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We integrate, for the first time in the literature, the following ingredients to deal with emerging dynamic spectrum management (DSM) problem in heterogeneous wireless sensors and actuators networks (WSANs), Internet of things (IoT) and Wi-Fi: (i) named-based routing to provide provenance and location-independent access to control plane; (ii) temporary storage of control data for efficient and cohesive control dissemination, as well as asynchronous communication between software-controllers and devices; (iii) contract-based control to improve trust-ability of actions; (iv) service-defined configuration of wireless devices, approximating their configurations to real services needs. The work is implemented using NovaGenesis architecture and a proof-of-concept is evaluated in a real scenario, demonstrating our approach to automate radio frequency channel optimization in Wi-Fi and IEEE 802.15.4 networks in the 2.4 GHz bands. An integrated cognitive radio system provides the dual-mode best channel indications for novel DSM services in NovaGenesis. By reconfiguring Wi-Fi/IoT devices to best channels, the proposed solution more than doubles the network throughput, when compared to the case of mutual interference. Therefore, environments equipped with the proposal provide enhanced performance to their users.

This work presents a numerical investigation of high-gain reconfigurable printed antenna arrays for mm-waves wireless aplications of broadband mobile communication. Two compact structures with reconfigurable radiation based on four broadside microstrip arrays of six elements are presented: the first one is a planar array with gain up to 20dBi; the second is treedimensional printed array with gain up to 15dBi. In order to estimate the electromagnetic performance of these antennas, a numerical analyzes were performed by ANSYS HFSS, which employs the Finite Element Method (FEM).Index Terms -Microstrip antennas, printed array, reconfigurable array.

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As redes de sensores sem fio utilizam de meios de comunicação compartilhados para a transmissão de dados. Com isto, se torna fácil para um atacante interferir nas transmissõs destas redes através de ataques de negação de serviço conhecidos como Jamming. Estes ataques podem ser feitos através de dispositivos chamados de Jammers, que emitem sinais aleatórios de dados, visando derrubar as comunicações das redes de sensores. Neste artigo, estudamos as características do ataque de interferência Jamming sobre a rede IEEE 802.15.4 e propomos uma contramedida a esse ataque utilizando um sistema de rádio cognitivo definido por software para detectar e proteger a rede.