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The virtualization of mobile network functions constitutes one of the main blocks for addressing the high flexibility requirements of fifth generation (5G) communication systems. Reconfigurable hotspots are expected to be massively deployed to enable on-demand services and dynamically adapt the network capacity according to traffic requirements. In this paper, we present the extensions and modifications of the long term evolution (LTE) module of the ns-3 simulator (LENA) to include a software defined radio (SDR) physical layer implementation. These extensions combine the native flexibility of the simulator with the SDR features of a real-time prototype. Moreover, the framework was designed to distribute the communication functions across different elements of the network with the possibility of adjusting several transmission parameters as in a network function virtualization (NFV) paradigm. Thanks to an emulated full network protocol stack, the prototype allows the experimentation of novel 5G solutions and the evaluation of relevant key performance indicators (KPIs) from the lower layer protocols up to application level. To this aim, we present the experimental evaluation of the KPIs of energy, latency, throughput and reconfiguration time in relevant scenarios. ; Grant numbers : projects partially supported by the Generalitat de Catalunya (2014 SGR 1551 and 2014 SGR 1397) and by the Spanish Government under project TEC2014-58341-C4-4-R and TEC2017-88373-R. © 2018 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.

Received 29.01.2021. The renminbi was included in the SDR basket from October 2016. In that time there were a lot of doubts about whether the renminbi was enough freely used currency to comply with the criteria of such inclusion. Other opinions focused on possibility that this inclusion would boost international usage of the renminbi. The author analyses statistics and comes to conclusion that the maximum boost of the renminbi usage was achieved right before the inclusion. The China's statistics shows the boost of renminbi usage in the external transactions in 2016–2020, but statistics of its trading partners and SWIFT reveal only moderate growth or even stagnation in this period. One of explanation of this discrepancy may be that despite Chinese banks' substantially increased external lending in renminbi in recent years, it looks that banks actually do not transfer renminbi abroad to borrowers. Banks just remit these sums to Chinese suppliers under the instructions by foreign borrowers. Then those borrowers repay those renminbi loans most likely in dollars. So China's statistics record boost of renminbi usage, but its trading partners do not see those renminbi. The key obstacle for widening international usage of renminbi is remaining restrictions (formal and informal) for transactions under the financial account of China's balance of payments. The author considers prospects of increasing the international role of the renminbi and comes to conclusion that it is likely that China is afraid of liberalisation of its financial accounts because there is a risk of long-term depreciation of the renminbi. Contrary to widely popular belief that China stands for and practiced with undervalued exchange rate of the renminbi the author statistically shows that in the past 25 years the renminbi was stronger than the G7's currencies and substantially stronger than the currencies of China's neighbour competitors. It looks that devaluation-averse sentiments hinder China's decision makers from introduction of real liberalisation of its financial account, because free transborder movements of capital may create sharp depreciating impact on the renminbi and thus undermine Chinese economic achievements of last decades. That's why it is unlikely that the renminbi will substantially increase its international role in the foreseeable future.

<p>Este trabalho discute as potencialidades para a silvicultura na área de abrangência da Secretaria de Desenvolvimento Regional de Joaçaba - SDR de Joaçaba, no estado de Santa Catarina. O objetivo deste estudo é analisar as potencialidades da produção da silvicultura madeireira na área de abrangência da SDR de Joaçaba. Para o desenvolvimento do presente estudo utilizou-se a pesquisa exploratória e descritiva com a abordagem qualitativa e quantitativa, e os procedimentos da pesquisa bibliográfica e documental. O estudo compreende os 13 municípios da região objeto deste trabalho. Os dados foram extraídos das bases do Instituto Brasileiro de Geografia e Estatística - IBGE e complementados com dados de outros organismos públicos e organismos privados representativos do setor de silvicultura. Os estudos consistiram da análise dos históricos da produção de carvão, lenha e madeira em toras para papel e celulose e para diversas finalidades. Também explorou-se documentos de estudos das características dos solos para identificar as características dos solos da região. Os resultados indicam que em sete municípios as potencialidades se caracterizam como pouco atrativas para o desenvolvimento da silvicultura para produção de madeira e biomassa, em dois municípios há possibilidades de expansão moderada, em três municípios é possível um aumento expressivo da produção, e em um município com grande volume de produção não foi possível definir as tendências.</p>