eCOPE: Energy efficient network coding scheme in multi-rate wireless networks

Recently energy-efficient system design in wireless networks, which in nature supports multi-rate transmissions, has become a focus in the research field. Meanwhile network coding has been proven as a very promising technique to improve wireless network throughput and energy-efficiency (EE). In multi-rate wireless networks, simply seeking more coding opportunities or coding more packets into one frame without exploiting multi-rate feature may lead to selecting low-rate links for transmission, and thus compromise the performance gain and EE brought by network coding. In this paper, we aim at exploiting the potential benefits brought by both multi-rate and network coding. We carefully address the bottleneck problem in applying energy-efficient network coding to multi-rate networks, and propose an energy-efficient COPE-like network coding scheme, which is called eCOPE and employs the energy-efficient Rate Adaptation(eRA) and Power Allocation(ePA) algorithm. Simulation experiments results based on NS-2 demonstrate that eCOPE can significantly improve network performances in terms of both throughput and end-to-end delay in 802.11 DCF multirate environment, at a relatively low cost of signaling overhead.