Dissertations / Theses: 'Dense radio access network'

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Thainesh, Joseph S. "Radio access network (RAN) signalling architecture for dense mobile network." Thesis, University of Surrey, 2016. http://epubs.surrey.ac.uk/811126/.

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Small cells are becoming a promising solution for providing enhanced coverage and increasing system capacity in a large-scale small cell network. In such a network, the large number of small cells may cause mobility signalling overload on the core network (CN) due to frequent handovers, which impact the users Quality of Experience (QoE). This is one of the major challenges in dense small cell networks. Such a challenge has been considered, this thesis addresses this challenging task to design an effective signalling architecture in dense small cell networks. First, in order to reduce the signalling overhead incurred by path switching operations in the small cell network, a new mobility control function, termed the Small Cell Controller (SCC) is introduced to the existing base station (BS) on the Radio-Access-Network(RAN)-side. Based on the signalling architecture, a clustering optimisation algorithm is proposed in order to select the optimal SCC in a highly user density environment. Specifically, this algorithm is designed to select multiple optimal SCCs due to the growth in number of small cells in the large-scale environment. Finally, a scalable architecture for handling the control plane failures in heterogeneous networks is proposed. In that architecture, the proposed SCC scheme controls and manages the affected small cells in a clustered fashion during the macro cell fail-over period. Particularly, the proposed SCC scheme can be flexibly configured into a hybrid scenario. For operational reduction (reducing a number of direct S1 connections to the CN), better scalability (reducing a number of S1 bearers on the CN) and reduction of signalling load on the CN, the proposed radio access network (RAN) signalling architecture is a viable and preferable option for dense small cell networks. Besides, the proposed signalling architecture is evaluated through realistic simulation studies.

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Jarrar, Majed. "Radio Over Fibre Passive Optical Network Integration for The Smart Grid." Thesis, Université d'Ottawa / University of Ottawa, 2015. http://hdl.handle.net/10393/32779.

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During the last three decades, the significant increase in electricity demand, and its consequences, has appeared as a serious concern for the utility companies, but no major changes have been applied to the conventional power grid infrastructure. Recently, researchers have identified efficient control and power distribution mechanisms as the immediate challenges for conventional power grids. The next step for conventional power grid towards the Smart Grid is to provide energy efficiency management along with higher reliability via smart services, in which the application of Information and Communication Technology (ICT) is inevitable. ICT introduces powerful tools to comply with the smart grid requirements. Among various ICT properties, the telecommunication network plays a key role for providing a secure infrastructure. The two-way digital communication system provides an interaction between energy suppliers and consumers for managing, controlling and optimizing energy distribution. We can also define the smart grid as a two-way flow of energy and control information, where the electricity consumers can generate energy using green energy resources. The main objective of this thesis is to select an effective data communication infrastructure to support the smart grid services by considering a hybrid wireless and optical communication technologies. Radio-over-Fibre (RoF) networks are considered as a potential solution to provide a fast, reliable and efficient network backbone with the optical access network integration and the flexibility and mobility of the wireless network. Therefore, we adopt the integration of RoF to Passive Optical Network (PON) as a broadband access network to transmit smart grid data along with the Fiber to the Home/Building/Curb (FTTx) traffic through the shared fibre, and utilizing Wavelength Division Multiplexing (WDM). Finally, we present and analyze the simulation results for the aforementioned infrastructure based on our enhanced ROF-PON integration model.

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Lim, Christopher. "Optimizing access radio in multi-radio mesh network /." View abstract or full-text, 2009. http://library.ust.hk/cgi/db/thesis.pl?CSED%202009%20LIM.

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Tsai, Pi-Kuang. "Indoor hybrid infrared-radio access network." Thesis, University of Cambridge, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.614020.

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Lei, Rui. "Cloud Radio Access Network in constrained fronthaul." Thesis, University of York, 2017. http://etheses.whiterose.ac.uk/21293/.

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The Cloud Radio Access Network (C-RAN) has been proposed for the provision of advanced fourth and fifth generation wireless communication services. The C-RAN system have been shown to reduce costs, and can provide high spectral efficiency and energy efficiency. The fronthaul in such networks, defined as the transmission links between Remote Radio Units (RRUs) and a central Baseband Unit (BBU), usually has high fronthaul load and constrained capacity. In this thesis, we explore and investigate the basic C-RAN system structure, based on which we propose two developed C-RAN systems. With each system we evaluate the Bit Error Ratio (BER) performance and transmission efficiency in multiple scenarios, and give advanced solutions to reduce the fronthaul load. We also analyse the effect of quantization on BPSK and QPSK modulation schemes, with different detection methods. Error control in fronthaul transmission is considered as erroneous frames may be received at the BBU. Error Detection Coding and Error Correction Coding approaches can be applied to the fronthaul network. They may increase the fronthaul latency, but great improve the end-to-end BER performance. Source compression techniques such as Slepian-Wolf (SW) coding can compress two correlated sources separately and de-compress them jointly. Since each RRU serves many user terminals, and some of them may also be served by another neighbour RRU, which results similarly in correlation of the received data between two RRUs. In this thesis, we applied the SW code to the C-RAN system and evaluate the compression rate achieved in fronthaul networks.

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Chang, Chia-Yu. "Cloudiﬁcation and Slicing in 5G Radio Access Network." Electronic Thesis or Diss., Sorbonne université, 2018. https://accesdistant.sorbonne-universite.fr/login?url=https://theses-intra.sorbonne-universite.fr/2018SORUS293.pdf.

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Au cours des dernières décennies, la croissance des statistiques d’utilisation de réseau exige une technologique évolutive. Une question naturelle surgit dans nos esprits: que sera la 5G? Pour répondre à cette question, l’architecture 5G doit être conçue avec un certain niveau de flexibilité via l’intégration des principes de softwarization et virtualisation. Le réseau peut être utilisé de manière efficace et indépendante via la création de plusieurs espaces séparées logiquement, appelés tranches de réseau. De plus, chaque réseau logique peut déployer ses fonctions de réseau dans un environnement de nuage avec la flexibilité d’exécution. À cette fin, l’objectif de cette thèse est d’étudier ces deux techniques: (a) C-RAN et (b) découpage de RAN. Dans la première partie, nous étudions C-RAN, dans lequel les stations de base monolithiques sont remplacées par (1) les éléments radio distribués et (2) les pools centralisés pour des unités de traitement en bande de base. Le concept C-RAN est toujours confronté à des exigences sévères en matière de capacité et de latence de l’interface fronthaul qui connecte l’unité de radio distante distribuée à l’unité de traitement en bande de base centralisée. Dans la deuxième partie, nous nous concentrons sur le découpage RAN non seulement pour permettre des différents niveaux d’isolation et de partage à chaque tranche de réseau, mais également pour customiser le plan de contrôle, le plan utilisateur et la logique de contrôle de réseau virtualisé. Par conséquent, nous proposons un environnement d’exécution flexible pour le système de slicing, nommé «RAN Runtime» pour héberger les instances de service sur chacun des modules RAN sous-jacents
Over the past few decades, the continuing growth of network statistics requires a constantly evolving technology. Therefore, a natural question arises in our minds: what will 5G be? To answer this question, the 5G architecture must be designed with a certain level of flexibility through the integration of softwarization and virtualization principles. Therefore, we can see that 5G will provide a paradigm shift beyond radio access technology in order to establish an agile and sophisticated communication system. The network can be used efficiently and independently by creating multiple logically separated spaces, called network slices. In addition, each logical network can deploy its network functions in a flexible cloud environment. To this end, the goal of this thesis is to study these two techniques: (a) Cloud-RAN and (b) RAN splitting. In the first part, our focus is on the C-RAN concept, in which monolithic base stations are replaced by (1) distributed radio elements and (2) centralized pools for baseband processing units. The C-RAN notion is still confronted with stringent capacity and latency requirements of the fronthaul interface that connects the distributed remote radio unit to the centralized baseband processing unit. In the second part, we focus on RAN cutting not only to allow different levels of isolation and sharing at each slice of network, but also to customize the control plane, user plane and control logic. Therefore, we provide a flexible runtime environment for the "RAN Runtime" slicing system to host service instances on each of the underlying RAN modules

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Montojo, Villasanta Javier, and Viñas Manuel Maqueda. "Congestion Identification in a Radio Access Transport Network." Thesis, KTH, Radio Systems Laboratory (RS Lab), 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-142437.

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The convergence of mobile services and Internet has brought a radical change in mobile networks. An all IP network architecture, an evolution of the radio access transport network, is required to support new high-bandwidth services. Unfortunately, existing control mechanisms are insufficient to guarantee end users a high quality of experience. However, coordinating radio and transport network resources is expected to yield a more efficient solution. This thesis project investigates the interactions between the congestion avoidance protocols, explicit congestion notification, and the traffic engineering metrics for latency and bandwidth, when using Open Shortest Path First with traffic engineering (OSPF-TE) as a routing protocol. Using knowledge of these interactions, it is possible to identify the appearance of bottlenecks and to control the congestion in the transport links within a radio access transport network. Augmenting a topology map with the network’s current characteristics and reacting to evidence of potential congestion, further actions, such as handovers can be taken to ensure the users experience their expected quality of experience. The proposed method has been validated in a test bed. The results obtained from experiments and measurements in this test bed provide a clear picture of how the traffic flows in the network. Furthermore, the behavior of the network observed in these experiments, in terms of real-time performance and statistical analysis of metrics over a period of time, shows the efficiency of this proposed solution.
Tjänstekonvergensen av Internet- och mobila tjänster har medfört en radikal förändring i mobilnäten. En ”All IP” nätverksarkitektur, en utveckling av radios transportnät. Utvecklingen krävs för att stödja de nya bredbandiga tjänsterna. Tyvärr är befintliga kontrollmekanismer otillräckliga för att garantera användarens kvalitetsupplevelse. Med att samordna radio- och transportnätverkets resurser förväntar man sig en effektivare lösning. Detta examensarbete undersöker samspelet mellan protokoll för att undvika överlast, direkt indikation av överlast och trafikal statistik för fördröjning och bandbredd med trafikstyrning baserat på fördröjning och bandbredd , vid användning av Open Shortest Path First ( OSPF - TE ) som routingprotokoll. Med hjälp av information om dessa interaktioner, är det möjligt att identifiera uppkomsten av flaskhalsar och för att styra trafikstockningar i transportförbindelser inom ett radioaccess transportnät. En utökad topologikarta med nätverkets aktuella egenskaper kommer att reagera på en potentiell överbelastning. Ytterligare åtgärder, till exempel överlämningar, vidtas i mobilnätet för att säkerställa användarens upplevda kvalitet. Den föreslagna metoden har validerats i en testmiljö. Resultaten från experiment och mätningar i denna testmiljö ger en tydlig bild av hur trafikflödena framskrider i nätverket. Beteendet hos nätverket som observeras i dessa experiment, i termer av realtidsprestanda och statistisk analys av mätvärden över en tidsperiod, visar effektiviteten av denna föreslagna lösning.

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Simard, François. "A packet radio network design for field, mobile multimedia communications, network configuration, radio channel access and network management." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ28459.pdf.

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Juarez, Maribel. "Structuring Lean Thinking in the Radio Access Network Area." Thesis, Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-110839.

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Customer’ demands, higher quality, faster and safer deliveries are some reasons for unexpected changes in the organizations. It has incremented complexity and cost. Lean production is known as a methodology to make improvements in manufacturing areas such as mentioned above and it is focused on the process of a product. But, Lean Thinking is a management strategy to make improvements in the process of a product or service and it is based on five principles. It allows having the process close to the customer eliminates tasks that do not add value and produces with low costs and high quality. However, there are some concepts ambiguous to be applied effectively to the Radio Access Network area in wireless telecom industry as a service company. Radio Access Network area transmits Radio frequency (RF) signals from the Radio Base Station (RBS) to the user equipment (UE) or mobile phone and is an area to present dynamic changes by high technology innovation. Therefore, the aim of this study is to identify improvements through for the Radio Access Network area. This thesis was structured to know how the five Lean principles and Lean tools can be used in the Radio Access Network area and the benefits that it could have. The study was realized through a qualitative research and five semi-structured interviews. A manager, team leaders and engineers of wireless telecom industry vendor and operators were the participants for this study. The results of major impact for Lean principles and Lean tools were VSM and Flow principles and Waste as Lean tool found for the Radio Access Network area. Project definition, resource planning and VOC were some improvements revealed for VSM principle. Furthermore, faster and optimal tools, training for engineers, knowledge in software and employee empowerment were some improvements found for Flow principle. Waste Lean tool showed some improvements found on customer’s focus, clear communication and waiting time reduction. Cross functional teams were other aspects that provided quality performance in the projects. This study seemingly is a good start for making decisions and for the high technology innovation and dynamic changes for telecom service companies.

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Al-Samman, Imad. "The integration of cloud radio access network in 5G." Thesis, University of Bristol, 2018. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.752772.

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Aruchamy, Logabharathi. "Analysis of Radio Access Network Buffer Filling Based on Real Network Data." Thesis, Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-6063.

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The 3G and 4G networks have drastically improved availability and quality in data transmission for bandwidth hungry services such as video streaming and location-based services. As 3G networks are very widely deployed, there exists increased capacity requirement and transport channel allocation to simultaneous users under a particular cell. Due to this reason, adequate resources are not available, which in turn degrades both service quality and user experienced quality. This research aims at understanding the characteristics of buffer filling during dedicated channel (DCH) transmission under fixed bit-rate assumptions on a per-user level taking different services into consideration. Furthermore, the resource utilisation in terms of empty buffer durations and user throughput achieved during dedicated channel transmission are also analysed for different data services existing in the mobile networks. The traces are collected from a real network and characteristics of the traffic are analysed prior to understanding its buffer filling in Radio Network Controller (RNC) during downlink data transmission. Furthermore, the buffer is modelled with some series of assumptions on channel bit-rates and simulations are performed taking single user scenario into consideration, for different services with the help of obtained traces as input to the buffer. This research is helpful in understanding the RNC buffer filling for different services, in turn yielding possible understanding on the existing transport channel switching scenario. With the help of analysing the buffer filling for different services and transport channel utilisation, we learn that most of the data services show low DCH utilisation of approximately around 20% and also found to have 80% of the total DCH session duration with empty buffer, causing sub-optimal radio resource utilization.

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Lyazidi, Mohammed Yazid. "Dynamic resource allocation and network optimization in the Cloud Radio Access Network." Thesis, Paris 6, 2017. http://www.theses.fr/2017PA066549/document.

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Le Cloud Radio Access Network (C-RAN) est une future direction dans les réseaux de communications sans fils pour déployer des systèmes cellulaires 4G et renforcer la migration des opérateurs vers la nouvelle génération 5G. En comparaison avec l'architecture traditionnelle des stations de base distribuées, l'architecture C-RAN apporte un lot d'avantages à l'opérateur: meilleure utilisation des ressources radio, flexibilité du réseau, minimisation de la puissance consommée et amenuisement des coûts de déploiement. Dans cette thèse, nous adressons le problème d'allocation dynamique des ressources et minimisation de la puissance des communications à liaison descendante dans le C-RAN. Notre recherche vise à allouer les ressources radio à des flux dynamiques d'utilisateurs, tout en trouvant les meilleures combinaisons entre points d'accès et unités de calculs, pour satisfaire la demande de trafic. Il s'agit en outre, d'un problème d'optimisation non linéaire et NP-difficile, comprenant plusieurs contraintes relatives aux demandes de ressources des utilisateurs, gestion d'interférences, capacités fixes des unités de calcul dans le Cloud et des liaisons de transport ainsi que la limitation de la puissance transmise maximale. Afin de surmonter la complexité inhérente à cette problématique du C-RAN, nous présentons différentes approches pour l'allocation dynamique des ressources en trois principales contributions. Les résultats de nos simulations prouvent l'efficacité de nos méthodes, comparé à celles existantes dans la littérature, en termes de taux de débit de satisfaction, nombre d'antennes actives, puissance consommée dans le Cloud, résilience et coût opérationnel du C-RAN
Cloud Radio Access Network (C-RAN) is a future direction in wireless communications for deploying cellular radio access subsystems in current 4G and next-generation 5G networks. In the C-RAN architecture, BaseBand Units (BBUs) are located in a pool of virtual base stations, which are connected via a high-bandwidth low latency fronthaul network to Radio Remote Heads (RRHs). In comparison to standalone clusters of distributed radio base stations, C-RAN architecture provides significant benefits in terms of centralized resource pooling, network flexibility and cost savings. In this thesis, we address the problem of dynamic resource allocation and power minimization in downlink communications for C-RAN. Our research aims to allocate baseband resources to dynamic flows of mobile users, while properly assigning RRHs to BBUs to accommodate the traffic and network demands. This is a non-linear NP-hard optimization problem, which encompasses many constraints such as mobile users' resources demands, interference management, BBU pool and fronthaul links capacities, as well as maximum transmission power limitation. To overcome the high complexity involved in this problem, we present several approaches for resource allocation strategies and tackle this issue in three stages. Obtained results prove the efficiency of our proposed strategies in terms of throughput satisfaction rate, number of active RRHs, BBU pool processing power, resiliency, and operational budget cost

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Milosavljevic, Milos. "Integrated wireless-PON access network architectures." Thesis, University of Hertfordshire, 2011. http://hdl.handle.net/2299/6371.

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Next generation access networks should be able to cultivate the ongoing evolution in services and applications. Advancements on that front are expected to exhibit the transformation of high definition television (HDTV) and 2D services into ultra-HDTV and individual interactive 3D services. Currently deployed passive optical networks (PONs) have been certified to be able to deliver high quality video and internet services while in parallel broadband wireless standards are increasing their spectral efficiency and subscriber utilisation. Exploiting the benefits of both by providing an integrated infrastructure benefiting from the wireless mobility and ease of scalability and escalating bandwidth of next generation PONs are expected to offer service providers the business models justifying the evolved services. In this direction, this thesis deals with the means of transparent routing of standard worldwide interoperability for microwave access (WiMAX) signal formats over legacy PONs to and from wireless end users based on radio over fibre (RoF). The concept of frequency division multiplexing (FDM) with RoF is used for efficient addressing of individual base stations, bandwidth on-demand provisioning across a cell/sector, simple remote radio heads and no interference with the baseband PON spectrum. Network performance evaluation, initially through simulation, has displayed, in the presence of optical non-linearites and multi-path wireless channels, standard error vector magnitudes (EVMs) at remote radio receivers and bit error rates (BERs) of 1E-4 for typical WiMAX rates bidirectionally. To provide enhanced scalability and dynamicity, a newly applied scheme based on extended wavelength band overlay over the splitter, wireless-enabled PONs has been progressively investigated. This allows for the routing of multiple FDM windows to different wavelengths resulting in significantly reduced optical and electrical component costs and no dispersion compensation over the fibre. This has been implemented through the application of a dense array wave guide grating (AWG) and tuneable filter in the optical line terminal (OLT) and optical network unit/base stations (ONU/BSs) respectively. Although with the use of a splitter the distribution point of the optical network remains largely the same, vertical cavity surface emitting laser (VCSEL) arrays provide colourless upstream transmission. In addition, an overlapping cell concept is developed and adopted for increased wireless spectral efficiency and resilience. Finally, an experimental test-bed using commercially available WiMAX transceivers was produced, which enabled repetition of the simulation outcomes and therefore confirmed the overall network performance.

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Xie, Qing Yan. "Performance Analysis of Opportunistc Spectrum Access on Cognitive Radio." University of Cincinnati / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1273173530.

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Mach, Tomasz Henryk. "Autonomously controlled terminal mobility in self-organising radio access network." Thesis, University of Surrey, 2014. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.659109.

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This thesis examines the mechanisms improving user terminal mobility in a wireless cellular network. It addresses the problem of the lack of self-organisation in the cell reselection algorithms used in the mobile radio access networks. This mechanism is an autonomous terminal mobility procedure used when moving between cells. This work refers to the practical examples of the evolution of cellular teclmologies specified by 3rd G~neration Partnership Project (3 GPP). FUlthermore, this thesis is based on the detailed system analysis of the cell reselection procedure, aiming to identifY areas where the system could be improved by the application of the self-organising design approach. It studies how the performance of the cell measurements mechanism, allowing a tenninal mobility in the network could be increased by using the self-organising concept, in terms of the better cell reselection performance and the terminal energy efficiency trade-off. The main goal of these improvements is providing better quality of service, enhanced user experience and increased network operational performance while minimising maintenance costs. The main contributions of this thesis can be summarised as follows. Firstly, it investigates the autonomously controlled user terniimil mobility, its drawbacks, and limitations during the mobility between macro cells. Then, techniques increasing the energy efficiency of the terminal, without compromising the system performance during the cell reselection, are identified. Also, signalling protocol aspects during the cell reselection algorithm are studied and performance improvements are proposed. Furthermore, an evaluation and optimization of the cell reselection performance is undeltaken, considering different system level and user experience criteria. It draws on simulation results to analyse the serving cell quality, mobility measurements effOli impacting terminal energy efficiency and the related performance trade-offs. Finally, a selforganising approach based framework, with a practical example of the possible mechanism allowing a cost efficient self-optimization ofthe autonomously controlled mobility is proposed. Key words: Cell Reselection, Energy Efficiency, Land Mobile Radio Cellular Systems, Neighbour Cells Measurements, Radio Access Network, Radio Resource Control Protocol, SelfOrganising Networks

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Jin, Jing. "Traffic Burst Prediction in Radio Access Network with Machine Learning." Thesis, KTH, Skolan för elektro- och systemteknik (EES), 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-197206.

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Motivated by the expansion of mobile data traffic, there is an increasingdemand for better allocation of radio resources in the radio access network(RAN). Recently, interest has shifted towards predictive resource allocationtechniques, which would enable a more intelligent RAN. A promising solutionfor developing predictive resource allocation techniques is to combine radioresource allocation algorithms with prediction algorithms based on Machinelearning (ML). In this project, the prediction of data traffic in RAN withML techniques is studied, with the objective to incorporate the predictor incarrier aggregation. The traffic predicted in this project is at the burst levelwhich is an aggregation of several consecutive packets, and the focus is onsupervised classification algorithms. The volume of the burst, burst durationtime and the time gap between two bursts are predicted. The performanceof prediction is evaluated with the receiver operating characteristic curve.
Motiverad av ökningen i mobil datatrafik, det finns en ökande efterfråganpå bättre fördelning av radioresurser i radioaccessnät (RAN). Nyligenhar intresset förskjutits mot prediktiva resursfördelnings tekniker, som skullemöjliggöra en mer intelligent RAN. En lovande lösning för att utvecklaprediktiva resursfördelning tekniker är att kombinera resurstilldelningsalgoritmermed förutsägelsealgoritmer baserade på maskininlärning (ML). I dettaprojekt studeras förutsägelsen av datatrafik i RAN med ML tekniker, i syfteatt använda prediktorn för bäraraggregering. Trafiken som betraktas i dettaprojekt är på skur nivå som är en sammanslagning av flera på varandraföljande paket, och fokus ligger på övervakade klassificeringsalgoritmer. Detär volymen av skuren, längden, och tidsskillnaden mellan två skurar somförutsägs. Prestandan hos förutsägelse utvärderas med receiver operatingcharacteristic kurvan.

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Foukas, Xenofon. "Towards a programmable and virtualized mobile radio access network architecture." Thesis, University of Edinburgh, 2018. http://hdl.handle.net/1842/31406.

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Emerging 5G mobile networks are envisioned to become multi-service environments, enabling the dynamic deployment of services with a diverse set of performance requirements, accommodating the needs of mobile network operators, verticals and over-the-top service providers. The Radio Access Network (RAN) part of mobile networks is expected to play a very significant role towards this evolution. Unfortunately, such a vision cannot be efficiently supported by the conventional RAN architecture, which adopts a fixed and rigid design. For the network to evolve, flexibility in the creation, management and control of the RAN components is of paramount importance. The key elements that can allow us to attain this flexibility are the programmability and the virtualization of the network functions. While in the case of the mobile core, these issues have been extensively studied due to the advent of technologies like Software-Defined Networking (SDN) and Network Functions Virtualization (NFV) and the similarities that the core shares with other wired networks like data centers, research in the domain of the RAN is still in its infancy. The contributions made in this thesis significantly advance the state of the art in the domain of RAN programmability and virtualization in three dimensions. First, we design and implement a software-defined RAN (SD-RAN) platform called FlexRAN, that provides a flexible control plane designed with support for real-time RAN control applications, flexibility to realize various degrees of coordination among RAN infrastructure entities, and programmability to adapt control over time and easier evolution to the future following SDN/NFV principles. Second, we leverage the capabilities of the FlexRAN platform to design and implement Orion, which is a novel RAN slicing system that enables the dynamic on-the-fly virtualization of base stations, the flexible customization of slices to meet their respective service needs and which can be used in an end-to-end network slicing setting. Third, we focus on the use case of multi-tenancy in a neutral-host indoors small-cell environment, where we design Iris, a system that builds on the capabilities of FlexRAN and Orion and introduces a dynamic pricing mechanism for the efficient and flexible allocation of shared spectrum to the tenants. A number of additional use cases that highlight the benefits of the developed systems are also presented. The lessons learned through this research are summarized and a discussion is made on interesting topics for future work in this domain. The prototype systems presented in this thesis have been made publicly available and are being used by various research groups worldwide in the context of 5G research.

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Mohamed, Abdelrahim. "Efficient radio access network with separated control and data functions." Thesis, University of Surrey, 2017. http://epubs.surrey.ac.uk/813133/.

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Future cellular systems need to cope with a huge amount of data and diverse service requirements in a flexible, sustainable, green and efficient way with minimal signalling overhead. This calls for network densification, a short length wireless link, efficient and proactive control signalling and the ability to switch off the power consuming devices when they are not in use. In this direction, the conventional always-on service and worst-case design approach has been identified as the main source of inefficiency, and a paradigm shift towards adaptive and on-demand systems is seen as a promising solution. However, the conventional radio access network (RAN) architecture limits the achievable gains due to the tight coupling between network and data access points, which in turn imposes strict coverage and signalling requirements irrespective of the spatio-temporal service demand, channel conditions or mobility profiles. This suggests a new clean slate RAN architecture with a logical separation between the ability to establish availability of the network and the ability to provide functionality or service. This separation of control and data planes provides a framework where limitations and constraints of the conventional RAN can be overcome. In this context, the aim of this thesis is to investigate the control/data separation architecture (CDSA) for futuristic RANs where data services are provided by data base stations (DBSs) under the umbrella of a coverage layer supported by control base stations (CBSs). A comprehensive literature survey of the CDSA is provided in this thesis. The concept, general structure and basic operation are discussed along with the separation framework and approaches. In addition, limitations of the conventional architecture are pointed out and superiority of the CDSA is discussed whilst focusing on futuristic deployment scenarios. Furthermore, the CDSA technical challenges and enabling technologies are identified, and preliminary standardisation proposals related to this research vision are presented. Three areas, namely energy efficiency, signalling overhead and latency, and mobility management, are identified as promising dimensions that can be substantially improved under CDSA configuration. Focusing on the signalling overhead dimension, a correlation-based adaptive DBS pilot signalling scheme is proposed by exploiting the separation property and the one-to-one nature of the DBS link. The proposed scheme considers channel estimation pilots in the downlink of a multi-carrier DBS air interface, and it depends on estimating the actual channel correlation function to redistribute the pilot signals dynamically. Simulation results show that the proposed adaptive scheme provides a significant saving of 74%-78% in pilot signalling overhead without (or with a marginal) performance penalty as compared with the conventional worst-case design approach. In addition, the out-of-band signalling related to mobility management is investigated by exploiting the relaxed constraints offered by the CDSA. In particular, the active state handover (HO) signalling in the DBS layer is tackled by proposing two predictive DBS HO signalling schemes with minimal HO latency. These include a history-based predictive DBS HO scheme that predicts future DBS HO events based on the user history, and a measurement-based context-aided predictive DBS HO scheme that predicts future DBS HO events along with the expected HO time by combining DBS signal measurements to physical proximity and user contextual information. In both schemes, the prediction outcome is utilised to perform the HO-related DBS RAN signalling in advance, resulting into light-weight HO procedures. Simulation results show that these predictive schemes can remarkably reduce the DBS HO signalling latency w.r.t. the benchmark. Precisely, up to 34% reduction in the HO signalling latency is achieved. Moreover, the dual connection feature of the CDSA and the large CBS footprint are utilised to minimise the HO-related core-network (CN) signalling load by proposing a CN-transparent HO signalling scheme. In the latter, the CBS is used as a mobility anchor point for the users and as a data plane anchor point for the DBSs. Thus, the control plane remains unchanged as long as the user mobility is within the same CBS, while the data plane is switched locally at the CBS. Furthermore, the additional data plane backhaul latency induced by the CDSA is modelled and an upper bound for the DBS density under latency constraints is derived. Numerical and simulation results show that the CDSA-based CN-transparent HO signalling scheme significantly outperforms the conventional architecture-based CN-visible HO approaches in terms of CN signalling load. In dense deployment scenarios, the CN-transparent HO scheme is found to be more beneficial where the gains reach 90% reduction in the CN signalling load. Additionally, the CN-transparent HO scheme is integrated with the predictive HO techniques, and simulation results show that the integrated scheme doubles the gains of the predictive-only HO approach in terms of reduction in DBS HO signalling latency.

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Di, Cicco Nicola. "Scalable Algorithms for Cloud Radio Access Network (C-RAN) Optimization." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2021. http://amslaurea.unibo.it/23755/.

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In the evolving scenario of 5G networks, resource allocation algorithms for the Cloud Radio Access Network (C-RAN) model have proven to be the key for managing ever increasing Capital Expenditure (CAPEX) and Operating Expenditure (OPEX) for mobile networks while ensuring high Quality of Service (QoS). In Chapter 1 a brief overview of the main elements of the C-RAN and of the methodologies that are employed in this work is provided. In Chapter 2, an exact scalable methodology for a static traffic scenario, based on lexicographic optimization, is proposed for the solution of a multi-objective optimization problem to achieve, among other goals, the minimization of the number of active nodes in the C-RAN while supporting reliability and meeting latency constraints. The optimal solution of the most relevant objectives for networks of several tens of nodes is obtained in few tens of seconds of computational time in the worst case. For the least relevant objective a heuristic is developed, providing near optimal solutions in few seconds of computing time. In Chapter 3, an optimization framework for dynamic C-RAN reconfiguration is developed. The objective is to maintain C-RAN cost optimization, while minimizing the cost of virtual network function migration. Significant savings in terms of migrations (above 82% for primary virtual BBU functions and above 75% for backup virtual BBU functions) can be obtained with respect to a static traffic scenario, with execution time of the optimization algorithm below 20 seconds in the worst cases, making its application feasible for dynamic scenarios. In Chapter 4, an alternative Column Generation model formulation is developed, and the quality of the computed lower bounds is evaluated. Further extensions from this baseline (e.g. Column Generation based heuristics, exact Branch&Price algorithms) are left as future work. In Chapter 5, the main results achieved in this work are summarized, and several possible extensions are proposed.

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20

Rabia, Tarek. "Virtualisation des fonctions d'un Cloud Radio Access Network(C-RAN)." Thesis, Sorbonne université, 2018. http://www.theses.fr/2018SORUS009/document.

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La nouvelle génération de réseaux mobiles (5G) devrait faire face, durant les cinq prochaines années, à une importante croissance du volume de données, échangé entre plusieurs milliards d'objets et d'applications connectés. En outre, l'émergence de nouvelles technologies, telles que Internet of Things (IoT), conduite autonome et réalité augmentée, impose de plus fortes contraintes de performance et de qualité de service (QoS). Répondre aux besoins cités, tout en réduisant les dépenses d'investissement et d'exploitation (CAPEX/OPEX), sont les objectifs poursuivis par les opérateurs télécom, qui ont défini une nouvelle architecture d'accès radio, appelée Cloud Radio Access Network (C-RAN). Le principe du C-RAN est de centraliser, au sein d'un pool, les parties de traitement, BaseBand Unit (BBU), d'un RAN traditionnel. Les BBU sont alors dissociées de la station de base et de la partie radio, Remote Radio Unit (RRU). Ces deux parties restent néanmoins connectées à travers un réseau intermédiaire appelé Fronthaul (FH). Dans cette thèse, nous allons concevoir une nouvelle architecture C-RAN partiellement centralisée qui intègrera une plateforme de virtualisation basée sur un environnement Xen, nommée " Metamorphic Network " (MNet). A travers cette architecture, nous viserons à : i) mettre en place un pool, dans lequel des ressources physiques (processeurs, mémoire, ports réseaux, etc.) seront partagées entre des BBU virtualisées et d'autres applications, ii) établir un réseau FH ouvert aux fournisseurs de services et aux tierces parties, facilitant ainsi le déploiement des services au plus près des utilisateurs, pour une meilleure qualité d'expérience, iii) exploiter, à travers le FH, les infrastructures Ethernet existantes pour réduire les CAPEX/OPEX et enfin, iv) atteindre les performances réseau préconisées pour la 5G. Dans la première contribution, nous allons définir une nouvelle architecture Xen pour la plateforme MNet, intégrant le framework de packet processing, OpenDataPlane (ODP), au sein d’un domaine Xen privilégié, nommé « Driver Domain ». Notre objectif, à travers cette architecture, est d’accélérer le traitement des paquets de données transitant par MNet, en évitant la surutilisation, par ODP, des cœurs du processeur physique (CPU) de la plateforme. Pour cela, des cœurs CPU virtuels (vCPU) seront alloués dans le Driver Domain pour être exploités durant le traitement des paquets par ODP. Cette nouvelle plateforme MNet servira de base pour notre architecture C-RAN. Dans la seconde contribution, nous allons implémenter, au sein du FH, deux solutions réseau. La première solution, consistera à déployer le réseau de couche 2, Transparent Interconnection of Lots of Links (TRILL), pour connecter les différents éléments de notre architecture C-RAN. La seconde solution, consistera à déployer un réseau Software Defined Network (SDN), géré par le contrôleur distribué ONOS, qui sera virtualisé dans le pool BBU. Une comparaison des performances réseau sera réalisée entre ces deux solutions
Over the next five years, the new generation of mobile networks (5G) would face a significant growth of the data volume, exchanged between billions of connected objects and applications. Furthermore, the emergence of new technologies, such as Internet of Things (IoT), autonomous driving and augmented reality, imposes higher performance and quality of service (QoS) requirements. Meeting these requirements, while reducing the Capital and Operation Expenditures (CAPEX/OPEX), are the pursued goals of the mobile operators. Consequently, Telcos define a new radio access architecture, called Cloud Radio Access Network (C-RAN). The C-RAN principle is to centralize, within a pool, the processing unit of a radio interface, named BaseBand Unit (BBU). These two units are interconnected through a Fronthaul (FH) network. In this thesis, we design a new partially centralized C-RAN architecture that integrates a virtualization platform, based on a Xen environment, called Metamorphic Network (MNet). Through this architecture, we aim to: i) implement a pool in which physical resources (processors, memory, network ports, etc.) are shared between virtualized BBUs and other applications; ii) establish an open FH network that can be used by multiple operators, service providers and third parties to deploy their services and Apps closer to the users for a better Quality of Experience (QoE); iii) exploit, through the FH, the existing Ethernet infrastructures to reduce CAPEX/OPEX; and finally iv) provide the recommended network performance for the 5G. In the first contribution, we define a new Xen architecture for the MNet platform integrating the packet-processing framework, OpenDataPlane (ODP), within a privileged Xen domain, called Driver Domain (DD). This new architecture accelerates the data packet processing within MNet, while avoiding the physical CPUs overuse by ODP. Thus, virtual CPU cores (vCPU) are allocated within DD and are used by ODP to accelerate the packet processing. This new Xen architecture improves the MNet platform by 15%. In the second contribution, we implement two network solutions within the FH. The first solution consist of deploying a layer 2 network protocol, Transparent Interconnection of Lots of Links (TRILL), to connect multiple elements of our C-RAN architecture. The second solution consists of implementing a Software Defined Network (SDN) model managed by Open Network Operating System (ONOS), a distributed SDN controller that is which is virtualized within BBU pool. Moreover, a network performance comparison is performed between these two solutions

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Abbood, Abdul Nasser Abdul Jabbar. "Optimised radio over fibre links for next generation radio access networks." Thesis, Brunel University, 2018. http://bura.brunel.ac.uk/handle/2438/17019.

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Optical fibre has become the dominant theme of transmission in long haul, high data rate communication systems due to its tremendous bandwidth and low loss. Radio over Fibre (RoF) technology facilitates the seamless integration between wireless and optical communication systems and found to be the most promising solution to meet the exponential bandwidth demands expected for the upcoming years. However, the main bit-rate/distance limitation in RoF systems is the chromatic dispersion. In this thesis, the two generations of RoF technologies, namely Analogue RoF (ARoF) and Digital RoF (DRoF) are investigated. The overall aim of this research is to optimise the optical bandwidth utilisation of these two approaches for a typical transmission of the fronthaul link proposed in the next generation Centralised Radio Access Network (C-RAN). Consequently, a number of physical layer design scenarios for the optimised transmission of the Radio Frequency (RF) signals over a Standards Single Mode Fibre (SSMF) are demonstrated. Firstly, for an ARoF transmission, where the analogue RF signals are transported over SSMF using an optical carrier, a bidirectional link transmitting four Downlink/Uplink channels in a chromatic dispersion limited scenario is designed. Simulation results have shown a clear constellation diagram of a 2.5 Gb/s RF signal transmission over 120 km fibre length. Secondly, a DRoF system with reduced optical bandwidth occupancy is proposed. This system employs an optical Duobinary transmission to the digitised RF signal at the transmitter side to reduce its spectrum and to address the chromatic dispersion effect, simultaneously. Simulation results demonstrate the capability of the proposed system to maintain high-quality transmission of the digitised signals over 70 km of fibre distance without dispersion compensation requirements. Finally, an advanced DRoF transmission link based on integrating digital Optical Single Sideband (OSSB) transmission with Duobinary encoding scheme is designed. Simulation results have clearly verified system's robustness against transmission impairments and have better performances in terms of the obtained BER and EVM with respect to the 3GPP standardised values. Moreover, the results show that both transmission distance and power budget are furtherly improved in comparison with two other digital transmission scenarios.

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Alfred, Asterjadhi. "Network Coding for Cognitive Radio Networks." Doctoral thesis, Università degli studi di Padova, 2011. http://hdl.handle.net/11577/3422021.

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Cognitive Radio Networks are a promising technology likely to be deployed in the very near future as a viable solution to the spectrum shortage problems faced by traditional wireless systems. Technological breakthroughs in the field of Software Defined Radios enabled the development of flexible cognitive radio transceivers capable of dynamically changing their transmission parameters in order to efficiently exploit the available wireless resources. This increased capability of cognitive radios to self adapt based on interactions with the surrounding environment makes them the perfect candidates for opportunistic spectrum access in those bands that are assigned to primary users. While these primary users are allowed to access their licensed spectrum resources anytime and anywhere, within the contractual limits imposed by spectrum management authorities, cognitive radios have to scan and identify any unused spectrum in the licensed bands. Most importantly, in order not to interfere with primary users, they have to rapidly vacate the licensed spectrum as soon as the primary user begins to use its legitimate spectrum resources. The coexistence of cognitive radios with such primary users is very challenging. When considering the natural evolution of cognitive radio networks to more complex systems, the challenges and problems to be faced increase substantially. More specifically, the inherent capability of cognitive radios to base their decisions on their view of the wireless spectrum makes their operation susceptible to a variety of malicious attacks. Hence, in such a challenging environment, mechanisms such as cooperation, learning, and negotiation help cognitive radios make the necessary decisions to ensure reliable communications in a non-interfering manner. We hereby investigate a novel architectural solution for Cognitive Radio Networks that uses network coding for fast control information exchange among cognitive radios, enabling them to maintain coherent and reliable information regarding the status of the wireless environment. This control information is used by cognitive radios to perform cooperative detection of primary users and efficient reuse of the available spectrum resources while guaranteeing robust communication and a prompt reaction to wireless environmental changes.
Le Reti Radio Cognitive sono una tecnologia promettente che potrà essere utilizzata in un futuro molto prossimo, come soluzione possibile al problema di spettro limitato riscontrato nelle reti wireless tradizionali. Le recenti innovazioni tecnologiche su Software Defined Radio hanno permesso lo sviluppo di ricetrasmettitori radio sufficientemente flessibili, in grado di modificare dinamicamente i loro parametri di trasmissione, al fine di sfruttare in modo efficiente le risorse radio disponibili. Questa maggiore capacita di auto-adattarsi in risposta alle interazioni con l'ambiente circostante rende le radio cognitive i candidati ideali per l'accesso opportunistico nelle bande dello spettro radio utilizzate dagli utenti primari. Poiché gli utenti primari hanno diritto ad accedere alle proprie risorse dello spettro in qualsiasi momento e luogo, entro i limiti contrattuali imposti dalle autorità di gestione dello spettro radio, le radio cognitive devono effettuare la scansione e identificare le porzioni dello spettro non utilizzate dagli utenti primari. Inoltre, al fine di non interferire con tali utenti, esse devono liberare rapidamente lo spettro radio, ogniqualvolta l'utente primario inizi ad utilizzare la propria banda di frequenze. La coesistenza tra radio cognitive e utenti primari e' un obiettivo molto ambizioso. Inoltre, quando si considera la normale evoluzione delle reti radio cognitive a sistemi più complessi, le sfide e i problemi da affrontare aumentano notevolmente. In particolare, la capacita intrinseca delle radio cognitive di basare le proprie decisioni sulla propria visione locale dello spettro radio rende il loro funzionamento sensibile a molte tipologie di attacco. Quindi, in tale ambiente, meccanismi come la cooperazione, l'apprendimento e la negoziazione sono di aiuto alle radio cognitive nel prendere le decisioni necessarie a garantire le proprie comunicazioni senza interferire con quelle degli utenti primari. In questa tesi si presenta un'architettura innovativa per le Reti Radio Cognitive che utilizza la tecnica di network coding per lo scambio di informazioni di controllo tra i nodi, riguardo lo stato dell'ambiente radio, in modo rapido, coerente e affidabile. Questa informazione viene successivamente utilizzata dalle radio cognitive per eseguire il rilevamento cooperativo degli utenti primari e il riutilizzo efficiente dello spettro a disposizione, garantendo una comunicazione robusta e una reazione tempestiva ai cambiamenti dello stato delle risorse radio.

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23

Khan, Muhammad. "A self-optimised cloud radio access network for emerging 5G architectures." Thesis, Brunel University, 2018. http://bura.brunel.ac.uk/handle/2438/16050.

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Network densification has become a dominant theme for capacity enhancement in cellular networks. However, it increases the operational complexity and expenditure for mobile network operators. Consequently, the essential features of Self-Organising Networks (SON) are considered to ensure the economic viability of the emerging cellular networks. This thesis focuses on quantifying the benefits of self-organisation in Cloud Radio Access Network (C-RAN) by proposing a flexible, energy efficient, and capacity optimised system. The Base Band Unit (BBU) and Remote Radio Head (RRH) map is formulated as an optimisation problem. A self-optimised C-RAN (SOCRAN) is proposed which hosts Genetic Algorithm (GA) and Discrete-Particle-Swarm-Optimisation algorithm (DPSO), developed for optimisation. Computational results based on different network scenarios demonstrate that DPSO delivers excellent performances for the key performance indicators compared to GA. The percentage of blocked users is reduced from 10.523% to 0.409% in a medium sized network scenario and 5.394% to 0.56% in a vast network scenario. Furthermore, an efficient resource utilisation scheme is proposed based on the concept of Cell Differentiation and Integration (CDI). The two-stage CDI scheme semi-statically scales the number of BBUs and RRHs to serve an offered load and dynamically defines the optimum BBU-RRH mapping to avoid unbalanced network scenarios. Computational results demonstrate significant throughput improvement in a CDI-enabled C-RAN compared to a fixed C-RAN, i.e., an average throughput increase of 45.53% and an average blocked users decrease of 23.149% is experienced. A power model is proposed to estimate the overall power consumption of C-RAN. Approximately 16% power reduction is calculated in a CDI-enabled C-RAN when compared to a fixed C-RAN, both serving the same geographical area. Moreover, a Divide-and-Sort load balancing scheme is proposed and compared to the SOCRAN scheme. Results show excellent performances by the Divide-and-Sort algorithm in small networks when compared to SOCRAN and K-mean clustering algorithm.

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Yao, Yong. "A Software Framework for Prioritized Spectrum Access in Heterogeneous Cognitive Radio Networks." Doctoral thesis, Blekinge Tekniska Högskola [bth.se], Faculty of Computing - Department of Communication Systems, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-00590.

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Today, the radio spectrum is rarely fully utilized. This problem is valid in more domains, e.g., time, frequency and geographical location. To provide an efficient utilization of the radio spectrum, the Cognitive Radio Networks (CRNs) have been advanced. The key idea is to open up the licensed spectrum to unlicensed users, thus allowing them to use the so-called spectrum opportunities as long as they do not harmfully interfere with licensed users. An important focus is laid on the limitation of previously reported research efforts, which is due to the limited consideration of the problem of competition among unlicensed users for spectrum access in heterogeneous CRNs. A software framework is introduced, which is called PRioritized Opportunistic spectrum Access System (PROAS). In PROAS, the heterogeneity aspects of CRNs are specifically expressed in terms of cross-layer design and various wireless technologies. By considering factors like ease of implementation and efficiency of control, PROAS provides priority scheduling based solutions to alleviate the competition problem of unlicensed users in heterogenous CRNs. The advanced solutions include theoretical models, numerical analysis and experimental simulations for performance evaluation. By using PROAS, three particular CRN models are studied, which are based on ad-hoc, mesh-network and cellular-network technologies. The reported results show that PROAS has the ability to bridge the gap between research results and the practical implementation of CRNs.

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Mawlawi, Baher. "Random access for dense networks : Design and Analysis of Multiband CSMA/CA." Thesis, Lyon, INSA, 2015. http://www.theses.fr/2015ISAL0112/document.

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Les protocoles de communications à accès aléatoires sont des candidats prometteurs pour les futurs systèmes de communications sans fil dédiés aux applications machine à machine (M2M). Ces méthodes d’accès sont généralement basées sur des techniques d'accès aléatoires mettant en œuvre des concepts simples de sondage de canal et de report de la transmission pour réduire les collisions, tout en évitant l'utilisation d'ordonnanceurs complexes. Parmi les différents protocoles, Carrier sense multiple access/collision avoidance with a Request-To-Send/Clear-To-Send (CSMA/CA-RTS/CTS) est un protocole qui pourrait être adopté pour les scénarios de M2M. Cette approche est efficace pour éviter les collisions entre les paquets de données. Cependant dans le cas d’un réseau très dense, les performances sont dégradées à cause de la forte probabilité de collisions. Pour atténuer cet effet, les collisions entre les messages de contrôles RTS doivent être réduites. Cette thèse propose de résoudre ce problème en divisant le canal commun en sous-canaux pour transmettre les messages de contrôle de demande d’accès au canal ; le canal commun est utilisé dans son ensemble pour la transmission de données. L’ajout d’un degré de liberté pour le message de demande d’accès permet de réduire la probabilité de collision, et donc d’améliorer les performances du système notamment dans des scénarios avec des nombres importants de nœuds souhaitant communiquer. Dans ce travail, nous dérivons ainsi une solution complète de méthode d’accès en s'appuyant sur le CSMA / CA - RTS / CTS et en multiplexant une configuration multi-canal pour les messages RTS et un canal unique pour la transmission de données. Une version améliorée, basée sur l'ordonnancement des utilisateurs, est également étudiée. Un modèle analytique a été développé, analysé et validé par simulations. Celui-ci est une extension du modèle Bianchi. Les performances en termes de débit saturé, de temps de transmission et de la probabilité de rejet de paquets sont discutées. Enfin, les impacts liés à la prise en compte d’une couche physique de type multi porteuses sont discutés dans le dernier chapitre
Opportunistic protocols are promising candidates for future wireless systems dedicated to machine to machine (M2M) communication. Such protocols are usually based on a random access with simple techniques of medium sensing and deferring to reduce collisions while avoiding the use of complex schedulers. Among different protocols, Carrier sense multiple access/collision avoidance with a Request-To-Send/Clear-To-Send (CSMA/CA-RTS/CTS) is an opportunistic protocol which could be adopted for M2M scenarios. Such approach is efficient to avoid collisions between data packets but in a very dense network, the random access used to send the RTS suffers itself from a high probability of collision which degrades the performance. In order to mitigate this effect, RTS collisions should be reduced. This thesis proposes to address this issue by splitting the common channel in sub-channels for transmitting the RTS messages. While the common channel is used as a whole for data transmission. Multiple nodes can then contend in time and frequency for these RTS sub-channels, thereby reducing RTS collisions and increasing overall efficiency. In this work, we thus derive a complete protocol solution relying on CSMA/CA - RTS/CTS multiplexing a multi-channel configuration for RTS messages and a unique channel for data transmission. An enhanced version based on users scheduling is integrated as well. In this thesis, the proposed protocol is investigated from a joint PHY-MAC point of view. This strategy is shown to provide better system performance particularly for loaded networks. An accurate analytical model derived as a straightforward extension of the Bianchi model is analyzed and validated by simulations. Performance in terms of saturation throughput, transmission delay and packet drop probability is discussed

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Mulligan, Jeanette. "A Performance Analysis of a CSMA Multihop Packet Radio Network." Thesis, Virginia Tech, 1997. http://hdl.handle.net/10919/36779.

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In a packet radio network, multiple terminals broadcast information over a shared communications medium. Messages are transmitted from a source terminal to a destination terminal over multiple relays or hops. The actions of one terminal in the network directly affect the actions of other terminals within its range.

The analysis of packet radio networks is complex because system performance depends on the topology of the terminals in the network along with the random access protocol used. Researchers have been unable to model a packet radio network in its most general form. In this project, a model is developed for specific topologies of a packet radio network with a given random access protocol.

The sponsor of this project has developed a packet radio network for an indoor wireless alarm system. At the start of the project, the effect of message collisions on system performance was unknown. As a result of this research, a collision model for the network has been developed for topologies of four, five, and six alarm units. The model has been validated with actual system testing. Furthermore, the effects of indoor propagation on system performance have been studied. The results of this work have led to the development of an installation plan for the indoor wireless alarm system.
Master of Science

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Shi, Lishen. "Coherent optical code division multiple access (CDMA) network employing CW semiconductor lasers." Thesis, University of Strathclyde, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.273787.

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Shahzad, Hamid, and Nishant Jain. "Internet Protocol based Mobile Radio Access Network Architecture for Remote Service Areas." Thesis, KTH, Kommunikationssystem, CoS, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-91940.

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When it comes to their Radio Access Network (RAN) infrastructure, no two Mobile Operators, serving remote service areas, are alike. Despite situations and technologies being diverse, a well designed optimized RAN solution must adapt itself to the existing networking technologies, both with regard to legacy core networks and modern telecommunication networks in order to produce the best network which is possible subject to many constraints. There is a misconception in technical circles that an optimized internet protocol (IP) enabled RAN architecture is more theoretical than practical. On the contrary, the aforesaid is highly dependent on the technology used. Packet optimized IP- GSM Radio Access Network (GRAN) architecture is proposed in this thesis, it uses Internet Protocol (IP) rather than proprietary protocols for communication between Base Transceiver Stations (BTS), Base Station Controllers (BSC), and the Network Switching Subsystem (NSS). This architecture must deliver carrier-grade mobility, scalability, and reliability; while being optimized for efficient roaming, routing and backhauling from remote service areas. In a geographic arena that spans across the globe, classical circuit-switched networks are not cost efficient due to their integrated call control (signaling) and switching architecture. A solution to this may be soft-switching which separates the call control (Media Gateway Controller (MGC)) and switching (Media Gateway (MG)) into separate nodes. This methodology would fundamentally change the way circuit-switched services, such as traditional voice telephony, are handled. For a service provider this enables a much more efficient network, because it allows optimized equipment location for voice termination into other carrier networks. Co-location of media gateways with satellite ground stations enables local termination to the public switched telephone network (PSTN), thus offloading a great deal of the traffic from the backhaul transmission network of the mobile operator. This thesis adopts soft-switching as part of the call routing processes. The thesis considers the problem of transporting voice and signaling from-to the remote service areas, efficient routing and backhaul to the location of most suitable operator’s point of presence. The thesis explores an alternative which uses a packet switched backbone (e.g. IP based) to transport the media as close (geographically) to the dialed party as possible before terminating it at the PSTN network, thus achieving optimal routing of voice and signaling. Considering the aforesaid, the thesis describes a detailed network architecture and an operational system prototype for maritime GSM network deployment, as a befitting and challenging example of remote service area.
När det gäller deras Radio access nät, finns det inte två Mobiloperatörer, som betjänar avlägsna områden, som är lika. Trots olika omständigheter och teknologier, ett väl designat optimerat RAN måste anpassa sig till den existerande nätverks teknologin, både med avseende på äldre befintlig teknologi och på moderna telekomnät, för att kunna skapa bästa möjliga nätverk givet många begränsningar. Det är en missuppfattning i tekniska kretsar att en optimerad IP anpassad RAN arkitektur är mer teoretisk än praktisk. Å andra sidan så är det ovan sagda väldigt beroende på vilken teknologi som har använts. En paket optimerad IP-GSM Radio Access Nätverks (IPGRAN) arkitektur är föreslagen i denna masters uppsats, den baseras på Internet Protokollet (IP) snarare än något egenutvecklat proprietärt protokol för komunikation mellan Basstation (BTS), Basstationscontroller (BSC), och nätets switchade subsystem (NSS). Denna arkitektur måste leverera carrier-grade (operatörs klassad) mobilitet, skalbarhet och tillgänglighet och samtidigt vara optimerat för effektiv roaming, routing och anslutning från avlägsna områden. På ett geografiskt område som sträcker sig runt hela jordklotet är inte klassiska kretskopplade nätverk kostnadseffektiva beroende på deras integrerade signallerings och samtals arkitektur. En bättre arkitektur kan vara en sk “softswitch” lösning som separerar samtalet i en (Media Gateway Controller (MGC)) och signaleringen (Media Gateway (MG)) i separata noder. Denna metod skulle på ett fundamentalt vis ändra det sätt på vilket traditionella kretskopplade tjänster som traditionell telefoni hanteras. För en tjänsteleverantör möjliggör detta ett mycket effektivare nätverk då det möjliggör optimerad utplacering av utrustning för terminering av rösttrafik in i andra operatörers nät. Samlokalisering av media gateways (MG:s) med jordstationer för satellitkommunikation möjliggör lokal anslutning till det allmänna telenätet (PSTN), vilket kraftigt minskar den trafik som behöver transporteras genom operatörens stomnät. Denna mastersuppsats behandlar “softswitching” som en del av metoden att växla och transportera samtalstrafik. Uppsatsen behandlar problemet med att skicka samtalstrafik och signalering från avlägsna områden, effektiv routing och transport av trafiken till den operatör som har den närmaste(alt. mest optimala) anslutningspunkten. Uppsatsen undersöker ett alternativ som använder ett paketförmedlat (IP baserat) transportsätt för att transportera trafiken geografiskt sett så nära den uppringda parten som möjligt innan den termineras i det allmänna telenätet (PSTN) varvid man uppnår optimal växling (alt. routing) av rösttrafik och signalering. I beaktande av ovanstående beskriver uppsatsen en detaljerad nätverksarkitektur och en funktionsduglig systemprototyp för ett maritimt GSM nät som ett utmanande exempel på ett avlägset beläget nät.

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29

Crews, Mark Conrad. "Dynamic sensing and signaling over the packet radio network multiple access channel." Thesis, Massachusetts Institute of Technology, 1986. http://hdl.handle.net/1721.1/14940.

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Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1987.
MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING.
Bibliography: leaves 129-130.
by Mark Conrad Crews.
M.S.

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30

Canton, Anne-Florence. "Modélisation et analyse des performances de l'UTRAN : Universal Terrestrial Radio Access Network." Paris, ENST, 2002. http://www.theses.fr/2002ENST0045.

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Les futurs systèmes UMTS devront être capables d'offrir des services bas et haut débit, permettant de transmettre voix, images et video, ainsi que d'effectuer des connexions Internet. Plusieurs niveaux de qualité de service devront donc être gérés. Pour ce faire, une architecture de qualité de service est en cours de normalisation au 3GPP. Cette thèse se propose d'étudier la réalisation de la qualité de service dans les systèmes UMTS. La réalisation de la qualité de service repose notamment sur les performances réalisables sur l'interface air, et l'impact de ces performances sur la qualité de service de bout-en-bout. Nos efforts se sont axés autour de deux points essentiels : d'une part, l'étude de l'impact de la qualité sur l'interface air sur la fiabilité de bout-en-bout, lorsque l'utilisateur UMTS est connecté avec un réseau IP externe ; d'autre part, la réalisation de la qualité de service sur l'interface air, via les fonctions radio avancées spécifiques à l'UMTS et mises en oeuvre au niveau du réseau d'accès. Dans un premier temps, nous étudions les performances de bout-en-bout du protocole TCP, sur une connexion non temps réel comportant une portion UMTS. Dans un deuxième temps, nous étudions la réalisation des performances sur l'interface air W-CDMA, via la mise en oeuvre de fonctions radio avancées. Nous étudions en particulier le design et le dimensionnement de l'UTRAN, afin de permettre la mise en oeuvre de ces fonctions radio. Dans cette étude, nous envisageons à la fois le trafic temps réel et le trafic non temps réel
Trends in UMTS systems are towards delivering voice, data and video, as well as Web trafic with appropriate end-to-end QoS guarantees as illustrated by the intensive standardization work on a QoS architecture in 3GPP. Key to its implementation is the air interface and its limiting performance to the end-to-end system. In this work, we consider an end-to-end architecture, where in a UMTS system interworks with a wired IP network and focus on two major topics. First, we consider the impact of the air interface on the end-to-end Qos, mainly in terms of reliability. Second, we investigate the feasibility of the implementation of advanced radio functions within the UTRAN. Typically, in wired networks, reliability for data traffic is guaranteed by the use of TCP at the transport layer. The wireless, mobile component adds error and delay to the end-to-end performance. In our work, we quantify the performance of TCP over ARQ, an error detection / retransmission mechanism present at the RLC layer. As of the UTRAN, the challenge is to guarantee low transport delay toboth real-time and non-real-time traffic, as dictated by the advanced radio functions. We particularly study the design and dimensionning of the UTRAN for both voice and data traffic in isolation as well as service differenciation in the case where both co-exist

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31

Canton, Anne-Florence. "Modélisation et analyse des performances de l'UTRAN : universal terrestrial radio access network /." Paris : École nationale supérieure des télécommunications, 2004. http://catalogue.bnf.fr/ark:/12148/cb40011571t.

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32

Oueis, Jad. "Radio access and core functionalities in self-deployable mobile networks." Thesis, Lyon, 2018. http://www.theses.fr/2018LYSEI095/document.

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Les réseaux mobiles auto-déployables sont des réseaux qui peuvent être rapidement déployés, facilement installés, sur demande, n’importe où, et n’importe quand. Ils visent divers cas d’utilisation pour fournir des services aux utilisateurs lorsque le réseau classique ne peut pas être utilisé, ou n’existe pas : lors d’événements publics, lors des situations critiques, ou dans les zones isolées. Ces réseaux font évoluer l’architecture d’un réseau classique, en éliminant la séparation physique qui existe entre le réseau d’accès et le cœur de réseau. Cette séparation est désormais uniquement fonctionnelle, vu qu’une station de base est colocalisée avec les fonctionnalités du réseau de cœur, telles que la gestion de session et le routage, en plus des serveurs d’applications. Une station de base, toute seule, sans connexion à un réseau externe, fournit des services aux utilisateurs dans sa zone de couverture. Lorsque plusieurs stations de base sont interconnectées, les liens entre elles forment un réseau d’interconnexion, qui risque d’avoir une capacité limitée. Dans ce travail, nous nous appuyons sur les propriétés distinguant les réseaux auto-déployables pour revisiter des problèmes classiques du réseau d’accès dans ce nouvel contexte, mais aussi pour aborder de nouveaux défis créés par l’architecture du réseau. Tout d’abord, nous proposons un algorithme qui retourne un schéma d’allocation de fréquences et de puissances pour les stations de base. Celui-ci augmente considérablement les débits des utilisateurs par rapport aux schémas classiques de réutilisation de fréquences. Ensuite, nous traitons le problème de placement des fonctionnalités du cœur du réseau. Pour le placement centralisé, nous proposons une nouvelle métrique de centralité qui permet de placer les fonctions de façon à maximiser le trafic pouvant être échangé dans le réseau. Pour le placement distribué, nous évaluons le nombre de fonctions nécessaires et leur placement optimal, en tenant compte de l’impact sur la capacité du réseau d’interconnexion. Nous démontrons aussi les avantages du placement distribué par rapport au centralisé en terme de consommation de ressources sur le réseau d’interconnexion. Dans le même contexte, nous abordons le problème d’attachement des utilisateurs, lorsque les fonctionnalités du cœur de réseau sont distribuées, pour déterminer par laquelle de ces fonctionnalités un utilisateur est-il servi. Enfin, avec le réseau d’accès configuré et le cœur de réseau organisé, les utilisateurs commencent à arriver. Alors, nous abordons le problème de l’association des utilisateurs. Nous proposons une nouvelle politique d’association adaptée aux propriétés des réseaux auto-déployables. Cette politique réduit la probabilité de blocage par rapport aux politiques classiques basées uniquement sur la qualité de la voie descendante, en tenant compte à la fois des ressources du réseau d’accès, des ressources sur le réseau d’interconnexion, et des demandes des utilisateurs
Self-deployable mobile networks are a novel family of cellular networks, that can be rapidly deployed, easily installed, and operated on demand, anywhere, anytime. They target diverse use cases and provide network services when the classical network fails, is not suitable, or simply does not exist: when the network saturates during crowded events, when first responders need private broadband communication in disaster-relief and mission-critical situations, or when there is no infrastructure in areas with low population density. These networks are challenging a long-standing vision of cellular networks by eliminating the physical separation between the radio access network (RAN) and the core network (CN). In addition to providing RAN functionalities, such as radio signal processing and radio resource management, a base station can also provide those of the CN, such as session management and routing, in addition to housing application servers. As a result, a base station with no backhaul connection to a traditional CN can provide local services to users in its vicinity. To cover larger areas, several base stations must interconnect. With the CN functions co-located with the RAN, the links interconnecting the BSs form the backhaul network. Being setup by the BSs, potentially in an ad hoc manner, the latter may have a limited bandwidth. In this thesis, we build on the properties distinguishing self-deployable networks to revisit classical RAN problems but in the self-deployable context, and address the novel challenges created by the core network architecture. Starting with the RAN configuration, we propose an algorithm that sets a frequency and power allocation scheme. The latter outperforms conventional frequency reuse schemes in terms of the achieved user throughput and is robust facing variations in the number of users and their distribution in the network. Once the RAN is configured, we move to the CN organization, and address both centralized and distributed CN functions placements. For the centralized placement, building on the shortages of state of the art metrics, we propose a novel centrality metric that places the functions in a way that maximizes the traffic that can be exchanged in the network. For the distributed placement, we evaluate the number of needed instances of the CN functions and their optimal placement, considering the impact on the backhaul bandwidth. We further highlight the advantages of distributing CN functions, from a backhaul point of view. Accordingly, we tackle the user attachment problem to determine the CN instances serving each user when the former are distributed. Finally, with the network ready to operate, and users starting to arrive, we tackle the user association problem. We propose a novel network-aware association policy adapted to self-deployable networks, that outperforms a traditional RAN-based policy. It jointly accounts for the downlink, the uplink, the backhaul and the user throughput request

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33

Kao, Tung-Yu. "On the throughput and delay of an adaptive channel access protocol in multihop packet radio network." Ohio : Ohio University, 1993. http://www.ohiolink.edu/etd/view.cgi?ohiou1175709407.

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34

Geoghegan, Mark. "Challenges of Implementing an iNET Transceiver for the Radio Access Network Standard (RANS)." International Foundation for Telemetering, 2011. http://hdl.handle.net/10150/595621.

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35

Banik, Pushpanjali. "Software defined virtualized cloud radio access network (SD-vCRAN) and programmable EPC for 5G." Thesis, Brunel University, 2018. http://bura.brunel.ac.uk/handle/2438/16225.

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This thesis focuses on proposing a Software Defined Network (SDN) based programmable and capacity optimized backhaul and core network which is critical for 5G network design. Cloud Radio Access networks (CRAN) which is key enabler of 5G networks can address a number of challenges that mobile operators face while trying to support ever-growing end-users' needs towards 5th generation of mobile networks (5G). A novel layered and modular programmable CRAN architecture called Software Defined Virtualised Cloud Radio Access Network (SD-vCRAN) is introduced with Network Function Virtualization (NFV) and Software Defined Network (SDN) capabilities. The SDN-Base Band Unit (BBU) pool is shifted to the programmable core network site, where a centralised SDN controller manages the network servers and virtualised network function entities - Mobile Management Entity (MME), Serving/Packet Data Network Data plane (S/PGW-D), Serving/Packet Data Network Control plane (S/PGW-C), Software Network Defined Baseband Unit (SDN-BBU) and Local controllers (LC) via OpenFlow (OF) protocol. This approach simplifies network operations, improve traffic management, enable system-wide optimisation of Quality of Service (QoS) and network-aware application development. The control plane (excluding the preserved 3GPP standard interfaces: S1-MME, S6a, Gx) managed by the network servers provides load balancing, traffic management and optimisation tools for the data plane. The proposed work starts by reviewing the requirements of 5G networks, followed by discussion on 5G backhaul and core challenge. Then, an overview of CRAN, Evolved Programmable Core (EPC), SDN, NFV and related works. The simulation details of the proposed architecture are discussed along with the challenges faced by adopting SDN and NFV in mobile core. A thorough assessment of the interfaces and protocols that should be conserved or enhanced on both data and control plane is conducted. The result enables an architecture where the SDN-BBU pool shares a single cloud with the programmable EPC and the control plane is migrated from the network elements to a centralized controller, running on a virtual machine in the mobile core. The data and control plane separation removes overlaps and provides better signalling, as well as efficient network functioning to comply with latency demands. The proposed system performance is validated in terms of throughput, datagram loss, and packet delay variation under three scenarios: 1. single policy installation, 2. multiple policy installation and 3. load balancing. The load balancing performance of proposed system is validated comparing the performance of two different SDN controllers: Floodlight and OpenDaylight, where the later performs better in terms of throughput (no bandwidth restriction), packet loss (below 0.3%) and jitter (below 0.2ms). Furthermore, a detailed comparison of two SDN controller's - Floodlight and OpenDaylight performances is presented, which shows that OpenDaylight performs better only for less dense networks which needs less processing of messages without being blocked, and the Floodlight performs better in ultra-dense network. Some directions and preliminary thoughts for future work and necessary information to operators for building their roadmap to the upcoming technologies is presented.

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36

Luo, Weizhi. "An intelligent radio access network selection and optimisation system in heterogeneous communication environments." Thesis, Queen Mary, University of London, 2010. http://qmro.qmul.ac.uk/xmlui/handle/123456789/544.

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The overlapping of the different wireless network technologies creates heterogeneous communication environments. Future mobile communication system considers the technological and operational services of heterogeneous communication environments. Based on its packet switched core, the access to future mobile communication system will not be restricted to the mobile cellular networks but may be via other wireless or even wired technologies. Such universal access can enable service convergence, joint resource management, and adaptive quality of service. However, in order to realise the universal access, there are still many pending challenges to solve. One of them is the selection of the most appropriate radio access network. Previous work on the network selection has concentrated on serving the requesting user, but the existing users and the consumption of the network resources were not the main focus. Such network selection decision might only be able to benefit a limited number of users while the satisfaction levels of some users are compromised, and the network resources might be consumed in an ineffective way. Solutions are needed to handle the radio access network selection in a manner that both of the satisfaction levels of all users and the network resource consumption are considered. This thesis proposes an intelligent radio access network selection and optimisation system. The work in this thesis includes the proposal of an architecture for the radio access network selection and optimisation system and the creation of novel adaptive algorithms that are employed by the network selection system. The proposed algorithms solve the limitations of previous work and adaptively optimise network resource consumption and implement different policies to cope with different scenarios, network conditions, and aims of operators. Furthermore, this thesis also presents novel network resource availability evaluation models. The proposed models study the physical principles of the considered radio access network and avoid employing assumptions which are too stringent abstractions of real network scenarios. They enable the implementation of call level simulations for the comparison and evaluation of the performance of the network selection and optimisation algorithms.

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37

Abdollahi, Seyedreza. "Fully-photonic digital radio over fibre for future super-broadband access network applications." Thesis, Brunel University, 2012. http://bura.brunel.ac.uk/handle/2438/10121.

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In this thesis a Fully-Photonic DRoF (FP-DRoF) system is proposed for deploying of future super-broadband access networks. Digital Radio over Fibre (DRoF) is more independent of the fibre network impairments and the length of fibre than the ARoF link. In order for fully optical deployment of the signal conversion techniques in the FP-DRoF architecture, two key components an Analogue-to-Digital Converter (ADC) and a Digital-to-Analogue Converter (DAC)) for data conversion are designed and their performance are investigated whereas the physical functionality is evaluated. The system simulation results of the proposed pipelined Photonic ADC (PADC) show that the PADC has 10 GHz bandwidth around 60 GHz of sampling rate. Furthermore, by changing the bandwidth of the optical bandpass filter, switching to another band of sampling frequency provides optimised performance condition of the PADC. The PADC has low changes on the Effective Number of Bit (ENOB) response versus analogue RF input from 1 GHz up to 22 GHz for 60 GHz sampling frequency. The proposed 8-Bit pipelined PADC performance in terms of ENOB is evaluated at 60 Gigasample/s which is about 4.1. Recently, different methods have been reported by researchers to implement Photonic DACs (PDACs), but their aim was to convert digital electrical signals to the corresponding analogue signal by assisting the optical techniques. In this thesis, a Binary Weighted PDAC (BW-PDAC) is proposed. In this BW-PDAC, optical digital signals are fully optically converted to an analogue signal. The spurious free dynamic range at the output of the PDAC in a back-to-back deployment of the PADC and the PDAC was 26.6 dBc. For further improvement in the system performance, a 3R (Retiming, Reshaping and Reamplifying) regeneration system is proposed in this thesis. Simulation results show that for an ultrashort RZ pulse with a 5% duty cycle at 65 Gbit/s using the proposed 3R regeneration system on a link reduces rms timing jitter by 90% while the regenerated pulse eye opening height is improved by 65%. Finally, in this thesis the proposed FP-DRoF functionality is evaluated whereas its performance is investigated through a dedicated and shared fibre links. The simulation results show (in the case of low level signal to noise ratio, in comparison with ARoF through a dedicated fibre link) that the FP-DRoF has better BER performance than the ARoF in the order of 10-20. Furthermore, in order to realize a BER about 10-25 for the ARoF, the power penalty is about 4 dBm higher than the FP-DRoF link. The simulation results demonstrate that by considering 0.2 dB/km attenuation of a standard single mode fibre, the dedicated fibre length for the FP-DRoF link can be increased to about 20 km more than the ARoF link. Moreover, for performance assessment of the proposed FP-DRoF in a shared fibre link, the BER of the FP-DRoF link is about 10-10 magnitude less than the ARoF link for -19 dBm launched power into the fibre and the power penalty of the ARoF system is 10 dBm more than the FP-DRoF link. It is significant to increase the fibre link’s length of the FP-DRoF access network using common infrastructure. In addition, the simulation results are demonstrated that the FP-DRoF with non-uniform Wavelength Division Multiplexing (WDM) is more robust against four wave mixing impairment than the conventional WDM technique with uniform wavelength allocation and has better performance in terms of BER. It is clearly verified that the lunched power penalty at CS for DRoF link with uniform WDM techniques is about 2 dB higher than non-uniform WDM technique. Furthermore, uniform WDM method requires more bandwidth than non-uniform scheme which depends on the total number of channels and channels spacing.

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38

Cuevas, Rodríguez Gabriel Ignacio. "Modelo de Propagación Electromagnética en una Red Utran (Umts Terrestrial Radio Access Network)." Tesis, Universidad de Chile, 2009. http://www.repositorio.uchile.cl/handle/2250/103521.

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En esta memoria se realiza un estudio de propagación de ondas electromagnéticas en una red de tercera generación 3G bajo el estándar UMTS. El trabajo está motivado por la necesidad de formalizar conceptos y procedimientos para el diseño de radio propagación en los sistemas de comunicaciones móviles de tercera generación. El objetivo general es el estudio de la propagación de ondas electromagnéticas en el espacio en el espectro utilizado por la tecnología 3G, mediante la consideración de los factores que la dominan y los principales modelos que las caracterizan. Como resultado se propone un modelo que permita predecir el nivel de potencia en un terminal móvil considerando las variaciones espaciales que experimenta la señal de radio frecuencia propagada. Los objetivos específicos de este trabajo consideran entender el funcionamiento de una red 3G bajo el estándar UMTS y la realización de un modelo que permita obtener las pérdidas de trayectoria en ambientes de propagación indoor y outdoor de una onda de radio frecuencia. El modelo es validado haciendo uso de la red 3G de Entel PCS y analizando el grado de eficiencia por comparación con los valores medidos de potencia recibida. El estudio enfatiza los fundamentos teóricos a través de una presentación analítica acuciosa. A partir de estos elementos son estudiados los modelos de propagación de Walfisch, Bertoni y Xia para el espacio outdoor, diversos modelos para la penetración de edificio y el modelo de factor de atenuación para el espacio indoor. Con el fin de validar el funcionamiento del modelo propuesto, que se basa en los anteriores, se realizan diversas pruebas en la red con resultados satisfactorios. Es necesario destacar que el modelo propuesto difiere de los modelos utilizados normalmente, en que combina los casos de propagación outdoor e indoor, permitiendo conocer la propagación de la señal en todos los ambientes de su trayectoria. Se concluye que para utilizar el modelo para la planificación de estas redes se requiere realizar un compromiso entre los resultados del modelo y los experimentales en las áreas donde se aplique, junto con un análisis de los mecanismos de propagación. Como futuros estudios en el tema, se propone la evaluación experimental en un mayor número de casos del modelo de propagación propuesto. Además se plantea la asociación de diversos modelos con el fin de obtener parámetros que permitan realizar una evaluación comparativa con respecto a otras alternativas.

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39

Hamdoun, Hassan. "Practical network coding schemes for energy efficient long term evolution radio access networks." Thesis, Swansea University, 2013. https://cronfa.swan.ac.uk/Record/cronfa42828.

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40

Unger, Peter [Verfasser]. "Radio Access Network Planning and Optimization of Hybrid Cellular and Broadcasting Systems / Peter Unger." Aachen : Shaker, 2010. http://d-nb.info/1081884878/34.

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41

Ntagkounakis, Konstantinos E. "Radio network deployment and interference mitigation methodologies for 2-11 GHz broadband wireless access." Thesis, University of Newcastle Upon Tyne, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.432491.

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42

Ramos, Reuben Elroy. "The design and performance evaluation of a point-to-multipoint millimetric radio network." Thesis, King's College London (University of London), 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.286158.

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43

Roy, Indranil. "A NOVEL APPROACH FOR PLACING ACCESS POINTS IN AN ULTRA-DENSE 5G NETWORK WITH OPTIMUM POWER AND BANDWIDTH." OpenSIUC, 2018. https://opensiuc.lib.siu.edu/theses/2303.

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In this paper we will consider the problem of optimally placing the access points (AP) in an ultra-dense 5G network which covers a rectangular region such that very point inside the rectangular region will be covered by at least one access point. We will analyze the sum of the total transmission power for all the access points and see how much wastage is there. We will measure the wastage in the transmission power by arranging the APs with touching and intersecting circles and try to minimize it with the factor that the whole area is covered. We will then propose a novel approach of placing the intersecting circles and show that the wastage on the total transmission power will be minimal. For intersecting circles we found the power wastage to be around 20.77% but it rises more from this value due to the wastage in the outer region on the boundary of the region considered. We have shown how the touching circles produce greater wastage in the region considered which around 81.4%. We have also shown how the value for the wastage varies with the increase in the length of the sides of the region considered. We have also developed an algorithm that will produce the centers of the circles for a scenario where circles of equal radius are considered. Ultimately we have shown that using four small circles of radius (0.5 times and 0.125 times) we can decrease the wastage value to around 29%. These circles are the one on the boundary who have most of their areas outside the region. So we have created a starting structure for future works.

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44

Andrioli, Leandro. "Elastic-RAN: Um modelo de elasticidade multinível com grão adaptativo para Cloud Radio Access Network." Universidade do Vale do Rio dos Sinos, 2018. http://www.repositorio.jesuita.org.br/handle/UNISINOS/7427.

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Submitted by JOSIANE SANTOS DE OLIVEIRA (josianeso) on 2018-11-13T11:19:19Z No. of bitstreams: 1 Leandro Andrioli_.pdf: 6621163 bytes, checksum: b4a58154b0441ad094c57bbbea979ac4 (MD5)
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Até o ano de 2020, espera-se que a área de cobertura das redes de celulares aumente em 10 vezes, com mais de 50 bilhões de dispositivos conectados, suportando 100 vezes mais equipamentos de usuários e elevando a capacidade da taxa de dados em 1000 vezes. Tal circunstância gerará um aumento massivo no tráfego de dados, fomentando o desenvolvimento da 5G e fazendo com que a indústria e as iniciativas científicas passem a voltar seus esforços para atender a essa demanda. Ganha força, então, as pesquisas relacionadas a Cloud Radio Access Networks (C-RANs), uma arquitetura que consolida as base stations (BSs) para um ponto centralizado na nuvem, mudando a ideia de atuar com recursos fixos e limitados, na medida em que se beneficia de uma das características chave da Computação em Nuvem: a elasticidade de recursos. Um dos grandes desafios na arquitetura C-RAN reside na complexidade em orquestrar todos esses recursos computacionais de forma que o processamento das requisições seja realizado com alto desempenho e com o menor custo de infraestrutura possível. Diante de todo esse contexto, a presente dissertação busca desenvolver o modelo Elastic-RAN, propondo um conceito de elasticidade multinível não bloqueante, com orquestração automática de recursos através da coordenação de BBU Pools e seus BBUs, junto a um mecanismo de grão elástico adaptativo. A elasticidade multinível não bloqueante permite controlar o nível de BBU Pool (máquina física), haja vista o alto volume de tráfego e a distância máxima sugerida entre as antenas e os pools, e o nível de BBU (máquina virtual), em razão do alto processamento de CPU e memória necessária para as requisições, de modo a não penalizar os processamentos correntes. O mecanismo de grão elástico adaptativo permite provisionar e mapear os recursos sob demanda e em tempo de execução, considerando o uso corrente dos recursos, para que cada ação elástica seja executada com um grão próximo das necessidades correntes de processamento. O modelo Elastic-RAN foi avaliado por intermédio de experimentos que simularam diferentes perfis de cargas, os quais são executados em uma aplicação intensiva de CPU e de tráfego na rede, explorando a transferência de streamings e processando decodificação de blocos. Como resultados, foi possível constatar que o Elastic-RAN pode atingir ganhos que vão de 4% a 26%, em relação aos custos de execução, quando comparado à abordagem de elasticidade tradicional. Além disso, obteve melhor eficiência para todos os perfis de carga e reduziu em até 55% a quantidade de operações elásticas necessárias. Outrossim, frente a abordagem sem elasticidade, os ganhos de custos foram ainda superiores, ficando entre 51% e 70%.
It is expected that, by 2020, cell phone networks will have been increased 10 times their coverage area, with more than 50 billion connected devices, supporting 100 times more user equipment and increasing data rate capacity by 1000 times. This will lead to a massive increase in data traffic, fostering the development of 5G and making industry and scientific initiatives turn their efforts to meet this demand. In this scenario, Cloud Radio Access Networks (C-RANs) based researches, an architecture that consolidates base stations (BSs) to a cloud-centric point, are gaining momentum, changing the idea of fixed and limited resources, as it benefits from one of the key features of Cloud Computing: resource elasticity. One of the major challenges in C-RAN architecture lies in the high complexity of orchestrating all of these computational resources in order to perform the requests processing with high performance and the lowest possible infrastructure cost. Considering this context, the present dissertation seeks to develop the Elastic-RAN model, proposing a multilevel non-blocking elasticity concept, with automatic orchestration of resources through the coordination of BBU Pools and their BBUs, with an adaptive elastic grain mechanism. The multilevel non-blocking elasticity allows it control the level of BBU Pool (physical machine), given the high volume of traffic and the suggested maximum distance between antennas and pools, and the level of BBU (virtual machine), due to the high CPU processing and memory required for the requests, so as not to penalize the current processing. The adaptive elastic grain mechanism allows the provisioning and mapping of resources on demand and at runtime, considering the current use of resources, so that each elastic action is performed with a grain close to the current processing needs. The Elastic-RAN model was evaluated through experiments that simulated different load profiles, which are executed in an intensive CPU and network traffic application, exploiting the transfer of streamings and processing block decoding. As a result, it was possible to observe that Elastic-RAN may achieve gains ranging from 4 % to 26 %, in relation to execution costs, when compared to the traditional elasticity approach. In addition, it achieved better efficiency for all load profiles and reduced by 55 % the amount of elastic operations required. Also, given the non-elasticity approach, cost gains were even higher, going from 51 % to 70 %.

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Galeana, Zapién Hiram. "Contribution to resource management in cellular access networks with limited backhaul capacity." Doctoral thesis, Universitat Politècnica de Catalunya, 2011. http://hdl.handle.net/10803/52811.

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La interfaz radio de los sistemas de comunicaciones móviles es normalmente considerada como la única limitación de capacidad en la red de acceso radio. Sin embargo, a medida que se van desplegando nuevas y más eficientes interfaces radio, y de que el tráfico de datos y multimedia va en aumento, existe la creciente preocupación de que la infraestructura de transporte (backhaul) de la red celular pueda convertirse en el cuello de botella en algunos escenarios. En este contexto, la tesis se centra en el desarrollo de técnicas de gestión de recursos que consideran de manera conjunta la gestión de recursos en la interfaz radio y el backhaul. Esto conduce a un nuevo paradigma donde los recursos del backhaul se consideran no sólo en la etapa de dimensionamiento, sino que además son incluidos en la problemática de gestión de recursos. Sobre esta base, el primer objetivo de la tesis consiste en evaluar los requerimientos de capacidad en las redes de acceso radio que usan IP como tecnología de transporte, de acuerdo a las recientes tendencias de la arquitectura de red. En particular, se analiza el impacto que tiene una solución de transporte basada en IP sobre la capacidad de transporte necesaria para satisfacer los requisitos de calidad de servicio en la red de acceso. La evaluación se realiza en el contexto de la red de acceso radio de UMTS, donde se proporciona una caracterización detallada de la interfaz Iub. El análisis de requerimientos de capacidad se lleva a cabo para dos diferentes escenarios: canales dedicados y canales de alta velocidad. Posteriormente, con el objetivo de aprovechar totalmente los recursos disponibles en el acceso radio y el backhaul, esta tesis propone un marco de gestión conjunta de recursos donde la idea principal consiste en incorporar las métricas de la red de transporte dentro del problema de gestión de recursos. A fin de evaluar los beneficios del marco de gestión de recursos propuesto, esta tesis se centra en la evaluación del problema de asignación de base, como estrategia para distribuir el tráfico entre las estaciones base en función de los niveles de carga tanto en la interfaz radio como en el backhaul. Este problema se analiza inicialmente considerando una red de acceso radio genérica, mediante la definición de un modelo analítico basado en cadenas de Markov. Dicho modelo permite calcular la ganancia de capacidad que puede alcanzar la estrategia de asignación de base propuesta. Posteriormente, el análisis de la estrategia propuesta se extiende considerando tecnologías específicas de acceso radio. En particular, en el contexto de redes WCDMA se desarrolla un algoritmo de asignación de base basado en simulatedannealing cuyo objetivo es maximizar una función de utilidad que refleja el grado de satisfacción de las asignaciones respecto los recursos radio y transporte. Finalmente, esta tesis aborda el diseño y evaluación de un algoritmo de asignación de base para los futuros sistemas de banda ancha basados en OFDMA. En este caso, el problema de asignación de base se modela como un problema de optimización mediante el uso de un marco de funciones de utilidad y funciones de coste de recursos. El problema planteado, que considera que existen restricciones de recursos tanto en la interfaz radio como en el backhaul, es mapeado a un problema de optimización conocido como Multiple-Choice Multidimensional Knapsack Problem (MMKP). Posteriormente, se desarrolla un algoritmo de asignación de base heurístico, el cual es evaluado y comparado con esquemas de asignación basados exclusivamente en criterios radio. El algoritmo concebido se basa en el uso de los multiplicadores de Lagrange y está diseñado para aprovechar de manera simultánea el balanceo de carga en la intefaz radio y el backhaul.

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Bolívar, Díaz Nicolás. "Medium access control messaging scheme for cognitive radio networks." Doctoral thesis, Universitat de Girona, 2012. http://hdl.handle.net/10803/84098.

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Cognitive Radio (CR) is one possible option for mitigating the inefficient wireless spectrum distribution that occurs as a result of fixed spectrum allocation. The use of Dynamic Spectrum Access capabilities will potentially enable secondary users to utilize available and unoccupied frequency slots (channels) whenever the licensed users for those channels are absent. In Cognitive Radio Networks (CRNs), whenever users access the spectrum in an opportunistic manner, control messaging is a crucial issue to ensure that secondary users, i.e. Cognitive Radio Users (CRUs), do not interfere with the licensed users, i.e. Primary Users. In CRNs, where not all CRUs share the same set of channels, i.e. CRUs with Heterogeneous Frequency Devices (HFD), a set of channels must be chosen with care to allow all CRUs in the network to be able to transmit and receive control information. The thesis considers how Control Messaging Schemes (CMSs) can be used within CRNs and proposes a novel CMS for a CRN supporting HFDs. The thesis starts by classifying the CMSs; generating a new taxonomy and identifying the main characteristics for an efficient CRN with HFD. Then, different mathematical approaches for choosing the set of channels used for control information are presented. Next, a CMS for a CRN with HFDs model based upon the aforementioned characteristics and calculating the minimum number of channels for transmitting control information is proposed. Finally the thesis concludes with a number of CMS being presented and evaluated in terms of their impact upon transmission efficiency.

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Kondareddy, Yogesh Reddy Agrawal Prathima. "MAC and routing protocols for multi-hop cognitive radio networks." Auburn, Ala, 2008. http://repo.lib.auburn.edu/EtdRoot/2008/SUMMER/Electrical_and_Computer_Engineering/Thesis/Kondareddy_Yogesh_18.pdf.

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Popescu, Alexandru. "Cognitive Radio Networks : Elements and Architectures." Doctoral thesis, Blekinge Tekniska Högskola, Institutionen för kommunikationssystem, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-00575.

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As mobility and computing becomes ever more pervasive in society and business, the non-optimal use of radio resources has created many new challenges for telecommunication operators. Usage patterns of modern wireless handheld devices, such as smartphones and surfboards, have indicated that the signaling traffic generated is many times larger than at a traditional laptop. Furthermore, in spite of approaching theoretical limits by, e.g., the spectral efficiency improvements brought by 4G, this is still not sufficient for many practical applications demanded by end users. Essentially, users located at the edge of a cell cannot achieve the high data throughputs promised by 4G specifications. Worst yet, the Quality of Service bottlenecks in 4G networks are expected to become a major issue over the next years given the rapid growth of mobile devices. The main problems are because of rigid mobile systems architectures with limited possibilities to reconfigure terminals and base stations depending on spectrum availability. Consequently, new solutions must be developed that coexist with legacy infrastructures and more importantly improve upon them to enable flexibility in the modes of operation. To control the intelligence required for such modes of operation, cognitive radio technology is a key concept suggested to be part of the so-called beyond 4th generation mobile networks. The basic idea is to allow unlicensed users access to licensed spectrum, under the condition that the interference perceived by the licensed users is minimal. This can be achieved with the help of devices capable of accurately sensing the spectrum occupancy, learning about temporarily unused frequency bands and able to reconfigure their transmission parameters in such a way that the spectral opportunities can be effectively exploited. Accordingly, this indicates the need for a more flexible and dynamic allocation of the spectrum resources, which requires a new approach to cognitive radio network management. Subsequently, a novel architecture designed at the application layer is suggested to manage communication in cognitive radio networks. The goal is to improve the performance in a cognitive radio network by sensing, learning, optimization and adaptation.

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Vassiliou, Vasos. "An integration framework and a signaling protocol for MPLS/DiffServ/HMIP radio access networks." Diss., Georgia Institute of Technology, 2002. http://hdl.handle.net/1853/13732.

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Shinde, Swapnil Sadashiv. "Radio Access Network Function Placement Algorithms in an Edge Computing Enabled C-RAN with Heterogeneous Slices Demands." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2020. http://amslaurea.unibo.it/20063/.

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Network slicing provides a scalable and flexible solution for resource allocation with performance guaranty and isolation from other services in the 5G architecture. 5G has to handle several active use cases with different requirements. The single solution to satisfy all the extreme requirements requires overspecifies and high-cost network architecture. Further, to fulfill the diverse requirements, each service will require different resources from a radio access network (RAN), edge, and central offices of 5G architecture and hence various deployment options. Network function virtualization allocates radio access network (RAN) functions in different nodes. URLLC services require function placement nearer to the ran to fulfill the lower latency requirement while eMBB require cloud access for implementation. Therefore arbitrary allocation of network function for different services is not possible. We aim to developed algorithms to find service-based placement for RAN functions in a multitenant environment with heterogeneous demands. We considered three generic classes of slices of eMBB, URLLC, mMTC. Every slice is characterized by some specific requirements, while the nodes and the links are resources constrained. The function placement problem corresponds to minimize the overall cost of allocating the different functions to the different nodes organized in layers for respecting the requirements of the given slices. Specifically, we proposed three algorithms based on the normalized preference associated with each slice on different layers of RAN architecture. The maximum preference algorithm places the functions on the most preferred position defined in the preference matrix. On the other hand, the proposed modified preference algorithm provides solutions by keeping track of the availability of computational resources and latency requirements of different services. We also used the Exhaustive Search Method for solving a function allocation problem.

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