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Browsing ICI - IT-UBI | Documentos por Auto-Depósito by Subject "5G"
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- Cost Benefit Analysis: Evaluation among the Millimetre Wavebands and Super High Frequency Bands of Small Cell 5G NetworksPublication . Teixeira, Emanuel; Ramos, Anderson; Lourenço, Marisa; Velez, Fernando J.; Peha, JonThis article discusses the benefit-cost analysis aspects of millimetre wavebands (mmWaves) and Super High Frequency (SHF). The devaluation along the distance of the carrier-to-noise-plus-interference ratio with the coverage distance is assessed by considering two different path loss models, the two-slope urban micro Line-of-Sight (UMiLoS) for the SHF band (from the ITU-R 2135 Report) and the modified Friis propagation model, for frequencies above 24 GHz. The equivalent supported throughput is estimated at the 5.62, 28, 38, 60, and 73 GHz frequency bands, and the influence of carrier-to-noise- plus-interference ratio in the radio and network optimization process is explored. Mostly owing to the lessening caused by the behaviour of the two-slope propagation model for SHF band, the supported throughput at this band is higher than at the millimetre wavebands only for the longest cell lengths. The benefit cost analysis of these pico-cellular networks was analysed for regular cellular topologies by considering unlicensed spectrum. For shortest distances, we can distinguish an optimal of the revenue in percentage terms for values of the cell length, R ≈ 10 m for the millimitre wavebands, and for longest distances, an optimal of the revenue can be observed at R ≈ 550 m for the 5.62 GHz. It is possible to observe that, for the 5.62 GHz band, the profit is slightly inferior than for millimetre wavebands, for the shortest Rs, and starts to increase for cell lengths approximately equal to the ratio between the break-point distance and the co-channel reuse factor, achieving a maximum for values of R approximately equal to 550 m.
- Hybrid Matched Filter Detection Spectrum SensingPublication . Brito, António; Sebastião, Pedro; Velez, Fernando J.The radio frequency spectrum is getting more congested day by day due to the growth of wireless devices, applications, and the arrival of fifth generation (5G) mobile communications. This happens because the radio spectrum is a natural resource that has a restricted existence. Access to all devices can be granted, but in a more efficient way. To resolve the issue, cognitive radio technology has come out as a way, because it is possible to sense the radio spectrum in the neighboring. Spectrum sensing has been recognized as an important technology, in cognitive radio networks, to allow secondary users (SUs) to detect spectrum holes and opportunistically access primary licensed spectrum band without harmful interference. This paper considers the Energy Detection (ED) and Matched Filter Detection (MFD) spectrum sensing techniques as the baseline for a study where the so-called Hybrid Matched Filter Detection (Hybrid MFD) was proposed. Apart from an analytical approach, Monte Carlo simulations have been performed in MATLAB. These simulations aimed at understanding how the variation of parameters like the probability of false alarm, the signal-to-noise ratio (SNR) and the number of samples, can affect the probability of miss-detection. Simulation results show that i) higher probability of miss-detection is achieved for the ED spectrum sensing technique when compared to the MFD and Hybrid MFD techniques; ii) More importantly, the proposed Hybrid MFD technique outperforms MFD in terms of the ability to detect the presence of a primary user in licensed spectrum, for a probability of false alarm slightly lower than 0.5, low number of samples and low signal-to-noise ratio.
- Impact of the Two-Slope Path Loss Model in the Service Quality of 4G and 5G Small CellsPublication . Paulo, Rui R.; Velez, Fernando J.Together with cell-free networks, small cells enable ultra-dense networks in 5G. Although small cell networks will be part of heterogeneous networks, the comparison of service quality of urban micro (UMi) small cells between 4G and 5G second phase scenarios is still of great relevance. Usage of video (VID), is considered. Quality of service (QoS) is determined by considering a packet loss ratio (PLR) lower than 2%, for different sub-6 GHz frequency bands. The aim is to compare the system capacity between 4G and 5G enhanced mobile broadband in different bands. ITU defined two UMi cell scenarios for urban micro cells that consider two-slope (TS) path loss models (PLMs). In this work, we have included TS-PLMs into the LTESim (4G) and 5G-air-simulator. The service quality and system performance bands have then been evaluated. Results shows that it is possible to support more user terminals (UTs) with 5G (up to 26 UTs) than with 4G (10 UTs only). When PLR<2%, the average delay decreases and the average goodput increases when 5G is considered. The maximum average goodput also increases with 5G.
- MOOC as a Way of Dissemination, Training and Learning of Telecommunication EngineeringPublication . Gil Jiménez, Víctor P.; Urquiza Villalonga, David Alejandro; López Morales, Manuel José; Medda, Daniele; Seitianitis, Ilias-Nektarios; Al-Sakkaf, Ahmed Gaafar; Khan, Bahram; García, M. Julia Fernández-Getino; García Armada, Ana; Chatzimisios, Periklis; Iossifides, Athanasios; Morales Céspedes, Máximo; Velez, FernandoIn this chapter, the use of massive open online courses (MOOCs) for the dissemination, training capabilities and learning of telecommunication engineering is described taking as example the successful MOOC ‘Ultra- Dense Networks for 5G and its Evolution’ developed under the European innovative training network (ITN) TeamUp5G. MOOCs are usually understood as a way of teaching or learning for massive potential students. Indeed, this is the main goal of any MOOC. However, we also propose its use for training and dissemination. The ITN TeamUp5G is a training network for 15 PhD students of seven different institutions (universities and companies) where the students make research on different interconnected topics for the common goal of Ultra dense networks for 5G. At the same time they researched, they prepared a MOOC to disseminate their most recent advances and their challenges. For the MOOC, they needed to collect their thoughts, organizse their knowledge and establish a common vision of the whole system. The cooperative work, the cross-related meetings and, the preparation of all the materials for the MOOC were very interesting and useful in their training process. The whole experience of designing and creating the MOOC is described in detail along with the challenges and lessons learned.
- Multicarrier Waveform Candidates for Beyond 5GPublication . khan, Bahram; Velez, Fernando J.To fulfil the requirements of 5G vision of “everything everywhere and always connected”, a new waveform must contain the features to support a greater number of users on high data rate. Although Orthogonal Frequency Division Multiplexing (OFDM) has been widely used in the 4th generation, but it can hardly meet the needs of 5G vision. However, many waveforms have been proposed to cope with new challenges. In this paper, we have presented a comparative analysis of several waveform candidates (FBMC, GFDM, UFMC, F-OFDM) on the basis of complexity, hardware design and other valuable characteristics. Filter based waveforms have much better Out of Band Emission (OoBE) as compared to OFDM. However, F-OFDM has smaller filter length compared to filter-based waveforms and provides better transmission with multiple antenna system without any extra processing, while providing flexible frequency multiplexing, shorter latency and relaxed synchronization as compared to other waveforms.
- Reference Scenarios and Key Performance Indicators for 5G Ultra-dense NetworksPublication . Campos, Luís Miguel; Ribeiro, Luís; Karydis, Ioannis; Karagiannis, Stelios; Pedro, Dário; Martins, Jorge; Marques, Carlos; Armada, Ana García; Perez Leal, Raquel; López-Morales, Manuel José; Velez, Fernando J.; Sebastião, Pedro; Ramos, AndersonThe so-called 5G will revolutionize the way we live, and work. In order to demonstrate the profound changes, we can expect to experience within the next 5 to 10 years, we present use cases for the planned research within the TeamUp5G project. Some use cases are strongly linked to the network layer and aim at developing solutions capable of optimizing the main promising benefits of 5G: extremely low latency and extremely high bandwidth (e.g., handle video streams, traffic congestion, user profiles), in the most efficient way possible. Other use cases focus on commercial applications that make use of middleware applications to enhance their performance. The latter fall into two main areas: real-time virtual reality and live video streaming, which are extremely demanding in terms of latency and bandwidth to provide an acceptable QoE/QoS to multiple users. The use cases presented are built assuming that 5G is essential for their support with appropriate QoE/QoS. Key performance indicators and their range of variation are also identified.