Cédric de Launois Marcelo Bagnulo 38-51 2006 8 IEEE Communications Surveys and Tutorials 1-4 http://dl.comsoc.org/cocoon/comsoc/servlets/OntologySearch?query=&node=TOC1669&render=false&type=1 db/journals/comsur/comsur8.html#LaunoisB06