Sixian Zheng Kuochen Wang Shiao-Li Tsao Pochun Lin Enhanced Sleep Mode Operations for Energy Saving in IEEE 802.16e. 261-272 2007 conf/euc/2007w EUC Workshops http://dx.doi.org/10.1007/978-3-540-77090-9_24 db/conf/euc/eucw2007.html#ZhengWTL07