1,435 research outputs found
Trajectory Aware Macro-cell Planning for Mobile Users
We design and evaluate algorithms for efficient user-mobility driven
macro-cell planning in cellular networks. As cellular networks embrace
heterogeneous technologies (including long range 3G/4G and short range WiFi,
Femto-cells, etc.), most traffic generated by static users gets absorbed by the
short-range technologies, thereby increasingly leaving mobile user traffic to
macro-cells. To this end, we consider a novel approach that factors in the
trajectories of mobile users as well as the impact of city geographies and
their associated road networks for macro-cell planning. Given a budget k of
base-stations that can be upgraded, our approach selects a deployment that
impacts the most number of user trajectories. The generic formulation
incorporates the notion of quality of service of a user trajectory as a
parameter to allow different application-specific requirements, and operator
choices.We show that the proposed trajectory utility maximization problem is
NP-hard, and design multiple heuristics. We evaluate our algorithms with real
and synthetic data sets emulating different city geographies to demonstrate
their efficacy. For instance, with an upgrade budget k of 20%, our algorithms
perform 3-8 times better in improving the user quality of service on
trajectories in different city geographies when compared to greedy
location-based base-station upgrades.Comment: Published in INFOCOM 201
Cooperative control of relay based cellular networks
PhDThe increasing popularity of wireless communications and the higher data
requirements of new types of service lead to higher demands on wireless networks.
Relay based cellular networks have been seen as an effective way to meet users’
increased data rate requirements while still retaining the benefits of a cellular
structure. However, maximizing the probability of providing service and spectrum
efficiency are still major challenges for network operators and engineers because of
the heterogeneous traffic demands, hard-to-predict user movements and complex
traffic models.
In a mobile network, load balancing is recognised as an efficient way to increase
the utilization of limited frequency spectrum at reasonable costs. Cooperative
control based on geographic load balancing is employed to provide flexibility for
relay based cellular networks and to respond to changes in the environment.
According to the potential capability of existing antenna systems, adaptive radio
frequency domain control in the physical layer is explored to provide coverage at
the right place at the right time.
This thesis proposes several effective and efficient approaches to improve
spectrum efficiency using network wide optimization to coordinate the coverage
offered by different network components according to the antenna models and
relay station capability. The approaches include tilting of antenna sectors,
changing the power of omni-directional antennas, and changing the assignment of
relay stations to different base stations. Experiments show that the proposed
approaches offer significant improvements and robustness in heterogeneous traffic
scenarios and when the propagation environment changes. The issue of predicting
the consequence of cooperative decisions regarding antenna configurations when
applied in a realistic environment is described, and a coverage prediction model is
proposed. The consequences of applying changes to the antenna configuration on
handovers are analysed in detail. The performance evaluations are based on a
system level simulator in the context of Mobile WiMAX technology, but the
concepts apply more generally
Energy-efficient wireless communication
In this chapter we present an energy-efficient highly adaptive network interface architecture and a novel data link layer protocol for wireless networks that provides Quality of Service (QoS) support for diverse traffic types. Due to the dynamic nature of wireless networks, adaptations in bandwidth scheduling and error control are necessary to achieve energy efficiency and an acceptable quality of service. In our approach we apply adaptability through all layers of the protocol stack, and provide feedback to the applications. In this way the applications can adapt the data streams, and the network protocols can adapt the communication parameters
A methodology for obtaining More Realistic Cross-Layer QoS Measurements in mobile networks: A VoIP over LTE Use Case
Los servicios de voz han sido durante mucho tiempo la primera fuente de ingresos para los operadores mĂłviles. Incluso con el protagonismo creciente del tráfico de datos, los servicios de voz seguirán jugando un papel importante y no desaparecerán con la transiciĂłn a redes basadas en el protocolo IP. Por otra parte, hace años que los principales actores en la industria mĂłvil detectaron claramente que los usuarios no aceptarĂan una degradaciĂłn en la calidad de los servicios de voz. Es por esto que resulta crĂtico garantizar la experiencia de usuario (QoE) en la transiciĂłn a redes de nueva generaciĂłn basadas en conmutaciĂłn de paquetes.
El trabajo realizado durante esta tesis ha buscado analizar el comportamiento y las dependencias de los diferentes servicios de Voz sobre IP (VoIP), asĂ como identificar configuraciones Ăłptimas, mejoras potenciales y metodologĂas que permitan asegurar niveles de calidad aceptables al mismo tiempo que se trate de minimizar los costes.
La caracterizaciĂłn del rendimiento del tráfico de datos en redes mĂłviles desde el punto de vista de los usuarios finales es un proceso costoso que implica la monitorizaciĂłn y análisis de un amplio rango de protocolos y parámetros con complejas dependencias. Para abordar desde la raĂz este problema, se requiere realizar medidas que relacionen y correlen el comportamiento de las diferentes capas. La metodologĂa de caracterizaciĂłn propuesta en esta tesis proporciona la posibilidad de recoger informaciĂłn clave para la resoluciĂłn de problemas en las comunicaciones IP, relaciolándola con efectos asociados a la propagaciĂłn radio, como cambios de celda o pĂ©rdida de enlaces, o con carga de la red y limitaciones de recursos en zonas geográficas especĂficas.
Dicha metodologĂa se sustenta en la utilizaciĂłn de herramientas nativas de monitorizaciĂłn y registro de informaciĂłn en smartphones, y la aplicaciĂłn de cadenas de herramientas para la experimentaciĂłn extensiva tanto en redes reales y como en entornos de prueba controlados. Con los resultados proporcionados por esta serie de herramientas, tanto operadores mĂłviles y proveedores de servicio como desarrolladores mĂłviles podrĂan ganar acceso a informaciĂłn sobre la experiencia real del usuario y sobre cĂłmo mejorar la cobertura, optimizar los servicios y adaptar el funcionamiento de las aplicaciones y el uso de protocolos mĂłviles basados en IP en este contexto.
Las principales contribuciones de las herramientas y métodos introducidos en esta tesis son los siguientes:
- Una herramienta de monitorización multicapa para smartphones Android, llamada TestelDroid, que permite la captura de indicadores clave de rendimiento desde el propio equipo de usuario. Asimismo proporciona la capacidad de generar tráfico de forma activa y de verificar el estado de alcanzabilidad del terminal, realizando pruebas de conectividad.
- Una metodologĂa de post-procesado para correlar la informaciĂłn presente en las diferentes capas de las medidas realizadas. De igual forma, se proporciona la opciĂłn a los usuarios de acceder directamente a la informaciĂłn sobre el tráfico IP y las medidas radio y de aplicar metodologĂas propias para la obtenciĂłn de mĂ©tricas.
- Se ha realizado la aplicaciĂłn de la metodologĂa y de las herramientas usando como caso de uso el estudio y evaluaciĂłn del rendimiento de las comunicaciones basadas en IP a bordo de trenes de alta velocidad.
- Se ha contribuido a la creaciĂłn de un entorno de prueba realista y altamente configurable para la realizaciĂłn de experimentos avanzados sobre LTE.
- Se han detectado posibles sinergias en la utilización de instrumentación avanzada de I+D en el campo de las comunicaciones móviles, tanto para la enseñanza como para la investigación en un entorno universitario
Wireless networks and EMF-paving the way for low-EMF networks of the future: the LEXNET project
While, according to the World Health Organization, no adverse health effects of radio-frequency (RF) electromagnetic fields (EMFs) have been established to date, EMF exposure from wireless communication networks is nonetheless often cited as a major cause of public concern and is frequently given considerable media coverage. This article presents the results of a new survey on RF-EMF exposure risk perception together with a comprehensive overview of the EMF footprint of existing and emerging networks. On the basis of these findings, we then put forward the rationale for EMF-aware networking. Subsequently, we highlight the gaps in existing systems, which impede EMF-aware networking, and outline the key concepts of the recently launched European Union (EU) Seventh Framework Programme (FP7) Integrated Project Low-EMF Exposure Future Networks (LEXNET): a new, all-encompassing, population-based metric of exposure and ways it can be used for low-EMF, quality of service (QoS)-aware network optimization.This paper reports work undertaken in the context of the project LEXNET. LEXNET is a project supported by the European Commission in the 7th Framework Programme (GA n°318273). For further information, please visit www.lexnet-project.e
Quadri-dimensional approach for data analytics in mobile networks
The telecommunication market is growing at a very fast pace with the evolution of new technologies to support high speed throughput and the availability of a wide range of services and applications in the mobile networks. This has led to a need for communication service providers (CSPs) to shift their focus from network elements monitoring towards services monitoring and subscribers’ satisfaction by introducing the service quality management (SQM) and the customer experience management (CEM) that require fast responses to reduce the time to find and solve network problems, to ensure efficiency and proactive maintenance, to improve the quality of service (QoS) and the quality of experience (QoE) of the subscribers. While both the SQM and the CEM demand multiple information from different interfaces, managing multiple data sources adds an extra layer of complexity with the collection of data.
While several studies and researches have been conducted for data analytics in mobile networks, most of them did not consider analytics based on the four dimensions involved in the mobile networks environment which are the subscriber, the handset, the service and the network element with multiple interface correlation.
The main objective of this research was to develop mobile network analytics models applied to the 3G packet-switched domain by analysing data from the radio network with the Iub interface and the core network with the Gn interface to provide a fast root cause analysis (RCA) approach considering the four dimensions involved in the mobile networks. This was achieved by using the latest computer engineering advancements which are Big Data platforms and data mining techniques through machine learning algorithms.Electrical and Mining EngineeringM. Tech. (Electrical Engineering
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