Traffic offloading in future, heterogeneous mobile networks

The rise of third-party content providers and the introduction of numerous applications has been driving the growth of mobile data traffic in the past few years. In order to tackle this challenge, Mobile Network Operators (MNOs) aim to increase their networks' capacity by expanding their infrastructure, deploying more Base Stations (BSs). Particularly, the creation of Heterogeneous Networks (HetNets) and the application of traffic offloading through the dense deployment of low-power BSs, the small cells (SCs), is one promising solution to address the aforementioned explosive data traffic increase. Due to their financial implementation requirements, which could not be met by the MNOs, the emergence of third parties that deploy small cell networks creates new business opportunities. Thus, the investigation of frameworks that facilitate the implementation of outsourced traffic offloading, the collaboration and the transactions among MNOs and third-party small cell owners, as well as the provision of participation incentives for all stakeholders is essential for the deployment of the necessary new infrastructure and capacity expansion. The aforementioned emergence of third-party content providers and their applications not only drives the increase in mobile data traffic, but also create new Quality of Service (QoS) as well as Quality of Experience (QoE) requirements that the MNOs need to guarantee for the satisfaction of their subscribers. Moreover, even though the MNOs accommodate this traffic, they do not get any monetary compensation or subsidization for the required capacity expansion. On the contrary, their revenues reduce continuously. To that end, it is necessary to research and design network and economic functionalities adapted to the new requirements, such as QoE-aware Radio Resource Management and Dynamic Pricing (DP) strategies, which both guarantee the subscriber satisfaction and maximization the MNO profit (to compensate the diminished MNOs' revenues and the increasing deployment investment). Following a thorough investigation of the state-of-the-art, a set of research directions were identified. This dissertation consists of contributions on network sharing and outsourced traffic offloading for the capacity enhancement of MNO networks, and the design of network and economic functions for the sustainable deployment and use of the densely constructed HetNets. The contributions of this thesis are divided into two main parts, as described in the following. The first part of the thesis introduces an innovative approach on outsourced traffic offloading, where we present a framework for the Multi-Operator Radio Access Network (MORAN) sharing. The proposed framework is based on an auction scheme used by a monopolistic Small Cell Operator (SCO), through which he leases his SC infrastructure to MNOs. As the lack of information on the future offered load and the auction strategies creates uncertainty for the MNOs, we designed a learning mechanism that assists the MNOs in their bid-placing decisions. Our simulations show that our proposal almost maximizes the social welfare, satisfying the involved stakeholders and providing them with participation incentives. The second part of the thesis researches the use of network and economic functions for MNO profit maximization, while guaranteeing the users' satisfaction. Particularly, we designed a model that accommodates a plethora of services with various QoS and QoE requirements, as well as diverse pricing, that is, various service prices and different charging schemes. In this model, we proposed QoE-aware user association, resource allocation and joint resource allocation and dynamic pricing algorithms, which exploit the QoE-awareness and the network's economic aspects, such as the profit. Our simulations have shown that our proposals gain substantial more profit compared to traditional and state-of-the-art solutions, while providing a similar or even better network performance.El aumento de los proveedores de contenido de terceros y la introducción de numerosas aplicaciones ha impulsado el crecimiento del tráfico de datos en redes móviles en los últimos años. Para hacer frente a este desafío, los operadores de redes móviles (Mobile Network Operators, MNOs) apuntan a aumentar la capacidad de sus redes mediante la expansión de su infraestructura y el despliegue de más estaciones base (BS). Particularmente, la creación de Redes Heterogéneas (Heterogenous Networks, HetNets) y la aplicación de descarga de tráfico a través del despliegue denso de BSs de baja potencia, las células pequeñas (small cells, SCs), es una solución prometedora para abordar el aumento del tráfico de datos explosivos antes mencionado. Debido a sus requisitos de implementación financiera, que los MNO no pudieron cumplir, la aparición de terceros que implementan redes de células pequeñas crea nuevas oportunidades comerciales. Por lo tanto, la investigación de marcos que faciliten la implementación de la descarga tercerizada de tráfico, la colaboración y las transacciones entre MNOs y terceros propietarios de células pequeñas, así como la provisión de incentivos de participación para todas las partes interesadas esencial para el despliegue de la nueva infraestructura necesaria y la expansión de la capacidad. La aparición antes mencionada de proveedores de contenido de terceros y sus aplicaciones no solo impulsa el aumento del tráfico de datos móviles, sino también crea nuevos requisitos de calidad de servicio (Quality of Service, QoS) y calidad de la experiencia (Quality of Experience, QoE) que los operadores de redes móviles deben garantizar para la satisfacción de sus suscriptores. Además, a pesar de que los operadores de redes móviles adaptan este tráfico, no obtienen ninguna compensación monetaria o subsidio por la expansión de capacidad requerida. Por el contrario, sus ingresos se reducen continuamente. Para ello, es necesario investigar y diseñar funcionalidades económicas y de red adaptadas a los nuevos requisitos, tales como las estrategias QoE-conscientes de gestión de recursos de radio y de precios dinámicos (Dynamic Pricing, DP), que garantizan la satisfacción del abonado y la maximización de la ganancia de operador móvil (para compensar los ingresos de los MNOs disminuidos y la creciente inversión de implementación). Después de una investigación exhaustiva del estado del arte, se identificaron un conjunto de direcciones de investigación. Esta disertación consiste en contribuciones sobre el uso compartido de redes y la descarga tercerizada de tráfico para la mejora de la capacidad de redes MNO, y el diseño de funciones económicas y de red para el despliegue y uso sostenible de las HetNets densamente construidas. Las contribuciones de esta tesis se dividen en dos partes principales, como se describe a continuación. La primera parte de la tesis presenta un enfoque innovador sobre la descarga subcontratada de tráfico, en el que presentamos un marco para el uso compartido de la red de acceso de radio de múltiples operadores (Multi-Operator RAN, MORAN). El marco propuesto se basa en un esquema de subasta utilizado por un operador monopólico de celda pequeña (Small Cell Operator, SCO), a través del cual arrienda su infraestructura SC a MNOs. Como la falta de información sobre la futura carga de red y las estrategias de subasta creaban incertidumbre para los MNO, diseñamos un mecanismo de aprendizaje que asiste a los MNO en sus decisiones de colocación de pujas. Nuestras simulaciones muestran que nuestra propuesta casi maximiza el bienestar social, satisfaciendo a las partes interesadas involucradas y proporcionándoles incentivos de participación. La segunda parte de la tesis investiga el uso de las funciones económicas y de red para la maximización de los beneficios de los MNOs, al tiempo que garantiza la satisfacción de los usuarios. Particularmente, diseñamos un modelo que acomoda una gran cantidad de servicios con diversos requisitos de QoS y QoE, tanto como diversos precios, es decir, varios precios de servicio y diferentes esquemas de cobro. En este modelo, propusimos algoritmos QoE-conscientes para asociación de usuarios, asignación de recursos y conjunta asignación de recursos y de fijación dinámica de precios, que explotan la conciencia de QoE y los aspectos económicos de la red, como la ganancia. Nuestras simulaciones han demostrado que nuestras propuestas obtienen un beneficio sustancial en comparación con las soluciones tradicionales y del estado del arte, a la vez que proporcionan un rendimiento de red similar o incluso mejor.Postprint (published version

Mobile Network Virtualization: A study of the techno-economic aspects

Οι τηλεπικοινωνιακοί πάροχοι σήμερα, έρχονται αντιμέτωποι με την συνεχώς αυξανόμενη ζήτηση δεδομένων ενώ καλούνται να βρίσκουν οικονομικά συμφέρουσες λύσεις για να καλύψουν αυτήν την ανάγκη. Ενώ γίνονται προσπάθειες να αυξηθεί ο ρυθμός που μεταδίδονται τα δεδομένα και να αυξηθεί η απόδοση στο φυσικό επίπεδο, κυρίως με την εισαγωγή της τεχνολογίας LTE, η ζήτηση για χρήση των πόρων είναι πολύ μεγαλύτερη από αυτά που μπορούν να προσφέρουν οι πάροχοι. Για τον λόγο αυτό κρίνεται αναγκαία η καλύτερη αξιοποίηση των δικτυακών πόρων. Το μοντέλο που επικρατούσε μέχρι σήμερα του διαμοιρασμού συγκεκριμένων πόρων δεν θεωρείται εποικοδομητικό. Επομένως κρίνεται απαραίτητη η αξιοποίηση της τηλεπικοινωνιακής υποδομής με νέες μεθόδους αυξάνοντας τα έσοδα ανά χρήστη και μειώνοντας τα έξοδα. Για τον λόγος αυτό γίνεται πλέον λόγος για τον όρο Network Virtualization. Πρόκειται για μία μέθοδο που έχει εφαρμοστεί επιτυχώς στα ενσύρματα δίκτυα και συμβάλλει στην απλοποίηση των δικτύων καθώς και στον καλύτερο διαμοιρασμό των πόρων. Οι όροι Software Defined Networks και Network Function Virtualization έχουν επίσης την ίδια βάση και αποσκοπούν στην καλύτερη αντιμετώπιση της μεγάλης ζήτησης με τον καλύτερο δυνατό τρόπο. Στην παρούσα διπλωματική θα εξετάσουμε τον τρόπο που εφαρμόζονται οι παραπάνω έννοιες στα κινητά δίκτυα και θα γίνει μία προσπάθεια παρουσίασης των τεχνο-οικονομικών μεταβλητών σχετικών με κόστη κεφαλαίου και λειτουργικά κόστη.One of the most indubitable challenges faced by the mobile network operators is to provide cost effective solutions to meet the growing demand of the mobile traffic. Whilst every effort has been made to increase the data rates and improve the physical layer performance especially with the introduction of Long Term Evolution-Advanced (LTE/LTE-A) systems, it is not sufficient to meet the exponential increase in traffic demand that is expected to become one order of magnitude larger than the bandwidth that the operators will be able to provide. As a consequence, operators need to achieve a better utilization of the scarce mobile network resources. However, the conventional business model followed by the network operators, based on a dedicated network infrastructure paradigm where each operator have access to a fixed set of network resources is no more considered a valuable approach for efficient radio resource management and utilization. Consequently, the mobile network operators are investigating new and innovative technologies to be able to effectively and efficiently utilize their network infrastructure while increasing the ARPU (Average Revenue Per User) and decrease the capital expenditure (CAPEX) and (OPEX) operational expenditures. To this end, aiming to avoid the underutilization of the physical resources, recently there has been a surge of interest for leveraging the benefits of Network Virtualization in mobile cellular networks. Network Virtualization (NV) has been successfully applied in wired networks as a means to provide abstraction of the network equipment and dramatically simplify the network configuration and resource management. The most prominent NV instances, such as Software Defined Networking (SDN) and Network Function Virtualization (NFV), are also envisioned by the mobile network operators as a way to address the explosive capacity demand of mobile traffic and reduce the costs burden faced to handle the increasing traffic demand. Accordingly, in this dissertation, we will discuss the ways to apply NV in telecoms and especially in mobile networks. This is supported by a techno-economic analysis so as to consider its effect on CAPEX and OPEX expenditures

Technical, financial and environmental evaluation of 4G long term evolution: advanced with femtocell base stations

Recent advances in mobile communication technology have allowed for considerable growth both in traffic and user numbers. However, in order to maintain acceptable quality of experience and service levels with increasing network capacity requirements, a mobile communications operator is challenged with high investment costs and high operating costs. Cost effectiveness and environmental sustainability are two major factors a mobile telecommunications operator must take into account in order to maintain its network planning techniques ready for the accelerated growth of traffic in future mobile networks. With the incoming LTE-Advanced system and with the increasing popularity of femtocells, it becomes necessary to evaluate and quantify the economic viability and sustainability of this new type of base station when used as a standalone deployment option, as well as when used in a two-tier network. Therefore, different cases were used with a deployment method based on capacity used with a varying non-uniform traffic distribution in order to assess the future resistance and flexibility of this proposed solution. A comparison was made between macro cell coverage only, full femtocell coverage and a two-tier joint solution. Our study has concluded that for low capacity demands, the best approach is a two-tier network with femtocells used for indoor backhaul. A joint solution also allows for the cost-effective resolution of indoor coverage issues. According to our future capacity requirements projected, it has been concluded that a full femtocell deployment, by far, the most economically viable option. A method for the quantification and suppression of carbon emissions due to energy consumption is also proposed, through which we studied and estimated the price for the achievement of a zero carbon emissions network.Os recentes avanços na tecnologia de comunicações móveis têm permitido um crescimento considerável da indústria, tanto em termos de tráfego como em número de clientes. No entanto, para conseguir manter uma qualidade de experiência aceitável e com elevada qualidade de serviço, um operador de comunicações móveis depara-se com elevados custos de investimento e operação. A eficácia em termos de custos e a pegada ambiental são dois factores que, entre outros, um operador de telecomunicações móveis deve ter em conta de modo a manter as suas técnicas de planeamento de rede preparadas para o acelerado crescimento do tráfego nas redes móveis do futuro. Com a chegada próxima do LTE-Advanced e com a crescente popularidade de femtocells, torna-se necessário avaliar e quantificar a viabilidade económica e o potencial de poupança de energia deste novo tipo de estação de base quando utilizado como uma opção de implantação autónoma, ou quando utilizado para suporte de uma rede de macro células. Dessa forma, foram dimensionados diferentes casos de implementação baseados nos requisitos de capacidade. Foi também aplicada uma distribuição de tráfego não-uniforme, a fim de avaliar a resistência ao futuro e a flexibilidade de aplicação desta solução proposta. Fez-se uma comparação entre uma implementação apenas com recurso a macro células, uma implementação feita completamente com recurso a femtocells e uma solução conjunta destes dois tipos de estação-base. O estudo concluiu que, para requisitos de baixa capacidade, a melhor implementação é uma rede de duas camadas, com femtocells utilizadas para o backhaul das ligações indoor. A solução conjunta permite ainda a resolução eficaz de problemas de cobertura no interior de edifícios. De acordo com a nossa projecção das necessidades futuras de capacidade concluiu-se que a implementação de uma rede apenas com recurso a femtocells é a melhor opção, do ponto de vista da capacidade, financeiro e ambiental. Também foi apresentada uma metodologia para quantificar a pegada ambiental devida ao consumo de energia, através da qual se estudou e estimou os custos associados à implementação de uma rede com pegada ambiental nula

Soluções partilhadas para redes de telecomunicações

Mestrado em Engenharia Eletrónica e de TelecomunicaçõesDespite the substantial increase in the percentage of the globe surface covered by mobile communications, there are issues that have hampered the implementation and development of cellular networks in regions where the market and economic power are still under development. Many of these issues are of economic and financial nature. It is curiously a contradictory fact, since mobile communications on several occasions proved to be a great ally for the growth and economic development of this type of regions. Therefore, in situations such as these, where the development or installation of cellular networks is blocked or conditioned by economic and financial factors, the adoption of infrastructure or service sharing methods can facilitate the implementation and expansion of cellular networks in these regions. The work developed in this dissertation seeks to identify and study the most common methods of cellular network sharing. Through the use of a numerical tool, the effects and techno-economic benefits that each sharing method will bring to the operators interested in entering markets with these characteristics will be analyzed.Apesar do crescente aumento da superfície terrestre coberta pelas comunicações móveis, há questões que têm dificultado à implementação e desenvolvimento das redes celulares nas regiões onde o mercado e o poder económico ainda estão em desenvolvimento. Muitas dessas questões são de carácter económico e financeiro. O que se torna, curiosamente, um facto contraditório, uma vez que as comunicações móveis em diversas ocasiões provaram ser um grande aliado para o crescimento e desenvolvimento económico deste tipo de regiões. Portanto para situações como estas, onde o desenvolvimento ou instalação de redes celulares é travado ou condicionado por factores de carácter económico e financeiro, a adopção de métodos de partilha de infraestruturas ou serviços consegue facilitar a implementação e expansão de redes celulares nestas regiões. O trabalho desenvolvido nesta dissertação procura identificar e estudar os métodos mais comum de partilha. Através do uso de uma ferramenta de cálculo, analisam-se também os efeitos e benefícios económicos que cada método de partilha trará para os operadores interessados em entrar em mercados com características aqui consideradas

Dynamic Capacity Enhancement using a Smart Antenna in Mobile Telecommunications Networks

This work describes an investigation into the performance of antennas for mobile base station applications and techniques for improving the coverage and capacity within a base station cell. The work starts by tracing the development of mobile systems, both in technical and commercial terms, from the earliest analogue systems to present day broadband systems and includes anticipated future developments. This is followed by an outline of how smart antenna systems can be utilised to improve cell coverage and capacity. A novel smart antenna system incorporating an array of slant ± 450 dual- polarised stacked patch elements four columns wide excited by a novel multi-beam forming and beam shaping network has been designed, simulated and implemented. It is found that for an ideal smart antenna array, four narrow overlapping beams, one wide “broadcast channel” beam and right and left shaped beams can be provided. Results are presented for the simulation of the smart antenna system using CST EM simulation software which inherently includes mutual coupling and the effects of a truncated ground plane on the element patterns. The results show some significant changes to the desired set of coverage patterns and various mutual coupling compensation techniques have been reviewed. An improved design technique has been developed for compensating the performance degrading effects of mutual coupling and finite ground plane dimensions in microstrip antenna arrays. The improved technique utilises combination of two previously known techniques: complex excitation weights compensation by inversion of the array mutual coupling scattering matrix and the incorporation of a WAIM (wide angle impedance matching) sheet. The technique has been applied to a novel multi-beam smart antenna array to demonstrate the efficacy of the technique by electromagnetic simulation. In addition, a demonstrator array has been constructed and tested which has yielded a positive conformation of the simulation results. For the developed demonstrator array which provides seven different beams, beams “footprints” have been predicted both for free space propagation and for urban propagation to evaluate the dynamic capacity performance of the smart antenna in a 3G mobile network. The results indicate that sector capacity can be dynamically tailored to user demand profiles by selection of the appropriate beam patterns provided by the novel smart antenna system

Increased energy efficiency in LTE networks through reduced early handover

“A thesis submitted to the University of Bedfordshire, in partial fulfilment of the requirements for the degree of Doctor of Philosophy”.Long Term Evolution (LTE) is enormously adopted by several mobile operators and has been introduced as a solution to fulfil ever-growing Users (UEs) data requirements in cellular networks. Enlarged data demands engage resource blocks over prolong time interval thus results into more dynamic power consumption at downlink in Basestation. Therefore, realisation of UEs requests come at the cost of increased power consumption which directly affects operator operational expenditures. Moreover, it also contributes in increased CO2 emissions thus leading towards Global Warming. According to research, Global Information and Communication Technology (ICT) systems consume approximately 1200 to 1800 Terawatts per hour of electricity annually. Importantly mobile communication industry is accountable for more than one third of this power consumption in ICT due to increased data requirements, number of UEs and coverage area. Applying these values to global warming, telecommunication is responsible for 0.3 to 0.4 percent of worldwide CO2 emissions. Moreover, user data volume is expected to increase by a factor of 10 every five years which results in 16 to 20 percent increase in associated energy consumption which directly effects our environment by enlarged global warming. This research work focuses on the importance of energy saving in LTE and initially propose bandwidth expansion based energy saving scheme which combines two resource blocks together to form single super RB, thereby resulting in reduced Physical Downlink Control Channel Overhead (PDCCH). Thus, decreased PDCCH overhead helps in reduced dynamic power consumption up to 28 percent. Subsequently, novel reduced early handover (REHO) based idea is proposed and combined with bandwidth expansion to form enhanced energy ii saving scheme. System level simulations are performed to investigate the performance of REHO scheme; it was found that reduced early handover provided around 35% improved energy saving while compared to LTE standard in 3rd Generation Partnership Project (3GPP) based scenario. Since there is a direct relationship between energy consumption, CO2 emissions and vendors operational expenditure (OPEX); due to reduced power consumption and increased energy efficiency, REHO subsequently proven to be a step towards greener communication with lesser CO2 footprint and reduced operational expenditure values. The main idea of REHO lies in the fact that it initiate handovers earlier and turn off freed resource blocks as compare to LTE standard. Therefore, the time difference (Transmission Time Intervals) between REHO based early handover and LTE standard handover is a key component for energy saving achieved, which is estimated through axiom of Euclidean geometry. Moreover, overall system efficiency is investigated through the analysis of numerous performance related parameters in REHO and LTE standard. This led to a key finding being made to guide the vendors about the choice of energy saving in relation to radio link failure and other important parameters

Electronics Thermal Management in Information and Communications Technologies: Challenges and Future Directions

This paper reviews thermal management challenges encountered in a wide range of electronics cooling applications from large-scale (data center and telecommunication) to smallscale systems (personal, portable/wearable, and automotive). This paper identifies drivers for progress and immediate and future challenges based on discussions at the 3rd Workshop on Thermal Management in Telecommunication Systems and Data Centers held in Redwood City, CA, USA, on November 4–5, 2015. Participants in this workshop represented industry and academia, with backgrounds ranging from data center thermal management and energy efficiency to high-performance computing and liquid cooling, thermal management in wearable and mobile devices, and acoustic noise management. By considering a wide range of electronics cooling applications with different lengths and time scales, this paper identifies both common themes and diverging views in the thermal management community