Dissertations / Theses on the topic 'Telecommunications access'
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Brittain, David. "Optimisation of the telecommunications access network." Thesis, University of Bristol, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.297846.
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Palm, Jonathan. "Optimization of 5G New Radio for Fixed Wireless Access." Thesis, Luleå tekniska universitet, Institutionen för system- och rymdteknik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-76077.
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With the advent of new 5G networks, the interest in connecting house-hold to the Internet via mobile networks has increased. One such way toconnect users is using completely stationary antennas. This use-case iscalled Fixed Wireless Access (FWA) and is seen as promising, cost-efficient means of expanding internet connectivity. Stationary users connected at high frequencies, such as 28 GHz, leads to a special use-case and environment for 5G New Radio (NR). This thesis investigates the characteristics of these FWA deployments and the control signaling on the physical layer of NR. The overhead and feasibility of eachsignal is considered. A FWA deployment in the 28 GHz band with 64 users is simulated with different line-of-sight settings and receiver placements. It is concluded that direct line-of-sight to the base station is vital for high user and cell throughput and that there are significant drawbacks of placing the receiver indoors. New algorithms for Channel State Information Reference Signal (CSI-RS) transmission for both beam management and link adaptation are proposed and evaluated. The beam management algorithms do not displayany significant performance gains over the default sweeping algorithm. Closer investigation of simulation results shows that several beams can have almost equal signal strength with the chosen antenna set up, minimizing potential gains of quickly adapting to environmental changes. Results show there are clear benefits of using an aperiodic and adaptive transmission scheme for CSI-RS transmissions over a fixed-rate transmission scheme, yielding a 7% increase in user goodput at similar levels of overhead.
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Oon, Tik bin. "Multiple access interference cancellation for CDMA." Thesis, University of Southampton, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.242678.
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Blackwelder, Reid B. "Local AMSA Telecommunications and its effect on Socioeconomics." Digital Commons @ East Tennessee State University, 2016. https://dc.etsu.edu/etsu-works/6975.
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Gunnarsson, Peter. "Role based access control in a telecommunications operations and maintenance network." Thesis, Linköping University, Department of Computer and Information Science, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-2875.
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Ericsson develops and builds mobile telecommunication networks. These networks consists of a large number of equipment. Each telecommunication company has a staff of administrators appointed to manage respective networks.
In this thesis, we investigate the requirements for an access control model to manage the large number of permissions and equipment in telecommunication networks. Moreover, we show that the existing models do not satisfy the identified requirements. Therefore, we propose a novel RBAC model which is adapted for these conditions.
We also investigate some of the most common used commercial tools for administrating RBAC, and evaluate their effectiveness in coping with our new proposed model. However, we find the existing tools limited, and thereby design and partly implement a RBAC managing system which is better suited to the requirements posed by our new model.
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Montoya, Benítez Andrés. "A proposal for universal access to basic telecommunications services in Colombia." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape9/PQDD_0022/MQ50951.pdf.
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Haimowitz, Bruce Raymond. "The Telecommunications Act of 1996 : business access, and implications for integrated carriers." Thesis, Massachusetts Institute of Technology, 1997. http://hdl.handle.net/1721.1/42607.
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Hansen, Bjørn. "Facility based competition in telecommunications : three essays on two-way access and one essay on three-way access /." Oslo : BI Norwegian School of Management, Dep. of Economics, 2006. http://www.gbv.de/dms/zbw/544126920.pdf.
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Jia, Long University of Ballarat. "Optimization based methods for solving some problems in telecommunications and the internet." University of Ballarat, 2005. http://archimedes.ballarat.edu.au:8080/vital/access/HandleResolver/1959.17/12802.
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The purpose of this thesis is to develop some new algorithms based on optimization techniques for solving some problems in some areas of telecommunications and the Internet. There are two main parts to this thesis. In the first part we discuss optimization based stochastic and queueing models in telecommunications network corrective maintenance. In the second part we develop optimization based clustering (OBC) algorithms for network evolution and multicast routing. The most typical scenario encountered during mathematical optimization modelling in telecommunications, for example, is to minimize the cost of establishment and maintenance of the networks subject to the performance constraints of the networks and the reliability constraints of the networks as well. Most of these optimization problems are global optimization, that is, they have many local minima and most of these local minima do not provide any useful information for solving these problems. Therefore, the development of effective methods for solving such global optimization problems is important. To run the telecommunications networks with cost-effective network maintenance,we need to establish a practical maintenance model and optimize it. In the first part of the thesis, we solve a known stochastic programming maintenance optimization model with a direct method and then develop some new models. After that we introduce queue programming models in telecommunications network maintenance optimization. The ideas of profit, loss, and penalty will help telecommunications companies have a good view of their maintenance policies and help them improve their service. In the second part of this thesis we propose the use of optimization based clustering (OBC) algorithms to determine level-constrained hierarchical trees for network evolution and multicast routing. This problem is formulated as an optimization problem with a non-smooth, non-convex objective function. Different algorithms are examined for solving this problem. Results of numerical experiments using some artifiicial and real-world databases are reported.Doctor of Philosophy
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Jia, Long. "Optimization based methods for solving some problems in telecommunications and the internet." University of Ballarat, 2005. http://archimedes.ballarat.edu.au:8080/vital/access/HandleResolver/1959.17/14637.
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The purpose of this thesis is to develop some new algorithms based on optimization techniques for solving some problems in some areas of telecommunications and the Internet. There are two main parts to this thesis. In the first part we discuss optimization based stochastic and queueing models in telecommunications network corrective maintenance. In the second part we develop optimization based clustering (OBC) algorithms for network evolution and multicast routing. The most typical scenario encountered during mathematical optimization modelling in telecommunications, for example, is to minimize the cost of establishment and maintenance of the networks subject to the performance constraints of the networks and the reliability constraints of the networks as well. Most of these optimization problems are global optimization, that is, they have many local minima and most of these local minima do not provide any useful information for solving these problems. Therefore, the development of effective methods for solving such global optimization problems is important. To run the telecommunications networks with cost-effective network maintenance,we need to establish a practical maintenance model and optimize it. In the first part of the thesis, we solve a known stochastic programming maintenance optimization model with a direct method and then develop some new models. After that we introduce queue programming models in telecommunications network maintenance optimization. The ideas of profit, loss, and penalty will help telecommunications companies have a good view of their maintenance policies and help them improve their service. In the second part of this thesis we propose the use of optimization based clustering (OBC) algorithms to determine level-constrained hierarchical trees for network evolution and multicast routing. This problem is formulated as an optimization problem with a non-smooth, non-convex objective function. Different algorithms are examined for solving this problem. Results of numerical experiments using some artifiicial and real-world databases are reported.Doctor of Philosophy
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Hadjitheodosiou, Michael H. "Performance optimisation of multiple access protocols for multiservice VSAT networks." Thesis, University of Surrey, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.362639.
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Abedi, Saied. "Genetic multi-user detection for code division multiple access systems." Thesis, University of Surrey, 2000. http://epubs.surrey.ac.uk/843016/.
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The origins of spread spectrum are in navigation and military systems. Techniques originally developed to reduce the effects of the intentional jamming also proved suitable for communications through dispersive channels in cellular applications. In 1949 the first time hoping spread spectrum multiple access system has been introduced by John Pierce. A direct-sequence spread spectrum system has been proposed by De Rosa-Rogoff later in 1950. He has also introduced the concept of processing gain. However the commercialisation of cellular direct-sequence code division multiple access (DS-CDMA) systems became possible only during the 1980's and 1990's. In 2000 and beyond we will be witness to the standardisation and commercialisation of wide band CDMA system with a bandwidth of 5 MHz or more. While CDMA presents a number of advantages for cellular mobile communications, it has its own drawbacks. Good air interface designs provide efficient solutions for the terrestrial cellular system. We first take a look at the problem of narrow-band and partial band interference suppression in a CDMA system. By using Poor's model for partial-band interference, some interference suppression techniques are analysed. Then the concept of hybrid genetic prediction is introduced which outperforms the nonlinear techniques in terms of SNR improvements. The performance of a CDMA system can be degraded by Multiple Access Interference (MAI) due to the presence of many users in the same bandwidth. After analysing the structure and performance of existing multi user detection techniques, a low complexity bit level detector is proposed to reduce MAI in synchronous CDMA (S-CDMA) system for an AWGN channel. It is shown how it is possible to reach almost the single user bound by combining detection theory and the fundamentals laws of evolution found in nature. Nonlinear mappings are added to the proposed detector to increase detector's performance by reducing the misleading effect of noise on the detection process. Then for Asynchronous CDMA (A-CDMA), a novel packet level genetic detector is proposed. The near-far resistance feature of the proposed detector is studied. The effect of different parameters of genetic engine i.e. chromosome length, gene's value or mutation and crossover probabilities on its performance are characterised. Different initialisation methods are introduced. For high bit rate CDMA system in multimedia applications in a dispersive CDMA channel, Inter Symbol Interference (ISI) becomes another highly important factor that degrades system performance. It is shown how it is possible to use a signal sub-space based detector as a core detector for a hybrid genetic Multi user detector.
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Yuvapoositanon, Peerapol. "Blind adaptive algorithms for direct-sequence code division multiple access receivers." Thesis, Imperial College London, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.271955.
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Kashorda, Meoli. "Adaptive speech transmission : a technique for customer access to communication networks." Thesis, University of Essex, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.278547.
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O'Farrell, Timothy. "Code-division multiple-access (CDMA) techniques in optical fibre local area networks." Thesis, University of Manchester, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.257164.
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Ceita, Yannick Soares de Barros de. "Shared solution for telecommunications networks." Master's thesis, Universidade de Aveiro, 2017. http://hdl.handle.net/10773/23613.
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Mestrado em Engenharia Eletrónica e de TelecomunicaçõesDespite the substantial increase in the percentage of the globe surface covered by mobile communications, there are issues that have hampered the implementation and development of cellular networks in regions where the market and economic power are still under development. Many of these issues are of economic and financial nature. It is curiously a contradictory fact, since mobile communications on several occasions proved to be a great ally for the growth and economic development of this type of regions. Therefore, in situations such as these, where the development or installation of cellular networks is blocked or conditioned by economic and financial factors, the adoption of infrastructure or service sharing methods can facilitate the implementation and expansion of cellular networks in these regions. The work developed in this dissertation seeks to identify and study the most common methods of cellular network sharing. Through the use of a numerical tool, the effects and techno-economic benefits that each sharing method will bring to the operators interested in entering markets with these characteristics will be analyzed.
Apesar do crescente aumento da superfície terrestre coberta pelas comunicações móveis, há questões que têm dificultado à implementação e desenvolvimento das redes celulares nas regiões onde o mercado e o poder económico ainda estão em desenvolvimento. Muitas dessas questões são de carácter económico e financeiro. O que se torna, curiosamente, um facto contraditório, uma vez que as comunicações móveis em diversas ocasiões provaram ser um grande aliado para o crescimento e desenvolvimento económico deste tipo de regiões. Portanto para situações como estas, onde o desenvolvimento ou instalação de redes celulares é travado ou condicionado por factores de carácter económico e financeiro, a adopção de métodos de partilha de infraestruturas ou serviços consegue facilitar a implementação e expansão de redes celulares nestas regiões. O trabalho desenvolvido nesta dissertação procura identificar e estudar os métodos mais comum de partilha. Através do uso de uma ferramenta de cálculo, analisam-se também os efeitos e benefícios económicos que cada método de partilha trará para os operadores interessados em entrar em mercados com características aqui consideradas.
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Kelso, Douglas Ross. "Open access to next generation broadband." Queensland University of Technology, 2008. http://eprints.qut.edu.au/16612/.
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Wireline telecommunications infrastructure in the customer access network or CAN is undergoing a veritable technological and commercial revolution. The paired-copper CAN is being modernised with optical fibre deployed ever closer to customers, culminating soon with fibre-to-the-home networks or some variant thereof. Although bandwidth ceases to be a scarce commodity, the underlying natural monopoly will most likely be strengthened. National competition policy desires open access to multiple service providers yet commercial pressure calls for closure. This has been the recent experience with the hybrid fibre coaxial networks delivering pay television and Internet access. This research asks the question: What are the factors that prevent open access to the broadband services of next generation wireline infrastructure? How can these obstacles be overcome? A particular focus is given to non-price considerations which come to the fore due to the unique strategic and technological characteristics of optical fibre in the access network. The methodological approach involves data gathering via three case studies - that of the Telstra/Foxtel pay television network, the TransACT broadband network and fibre-to-the-home networks in general. Although the ultimate focus is on the research question above, these cases are discussed in a holistic way with consideration of a number of contextual factors. The research also examines the relationship between the concepts of 'open access' and 'network neutrality', visiting the concept of 'common carriage' in doing so. Several findings are reached that illuminate the field of telecommunications access regulation as applied to infrastructure capable of delivering truly next generation broadband services. Since 1993, our politicians have only paid lip service to the importance of competition and have deferred to the demands of the dominant builder of telecommunications infrastructure. From the viewpoints of end-users and access seekers, the access regime is found to be incapable of dealing with the technical and commercial bottlenecks arising from optical fibre in the CAN. It is concluded that communication between users should be recognised as the prime purpose of telecommunications and that the regulatory regime should not reward discriminatory practices detracting from the development of a networked information economy. It is also concluded that dominant players should never be rewarded with access holidays which could otherwise entrench market dominance through the creation of new bottlenecks. Access regulation is ill-equipped to cope with optical fibre in the CAN until it also recognizes the strategic potential of such infrastructure.
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Tercero, Vargas Miurel. "Topics in Dynamic Spectrum Access : Market Based Spectrum Sharing and Secondary User Access in Radar Bands." Licentiate thesis, KTH, Kommunikationssystem, CoS, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-33791.
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The steady growth in demand for spectrum has increased research interest in dynamic spectrum access schemes. This thesis studies some challenges in dynamic spectrum access based on two strategies: open sharing and hierarchical access. (1) In the open sharing model, the channels are allocated based on an auction process, taking into account the propagation characteristics of the channels, termed as channel heterogeneity. Two distributed dynamic spectrum access schemes are evaluated, sequential and concurrent. We show that the concurrent accessmechanismperforms better in terms of channel utilization and energy consumption, especially in wireless cellular network with an energy constraint. (2) In the hierarchical model, we assess the opportunities for secondary access in the radar band at 5.6GHz. The primary user is a meteorological radar and WLANs are the secondary users. The secondary users implement an interference protection mechanism to protect the radar, such that the WLAN’s transmission is regulated by an interference threshold. We evaluate the aggregate interference caused to the radar from multiple WLANs transmitting. We derive a mathematicalmodel to approximate the probability distribution function of the aggregate interference at the primary user, considering two cases: when secondary users are homogeneously distributed, and when they are heterogeneously distributed. The heterogeneous distribution of secondary users is modeled using an annulus sector with a higher density, called a hot zone. Finally, we evaluate opportunities for secondary access when WLANs employ an interference protection mechanism that considers the radar’s antenna pattern, such that temporal opportunities for transmission exist. The analytical probability distribution function of the interference is verified showing a good agrement with a Monte Carlo simulation. We show that the aggregate interference is sensitive to the propagation environment, thus in the rural case interference is more severe when compared to the urban case. In the evaluation of the hot zonemodel, we observe that the heterogenous distribution of secondary users has impact on the aggregate interference if the hot zone is near to the radar. The mathematical framework presented in this thesis can easily be adapted to assess interference to other types of primary and secondary users.QC 20110523
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Bremner, Duncan James. "25 years of network access technologies : from voice to internet : the changing face of telecommunications." Thesis, University of Glasgow, 2015. http://theses.gla.ac.uk/6670/.
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This work contributes to knowledge in the field of semiconductor system architectures, circuit design and implementation, and communications protocols. The work starts by describing the challenges of interfacing legacy analogue subscriber loops to an electronic circuit contained within the Central Office (Telephone Exchange) building. It then moves on to describe the globalisation of the telecom network, the demand for software programmable devices to enable system customisation cost effectively, and the creation of circuit and system blocks to realise this. The work culminates in the application challenges of developing a wireless RF front end, including antenna, for an Ultra Wideband communications systems applications. This thesis illustrates how higher levels of integration over the period of 1981 to 2010 have influenced the realisation of complex system level products, particularly analogue signal processing capabilities for communications applications. There have been many publications illustrating the impact of technology advancement from an economic or technology perspective. The thesis shows how technology advancement has impacted the physical realisation of semiconductor products over the period, at system, circuit, and physical implementation levels.
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OLAYINKA, ABDULAZEEZ, and KEHINDE ADENUGA. "SECURITY FOR BROADBAND METROPOLITAN AND WIDE AREA NETWORK AT THE ACCESS INTERFACE LEVEL." Thesis, Blekinge Tekniska Högskola, Avdelningen för telekommunikationssystem, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-3823.
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These thesis report deals with a range of secure high-speed networking over a metropolitan or wide area. Since this is quite active research area, a full report is given of the interfaces that thrive in removing the bandwidth burden from long distance networks. Only those with the status or potential of a standard are taking into consideration. Next, the position of security is evaluated. It is recommended that the access Interface enjoys certain advantages over the upper layers. Hence, the results of this work are directly applicable to virtually any layered communication architecture. Amongst the security protocols that are available, the IEEE802.11 represents the only viable solution to have the CLS service properly secured. This protocol is designed for a different type of environment and the implications of this are known. In the real sense, IEEE802.11 proves to be a very valuable tool to built multi-level secure private and public networks using the most recent MAN/WAN technologies. Furthermore, it shows how to enhance the security issues related to Metropolitan and Wide Area Network considering the required security services and mechanism.
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Dakkak, M. Rabih. "Random access procedure in Non-Terrestrial 5G Networks." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2020.
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The goal of non-terrestrial networks (NTN) is to complement terrestrial 5G networks by providing enhanced coverage and service continuity for unserved areas of 5G terrestrial networks.
One of the pivotal factors in the effective deployment of mobile satellite systems in the 5G network is to maximize the utilization of the current technology in terrestrial systems, to lower the implementation costs.
The efficient design and integration of NTN to 5G systems depend on the consideration of some unique features of satellite communication systems, such as large propagation delays and large Doppler frequency shifts. Specifically, geostationary earth orbit (GEO) communication satellites experience large propagation delays, while low earth orbit (LEO) communication satellites are prone to large Doppler frequency shifts due to the fast mobility of LEO satellites and/or user equipment (UE).
These factors affect some of the currently used algorithms of the radio access network (RAN) of terrestrial 5G systems. Specifically affected is the random access channel (RACH).
This work will focus on the analysis, assessment and improvement of Physical Random Access Channel (PRACH) in (5G) to be adopted for (NTN), the implemented work is comprising of AWGN channel, RACH transmitter, which doesn't have a big challenge as the case of RACH receiver regarding the detection with the satellite impairments.
Hence, the work focused on the receiver performance in two different scenarios: Near GEO Sat and LEO Sat.
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Guermazi, Boutheina. "Bridging the digital divide : beyond the basic telecommunications agreement towards a global universal service and access regime." Thesis, McGill University, 2002. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=84211.
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A tremendous disparity exists between the few countries with expansive access to information and communications technologies, and the many others still lacking the basic infrastructure and unable to participate in the information age.While the current trade regime under the Basic Telecommunications Agreement, which forms part of the General Agreement on Trade in Services, offers many opportunities for developing countries, its potential for bridging the digital divide through increased flows of FDI is likely to benefit only those countries with large, lucrative markets. Global market failures would result in deepening the digital divide facing the poorest of the developing countries. Unable to come under the new liberalization paradigm, these countries are likely to be left even further behind.
A legal approach to bridging the digital divide requires going beyond the current trade regime and engaging in a new regime-building exercise. Drawing upon the domestic universal service concept, this thesis calls for a global universal service and access (GUSA) regime. Such a regime entails a new form of international cooperation that harnesses all available resources and includes the recasting of international accounting rates and a revitalization of official development assistance. It also involves institutional reform and reconfiguration through the creation of a new international financial institution, a Global Universal Service Fund (GUSF) as well as the strengthening of the role of the ITU as the custodian of the GUSA regime.
The GUSF would be an independently managed, politically balanced and internationally accountable institution. Because of its flexibility and its mandate to supplement market mechanisms and respond to global market failures, the fund would go a long way towards subsidizing network build out programs in the poorest developing countries, and ensuring widespread connectivity. The proposal is legally defensible under human rights law as well as trade and telecommunications laws, is economically justified under the global public goods doctrine, and technologically feasible given current capacity to connect the world and create the global village.
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Brand, Alex Emin. "A PRMA based medium access control protocol for the uplink of a third generation hybrid CD/TDMA air interface." Thesis, King's College London (University of London), 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.391769.
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Schnurr, Daniel [Verfasser], and J. [Akademischer Betreuer] Krämer. "Open Access to Telecommunications Infrastructure and Digital Services: Competition, Cooperation and Regulation / Daniel Schnurr ; Betreuer: J. Krämer." Karlsruhe : KIT-Bibliothek, 2016. http://d-nb.info/1119242940/34.
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Ni, Jian. "Connectivity, dynamic performance of random radio networks & state independent uniquely decodable codes, codeword synchronisation of collaborative coding multiple access communications." Thesis, University of Warwick, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.282534.
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Lin, You-Hung. "The constitutionality and legality of telecoms forced access mechanisms : a comparative study of the EU and Taiwan." Thesis, University of Edinburgh, 2016. http://hdl.handle.net/1842/22016.
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Telecoms industry is a highly specialised industry and there is a general consensus that it requires a specially designed regulatory system. Besides the many technology-oriented regulations, this regulatory system not only integrates many economic theories and concepts taken from competition law, but also features several measures designed ad hoc to deal with the character of the industry, such as a natural monopoly, bottlenecks and a public service. A major category of these regulatory measures is forced access mechanisms. "Forced access" in this thesis refers to the forcing open of certain property – mostly telecoms networks and relevant facilities – to be accessed by others, especially other competitors in the market. While these mechanisms do indeed promote competition in the telecoms market and benefit the public, they also limit the fundamental rights of telecoms companies – mostly incumbents – as legal persons, especially concerning their property rights and freedom to conduct a business, and it does not need emphasising further that the protection of fundamental rights is a general principle in the European Union and a constitutional value in modern democratic states. This thesis aims to take three distinct telecoms forced access mechanisms (interconnection, local loop unbundling and separation), with different regulatory intensities, as examples to discuss the possible fundamental rights derogation issues of two targeted jurisdictions – the European Union and Taiwan. There are some substantial reasons for this comparative study. On the one hand, many of the regulatory concepts of the telecoms regulatory framework in the European Union, together with those in the United States, have been adopted by Taiwan; on the other hand, the protection of fundamental rights in the European Union is inspired by the constitutional traditions common to Member States, and the German Basic Law (Grundgesetz) plays an important role, while the Taiwanese Constitution and the constitutionality reviews system derive from Germany (continental law) and the United States (common law). The reasoning of Taiwanese constitutional review does not therefore just reflect the fundamental rights protection system but also introduces the constitutionality review system of the United States as a reference. This thesis starts with an introduction to telecoms forced access mechanisms in the European Union and Taiwan, with a special focus on three selected forced access mechanisms. Then, fundamental rights protection system under the two jurisdictions will be discussed, followed by an in-depth discussion of the concepts of property rights and freedom to conduct a business. This thesis goes on to analyse how to appraise the three telecoms forced access mechanisms in relation to the fundamental rights protection system and to discuss the reasonableness of such an analysis. The final part of the thesis will, by reviewing the legal frameworks of the two jurisdictions, offer answers to the questions raised in the analysis.
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Suriyasarn, Busakorn. "Analysis of Thai Internet and telecommunications policy formation during the period 1992-2000." Ohio University / OhioLINK, 2002. http://catalog.hathitrust.org/api/volumes/oclc/55694256.html.
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Poojala, Sankeerth Kumar, and Venkata Sai Teja Vedavalli. "Performance Analysis of a Non-Orthogonal Multiple Access in MIMO Setup." Thesis, Blekinge Tekniska Högskola, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-21187.
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With the advancement of wireless communication systems, the demand for higher data rates is increasing exponentially. Non Orthogonal Multiple Access (NOMA) is expected to play an important role in 5G new radio networks. In contrast to conventional multiple access schemes, NOMA allows different users to efficiently share the same resources (i.e., time, frequency and code) at different power levels so that the user with lower channel gain is served with a higher power and vice versa. Multiple Input Multiple Output (MIMO) technology to support multiple users, employ tens or even hundreds of antennas at the base station which increases throughput and spectrum efficiency. The combination of NOMA and MIMO techniques can achieve significant performance gains and provide better wireless services to cope with the demands of massive connectivity. In this thesis, we analyze the performance of NOMA-MIMO system. We derive analytical expressions for the performance metrics like Outage Probability (OP) and Symbol Error Rate (SER) in power domain of NOMA-MIMO communication system. The numerical results are validated with the simulation results in MATLAB and the influencing factors for better performance of the system are analysed.
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Cavallero, Sara. "Medium Access Control Protocols for Terahertz Communication." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2021.
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This thesis proposes and studies a Medium Access Control (MAC) protocol for networks of tags deployed over an industrial machine using THz communications.
Despite the great advantages of these frequencies, there are drawbacks that cannot be ignored, such as propagation delays that, even at small distances, are of the same order of magnitude as packet transmission times. For this reason, the mathematical models developed for Contention-Free and Contention-Based protocols take into account the propagation delay.
The main focus of this thesis is on the CSMA/CA protocol, which introduces channel sensing to reduce collisions and increase performance. The performance of the protocol are compared with two benchmarks, based on Polling and Aloha, considering an industrial machine scenario and accounting for physical and MAC layers features.
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Moussis, Vassilios. "Access to telecommunications markets : the interrelation between general competition rules and sector-specific rules in the EU and Japan." Thesis, University College London (University of London), 2003. http://discovery.ucl.ac.uk/1370640/.
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The starting point of the thesis is the key competition law issues that arise in relation to access to telecommunications markets in the EU and Japan. This issue is presently regulated in the EU and Japan by a dual regime combining general competition law regulation and sector-specific regulation aimed at opening up the markets. Chapter 1 analyses the relevant general competition rules (i.e. dominance and its abuse, including the doctrine of essential facilities) and the relevant sector-specific rules (i.e. interconnection) that apply to access to EU telecommunications markets. Chapter 2 does the same exercise for Japan through the analysis of the relevant general competition rules (i.e. refusal to deal) and sector-specific rules (i.e. general market access regulation and interconnection) that apply to access to Japanese telecommunications markets. The analysis described above leads to the core object of the thesis which is the study, undertaken at Chapter 3, of the interrelation between general competition rules and sector-specific rules as they apply to access to telecommunications markets in the EU and Japan. This thesis will argue that the dual regime presently regulating access to the EU and Japanese telecommunications industries needs to be maintained. However, the increasing complexity and dynamic character of the telecommunications industry means that a change in the current interrelation between the two types of regulation is necessary. It will be argued that the future balance between the two types of regulation should be one where sector-specific rules will increasingly serve limited functions and where general competition rules will progressively take precedence over the regulation of third party access to telecommunications markets.
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Madureira, Carla Raquel Castro da Rocha. "New generation networks and the telecommunications universal service in Portugal." Doctoral thesis, Universidade de Aveiro, 2014. http://hdl.handle.net/10773/14096.
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Doutoramento em Engenharia EletrónicaThis thesis addresses the issue of Universal Service for telecommunications in the context of the access networks of next generation. This work aims to contribute to the redefinition of the concept of universal telecommunications service focusing primarily on extending it to broadband services as economic and social development factor and taking into account the degree of dependence that currently, modern societies have for the different communication and information services. Complementarily it also intended to meet some of the challenges set out in the European 2020 agenda. Universal Service is defined here as access to a telecommunications network (with obligations in terms of type and quality of service for the operator), by of all citizens at any country's geographical location, with uniform and accessible price. The approach adopted is the State as a mentor for social equity, respectful of the liberalized market dynamics but also knowledgeable of the requirements of modern telecommunications services and its relationship with the different technologies available. The possibility of subsidizing is assumed. The Universal Service´s provision is subject to open to all operators, which are assumed to possess other profitability businesses, than the Universal Service, using technologies similar to those prescribed for the respective Universal Service provision contest. Although the work has components of economic and financial analysis, the approach is the engineering point of view, looking for help to identify technical and organizational solutions which offer prospects for the dissemination and adoption of next generation network solutions. As a point of departure the work gives an overview on the state of the art access networks , trying to identify which of the differences between this reality and possible scenarios for next-generation network with potential access to the generality of the people . The case of the Portuguese reality will be given special attention, taking into account their specific characteristics in terms of geography, demography, economics and market dynamics. The main results of this work are: • Identification of possible scenarios for the evolution of existing networks, in particular in areas with deficit coverage. • Identification of possible operating models and business to the materialization of the above scenarios developed and its economic analysis in an attempt to determine the critical factors associated with sustainability and / or need for subsidies. • Contribution to the regulatory framework of new generation networks from the point of view of the constraints of technology and the specifics of the Universal Service.
Esta tese aborda a questão do serviço universal de telecomunicações no contexto das redes de acesso de nova geração. Este trabalho pretende contribuir para a redefinição do conceito de Serviço Universal de Telecomunicações concentrando-se principalmente em estendê-lo a serviços de banda larga como factor de desenvolvimento económico e social e tendo em conta o grau de dependência que, actualmente, as sociedades modernas têm em relação aos diferentes serviços de comunicação e informação. De forma complementar pretende-se também ir ao encontro de alguns dos desafios enunciados na Agenda Europeia 2020. Serviço Universal é aqui definido como o acesso a uma rede de telecomunicações (com obrigações em termos de tipo e qualidade de serviço para o operador), por parte de todos os cidadãos, em qualquer localização geográfica do país, a preços uniformes e acessíveis. A perspectiva adoptada é a Estatal como mentor da equidade social, respeitador das dinâmicas de mercado liberalizado mas também conhecedor dos requisitos dos modernos serviços de telecomunicações e da sua relação com as diferentes tecnologias disponíveis. A possibilidade de subsidiação é assumida. A prestação de Serviço Universal é sujeita a concurso aberto a todos os operadores, que se assume possuírem outros negócios, que não apenas o Serviço Universal, com rentabilidade e usando tecnologias semelhantes às preconizadas para a respectiva prestação de Serviço Universal. Embora o trabalho desenvolvido tenha componentes de análise económico-financeira, a abordagem utilizada é a de engenharia, procurando contribuir para a identificação de soluções técnicas e organizacionais que possam oferecer perspectivas sustentáveis para a disseminação e adopção das soluções redes de nova geração. Como ponto de partida o trabalho apresenta uma visão geral sobre o estado da arte das redes de acesso, procurando identificar quais os diferenciais existentes entre essa realidade e a de possíveis cenários de rede de próxima geração com potencial de acesso para a generalidade dos cidadãos. O caso da realidade Portuguesa será objecto de uma atenção especial, tendo em consideração as suas especificidades em termos de geografia, demografia, economia e dinâmicas do mercado. Os principais resultados deste trabalho são os seguintes: • Identificação de possíveis cenários para a evolução das redes actuais, nomeadamente em áreas com deficit de cobertura de rede. • Identificação de possíveis modelos de operação e negócio para a materialização dos cenários acima desenvolvidos e respectiva análise económica, como tentativa de determinar os factores críticos associados à sua sustentabilidade e /ou necessidade de subsidiação. • Contributo para o quadro regulatório das Redes de Nova Geração sob o ponto de vista dos constrangimentos das tecnologias e das especificidades do Serviço Universal.
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LEMASTERS, JENNIFER GRACE. "TELNET CONSTRUCT." University of Cincinnati / OhioLINK, 2003. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1053622006.
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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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Susani, Nahid. "On Open Platform for Multi-Access Edge Computing." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2018.
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The Idea of moving the functions of centralized cloud computing to the edge devices of the network, brought several advantages such as low latency, higher spectral efficiency, supporting machine to machine communication. The idea of decoupling network function from infrastructure well applied for this revolution. Therefor, the concept of software defined network (SDN) and network function virtualization considered as emerging solutions for the future network. With applying NFV in the edge devices, computing services and also using network functions would be possible through using virtual machines provided by NFV. In the first chapter, there are introductions of cloud, Edge cloud computing and SDN/NFV due to the importance of these topics. Containerization of application is an another proposed concept as lightweight virtualization solution which besides NFV can be proper solution for delivering, implementing and running application in the edge network and using advantages. In fact, developer encapsulate applications inside of the containers and containerization will allows to delivery applications across different environments. In second chapter, centralized cloud and Edge Cloud had been explained and it had been moved to introducing kubernetes as Edge cloud orchestrator in third chapter. In this project, Kubernetes has been used as an open source platform for multi access edge computing which works as container cluster orchestrator. Forth chapter has been dedicated to Implementation and Evaluation of the work. Main targets of this real implementation will be extending platform of container cluster from single platform architecture to multi-platform architecture made by different physical infrastructure of AMD64 on Intel and ARM on Raspberry pi using docker containers. The second target of implementation is checking the feasibility of autoscalling number of pods based on CPU utilization of pods, across nodes with heterogeneous platform inside the same cluster.
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Poluru, Raja Rohit. "Random Access Procedures for Narrow-Band Internet of Things via Non-Terrestrial Networks." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2021.
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The Internet of Things (IoT) is a fundamental pillar in the digital transformation since it enables the interaction with the physical world by means of sensing and actuation. 3GPP recognized the importance of IoT by introducing new features aimed at supporting this technology. In details, in Rel.13, the 3GPP has launched the NB-IoT to provide support for LPWAN. Since these devices will be distributed also in such area where the terrestrial networks are not feasible or commercially viable, satellite networks will have a complementary role thanks to their capability to provide worldwide connectivity through their large footprint size and short service deployment time. In this context, the aim of this thesis is to analyze the feasibility of integration of the NB-IoT technology with satellite communication systems focusing on the Random-Access Procedure. Indeed, the RA is the most critical procedure since it allows the UE to achieve uplink synchronization, obtain the permanent ID, and get the resources for the uplink transmission. The objective of the thesis is the assessment of the preamble detection in the SatCom environment. The elaborate is divided in four chapters: the first one highlights the main characteristics of the NBIoT technology. In the second chapter, a detail description of the synchronization and RA procedures is presented with a review of the Stat of Art of the detection of the preamble; in the third chapter the main features of SatCom systems are shown, with particular emphasis on the impairments which could hamper the RA procedure. In the fourth chapter, a thorough analysis on the detection process and the implementation of the transmission and reception chain, obtained by the means of simulator built in MATLAB, are provided, with the results. Finally, chapter five concludes this work.
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Jeroschewski, Arne [Verfasser], Felix [Gutachter] Höffler, and Jürgen [Gutachter] Weigand. "The struggle for dynamic efficiency in telecommunications regulation : analyzing challenges imposed by next generation access networks / Arne Jeroschewski. Gutachter: Felix Höffler ; Jürgen Weigand." Vallendar : WHU - Otto Beisheim School of Management, 2016. http://d-nb.info/1113538368/34.
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Wagner, Benjamin. "Understanding Internet Shutdowns: A Case Study from Pakistan." USC Annenberg School for Communication and Journalism, 2018. http://epub.wu.ac.at/6661/1/8545%2D33917%2D1%2DPB.pdf.
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This article provides an overview of Internet shutdowns in Pakistan, which have become
an increasingly common phenomenon, with 41 occurring between 2012 and 2017. It
argues that to understand how shutdowns became normalized in Pakistan, it is necessary
to look at the specific dynamics of how the shutdowns take place. In doing so, the concept
of communicative ruptures develops to better understand intentional government
shutdowns of communications. The article argues that strategic prevention of mobilization
is key for short-term shutdowns, whereas long-term shutdowns can be better explained
by looking at disciplinary mechanisms and denying the existence of "others". The article
then discusses Internet shutdowns in the wider context of authoritarian practices before
concluding with the urgent need for further research on this topic, both in Pakistan and
beyond.
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Yılmazer, Şafak Enes. "Integrated Coverage Measurement and Analysis System for Outdoor Coverage WLAN." Thesis, Blekinge Tekniska Högskola, Sektionen för ingenjörsvetenskap, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-2185.
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Daily usage of Wireless Local Area Networks (WLAN) in business life for specific purposes has became much more critical than before since it is sometimes crucial to have wireless connectivity and seamless roaming around the working environment. In this thesis, steps required in order to design and implement a large scale outdoor IEEE 802.11g WLAN will be shown. This WLAN project has been deployed in north of Sweden and target coverage was an open area consisting of a deep pit mine, connecting roads, workshops, offices, dumps and storage areas. All telecommunications equipment used in this project is from the manufacturer Cisco using centralized solution. The special purpose of this project is to collect and analyze a series of coverage measurement data and correlate this data to predict the coverage area. Linux bash scripting and Gnuplot has been used to analyze coverage data. Finally, WRAP spectrum management and radio planning software has been used in modeling and designing of the whole network.
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Frank, Florian. "Hybrid analogue & digital access network architectures for the mobile/fixe infrastructure convergence." Phd thesis, Université Paris-Est, 2011. http://tel.archives-ouvertes.fr/tel-00665650.
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In order to realize the convergence of the optical infrastructure of fixed and mobile access networks, the objective of this thesis is to study the solutions for distributing native radio carriers through typical optical access networks.The first Part describes the contexts and the main physical properties of the optical and radio access networks: from nowadays deployed Fiber To The Home (FTTH) systems, and their expected evolutions, to the current radio system Universal Mobile Telecommunications System (UMTS) towards the expected requirements of modern mobile radio systems. This allows to settle the optical environment in which the Radio over Fiber(RoF)-functionalities will have to be integrated, and to know on which radio systems'figures of merits to focus on when implementing it. The second Part shows the benefit and possibilities of re-using the optical infrastructure of the fixed access networks for distributed radio systems. Then a review of the analog and digital RoF techniques is proposed, and their feasibility of integration into legacy FTTH systems is discussed. The third part deals with the computing and simulations of an analog RoF-system where the optical link is either passive or optically pre-amplified, and even boosted. The goal is to provide numerical results to the practical lab. results of the second half of the fourth part where the Signal to Noise Ratio (SNR) matters. Therefore successively formal expressions, numerical results for simple 2-tone signals and more realistic UMTS signals are considered. The fourth and last part deals with the obtained practical results. These can be split into two main categories : Error Vector Magnitude (EVM)-oriented results where an Avalanche Photo-Detector (APD) is used for legacy and extended-reach PON architectures using a direction shared Semiconductor Optical Amplifier (SOA) ; and an Adjacent/Alternate Channel power Leakage Ratio (ACLR)-driven part where the focus is seton a very critical figure of merit of radio systems, especially in the downlink. The latter part turned out to be mandatory and prevailing over the initially considered EVM concerns. Hence several RoF architectures, compatible with PONs, are introduced in order to overcome the non-linearities undergone by the RoF-signals, induced by the chromatic dispersion of the PON's fiber and the laser chirp, and degrading the ACLR performances
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Materia, Francesco. "Review and analysis of institutional and regulatory frameworks for fixed Next Generation Access networks." Thesis, Paris Sciences et Lettres (ComUE), 2017. http://www.theses.fr/2017PSLED049.
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Aujourd’hui, l’usage des données lié aux services et contenus proposés sur Internet est en croissance continue et les opérateurs de télécommunications font face à une demande croissante en connectivité. Dans ce contexte, il est indispensable que la transition vers les réseaux très haut débit soit gérée de manière efficace afin de préserver, voire incrémenter, le niveau de concurrence sur le marché ainsi que maximiser l’investissement efficace au bénéfice des consommateurs à travers une combinaison appropriée de différentes formes de concurrence, de différentes technologies et d’investissement à la fois privé et public. Si accompagnée de manière efficace, cette transition peut représenter une grande opportunité pour les marchés des télécommunications européens, les transformant en marchés modernes et concurrentiels et permettant à la régulation ex ante de se retirer progressivement. Nous passons en revue les cadres institutionnels et réglementaires pour les réseaux d’accès fixes de nouvelle génération implémentés en France, Allemagne, Italie, Royaume-Uni et Espagne. A partir d’un modèle de concurrence calibré, nous simulons l’évolution des marchés à horizon 2050 et analysons dans quelle mesure ces cadres paraissent efficaces afin de restituer les meilleurs résultats pour le secteur et pour les consommateurs. Les résultats de notre modèle calibré suggèrent que, afin d’obtenir des meilleurs résultats en terme de bien-être total de long-terme, dans des proportions plus ou moins grandes, certains ajustements pourraient être introduits dans les cadres institutionnels et réglementaires considérés.Nous formulons ainsi, pour chacun des pays analysés, des recommandations visant à accélérer la couverture en très haut débit et à améliorer le niveau de concurrenceToday, data usage driven by content and service providers over the Internet is constantly increasing and telecoms operators are expected to meet an increasing demand for connectivity. In this context, it is vital that the transition between legacy and ultrabroadband networks is properly managed in order both to preserve or improve the state of competition in the market and to maximize efficient investment to the benefit of consumers through an appropriate combination of different forms of competition, of different technologies and of private and public investment. If properly accompanied, the transition from legacy to next generation access networks can represent a major opportunity for the current European telecommunications markets, definitively transforming them into competitive and modern markets and allowing ex ante regulation to progressively step-back.We review the institutional and regulatory frameworks for fixed next generation access networks currently implemented in France, Germany, Italy, United Kingdom and Spain. Based on a calibrated competition model, we simulate market evolution up to 2050 and appraise to what extent these frameworks seem effective in order to achieve the best long-term results both for the industry and for consumers. The results of our calibrated model suggest that, to a greater or lesser extent, some adjustments might be introduced in the above-mentioned frameworks in order to achieve better outcomes in terms of total welfare in the long run. For each of the countries reviewed, we formulate policy recommendations aimed to accelerate NGA coverage and to improve the state of competition in ultrabroadband
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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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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 chapitreOpportunistic 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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Unver, Mehmet Bilal. "Essential Facilities Doctrine Under Ec Competition Law And Particular Implications Of The Doctrine For Telecommunications Sectors In Eu And Turkey." Master's thesis, METU, 2004. http://etd.lib.metu.edu.tr/upload/12605496/index.pdf.
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In this study, the origin and main parameters of the Essential Facilities Doctrine are analysed through the case-law that developed out of the application of the EC Competition Rules. Besides putting forward the historical roots, the basic criteria and limitations that apply to the Doctrine are elaborated so as to clarify the legal and analytical foundations of the Doctrine in the EU context. In addition, the added value attributed to the Doctrine in realm of competition policies pursued in network-based industries is expounded with special emphasis on telecommunications sectors. With this regard, the potential role of EFD against the challenging effects of &lsquoconvergence&rsquo
phenomenon and the technological changes is discussed. At last, the effects of EFD on the competitive dynamics of Turkish telecommunications sector which is undergoing a liberalisation process are also examined with the accompanied Turkish case-law.
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Bharthur, Deepti. "Bridging the Last Mile: An Exploration of ICT Policy Through Bharatnet." Bowling Green State University / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1448024842.
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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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Briglauer, Wolfgang, Georg Ecker, and Klaus Gugler. "Regulation and Investment in Next Generation Access Networks: Recent Evidence from the European Member States." Forschungsinstitut für Regulierungsökonomie, WU Vienna University of Economics and Business, 2011. http://epub.wu.ac.at/3291/1/next_generation_access_eu.pdf.
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Fiber-deployment of future telecommunications networks ("Next Generation Access" - NGA) is
currently a major challenge for sector-specific regulators as well as for investing firms. Although the
future socio-economic importance of new telecommunications networks is uncontroversial, the related
investment activities vary substantially in international comparison.
This work intends to identify the most important determinants of previous NGA deployment using
data from the EU27 member states for the years 2005 to 2010. For our analysis, we employ latest data
on NGA deployment, relevant competition and regulatory indicators as well as other supply and
demand side controls. Our econometric model incorporates: i) aggregated country level data; ii)
structurally modeled dynamics of the deployment process which allows us to disentangle long-term
and short-term effects; finally, iii) we argue that there is no endogeneity problem with respect to
investment activities and regulation since we refer to regulation in preceding broadband markets. For
our econometric analysis, we employ several dynamic panel data methods, such as GMM and
LSDVC.
Our results indicate that stricter previous broadband access regulation has a negative impact on NGA
deployment. As regards the dynamics of the adjustment process, we find that there are severe
adjustment costs and stickiness towards the desired long-term level of NGA infrastructure. (author's abstract)Series: Working Papers / Research Institute for Regulatory Economics
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Erpina, Rahul Chowdary, and Viswakanth Reddy Gopireddy. "Performance of a Non-Orthogonal Multiple Access System with Full-duplex Relaying over Nakagami-m Fading." Thesis, Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-21202.
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In our thesis work, we analyze the performance analysis of a power domain NonOrthogonal Multiple Access (NOMA) system in which the closer user acts as fullduplex relaying to forward the signal to farther user. Because Nakagami-m distribution is a generalized case including the two common fading distributions as specialcases: Rayleigh distribution (m=1), Rician distribution (m>1). We assume that thesystem experiences Nakagami-m fading. Then, we have to analyze outage probabilityof NOMA system. Numerical results are provided for outage probability to show theeffect of system parameters on the performance of the NOMA system in full duplexrelaying over Nakagami-m fading.
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Barretta, Salvatore. "UAV based Narrowband - Internet of things." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2021. http://amslaurea.unibo.it/22761/.
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in this thesis we simulated via Java and Matlab environments a scenario in which a single drone is exploited to carry the NB-IoT base station over an a-priori known area. More specifically, we examined the performance of a drone flying over a area where IoT devices are grouped in clusters and trying to serve as many nodes as possible, with the trajectory solved exploiting the well-known solution of the Travel Salesman Problem (TSP), through which the UAV, that in this study we consider starting from the center of a cluster, finds the minimum path to subsequently reach the center of all the other clusters before reaching again the starting point, where the flight is considered ended. Starting from this assumption we wanted to find the scenario that can best benefit from joint use of NB-IoT and UAV, analyzing both its network throughput and how resources are scheduled by this standard. Then we want to compare the previous results with the new ones obtained changing the way random access is simulated in the code.
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Ahmed, Sabbir. "Performance of Multi-Channel Medium Access Control Protocol incorporating Opportunistic Cooperative Diversity over Rayleigh Fading Channel." Thesis, Blekinge Tekniska Högskola, Avdelningen för signalbehandling, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-6171.
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This thesis paper proposes a Medium Access Control (MAC) protocol for wireless networks, termed as CD-MMAC that utilizes multiple channels and incorporates opportunistic cooperative diversity dynamically to improve its performance. The IEEE 802.11b standard protocol allows the use of multiple channels available at the physical layer but its MAC protocol is designed only for a single channel. The proposed protocol utilizes multiple channels by using single interface and incorporates opportunistic cooperative diversity by using cross-layer MAC. The new protocol leverages the multi-rate capability of IEEE 802.11b and allows wireless nodes far away from destination node to transmit at a higher rate by using intermediate nodes as a relays. The protocol improves network throughput and packet delivery ratio significantly and reduces packet delay. The performance improvement is further evaluated by simulation and analysis.sabbir@linuxmail.org
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Ben, Khalifa Abderrahman. "Medium access control layer for dedicated IoT networks." Thesis, Lyon, 2020. http://www.theses.fr/2020LYSEI063.
Full textAbstract:
Les réseaux dédiés pour l’Internet des Objets sont apparus avec la promesse de connecter des milliers de nœuds, voire plus, à une seule station de base dans une topologie en étoile. Cette nouvelle logique représente un changement fondamental dans la façon de penser les réseaux, après des décennies pendant lesquelles les travaux de recherche se sont focalisés sur les réseaux multi-sauts. Les réseaux pour l’Internet des Objets se caractérisent par la longue portée des transmissions, la vaste couverture géographique, une faible consommation d’énergie et un bas coût de mise en place. Cela a rendu nécessaire des adaptations à tous les niveaux protocolaires afin de satisfaire les besoins de ces réseaux. Plusieurs acteurs sont en concurrence sur le marché de l’Internet des Objets, essayant chacun d’établir la solution la plus efficiente. Ces acteurs se sont concentrés sur la modification de la couche physique, soit au niveau de la partie matérielle, soit par la proposition de nouvelles techniques de modulation. Toutefois, en ce qui concerne la solution de contrôle d’accès au canal (connue sous le nom de couche MAC), toutes les solutions proposées par ces acteurs se fondent sur des approches classiques, tel que Aloha et CSMA. L'objectif de cette thèse est de proposer une solution MAC dynamique pour les réseaux dédiés à l’Internet des Objets. La solution proposée a la capacité de s'adapter aux conditions du réseau. Cette solution est basée sur un algorithme d'apprentissage automatique, qui apprend de l'historique du réseau afin d'établir la relation entre les conditions du réseau, les paramètres de la couche MAC et les performances du réseau en termes de fiabilité et de consommation d'énergie. La solution possède également l'originalité de faire coexister des nœuds utilisant de différentes configurations MAC au sein du même réseau. Les résultats de simulations ont montré qu'une solution MAC basée sur l'apprentissage automatique pourrait tirer profit des avantages des différents protocoles MAC classiques. Les résultats montrent aussi qu'une solution MAC cognitive offre toujours le meilleur compromis entre fiabilité et consommation d'énergie, tout en prenant en compte l'équité entre les nœuds du réseau. La solution MAC cognitive testée pour des réseaux à haute densité a prouvé des bonnes propriétés de passage à l’échelle par rapport aux protocoles MACs classiques, ce qui constitue un autre atout important de notre solutionDedicated networks for the Internet of Things appeared with the promise of connecting thousands of nodes, or even more, to a single base station in a star topology. This new logic represents a fundamental change in the way of thinking about networks, after decades during which research work mainly focused on multi-hop networks. Internet of Things networks are characterized by long transmission range, wide geographic coverage, low energy consumption and low set-up costs. This made it necessary to adapt the protocols at different architectural layers in order to meet the needs of these networks. Several players compete in the Internet of Things market, each trying to establish the most efficient solution. These players are mostly focused on modifying the physical layer, on the hardware part or through proposing new modulations. However, with regard to the channel access control solution (known as the MAC protocol), all the solutions proposed by these players are based on classic approaches such as Aloha and CSMA. The objective of this thesis is to propose a dynamic MAC solution for networks dedicated to the Internet of Things. The proposed solution has the ability to adapt to network conditions. This solution is based on a machine learning algorithm that learns from network history in order to establish the relationship between network conditions, MAC layer parameters and network performance in terms of reliability and energy consumption. The solution also has the originality of making possible the coexistence of nodes using different MAC configurations within the same network. The results of simulations have shown that a MAC solution based on machine learning could take advantage of the good properties of different conventional MAC protocols. The results also show that a cognitive MAC solution always offers the best compromise between reliability and energy consumption, while taking into account the fairness between the nodes of the network. The cognitive MAC solution tested for high density networks has proven better scalability compared to conventional MAC protocols, which is another important advantage of our solution