Raja Jurdak Antonio G. Ruzzelli Gregory M. P. O'Hare Adaptive Radio Modes in Sensor Networks: How Deep to Sleep? 386-394 2008 SECON http://dx.doi.org/10.1109/SAHCN.2008.54 conf/secon/2008 db/conf/secon/secon2008.html#JurdakRO08