IEEE Communications Magazine
IEEE Communications Magazine > 2008 > 46 > 9 > 104 - 109
IEEE Communications Magazine > 2008 > 46 > 9 > 136 - 143
IEEE Communications Magazine > 2010 > 48 > 12 > 76 - 82
IEEE Communications Magazine > 2011 > 49 > 12 > 84 - 93