Performance Evaluation of an Energy Efficient Traffic Offloading Protocol for Vehicular Networks

Offloading data traffic from infrastructure-tovehicle(I2V) to vehicle-to-vehicle (V2V) communications isa powerful tool for increasing spectral efficiency, as well asenergy efficiency, of a vehicular network. Typically, trafficoffloading is achieved by exploiting caching capabilities ofthe mobile nodes (vehicles) and direct V2V communicationtechnologies. In prior network-level studies on trafficoffloading, the physical features of wireless channels aretaken into account using relatively simplistic models. Inthis study, we propose an offloading protocol based on V2Vcommunications and evaluate its performance taking intoaccount realistic models of the wireless channel, focusingon energy efficiency as a performance metric. Specifically,we compare the results obtained by using a set of wirelesschannels and interference models, ranging from simplisticmodels based on deterministic path loss formulas to a veryaccurate channel model that has been developed inn therecent years for LTE-A networks. Our goal is twofold: onone hand, we aim to quantify the achieved benefits in termsof energy efficiency; on the other hand, we investigatethe impact of using different wireless channel models inthe evaluation of the energy efficiency of V2V offloadingprotocols.