On Combining Duty-cycling with Network Coding in Flood-based Sensor Networks

Network coding and duty-cycling are two popular techniques for saving energy in wireless sensor networks. To the best of our knowledge, the idea to combine these two techniques, for even more aggressive energy savings, has not been explored. One explanation is that these two techniques achieve energy efficiency through conflicting means, e.g., network coding saves energy by exploiting overhearing, whereas dutycycling saves energy by cutting idle listening and, thus, overhearing. In this thesis, we thoroughly evaluate the use of network coding in duty-cycled sensor networks. We propose a scheme called DutyCode, in which a MAC protocol implements packet streaming and allows the application to decide when a node can sleep. Additionally, a novel, efficient coding scheme decision algorithm, ECSDT, assists DutyCode to reduce further energy consumption by minimizing redundant packet transmissions, while an adaptive mode switching algorithm allows smooth and timely transition between DutyCode and the default MAC protocol, without any packet loss. We investigate our solution analytically, implement it on mote hardware, and evaluate it in a 42-node indoor testbed. Performance evaluation results show that our scheme saves 30-46% more energy than solutions that use network coding, without using duty-cycling.