Jorge Navarro-Ortiz

University of Granada | UGR · Department of Signal Theory, Telematics and Communications

In this work, an architecture for IoT networks oriented towards environmental sustainability is presented. Due to the suitability of its characteristics in terms of coverage, power and support of a large number of devices, an enhanced LoRaWAN network has been chosen as the basis for this proposal. The architecture is completed with the virtualizati...

This article proposes a system based on a long-distance communications system with low economic and energy costs that allows connectivity to be carried out independently from the existing cellular coverage in the area. In addition, it describes the design, development, implementation and analysis of an Internet of Things (IoT) architecture based on...

The number of connected IoT devices is significantly increasing and it is expected to reach more than two dozens of billions of IoT connections in the coming years. Low Power Wide Area Networks (LPWAN) have become very relevant for this new paradigm due to features such as large coverage and low power consumption. One of the most appealing technolo...

The massive deployment of Small Cells (SCs) is increasingly being adopted by mobile operators to face the exponentially growing traffic demand. Using the millimeter-wave (mmWave) band in the access and backhaul networks will be key to provide the capacity that meets such demand. However, dimensioning and planning have become complex tasks, because...

The new fifth generation (5G) era has transformed previous mobile generations into fast, smart networks that will be more responsive and customizable. With network slicing, 5G networks can be dynamically adapted to the different needs of specific vertical industries. This capability has opened the opportunity to new business models whereby infrastr...

The fifth-generation mobile initiative, 5G, is a tremendous and collective effort to specify, standardize, design, manufacture, and deploy the next cellular network generation. 5G networks will support demanding services such as enhanced Mobile Broadband, Ultra-Reliable and Low Latency Communications and massive Machine-Type Communications, which w...

Network Functions Virtualization facilitates the automation of the management operations and orchestration of future networks. The envisioned management practices include the introduction of automation in the deployment and scaling of softwarized network services (SNSs). However, the realization of such a scenario requires a way to determine the ne...

Narrowband Internet of Things (NB-IoT) technology emerged in Release 13 as one of the solutions to provide cellular IoT connectivity. NB-IoT is designed to achieve better indoor coverage, support of a massive number of low-throughput devices, with relaxed delay requirements, and lower energy consumption. Particularly, the extensive coverage of NB-I...

The Internet of Things is one of the hottest topics in communications today, with current revenues of $151B, around 7 billion connected devices, and an unprecedented growth expected for next years. A massive number of sensors and actuators are expected to emerge, requiring new wireless technologies that can extend their battery life and can cover l...

The necessity of a flexible, scalable, faster and programmable network to offer new services is challenging to telecommunication operators. These characteristics along with robustness and availability are essential in order to guarantee a Quality of Service (QoS) and Quality of Experience (QoE) in the users. Software Defined Networking (SDN) has em...

The introduction of Narrowband Internet of Things (NB-IoT) as a cellular IoT technology aims to support massive Machine-Type Communications applications. These applications are characterized by massive connections from a large number of low-complexity and low-power devices. One of the goals of NB-IoT is to improve coverage extension beyond existing...

The tremendous growth of services and costumers' demands have rendered traditional networks inefficient. Telecommunication operators need a more flexible, scalable, faster and programmable architecture to offer users these new services. Software Defined Networking (SDN) has emerged as a natural solution to this situation as it enables network progr...

Current forecasts predict that the Industrial Internet of Things will account for about 10 billion devices by 2020. Simultaneously, unlicensed low-power wide area networks are gaining momentum due to their low cost, low power, and long range characteristics, which are suitable for many IIoT applications, in addition to the usage of unlicensed bands...

El uso de Ethernet como tecnologı́a de red pararedes corporativas se justifica por su bajo coste y facilidadde configuración y mantenimiento. Sin embargo, estas redesno son muy escalables, debido en parte a las inundacioneso tormentas de broadcasts, que afectan al rendimiento tantode los dispositivos de red como finales. Para mitigar elimpacto de l...

En los últimos años las tecnologías TIC se han ido incorporando en los diferentes ámbitos de la enseñanza, desde las pizarras electrónicas para las clases magistrales hasta el uso de tabletas para la visualización de libros docentes en formato electrónico. De hecho, resulta cada vez más frecuente que los docentes empleen sus portátiles para present...

La demanda de cursos de redes a distancia y semipresenciales está aumentando día a día en el sector de las tecnologías de la información y comunicación (TIC). Para realizar este tipo de cursos se precisa tener laboratorios específicos que permitan la conexión remota, por lo que requieren que estén continuamente encendidos para su acceso. Este hecho...

Large-scale deployments of massive Machine Type Communications (mMTC) involve several challenges on cellular networks. To address the challenges of mMTC, or more generally, Internet of Things (IoT), the 3rd Generation Partnership Project has developed NarrowBand IoT (NB-IoT) as part of Release 13. NB-IoT is designed to provide better indoor coverag...

A lower bound of the total co-channel interference is proposed for the channel allocation problem when applied to a reduced set of nodes. The rest of the network nodes remain unaffected. This bound is independent of the particular channel allocation algorithm employed and no assumptions are made about the propagation model or the deployment scenari...

This paper proposes the design of a scheduling framework for the downlink of the Long Term Evolution (LTE) system with the objective of meeting the Quality of Service (QoS) requirements as defined by the QoS architecture of the 3G Partnership Project (3GPP) specifications. We carry out a thorough review of 3GPP specifications analyzing the requirem...

The exponential growth of data traffic and connected devices, and the reduction of latency and costs, are considered major challenges for future mobile communication networks. The satisfaction of these challenges motivates revisiting the architecture of these networks. We propose an SDN-based design of a hierarchical architecture for the 5G packet...

The TCP was originally designed for wired networks, assuming transmission errors were negligible. Actually, any acknowledgment time-out unconditionally triggers the congestion control mechanism, even in wireless networks in which this assumption is not valid. Consequently, in wireless networks, TCP performance significantly degrades. To avoid this...

In this work we present the characterization of the mobile network traffic generated by one of the most relevant social networking applications: YouTube. Understanding its characteristics is of major importance to evaluate its impact on mobile networks and optimize network or application design. For this purpose, we have performed a set of experime...

The operation of small cells in TV white spaces (TVWSs) represents a coexistence challenge due to their unplanned deployment, their heterogeneous transmission technologies, and the scarcity of TVWS channels in crowded cities. Whenever a new small cell is switched on, a spectrum reassignment of already deployed small cells can be used to avoid high...

A Method and a System for scheduling the downlink in Long Term Evolution (LTE) networks based on Quality of Service (QoS) The method comprises: performing a packet scheduling for a plurality of user terminals (UEs) based on information regarding QoS classes, said information regarding QoS classes is included in QoS class identifiers received from a...

In this paper, we study the performance of the YouTube service over 3G Long Term Evolution (LTE) by means of dynamic network simulations. We consider a typical configuration of an LTE network for TCP traffic and the traffic generation model for YouTube 'Flash' videos downloaded onto a personal computer (PC). Furthermore, in order to achieve more re...

HTTP progressive video downloading is becoming increasingly relevant in wireless and mobile networks. Therefore, improving the quality of experience (QoE) for this service is important for customer satisfaction. In this letter we propose a QoE-aware scheduling solution for the HTTP progressive video downloading in OFDMA systems. Whereas most schedu...

This article studies the impact on the design of scheduling algorithms for Orthogonal Frequency Division Multiple Access (OFDMA) systems of two traffic models described in the evaluation methodology proposals from standardization bodies: the full buffer and the finite buffer traffic models. The analysis concentrates on utility-based scheduling with...

This paper presents an extensible and reusable framework which addresses the problem of video quality assessment over IP networks. The proposed tool (referred to as Video-Tester) supports raw uncompressed video encoding and decoding. It also includes different video over IP transmission methods (i.e.: RTP over UDP unicast and multicast, as well as...

YouTube currently accounts for a significant percentage of the Internet's global traffic. Hence, understanding the characteristics of the YouTube traffic generation pattern can provide a significant advantage in predicting user video quality and in enhancing network design. In this paper, we present a characterisation of the traffic generated by Yo...

In this paper, we propose a simple model for predicting the number of rebuffering events and their duration in progressive downloads from YouTube. These metrics are necessary to predict the quality perceived by YouTube users. The proposed rebuffering model is based on two thresholds of the amount of data stored by the player buffer: the first thres...

To deal with congestion control in internet protocol (IP) networks, different active queue management schemes have been successfully proposed. However, many of these schemes do not take into consideration the particular Voice over Internet Protocol (VoIP) requirements, thereby potentially penalizing this traffic. In this paper, we propose and evalu...

Periodista Daniel Saucedo Aranda s/n 18071 GRANADA (Spain). {josecamacho@, pablopadilla@, valhala@correo., gmacia@, jorgenavarro@, jjramos@, fjsalc@, ftoro@}ugr.es Resumen—En este trabajo se presentan las iniciativas docentes realizadas por profesores deí area de ingeniería telemática de la Universidad de Granada en el marco del Proyecto de Innovac...

Tesis Univ. Granada. Departamento de Teoría de la Señal, Telemática y Comunicaciones. Leída el 20 de julio de 2010

The provision of high speed access to Internet and IP-based services is one of the main goals of beyond 3G (B3G) wireless systems. These systems will benefit from cross-layer protocol designs that will introduce interactions between different layers to obtain performance gains. The majority of the research in the field of cross-layer in B3G systems...

When dealing with multiple traffic classes, it is often difficult to define a single resource sharing criterion. For instance, VoIP flows require low delay and losses, whereas FTP traffic requires high throughput. In this paper, we propose to use the Mean Opinion Score (MOS) as a unifying criterion, and to share resources so as to keep the MOS of t...

An interesting approach for designing scheduling algorithms in OFDMA systems consists on incorporating a utility function that maps a certain resource or performance criterion into a value that measures the degree of user satisfaction. The current paper proposes a utility function that maps the user data rate into the quality of experience (QoE) pe...

In this paper we present a solution for the IEEE 802.11e HCCA (Hybrid coordination function Controlled Channel Access) mechanism which aims both at supporting strict real-time traffic requirements and, simultaneously, at handling TCP applications efficiently. Our proposal combines a packet scheduler and a dynamic resource allocation algorithm. The...

The current paper presents the design of a laboratory targeted for educational purposes in telematic networks and technologies. The laboratory has been designed to offer a wide range of teaching possibilities in the disciplines of Wide Area Networks, Local Area Networks, switching and access technologies. It allows practical training in fields such...

IntroductionService Performance CharacterizationData Link EffectsTransport and Application Layer EffectsImpact of Network Dimensioning in the Service PerformanceReferences

A traffic management method includes the steps of dividing a time slot into sub-blocks, defining the amount of available capacity for non-real time use in a time slot, defining the number of sub-blocks reserved by real time use in a time slot, defining the number of sub-blocks reserved by non-real time use in a time slot, defining the number of fre...

Introduction to Control ChannelsPhysical Layer ReliabilitySignalling Reliability and DelaysControl Channels versus AMR TCHSignalling CapacityReferences

Due to the introduction of new packet switched services as GPRS and EGPRS in the existing GSM networks, the effects on these networks need to be analysed. We address the effect of (E)GPRS services in the signaling capacity of GSM networks. The standards allow one to have separated pools for traffic channels, in order to make the resources for voice...

This paper presents throughput distributions for EGPRS and GPRS services based on measurements from a real network. First, CIR distributions for different frequency reuses are estimated based on mobile measurements reports and in a method here presented. Second, throughput and spectral efficiency values are calculated considering the estimated CIR...