81 research outputs found

    Planning and dynamic spectrum management in heterogeneous mobile networks with QoE optimization

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    The radio and network planning and optimisation are continuous processes that do not end after the network has been launched. To achieve the best trade-offs, especially between quality and costs, operators make use of several coverage and capacity enhancement methods. The research from this thesis proposes methods such as the implementation of cell zooming and Relay Stations (RSs) with dynamic sleep modes and Carrier Aggregation (CA) for coverage and capacity enhancements. Initially, a survey is presented on ubiquitous mesh networks implementation scenarios and an updated characterization of requirements for services and applications is proposed. The performance targets for the key parameters, delay, delay variation, information loss and throughput have been addressed for all types of services. Furthermore, with the increased competition, mobile operator’s success does not only depend on how good the offered Quality of Service (QoS) is, but also if it meets the end user’s expectations, i.e., Quality of Experience (QoE). In this context, a model for the mapping between QoS parameters and QoE has been proposed for multimedia traffic. The planning and optimization of fixed Worldwide Interoperability for Microwave Access (WiMAX) networks with RSs in conjunction with cell zooming has been addressed. The challenging case of a propagation measurement-based scenario in the hilly region of Covilhã has been considered. A cost/revenue function has been developed by taking into account the cost of building and maintaining the infrastructure with the use of RSs. This part of the work also investigates the energy efficiency and economic implications of the use of power saving modes for RSs in conjunction with cell zooming. Assuming that the RSs can be switched-off or zoomed out to zero in periods when the traffic exchange is low, such as nights and weekends, it has been shown that energy consumption may be reduced whereas cellular coverage and capacity, as well as economic performance may be improved. An integrated Common Radio Resource Management (iCRRM) entity is proposed that implements inter-band CA by performing scheduling between two Long Term Evolution – Advanced (LTE-A) Component Carriers (CCs). Considering the bandwidths available in Portugal, the 800 MHz and 2.6 GHz CCs have been considered whilst mobile video traffic is addressed. Through extensive simulations it has been found that the proposed multi-band schedulers overcome the capacity of LTE systems without CA. Result shown a clear improvement of the QoS, QoE and economic trade-off with CA

    Adaptive Resource Allocation Strategies for Dynamic Heterogeneous Traffic in Td-cdma/Tdd Systems

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    The purpose of this study was to investigate the co-channel interference present in TD-CDMA/TDD systems and TDMA/TDD systems and propose methods to avoid the co-channel interference. Time Slot Opposing algorithm which avoids co-channel interference in TD-CDMA/D-TDD system is reviewed as part of background study. The interference scenarios in TDMA/D-TDD systems are then studied and methods to avoid co-channel interference are proposed. The algorithms are then tested using real Internet data traffic to obtain a realistic analysis. Based on the background research, an extended Max {SIR} algorithm is proposed to avoid co-channel interference in TDMA/D-TDD systems. This algorithm is a centralized dynamic channel allocation algorithm that uses information from all the cells in the system to avoid co-channel interference and increase the signal power-to-interference power outage probability ratio. The proposed algorithm is then applied to a TDMA/D-TDD system that have subscribers grouped based on priority. As a last step of the research, traffic in TDMA/D-TDD systems is modeled using the ON-OFF traffic modeling and the Max {SIR} algorithm is applied. The results obtained using ON-OFF traffic modeling matched with the results obtained using analytical simulations.School of Electrical & Computer Engineerin

    Mobile network design : Orange UK 2G to 3G mobile backhaul evolution

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    The research presented in this thesis is focused on the evolution of a GSM/GPRS (2G) cellular mobile network to UMTS (3G) and then subsequently, HSDPA. The particular technical area of research relates to the mobile backhaul network which provides the connectivity between radio cell sites which support the wide area radio coverage, and the mobile network operator’s core network. Due to the evolution of UMTS with HSDPA, the research covers the initial UMTS network rollout and then addresses the evolution of this infrastructure to support mobile broadband communications, through the introduction of HSDPA as a network upgrade. The two research questions being addressed are therefore: •How is it possible to evolve a GSM/GPRS mobile backhaul network to support a converged GSM/GPRS and UMTS cellular mobile service? •How is it possible to ensure scalability of the converged backhaul network given the introduction of HSDPA and associated mobile broadband data growth? The starting point of the research is an established GSM and GPRS commercial network in the UK and the study is based on the design of the Orange network and focused on the period 2000 to 2010. During this period the author was working as Principal Network Designer within Orange and had overall responsibility for the strategy, architecture and design of the UK mobile backhaul network. The thesis provides a detailed explanation of the novel network design that was adopted and how it was evolved throughout the ten year period covered by the research. The research proves that the original static TDM approach was not suitable for UMTS and therefore the outcome was the introduction of an ATM network with optimisation based on traffic class rt-VBR over protected STM-1 transmission links. HSDPA drove further traffic growth and resulted in an evolution of the solution to ensure massive scalability was supported through the migration to Carrier Ethernet and implementation of pseudo-wires. In addition, to providing a technical description of the network design, the thesis also aims to provide a historical record of the technologies and equipment used during this period of rapid change within the UKs mobile networks

    State-of-the-Art Sensors Technology in Spain 2015: Volume 1

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    This book provides a comprehensive overview of state-of-the-art sensors technology in specific leading areas. Industrial researchers, engineers and professionals can find information on the most advanced technologies and developments, together with data processing. Further research covers specific devices and technologies that capture and distribute data to be processed by applying dedicated techniques or procedures, which is where sensors play the most important role. The book provides insights and solutions for different problems covering a broad spectrum of possibilities, thanks to a set of applications and solutions based on sensory technologies. Topics include: • Signal analysis for spectral power • 3D precise measurements • Electromagnetic propagation • Drugs detection • e-health environments based on social sensor networks • Robots in wireless environments, navigation, teleoperation, object grasping, demining • Wireless sensor networks • Industrial IoT • Insights in smart cities • Voice recognition • FPGA interfaces • Flight mill device for measurements on insects • Optical systems: UV, LEDs, lasers, fiber optics • Machine vision • Power dissipation • Liquid level in fuel tanks • Parabolic solar tracker • Force sensors • Control for a twin roto

    A survey of 5G technologies: regulatory, standardization and industrial perspectives

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    In recent years, there have been significant developments in the research on 5th Generation (5G) networks. Several enabling technologies are being explored for the 5G mobile system era. The aim is to evolve a cellular network that is intrinsically flexible and remarkably pushes forward the limits of legacy mobile systems across all dimensions of performance metrics. All the stakeholders, such as regulatory bodies, standardization authorities, industrial fora, mobile operators and vendors, must work in unison to bring 5G to fruition. In this paper, we aggregate the 5G-related information coming from the various stakeholders, in order to i) have a comprehensive overview of 5G and ii) to provide a survey of the envisioned 5G technologies; their development thus far from the perspective of those stakeholders will open up new frontiers of services and applications for next-generation wireless networks. Keywords: 5G, ITU, Next-generation wireless network
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