Massimo Condoluci Leonardo Militano Antonino Orsino Jesus Alonso-Zarate Giuseppe Araniti LTE-direct vs. WiFi-direct for machine-type communications over LTE-A systems. 2298-2302 2015 PIMRC https://doi.org/10.1109/PIMRC.2015.7343681 conf/pimrc/2015 db/conf/pimrc/pimrc2015.html#CondoluciMOAA15