Joel Rodrigues is Professor in the Department of Informatics of the University of Beira Interior, Covilhã, Portugal, and senior researcher at the Instituto de Telecomunicações, Portugal. He is also with the University of Fortaleza (UNIFOR), Ceará, Brazil and Instituto Nacional de Telecomunicações (Inatel), Brazil.

Sandra Sendra Compte is a researcher in « Communications and Netwoks » at the Polytechnic University of Valencia, Spain.

Isabel de la Torre Diez is Associate Professor in the Department of Signal Theory, Communications and Telematics Engineering at the University of Valladolid, Spain.