Applying Genetic Algorithms to the Data Traffic Scheduling and Performance Analysis of a Long-Term Evolution System

[[abstract]]In this study it develops a superior transmission resource allocation method by using genetic algorithm. The convergence properties of genetic algorithm are employed to increase the transmission resource use efficiency of a base (station) to allow users to access wider bandwidth and to improve the system throughput and packet service rate. In this paper, it also studies the genetic algorithm convergent phenomena. The calculated system convergent time is significantly less than that of a long term evolution (LTE) frame duration. Finally, the system performances with and without implementing the genetic algorithm in resource allocations are simulated; their performances are compared to study the effectiveness of using the genetic algorithm in resource allocation.[[notice]]補正完畢[[booktype]]電子

Protocol-Level Simulations of Massive Medium Access for Machine-Type Communications

In recent years, Machine-Type Communications (MTC) has become one of the most attractive technologies in the area of wireless networking. Different sources are predicting a large grow of smart grid machine-to-machine deployments in several decades, which also means that the total number of wireless devices will increase dramatically. In connection to this problem, the choice of the standard, which will satisfy all the MTC requirements without harming current wireless deployments has become very relevant. Because of these reasons, many companies are proposing to modify one (or several) of the current wireless standard in a way that it will be possible to use for MTC purposes. This will be perfect from point of view of interference problems, because they will be already included in a standard itself. Third Generation Partnership Project (3GPP) Long Term Evolution-Advanced (LTE- A) is one of the most rapidly developing wireless technologies, that seems to be an ideal candidate for future MTC implementation. However, while the capacity of typical LTE-A network should be enough to satisfy traffic demands of large number of MTC devices, the signaling is not ready to face new requirements. In this Thesis, we are considering and partly solving problems, that could occur in LTE-A signaling channels under MTC conditions. Particularly, these are data access mechanisms, which could be realized via Physical Uplink Control Channel (PUCCH) and Physical Random Access Channel (PRACH). Speaking about assessment methods, the research made in this work is based on 2 approaches: simulation and analysis. Both of them are also in details described in the pages of this Thesis. As a conclusion it could be said that PUCCH channel is not suitable for the MTC data access, while PRACH is having problems only in heavily loaded (overloaded) cases and should be slightly modified to face them

Device-to-Device Communication and Multihop Transmission for Future Cellular Networks

The next generation wireless networks i.e. 5G aim to provide multi-Gbps data traffic, in order to satisfy the increasing demand for high-definition video, among other high data rate services, as well as the exponential growth in mobile subscribers. To achieve this dramatic increase in data rates, current research is focused on improving the capacity of current 4G network standards, based on Long Term Evolution (LTE), before radical changes are exploited which could include acquiring additional/new spectrum. The LTE network has a reuse factor of one; hence neighbouring cells/sectors use the same spectrum, therefore making the cell edge users vulnerable to inter-cell interference. In addition, wireless transmission is commonly hindered by fading and pathloss. In this direction, this thesis focuses on improving the performance of cell edge users in LTE and LTE-Advanced (LTE-A) networks by initially implementing a new Coordinated Multi-Point (CoMP) algorithm to mitigate cell edge user interference. Subsequently Device-to-Device (D2D) communication is investigated as the enabling technology for maximising Resource Block (RB) utilisation in current 4G and emerging 5G networks. It is demonstrated that the application, as an extension to the above, of novel power control algorithms, to reduce the required D2D TX power, and multihop transmission for relaying D2D traffic, can further enhance network performance. To be able to develop the aforementioned technologies and evaluate the performance of new algorithms in emerging network scenarios, a beyond-the-state-of-the-art LTE system-level simulator (SLS) was implemented. The new simulator includes Multiple-Input Multiple-Output (MIMO) antenna functionalities, comprehensive channel models (such as Wireless World initiative New Radio II i.e. WINNER II) and adaptive modulation and coding schemes to accurately emulate the LTE and LTE-A network standards. Additionally, a novel interference modelling scheme using the ‘wrap around’ technique was proposed and implemented that maintained the topology of flat surfaced maps, allowing for use with cell planning tools while obtaining accurate and timely results in the SLS compared to the few existing platforms. For the proposed CoMP algorithm, the adaptive beamforming technique was employed to reduce interference on the cell edge UEs by applying Coordinated Scheduling (CoSH) between cooperating cells. Simulation results show up to 2-fold improvement in terms of throughput, and also shows SINR gain for the cell edge UEs in the cooperating cells. Furthermore, D2D communication underlaying the LTE network (and future generation of wireless networks) was investigated. The technology exploits the proximity of users in a network to achieve higher data rates with maximum RB utilisation (as the technology reuses the cellular RB simultaneously), while taking some load off the Evolved Node B (eNB) i.e. by direct communication between User Equipment (UE). Simulation results show that the proximity and transmission power of D2D transmission yields high performance gains for a D2D receiver, which was demonstrated to be better than that of cellular UEs with better channel conditions or in close proximity to the eNB in the network. The impact of interference from the simultaneous transmission however impedes the achievable data rates of cellular UEs in the network, especially at the cell edge. Thus, a power control algorithm was proposed to mitigate the impact of interference in the hybrid network (network consisting of both cellular and D2D UEs). It was implemented by setting a minimum SINR threshold so that the cellular UEs achieve a minimum performance, and equally a maximum SINR threshold to establish fairness for the D2D transmission as well. Simulation results show an increase in the cell edge throughput and notable improvement in the overall SINR distribution of UEs in the hybrid network. Additionally, multihop transmission for D2D UEs was investigated in the hybrid network: traditionally, the scheme is implemented to relay cellular traffic in a homogenous network. Contrary to most current studies where D2D UEs are employed to relay cellular traffic, the use of idle nodes to relay D2D traffic was implemented uniquely in this thesis. Simulation results show improvement in D2D receiver throughput with multihop transmission, which was significantly better than that of the same UEs performance with equivalent distance between the D2D pair when using single hop transmission

Energy Efficient and Cooperative Solutions for Next-Generation Wireless Networks

Energy efficiency is increasingly important for next-generation wireless systems due to the limited battery resources of mobile clients. While fourth generation cellular standards emphasize low client battery consumption, existing techniques do not explicitly focus on reducing power that is consumed when a client is actively communicating with the network. Based on high data rate demands of modern multimedia applications, active mode power consumption is expected to become a critical consideration for the development and deployment of future wireless technologies. Another reason for focusing more attention on energy efficient studies is given by the relatively slow progress in battery technology and the growing quality of service requirements of multimedia applications. The disproportion between demanded and available battery capacity is becoming especially significant for small-scale mobile client devices, where wireless power consumption dominates within the total device power budget. To compensate for this growing gap, aggressive improvements in all aspects of wireless system design are necessary. Recent work in this area indicates that joint link adaptation and resource allocation techniques optimizing energy efficient metrics can provide a considerable gain in client power consumption. Consequently, it is crucial to adapt state-of-the-art energy efficient approaches for practical use, as well as to illustrate the pros and cons associated with applying power-bandwidth optimization to improve client energy efficiency and develop insights for future research in this area. This constitutes the first objective of the present research. Together with energy efficiency, next-generation cellular technologies are emphasizing stronger support for heterogeneous multimedia applications. Since the integration of diverse services within a single radio platform is expected to result in higher operator profits and, at the same time, reduce network management expenses, intensive research efforts have been invested into design principles of such networks. However, as wireless resources are limited and shared by clients, service integration may become challenging. A key element in such systems is the packet scheduler, which typically helps ensure that the individual quality of service requirements of wireless clients are satisfied. In contrastingly different distributed wireless environments, random multiple access protocols are beginning to provide mechanisms for statistical quality of service assurance. However, there is currently a lack of comprehensive analytical frameworks which allow reliable control of the quality of service parameters for both cellular and local area networks. Providing such frameworks is therefore the second objective of this thesis. Additionally, the study addresses the simultaneous operation of a cellular and a local area network in spectrally intense metropolitan deployments and solves some related problems. Further improving the performance of battery-driven mobile clients, cooperative communications are sought as a promising and practical concept. In particular, they are capable of mitigating the negative effects of fading in a wireless channel and are thus expected to enhance next-generation cellular networks in terms of client spectral and energy efficiencies. At the cell edges or in areas missing any supportive relaying infrastructure, client-based cooperative techniques are becoming even more important. As such, a mobile client with poor channel quality may take advantage of neighboring clients which would relay data on its behalf. The key idea behind the concept of client relay is to provide flexible and distributed control over cooperative communications by the wireless clients themselves. By contrast to fully centralized control, this is expected to minimize overhead protocol signaling and hence ensure simpler implementation. Compared to infrastructure relay, client relay will also be cheaper to deploy. Developing the novel concept of client relay, proposing simple and feasible cooperation protocols, and analyzing the basic trade-offs behind client relay functionality become the third objective of this research. Envisioning the evolution of cellular technologies beyond their fourth generation, it appears important to study a wireless network capable of supporting machine-to-machine applications. Recent standardization documents cover a plethora of machine-to-machine use cases, as they also outline the respective technical requirements and features according to the application or network environment. As follows from this activity, a smart grid is one of the primary machine-to-machine use cases that involves meters autonomously reporting usage and alarm information to the grid infrastructure to help reduce operational cost, as well as regulate a customer's utility usage. The preliminary analysis of the reference smart grid scenario indicates weak system architecture components. For instance, the large population of machine-to-machine devices may connect nearly simultaneously to the wireless infrastructure and, consequently, suffer from excessive network entry delays. Another concern is the performance of cell-edge machine-to-machine devices with weak wireless links. Therefore, mitigating the above architecture vulnerabilities and improving the performance of future smart grid deployments is the fourth objective of this thesis. Summarizing, this thesis is generally aimed at the improvement of energy efficient properties of mobile devices in next-generation wireless networks. The related research also embraces a novel cooperation technique where clients may assist each other to increase per-client and network-wide performance. Applying the proposed solutions, the operation time of mobile clients without recharging may be increased dramatically. Our approach incorporates both analytical and simulation components to evaluate complex interactions between the studied objectives. It brings important conclusions about energy efficient and cooperative client behaviors, which is crucial for further development of wireless communications technologies

Electronic communication continuity planning from the perspective of an individual

It is beyond doubt that technology has changed the way people in modern society live their daily lives. While a modern society eagerly adopts new technology, the loss of the services provided by these technologies is hardly ever considered. Therefore, this research project will evaluate the importance of communication technology and how critical it is for an individual. Furthermore, this research will provide a framework to improve the availability of current communication technologies from the perspective of the individual

Electronic communication continuity planning from the perspective of an individual

It is beyond doubt that technology has changed the way people in modern society live their daily lives. While a modern society eagerly adopts new technology, the loss of the services provided by these technologies is hardly ever considered. Therefore, this research project will evaluate the importance of communication technology and how critical it is for an individual. Furthermore, this research will provide a framework to improve the availability of current communication technologies from the perspective of the individual

Impacto das comunicações M2M em redes celulares de telecomunicações

Mestrado em Engenharia Electrónica e de TelecomunicaçõesAs comunicações Máquina-Máquina (M2M) apresentam um crescimento muito significativo e algumas projeções apontam para que esta tendência se acentue drasticamente ao longo dos próximos anos. O tráfego gerado por este tipo de comunicações tem caraterísticas muito diferentes do tráfego de dados, ou voz, que atualmente circula nas redes celulares de telecomunicações. Assim, é fundamental estudar as caraterísticas dos tipos de tráfego associados com comunicações M2M, por forma a compreender os efeitos que tais caraterísticas podem provocar nas redes celulares de telecomunicações. Esta dissertação procura identificar e estudar algumas das caraterísticas do tráfego M2M, com especial enfoque na sinalização gerada por serviços M2M. Como resultado principal deste trabalho surge o desenvolvimento de modelos que permitem a construção de uma ferramenta analítica de orquestração de serviços e análise de rede. Esta ferramenta permite orquestrar serviços e modelar padrões de tráfego numa rede UMTS, possibilitando uma análise simultânea aos efeitos produzidos no segmento core da mesma rede. Ao longo deste trabalho procura-se que a abordagem aos problemas apresentados permita que os resultados obtidos sejam válidos, ou adaptáveis, num âmbito mais abrangente do que apenas as comunicações M2M.Machine to Machine (M2M) communications present significant growth and some projections indicate that this trend is going to increase dramatically over the coming years. The traffic generated by this type of communication has very different characteristics when compared to data or voice traffic currently going through cellular telecommunications networks. Thus, it is essential to study the characteristics of traffic associated with M2M communications in order to understand the effects that its features can imply to cellular telecommunications networks. This dissertation tries to identify and study some of the characteristics of M2M traffic, with particular focus on signaling generated by M2M services. A number of models, that enable the development of an analytic tool for service orchestration and network analysis, are presented. This tool enables service orchestration and traffic modeling on a UMTS network, with simultaneous visualization of the impacts on the core of such network. The work presented in this document seeks to approach the problems at study in ways ensuring that its outcomes are valid for a wider scope than just M2M communications

Analytical Performance Evaluation of Cooperative and Multi-Radio Concepts in Emerging Wireless Networks

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Fast-tracking the digital revolution : broadband for Latin America and the Caribbean

This study is based on the premise that broadband is central to a technological, organizational and social innovation system, one which calls for new policies that are flexible, long-term approaches encompassing the objectives of greater productivity, innovation, competitiveness, social inclusion and sustainability. The study focuses on improving and developing broadband accessibility in Latin America and Caribbean (LAC) countries, alongside strategies for the development of public policies, including the role of the State, the role of regulation in market growth and service access, demand incentives, and the proper management of scarce resources such as spectrum availability