208 research outputs found

    Measurement and Optimization of LTE Performance

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    4G Long Term Evolution (LTE) mobile system is the fourth generation communication system adopted worldwide to provide high-speed data connections and high-quality voice calls. Given the recent deployment by mobile service providers, unlike GSM and UMTS, LTE can be still considered to be in its early stages and therefore many topics still raise great interest among the international scientific research community: network performance assessment, network optimization, selective scheduling, interference management and coexistence with other communication systems in the unlicensed band, methods to evaluate human exposure to electromagnetic radiation are, as a matter of fact, still open issues. In this work techniques adopted to increase LTE radio performances are investigated. One of the most wide-spread solutions proposed by the standard is to implement MIMO techniques and within a few years, to overcome the scarcity of spectrum, LTE network operators will offload data traffic by accessing the unlicensed 5 GHz frequency. Our Research deals with an evaluation of 3GPP standard in a real test best scenario to evaluate network behavior and performance

    4G Technology Features and Evolution towards IMT-Advanced

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    Kiinteiden- ja mobiilipalveluiden kysyntĂ€ kasvaa nopeasti ympĂ€ri maailmaa. ÄlykkĂ€iden pÀÀtelaitteiden, kuten iPhone:n ja Nokia N900:n markkinoilletulo yhdistettynĂ€ nĂ€iden korkeaan markkinapenetraatioon ja korkealuokkaiseen kĂ€yttĂ€jĂ€kokemukseen lisÀÀvĂ€t entisestÀÀn palveluiden kysyntÀÀ ja luovat tarpeen jatkuvalle innovoinnille langattomien teknologioiden alalla tavoitteena lisĂ€kapasiteetin ja paremman palvelunlaadun tarjoaminen. Termi 4G (4th Generation) viittaa tuleviin neljĂ€nnen sukupolven mobiileihin langattomiin palveluihin, jotka International Telecommunications Union:in Radiocommunication Sector (ITU-R) on mÀÀritellyt ja nimennyt International Mobile Telecommunications-Advanced (IMT-Advanced). NĂ€mĂ€ ovat jĂ€rjestelmiĂ€, jotka pitĂ€vĂ€t sisĂ€llÀÀn IMT:n ne uudet ominaisuudet, jotka ylittĂ€vĂ€t IMT-2000:n vaatimukset. Long Term Evolution-Advanced (LTE-Advanced) ja IEEE 802.16m ovat IMT-A sertifiointiin lĂ€hetetyt kaksi pÀÀasiallista kandidaattiteknologiaa. TĂ€ssĂ€ diplomityössĂ€ esitellÀÀn kolmannen sukupolven jĂ€rjestelmien kehityspolku LTE:hen ja IEEE 802.16e-2005 asti. LisĂ€ksi työssĂ€ esitetÀÀn LTE-Advanced:n ja IEEE 802.16m:n uudet vaatimukset ja ominaisuudet sekĂ€ vertaillaan nĂ€iden lĂ€hestymistapoja IMT-A vaatimusten tĂ€yttĂ€miseksi. Lopuksi työssĂ€ luodaan katsaus LTE ja IEEE 802.16e-2005 (markkinointinimeltÀÀn Mobile WiMAX) -jĂ€rjestelmien markkinatilanteeseen.The demand for affordable bandwidth in fixed and mobile services is growing rapidly around the world. The emergence of smart devices like the iPhone and Nokia N900, coupled with their high market penetration and superior user experience is behind this increased demand, inevitably driving the need for continued innovations in the wireless data technologies industry to provide more capacity and higher quality of service. The term "4G" meaning the 4th Generation of wireless technology describes mobile wireless services which have been defined by the ITU's Radiocommunication Sector (ITU-R) and titled International Mobile Telecommunications-Advanced (IMT-Advanced). These are mobile systems that include the new capabilities of IMT that go beyond those of IMT-2000. Long Term Evolution-Advanced (LTE-Advanced) and IEEE 802.16m are the two main candidate technologies submitted for IMT-Advanced certification. This thesis reviews the technology roadmap up to and including current 3G systems LTE from the 3rd Generation Partnership Project (3GPP) and IEEE 802.16e-2005 from the Institute of Electrical and Electronics Engineers (IEEE). Furthermore, new requirements and features for LTE-Advanced and IEEE 802.16m as well as a comparative approach towards IMT-Advanced certification are presented. Finally, the thesis concludes with a discussion on the market status and deployment strategies of LTE and IEEE 802.16e-2005, or Mobile WiMAX as it is being marketed

    D4.3 Final Report on Network-Level Solutions

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    Research activities in METIS reported in this document focus on proposing solutions to the network-level challenges of future wireless communication networks. Thereby, a large variety of scenarios is considered and a set of technical concepts is proposed to serve the needs envisioned for the 2020 and beyond. This document provides the final findings on several network-level aspects and groups of solutions that are considered essential for designing future 5G solutions. Specifically, it elaborates on: -Interference management and resource allocation schemes -Mobility management and robustness enhancements -Context aware approaches -D2D and V2X mechanisms -Technology components focused on clustering -Dynamic reconfiguration enablers These novel network-level technology concepts are evaluated against requirements defined by METIS for future 5G systems. Moreover, functional enablers which can support the solutions mentioned aboveare proposed. We find that the network level solutions and technology components developed during the course of METIS complement the lower layer technology components and thereby effectively contribute to meeting 5G requirements and targets.Aydin, O.; Valentin, S.; Ren, Z.; Botsov, M.; Lakshmana, TR.; Sui, Y.; Sun, W.... (2015). D4.3 Final Report on Network-Level Solutions. http://hdl.handle.net/10251/7675

    Experimental Study on Real-Time Wireless Networks for Motion Control of Manipulator and Mobile Platform in Industrial Robotics

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    The integration of ICT with manufacturing technologies is a key step towards intelligent manufacturing. The goal is to investigate some industrial application scenarios and evaluate the performance of selected wireless technologies. A recently standardized industrial wireless technology, WIA-FA, has shown good performance in practical deployments. Two experimental applications are considered: path planning testing with different wireless technologies and CANbus bridging with WIA-FA.openEmbargo temporaneo per motivi di segretezza e/o di proprietĂ  dei risultati e informazioni di enti esterni o aziende private che hanno partecipato alla realizzazione del lavoro di ricerca relativo alla tes

    Interference Mitigation in Frequency Hopping Ad Hoc Networks

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    Radio systems today exhibit a degree of flexibility that was unheard of only a few years ago. Software-defined radio architectures have emerged that are able to service large swathes of spectrum, covering up to several GHz in the UHF bands. This dissertation investigates interference mitigation techniques in frequency hopping ad hoc networks that are capable of exploiting the frequency agility of software-defined radio platforms

    Interference mitigation in cognitive femtocell networks

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    “A thesis submitted to the University of Bedfordshire, in partial fulfilment of the requirements for the degree of Doctor of Philosophy”.Femtocells have been introduced as a solution to poor indoor coverage in cellular communication which has hugely attracted network operators and stakeholders. However, femtocells are designed to co-exist alongside macrocells providing improved spatial frequency reuse and higher spectrum efficiency to name a few. Therefore, when deployed in the two-tier architecture with macrocells, it is necessary to mitigate the inherent co-tier and cross-tier interference. The integration of cognitive radio (CR) in femtocells introduces the ability of femtocells to dynamically adapt to varying network conditions through learning and reasoning. This research work focuses on the exploitation of cognitive radio in femtocells to mitigate the mutual interference caused in the two-tier architecture. The research work presents original contributions in mitigating interference in femtocells by introducing practical approaches which comprises a power control scheme where femtocells adaptively controls its transmit power levels to reduce the interference it causes in a network. This is especially useful since femtocells are user deployed as this seeks to mitigate interference based on their blind placement in an indoor environment. Hybrid interference mitigation schemes which combine power control and resource/scheduling are also implemented. In a joint threshold power based admittance and contention free resource allocation scheme, the mutual interference between a Femtocell Access Point (FAP) and close-by User Equipments (UE) is mitigated based on admittance. Also, a hybrid scheme where FAPs opportunistically use Resource Blocks (RB) of Macrocell User Equipments (MUE) based on its traffic load use is also employed. Simulation analysis present improvements when these schemes are applied with emphasis in Long Term Evolution (LTE) networks especially in terms of Signal to Interference plus Noise Ratio (SINR)
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