Hang Su Xi Zhang CREAM-MAC: An efficient Cognitive Radio-enAbled Multi-Channel MAC protocol for wireless networks. 1-8 2008 WOWMOM http://dx.doi.org/10.1109/WOWMOM.2008.4594853 conf/wowmom/2008 db/conf/wowmom/wowmom2008.html#SuZ08