-fillers, and proposes an algorithm based on the technical planning optimization called Simulated Annealing (SA). The SA is a discrete process of optimization based on the method of annealing in the metallurgy. The most important characteristic of the SA is that a worse state can be accepted, and by this way the SA is able to “escape” from local minimum. It is generally acknowledged that it is relatively easy to make the SA work, but it is difficult to make it work well. The objective of the algorithm accomplished is to minimize the network deployment costs for an objective of coverage, optimizing at the same time the power transmitted by both type of transmitters and the azimuth of the transmitting antennas of the gap-fillers. The article presents and analyzes the necessary adjustments of the algorithm for adapt it to the problem of optimization and the results obtained by the SA in a realistic scenario (city of Valencia, Spain). These results are compared with the results of the genetic multi-objective algorithm (NSGAII, Non-dominated Sorting Genetic Algorithm). Finally, it shows that the SA gets better results than the genetic algorithm.KEYWORDS: DVB-H based mobile TV network, Minimize the network deployment costs, Simulated Annealing

Planificación de redes de tdt móvil dvb-h en entornos urbanos mediante simulated annealing

In December 2011, Colombia updated its national Digital Terrestrial Television (DTT) standard from DVB-T to DVBT2, the second-generation European DTT standard. DVBT2 is the current state-of-the art DTT system in the world, and it brings very significant improvements in terms of capacity, robustness and flexibility compared with any other DTT technology. The iTEAM Research Institute was very involved in the promotion and adoption of DVB-T2 in Colombia. The case of Colombia is unique because it was the first country to deploy DVB-T2 with 6 MHz channelization, and because the digital networks will co-exist with the analogue NTSC network until the analogue switch-off and with digital ISDB-Tb and DVB-T networks in the neighbor countries. Furthermore, DVB-T2 networks will be deployed from scratch without any constraint imposed by existing DVB-T infrastructure. This paper provides an overview of the frequency and network DVB-T2 planning activities performed by the iTEAM Research Institute in cooperation with the Spectrum Regulator of Colombia.

Frequency and Network Planning and Optimization of the Digital Terrestrial Television DVB-T2 Networks in Colombia

The allocation of parts of the Ultra High Frequency (UHF) band to International Mobile Telecommunications (IMT) technologies on a co-primary basis with terrestrial broadcasting technologies has been the major change in worldwide spectrum allocation in recent years. Nowadays, thanks to the Second Generation for Terrestrial Digital Video Broadcasting (DVB-T2) and the Long Term Evolution Advanced (LTE-A) technologies a new model of cooperation between cellular and broadcasting systems arises, where the cellular network can use of broadcast spectrum using time multiplexing. This paper proposes the cooperative spectrum sharing of DTT spectrum between DVB-T2 systems and LTE-A cellular networks by means of the use of DVB-T2 FEF for LTE-A analyzing the potential benet.

https://riunet.upv.es/bitstream/handle/10251/46750/Calabuig;Monserrat;David%20Gomez-Barquero%20-%20Cooperative%20Spectrum%20Sharing%20of%20Cellular%20LTE-Advanced%20a....pdf?sequence=1

Cooperative Spectrum Sharing of Cellular LTE-Advanced and Broadcast DVB-T2 Systems

In this paper we describe the potential of multi-antenna techniques (MIMO) in the context of digital video broadcasting (DVB) systems. DVB standards have been challenged by the increasing demand of high data rate applications and larger indoor coverage area. MIMO is a key technology to increase the system capacity and link reliability without any additional bandwidth or transmit signal power. The Mobile Communications Group of iTEAM research institute has been actively participating in the standardization process of the next generation of mobile TV broadcasting DVB-NGH (digital video broadcasting – next generation handheld) for the validation of the various MIMO signaling techniques. In this paper, we describe the benefits in the utilization of MIMO and its application to DVB standards, i.e. DVB-NGH and DVB-T2 (Terrestrial 2nd generation). Following a description of the transmission techniques adopted for the DVB-NGH specification, we furthermore provide theoretical and physical layer simulation results to illustrate the performance gains of MIMO in various channel models.

Narciso Cardona Marcet

Papers

Realistic Implementation of X2-based Interface Management for LTE Femtocells

Planificación de redes de tdt móvil dvb-h en entornos urbanos mediante simulated annealing

Frequency and Network Planning and Optimization of the Digital Terrestrial Television DVB-T2 Networks in Colombia

Cooperative Spectrum Sharing of Cellular LTE-Advanced and Broadcast DVB-T2 Systems

Multi Antenna Techniques for Digital Video Broadcasting (DVB) Systems