3,288 research outputs found
Green Cellular Networks: A Survey, Some Research Issues and Challenges
Energy efficiency in cellular networks is a growing concern for cellular
operators to not only maintain profitability, but also to reduce the overall
environment effects. This emerging trend of achieving energy efficiency in
cellular networks is motivating the standardization authorities and network
operators to continuously explore future technologies in order to bring
improvements in the entire network infrastructure. In this article, we present
a brief survey of methods to improve the power efficiency of cellular networks,
explore some research issues and challenges and suggest some techniques to
enable an energy efficient or "green" cellular network. Since base stations
consume a maximum portion of the total energy used in a cellular system, we
will first provide a comprehensive survey on techniques to obtain energy
savings in base stations. Next, we discuss how heterogeneous network deployment
based on micro, pico and femto-cells can be used to achieve this goal. Since
cognitive radio and cooperative relaying are undisputed future technologies in
this regard, we propose a research vision to make these technologies more
energy efficient. Lastly, we explore some broader perspectives in realizing a
"green" cellular network technologyComment: 16 pages, 5 figures, 2 table
Energy and cost management in shared heterogeneous network deployments
Pla de Doctorat industrial de la Generalitat de CatalunyaDuring the recent years, a huge augmentation of the data traffic volume has been noticed, while a further steep increase is expected in the following years. As a result, questions have been raised over the years about the energy consumption needs of the wireless telecommunication networks, their carbon dioxide emissions and their operational expenses.
Aiming at meeting the high traffic demands with flat energy consumption and flat incurred expenses, mobile network operators (MNOs) have opted to improve their position (i) by deploying heterogeneous networks (HetNets), which are consisted of macrocell base stations (MBSs) and small cell base stations (SBSs) and (ii) by sharing their infrastructure.
However, questions could be raised about the extend to which HetNet densification is of aid. Given that network planning is executed according to high traffic load volumes, BS underutilisation during low-traffic hours cannot be neglected. Similarly, the aggregated energy needs of multiple SBSs equals the ones of an energy hungry MBS, having thus a respectable share of the net energy consumption.
In this context, a set of research opportunities have been identified. This thesis provides contribution toward the achievement of a greener and more cost efficient operation of HetNet deployments, where multiple stakeholders develop their activity and where energy support can have the form of various alternate schemes, including renewable energy (RE) sources. Depending on the network energy support, i.e., whether RE sources are used in the network or not, the main body of this thesis is divided in two research directions.
The first part of the thesis uses the technology of switching off strategies in order to explore their efficiency in terms of both energy and costs in a HetNet. The HetNet is assumed to be a roaming-based cooperative activity of multiple MNOs that is powered exclusively by grid energy. A switching off and a cost allocation scheme are proposed, using as criteria the BS type, the BS load and the roaming cost for traffic offloading. The performance of the proposed schemes is evaluated with respect to energy efficiency,
cost savings and fairness, using computer-based simulations. The second part of the thesis explores energy and cost management issues in energy harvesting (EH) HetNet deployments where EH-BSs use an EH system (EHS), an energy storage system (ESS) and the smart grid (SG) as energy procurement sources. The EH-HetNet is assumed a two-tier network deployment of EH-MBSs that are passively shared among an MNO set and EH-SBSs that are provided to MNOs by an infrastructure provider. Taking into consideration the infrastructure location and the variety of stakeholders involved in the network deployment, approaches of RE exchange (REE) are proposed as a cooperative RE sharing for the shared EH-MBSs, based on bankruptcy theory, and a non-cooperative, aggregator-assisted RE trading, based on double auctions, for the EH-SBSs. The performance of the proposed schemes is evaluated in terms of the hours of independence of the studied system from the SG, the fairness regulated by the provided solution and the economical payoffs extracted for the stakeholdersDurante los Ăşltimos años, se ha notado un aumento enorme del volumen de tráfico de datos, mientras que se espera un nuevo aumento en los prĂłximos años. Como resultado, se han planteado preguntas sobre las necesidades de consumo de energĂa de las redes inalámbricas de telecomunicaciones, sus emisiones de diĂłxido de carbono y sus gastos operativos.
Con el objetivo de satisfacer las altas demandas de tráfico con consumo de energĂa constante y con gastos incurridos constantes, además de utilizar soluciones basadas en la nube, los operadores de redes mĂłviles (MNOs) han optado por mejorar su posiciĂłn (i) desplegando redes heterogĂ©neas (HetNets), que consisten en estaciones base de macro-cĂ©lulas (MBSs) y estaciones base de cĂ©lulas pequeñas (SBSs), y (ii) compartiendo su infraestructura.
Sin embargo, podrĂan plantearse preguntas sobre hasta quĂ© punto la densificaciĂłn de una HetNet es de ayuda. Dado que la planificaciĂłn de la red se ejecuta de acuerdo con los volĂşmenes de carga de tráfico más elevados, no se puede descuidar la subutilizaciĂłn de las estaciones base (BS) durante las horas de poco tráfico. De manera similar, las necesidades de energĂa agregadas de mĂşltiples SBSs son iguales a las de una MBS que consume mucha energĂa, teniendo asĂ una parte respetable del consumo neto de energĂa.
En este contexto, se ha identificado un conjunto de oportunidades de investigaciĂłn. Esta tesis contribuye al logro de una operaciĂłn más ecolĂłgica y rentable de las implementaciones de HetNet, donde mĂşltiples partes interesadas desarrollan su actividad y donde el apoyo energĂ©tico puede tener la forma de varios esquemas alternativos, incluidas las fuentes de energĂa renovables (RE). Dependiendo del soporte de energĂa de red, es decir, si las fuentes de RE se usan en la red o no, el cuerpo principal de esta tesis se divide en dos direcciones de investigaciĂłn.
La primera parte de la tesis utiliza la tecnologĂa de las estrategias de apagado con el objetivo de explorar su eficiencia en tĂ©rminos de energĂa y gastos en una HetNet. Se asume que la HetNet es una actividad cooperativa basada en la itinerancia de mĂşltiples MNO que se alimenta exclusivamente de energĂa de la red. Se propone un esquema de desconexiĂłn y de asignaciĂłn de costes, que utiliza como criterios el tipo de BS, la carga de BS y el coste de la itinerancia para la descarga de tráfico. El rendimiento de los esquemas propuestos se evalĂşa con respecto a la eficiencia energĂ©tica, el ahorro de costes y la equidad, usando simulaciones en computadora.
La segunda parte de la tesis explora los problemas de gestiĂłn de energĂa y de costes en las implementaciones de HetNet donde las estaciones base recolectan energĂa usando un sistema EH (EHS), un sistema de almacenamiento de energĂa (ESS) y la red elĂ©ctrica inteligente (SG) como sistemas de adquisiciĂłn de energĂa. Se asume que el EH-HetNet es una implementaciĂłn de redes de dos niveles donde los EH-MBSs se comparten pasivamente entre un conjunto de MNOs y EH-SBSs se proporcionan a los MNOs de un proveedor de infraestructura. Teniendo en cuenta la ubicaciĂłn de la infraestructura y la variedad de partes interesadas e involucradas en el despliegue de la red, se proponen enfoques de intercambio de RE (REE) como un intercambio cooperativo de RE para los EH-MBS compartidos, basado en la teorĂa de bancarrota, y un no cooperativo comercio de RE para los EH-SBSs, que es asistido por un agregador y basado en las subastas dobles. El rendimiento de los esquemas propuestos se evalĂşa en tĂ©rminos de las horas de independencia del sistema estudiado con respecto al SG, la imparcialidad regulada por la soluciĂłn proporcionada y los beneficios econĂłmicos extraĂdos para las interesadas.Postprint (published version
Energy and cost management in shared heterogeneous network deployments
During the recent years, a huge augmentation of the data traffic volume has been noticed, while a further steep increase is expected in the following years. As a result, questions have been raised over the years about the energy consumption needs of the wireless telecommunication networks, their carbon dioxide emissions and their operational expenses.
Aiming at meeting the high traffic demands with flat energy consumption and flat incurred expenses, mobile network operators (MNOs) have opted to improve their position (i) by deploying heterogeneous networks (HetNets), which are consisted of macrocell base stations (MBSs) and small cell base stations (SBSs) and (ii) by sharing their infrastructure.
However, questions could be raised about the extend to which HetNet densification is of aid. Given that network planning is executed according to high traffic load volumes, BS underutilisation during low-traffic hours cannot be neglected. Similarly, the aggregated energy needs of multiple SBSs equals the ones of an energy hungry MBS, having thus a respectable share of the net energy consumption.
In this context, a set of research opportunities have been identified. This thesis provides contribution toward the achievement of a greener and more cost efficient operation of HetNet deployments, where multiple stakeholders develop their activity and where energy support can have the form of various alternate schemes, including renewable energy (RE) sources. Depending on the network energy support, i.e., whether RE sources are used in the network or not, the main body of this thesis is divided in two research directions.
The first part of the thesis uses the technology of switching off strategies in order to explore their efficiency in terms of both energy and costs in a HetNet. The HetNet is assumed to be a roaming-based cooperative activity of multiple MNOs that is powered exclusively by grid energy. A switching off and a cost allocation scheme are proposed, using as criteria the BS type, the BS load and the roaming cost for traffic offloading. The performance of the proposed schemes is evaluated with respect to energy efficiency,
cost savings and fairness, using computer-based simulations. The second part of the thesis explores energy and cost management issues in energy harvesting (EH) HetNet deployments where EH-BSs use an EH system (EHS), an energy storage system (ESS) and the smart grid (SG) as energy procurement sources. The EH-HetNet is assumed a two-tier network deployment of EH-MBSs that are passively shared among an MNO set and EH-SBSs that are provided to MNOs by an infrastructure provider. Taking into consideration the infrastructure location and the variety of stakeholders involved in the network deployment, approaches of RE exchange (REE) are proposed as a cooperative RE sharing for the shared EH-MBSs, based on bankruptcy theory, and a non-cooperative, aggregator-assisted RE trading, based on double auctions, for the EH-SBSs. The performance of the proposed schemes is evaluated in terms of the hours of independence of the studied system from the SG, the fairness regulated by the provided solution and the economical payoffs extracted for the stakeholdersDurante los Ăşltimos años, se ha notado un aumento enorme del volumen de tráfico de datos, mientras que se espera un nuevo aumento en los prĂłximos años. Como resultado, se han planteado preguntas sobre las necesidades de consumo de energĂa de las redes inalámbricas de telecomunicaciones, sus emisiones de diĂłxido de carbono y sus gastos operativos.
Con el objetivo de satisfacer las altas demandas de tráfico con consumo de energĂa constante y con gastos incurridos constantes, además de utilizar soluciones basadas en la nube, los operadores de redes mĂłviles (MNOs) han optado por mejorar su posiciĂłn (i) desplegando redes heterogĂ©neas (HetNets), que consisten en estaciones base de macro-cĂ©lulas (MBSs) y estaciones base de cĂ©lulas pequeñas (SBSs), y (ii) compartiendo su infraestructura.
Sin embargo, podrĂan plantearse preguntas sobre hasta quĂ© punto la densificaciĂłn de una HetNet es de ayuda. Dado que la planificaciĂłn de la red se ejecuta de acuerdo con los volĂşmenes de carga de tráfico más elevados, no se puede descuidar la subutilizaciĂłn de las estaciones base (BS) durante las horas de poco tráfico. De manera similar, las necesidades de energĂa agregadas de mĂşltiples SBSs son iguales a las de una MBS que consume mucha energĂa, teniendo asĂ una parte respetable del consumo neto de energĂa.
En este contexto, se ha identificado un conjunto de oportunidades de investigaciĂłn. Esta tesis contribuye al logro de una operaciĂłn más ecolĂłgica y rentable de las implementaciones de HetNet, donde mĂşltiples partes interesadas desarrollan su actividad y donde el apoyo energĂ©tico puede tener la forma de varios esquemas alternativos, incluidas las fuentes de energĂa renovables (RE). Dependiendo del soporte de energĂa de red, es decir, si las fuentes de RE se usan en la red o no, el cuerpo principal de esta tesis se divide en dos direcciones de investigaciĂłn.
La primera parte de la tesis utiliza la tecnologĂa de las estrategias de apagado con el objetivo de explorar su eficiencia en tĂ©rminos de energĂa y gastos en una HetNet. Se asume que la HetNet es una actividad cooperativa basada en la itinerancia de mĂşltiples MNO que se alimenta exclusivamente de energĂa de la red. Se propone un esquema de desconexiĂłn y de asignaciĂłn de costes, que utiliza como criterios el tipo de BS, la carga de BS y el coste de la itinerancia para la descarga de tráfico. El rendimiento de los esquemas propuestos se evalĂşa con respecto a la eficiencia energĂ©tica, el ahorro de costes y la equidad, usando simulaciones en computadora.
La segunda parte de la tesis explora los problemas de gestiĂłn de energĂa y de costes en las implementaciones de HetNet donde las estaciones base recolectan energĂa usando un sistema EH (EHS), un sistema de almacenamiento de energĂa (ESS) y la red elĂ©ctrica inteligente (SG) como sistemas de adquisiciĂłn de energĂa. Se asume que el EH-HetNet es una implementaciĂłn de redes de dos niveles donde los EH-MBSs se comparten pasivamente entre un conjunto de MNOs y EH-SBSs se proporcionan a los MNOs de un proveedor de infraestructura. Teniendo en cuenta la ubicaciĂłn de la infraestructura y la variedad de partes interesadas e involucradas en el despliegue de la red, se proponen enfoques de intercambio de RE (REE) como un intercambio cooperativo de RE para los EH-MBS compartidos, basado en la teorĂa de bancarrota, y un no cooperativo comercio de RE para los EH-SBSs, que es asistido por un agregador y basado en las subastas dobles. El rendimiento de los esquemas propuestos se evalĂşa en tĂ©rminos de las horas de independencia del sistema estudiado con respecto al SG, la imparcialidad regulada por la soluciĂłn proporcionada y los beneficios econĂłmicos extraĂdos para las interesadas
Energy efficient cooperative computing in mobile wireless sensor networks
Advances in future computing to support emerging sensor applications are becoming more important as the need to better utilize computation and communication resources and make them energy efficient. As a result, it is predicted that intelligent devices and networks, including mobile wireless sensor networks (MWSN), will become the new interfaces to support future applications. In this paper, we propose a novel approach to minimize energy consumption of processing an application in MWSN while satisfying a certain completion time requirement. Specifically, by introducing the concept of cooperation, the logics and related computation tasks can be optimally partitioned, offloaded and executed with the help of peer sensor nodes, thus the proposed solution can be treated as a joint optimization of computing and networking resources. Moreover, for a network with multiple mobile wireless sensor nodes, we propose energy efficient cooperation node selection strategies to offer a tradeoff between fairness and energy consumption. Our performance analysis is supplemented by simulation results to show the significant energy saving of the proposed solution
Energy Efficient and Secure Wireless Sensor Networks Design
Wireless Sensor Networks (WSNs) are emerging technologies that have the ability to sense, process, communicate, and transmit information to a destination, and they are expected to have significant impact on the efficiency of many applications in various fields. The resource constraint such as limited battery power, is the greatest challenge in WSNs design as it affects the lifetime and performance of the network. An energy efficient, secure, and trustworthy system is vital when a WSN involves highly sensitive information. Thus, it is critical to design mechanisms that are energy efficient and secure while at the same time maintaining the desired level of quality of service. Inspired by these challenges, this dissertation is dedicated to exploiting optimization and game theoretic approaches/solutions to handle several important issues in WSN communication, including energy efficiency, latency, congestion, dynamic traffic load, and security. We present several novel mechanisms to improve the security and energy efficiency of WSNs. Two new schemes are proposed for the network layer stack to achieve the following: (a) to enhance energy efficiency through optimized sleep intervals, that also considers the underlying dynamic traffic load and (b) to develop the routing protocol in order to handle wasted energy, congestion, and clustering. We also propose efficient routing and energy-efficient clustering algorithms based on optimization and game theory. Furthermore, we propose a dynamic game theoretic framework (i.e., hyper defense) to analyze the interactions between attacker and defender as a non-cooperative security game that considers the resource limitation. All the proposed schemes are validated by extensive experimental analyses, obtained by running simulations depicting various situations in WSNs in order to represent real-world scenarios as realistically as possible. The results show that the proposed schemes achieve high performance in different terms, such as network lifetime, compared with the state-of-the-art schemes
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