UC Berkeley UC Berkeley Networks of low power wireless devices introduce novel IP routing issues. Low-power wireless devices, such as sensors, actuators and smart objects, have difficult constraints: very limited memory, little processing power, and long sleep periods. As most of these devices are battery-powered, energy efficiency is critically important. Wireless link qualities can vary significantly over time, requiring protocols to make agile decisions yet minimize topology change energy costs. Routing over such low power and lossy networks has requirements that existing mesh protocols only partially address. This document provides a brief survey of the strengths and weaknesses of existing protocols with respect to this class of networks. It provides guidance on how lessons from existing and prior efforts can be leveraged in future protocol design.