Energy Metrics
	n What is an “energy-efficient” routing protocol? n Possible Metrics: Ø Minimize energy consumed/packet, Ø Maximize time to network partition, Ø Minimize variance in node energy levels, Ø Minimize cost/packet, and Ø Minimize maximum node cost. n We used: average overall amount of consumed energy n Note: if minimizing energy consumption was only goal, a trivial optimal solution exists: drop all packets  n Therefore, need to also consider packet delivery ratio