Energy Efficient Cooperative Communications using Location based Relaying

Geographic random forwarding (GeRaF) is a location based distributed routing protocol that allows wireless networks with aggressive sleep cycles of its nodes to deliver messages with low latency. Hybrid-automatic repeat request (H-ARQ) based intra-cluster geographically informed relaying (HARBINGER) is a protocol based on GeRaF with link-layer based adaptive error control techniques and promises better performance than GeRaF. In this paper we will study the performance of HARBINGER relative to GeRaF. We study the energies required for a message to reach its destination with a given latency bound, for both GeRaF and HARBINGER, with a practical high speed data packet access (HSDPA) based system. In particular, we highlight the different circumstances under which each protocol delivers a better energy efficiency. We propose simple modifications to the GeRaF protocol with which it can achieve the same or better performance as HARBINGER at lower node densities with lesser implementation complexity.