Yes / Next-generation cellular networks such as fifth-generation (5G) will experience tremendous growth in traffic. To accommodate such traffic demand, there is a necessity to increase the network capacity that eventually requires the deployment of more base stations (BSs). Nevertheless, BSs are very expensive and consume a significant amount of energy. Meanwhile, cloud radio access networks (C-RAN) has been proposed as an energy-efficient architecture that leverages cloud computing technology where baseband processing is performed in the cloud, i.e., the computing servers or baseband processing units (BBUs) are located in the cloud. With such an arrangement, more energy saving gains can be achieved by reducing the number of BBUs used. This paper proposes a bin packing scheme with three variants such as First-fit (FT), First-fit decreasing (FFD) and Next-fit (NF) for minimizing energy consumption in 5G C-RAN. The number of BBUs are reduced by matching the right amount of baseband computing load with traffic load. In the proposed scheme, BS traffic items that are mapped into processing requirements, are to be packed into computing servers, called bins, such that the number of bins used are minimized and idle servers can then be switched off to save energy. Simulation results demonstrate that the proposed bin packing scheme achieves an enhanced energy performance compared to the existing distributed BS architecture.

Yes / By 2020, next generation (5G) cellular networks are expected to support a 1000 fold traffic increase. To meet such traffic demands, Base Station (BS) densification through small cells are deployed. However, BSs are costly and consume over half of the cellular network energy. Meanwhile, Cloud Radio Access Networks (C-RAN) has been proposed as an energy efficient architecture that leverage cloud computing technology where baseband processing is performed in the cloud. With such an arrangement, more energy gains can be acquired through statistical multiplexing by reducing the number of BBUs used. This paper proposes a green Intelligent Traffic and Resource Elastic Energy (iTREE) scheme for C-RAN. In iTREE, BBUs are reduced by matching the right amount of baseband processing with traffic load. This is a bin packing problem where items (BS aggregate traffic) are to be packed into bins (BBUs) such that the number of bins used are minimized. Idle BBUs can then be switched off to save energy. Simulation results show that iTREE can reduce BBUs by up to 97% during off peak and 66% at peak times with RAN power reductions of up to 27% and 18% respectively compared with conventional deployments.

Le réseau d'accès radio centralisé (C-RAN) peut fortement augmenter la capacité des réseaux mobiles. Cependant, la faisabilité de C-RAN est limitée par le débit considérable engendré sur les liaisons de transport, appelées également fronthaul. L'objectif de cette thèse est d'améliorer les performances de C-RAN tout en considérant les limitations du débit sur le frontaul, l'allocation de ressources et l'ordonnancement des utilisateurs.Nous étudions d'abord les séparations fonctionnelles possibles entre les têtes radios distantes (RRH) et les unités de traitement en bande de base (BBU) sur la liaison montante pour réduire le débit de transmission sur le fronthaul : certaines fonctions de couche basse sont déplacées du BBU vers les RRH. Nous fournissons une analyse quantitative des améliorations de performances ainsi obtenues.Nous nous concentrons ensuite sur la transmission coordonnée Multi-point (CoMP) sur le lien descendant. CoMP peut améliorer l'efficacité spectrale mais nécessite une coordination inter-cellule, ce qui est possible uniquement si une capacité fronthaul élevée est disponible. Nous comparons des stratégies de transmission avec et sans coordination inter-cellule. Les résultats de simulation montrent que CoMP doit être préféré pour les utilisateurs situés en bordure de cellule et lorsque la capacité du fronthaul est élevée. Nous en déduisons une stratégie hybride pour laquelle Les utilisateurs sont divisés en deux sous-ensembles en fonction de la puissance du signal. Les utilisateurs situés dans les zones centrales sont servis par un seul RRH avec une coordination simple et ceux en bordure de cellule sont servis en mode CoMP. Cette stratégie hybride constitue un bon compromis entre les débits offerts aux utilisateurs et les débits sur le fronthaul. / Centralized/Cloud Radio Access Network (C-RAN) is a promising mobile network architecture, which can potentially increase the capacity of mobile networks while reducing operators¿ cost and energy consumption. However, the feasibility of C-RAN is limited by the large bit rate requirement in the fronthaul. The objective of this thesis is to improve C-RAN performance while considering fronthaul throughput reduction, fronthaul capacity allocation and users scheduling.We first investigate new functional split architectures between Remote Radio Heads (RRHs) and Baseband Units (BBU) on the uplink to reduce the transmission throughput in fronthaul. Some low layer functions are moved from the BBU to RRHs and a quantitative analysis is provided to illustrate the performance gains. We then focus on Coordinated Multi-point (CoMP) transmissions on the downlink. CoMP can improve spectral efficiency but needs tight coordination between different cells, which is facilitated by C-RAN only if high fronthaul capacity is available. We compare different transmission strategies without and with multi-cell coordination. Simulation results show that CoMP should be preferred for users located in cell edge areas and when fronthaul capacity is high. We propose a hybrid transmission strategy where users are divided into two parts based on statistical Channel State Informations (CSIs). The users located in cell center areas are served by one transmission point with simple coordinated scheduling and those located in cell edge areas are served with CoMP joint transmission. This proposed hybrid transmission strategy offers a good trade-off between users¿ transmission rates and fronthaul capacity cost.

Helmholtz Zentrum Berlin (HZB) baut seit 2011 eine Testanlage Energy Recovery Linac (ERL) Project – BERLinPro. Das Ziel dieses Projektes ist den hohen Strom und hohe Brillanz von dem Elektronenstrahl in einem ERL zu demonstrieren. Die angestrebten Strahlparameter sind vergleichbar mit den Parametern von e.g. zukünftigen ERL-basierten Lichtquellen. Eine von solchen Anlagen ist Femto-Science Factory (FSF), die am HZB konzipiert wurde. FSF ist eine Lichtquelle in Röntgenbereich auf Basis von einem mehrumläufigen ERL mit zweistüfiger Injektion und Energie von einigen GeV. Die Quelle soll Diffraktionslimitiert sein und kurze (Femtosekundenbereich) Lichtpulse erzeugen. Die durchschnittliche und spitzen- Brillanz soll mindesten eine Größenordnung höher liegen als die Brillanz der modernen Speicherring-basierten Lichtquellen. Ein Überblick von BERLinPro und FSF ist gegeben. Eine potentielle Schwäche von ERL besteht in Strahlinstabilitäten, insbesondere regenerative Beam Break Up (BBU). Die Instabilität kann den erreichbaren durchschnittlichen Strom in einem ERL begrenzen. Der Grenzstrom von der BBU für BERLinPro ist berechnet in der Dissertation. Vergleich von zwei Linacs mit zwei verschiedenen supraleitenden Kavitätendesigns ist vorgestellt. Drei Methoden für Strahlstabilisierung (Einfluss von Strahlrotation mit einem Soleniod, Pseudoreflektor, und Tripleten von Quadrupolen in dem Linac auf den Grenzstrom) sind untersucht. Analytische Lösungen für die Twiss-Parameter wurden gefunden für die beste Linacoptik mit und ohne zusätzliche optische Elemente. Zukünftige große ERLs können unterschiedliche Beschleunigungsschemen benutzen. Diese Dissertation vergleicht drei Schemas: unmittelbare Injektion in einen 6 GeV Linac; zweistufige Injektion in einen 6 GeV Linac; und zweistufige Injektion in einen mehrumläufigen Beschleuniger mit geteiltem Hauptlinac in zwei 1 GeV Linacs. Der Basis für den Vergleich ist die Vollkostenanalyse sowie erreichbarer Grenzstrom von den Instabilitäten. / In January 2011 Helmholtz-Zentrum Berlin officially started the realization of the Berlin Energy Recovery Linac (ERL) Project – BERLinPro. The goal of this compact ERL is to develop the accelerator physics and technology required to accelerate a high-current (100 mA) low emittance beam. The parameters are desired for future large scale facilities based on ERLs, e.g. ERL-based synchrotron light sources. One of such large scale facilities is in the design phase at Helmholtz-Zentrum Berlin. This facility is called Femto-Science Factory (FSF). It is a GeV-scale multi-turn ERL-based light source. This light source will operate in the diffraction limited regime for X-rays and offer a short length of a light pulse in the femtosecond region. The average and peak brightness will be at least an order of magnitude higher than achievable from storage rings. In this work an overview of these two projects is given. One potential weakness of the Energy Recovery Linacs is a regenerative form of BBU – transverse beam break up instability. This instability can limit a beam current. In this work the threshold current of the BBU instability was calculated for BERLinPro. The comparison of two linacs based on different types of superconducting cavities is made. Different methods of BBU suppression are investigated (e.g. the influence of solenoid, pseudo-reflector and quadruple triplets in the linac structure on the BBU threshold). Analytic solutions of the Twiss parameters are used to find the best optic in the linac with and without external focusing are presented. Large scale ERL facilities can be realized on different schemes of beam acceleration. This dissertation compares a direct injection scheme with acceleration in a 6 GeV linac, a two-stage injection with acceleration in a 6 GeV linac and a multi-turn (3-turn) scheme with a two-stage injection and two main 1 GeV linacs. The key points of the comparison were total costs and BBU instability. Linac optic solutions are presented.

De nos jours, la demande en trafic mobile a considérablement augmenté. Face à cette croissance, plusieurs propositions font l'objet d'étude pour remédier à un tel défi. L’architecture des réseaux d’accès de type Cloud (C-RAN) est l’une des propositions pour faire face à cette demande croissante, et constitue une solution candidate potentielle pour les réseaux futurs 5G. L'architecture C-RAN dissocie deux éléments principaux de la station de base: La BBU ou ``Baseband Unit", qui constitue une unité intelligente pour le traitement des données en bande de base, et le RRH ou ``Remote Radio Head", constituant en une antenne passive pour fournir l'accès aux utilisateurs (UEs). Grâce à l’architecture C-RAN, les BBUs sont centralement regroupées, alors que les RRHs sont distribués sur plusieurs sites. Plusieurs avantages sont ainsi dérivés, tels que le gain en multiplexage statistique, l’efficacité d’utilisation des ressources, et l’économie de puissance. Contrairement à l’architecture conventionnelle où chaque RRH est exclusivement associé à une BBU, dans l’architecture C-RAN, plusieurs RRHs sont regroupés en une seule BBU lorsque les conditions de charge sont faibles. Ceci présente plusieurs avantages, tel que l’amélioration en efficacité énergétique et la minimisation en consommation de puissance. Dans cette thèse, nous adressons le problème d’optimisation des associations BBU-RRH. Nous nous intéressons à l’optimisation des regroupements des RRHs aux BBUs en tenant compte de critères multiples. Plusieurs contraintes sont ainsi envisagées, tel que la réduction de la consommation d'énergie sous garantie de Qualité de Service (QoS) minimale. En outre, la prise en compte du changement du niveau d’interférence en activant/désactivant les BBUs est primordiale pour l’amélioration de l’efficacité spectrale. En plus, décider dynamiquement de la réassociation des RRHs aux BBUs sous des conditions de charges variables représente un défi, vu que les UEs connectés aux RRHs changeant leurs associations font face à des ``handovers" (HOs). / The demand on mobile traffic has been largely increasing nowadays. Facing such growth, several propositions are being studied to cope with this challenge. Cloud-Radio Access Networks Architecture (C-RAN) is one of the proposed solutions to address the increased demand, and is a potential candidate for future 5G networks. The C-RAN architecture dissociates two main elements composing the base station: The Baseband Unit (BBU), consisting in an intelligent element to perform baseband tasks functionalities, and the Remote Radio Head (RRH), that consists in a passive antenna element to provide access for serviced User Equipments (UEs). In C-RAN architecture, the BBUs migrate to a Cloud data center, while RRHs remain distributed across multiple sites. Several advantages are derived, such as statistical multiplexing gain, efficiency in resource utilization and power saving. Contrarily to conventional architecture, where each RRH is associated to one BBU, in C-RAN architecture, multiple RRHs can be embraced by one single BBU when network load conditions are low, bringing along several benefits, such as enhanced energy efficiency, and power consumption minimization. In this thesis, the BBU-RRH association optimization problem is addressed. Our aim is to optimize the BBU-RRH association schemes, taking into consideration several criteria. The problem presents many constraints: For example, achieving minimized power consumption while guaranteeing a minimum level of Quality of Service (QoS) is a challenging task. Further, taking into account the interference level variation while turning ON/OFF BBUs is paramount to achieve enhanced spectral efficiency. Moreover, deciding how to re-associate RRHs to BBUs under dynamic load conditions is also a challenge, since connected UEs face handovers (HOs) when RRHs change their associations.

Made available in DSpace on 2014-06-11T19:26:03Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-02-27Bitstream added on 2014-06-13T19:12:48Z : No. of bitstreams: 1 stafuzza_nb_me_sjrp.pdf: 331396 bytes, checksum: 62bedf496f7c8ad27e32a8ea0d781c57 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Nesse trabalho apresentamos o primeiro mapa comparativo do cromossomo 6 do búfalo de rio (BBU6), desenvolvido a partir da utilização de um painel de células somáticas híbridas irradiadas búfalo-roedor com fragmentação de 5000 rads. O mapa preliminar construído é composto por 33 marcadores, os quais estão ordenados em dois grupos de ligação compostos por 12 microssatélites, 19 genes codificantes e duas ESTs. A freqüência de retenção observada entre os marcadores variou de 14.4% a 40%. A ordem dos marcadores dentro dos grupos de ligação do BBU6, em sua maioria, é consistente com o mapa RH bovino. Esse mapa preliminar do BBU6 é um ponto de partida para comparar a ordem dos genes entre as espécies, fornecendo uma oportunidade para estudar micro-arranjos nesse cromossomo, além de possibilitar a clonagem posicional em búfalo de rio. / We present the first radiation hybrid map of BBU6 developed from a recently constructed river buffalo whole-genome radiation hybrid panel (BBURH5000). The preliminary map contains 33 cattle-derived markers, including 12 microsatellites, 19 coding genes and two ESTs, distributed in two linkage groups. The retention frequency of individual markers ranged from 14.4% to 40.0%. Most of the marker order within the linkage groups is consistent with the cattle RH maps. This preliminary BBU6 RH map is the starting point for comparing gene order between both species, presenting opportunity for examination of micro-rearrangements of these chromosomes and, thereby enhancing the possibility of positional candidate cloning in river buffalo.

La presente tesina consiste en el diseño de migración de nodos B aplicado para una RNC caída de una red móvil, con la finalidad de solucionar los problemas que se presenten ante un incidente que afecte los servicios de voz y datos de los usurarios de una red móvil. En el desarrollo de la tesina, se describe el planteamiento del problema, el marco teórico de la tecnología UMTS y posteriormente nos centramos en los elementos principales de esta tecnología. También describimos los equipos importantes a utilizar en desarrollo del proyecto, en este caso nos enfocamos en la descripción de la RNC. Y finalmente describimos el desarrollo del proyecto, el diseño de la solución e implementación de la misma, y en donde se presentan los resultados del diseño. This thesis is the design of migration of nodes B and its a applied when RNC fall for a mobile network, in order to solve the problems that arise before an incident affecting voice and data services from a mobile network. In developing the thesis, we describe the theoretical framework of UMTS technology and then we focus on the main elements of this technology. We also describe the important equipment used in project development; in this case we focus on the description of the RNC. And finally we describe the solution of design and implementation .Also, the results of this project.