Energy Efficiency of Hybrid-ARQ Based Geographic Routing

In this paper, we propose a new energy efficient Location Error Aware Routing (LEAR) protocol, which takes into account the location error being experienced by the forwarding relay. The majority of geographically informed routing algorithms assume access to accurate location information. However, in practical systems location measurements are prone to inaccuracies. In this work, we investigate how the energy efficiency of state-of-the-art geographic routing protocols are degraded by location dependent location errors. For the size of location errors anticipated in typical wireless networks we find that the energy efficiency of current location based routing schemes decreases by up to 150%. To counter such degradation in performance, we propose LEAR protocol, which is based on selecting a relay closest to the destination having a standard deviation of location error (SDLE) less than a predefined threshold. We show that the performance of LEAR is 80% better than current state-of-the art protocols, which do not consider location-errors in routing. An analysis and detailed simulation over a High Speed Data Packet Access (HSDPA) based system is provided in support of our results.