A practical power-control mechanism implementation for future wireless communications scenarios Vicknesan Ayadurai and Mikael Prytz Ericsson Research With rapidly increasing traffic in todays networks, compounded by limited spectrum availability, new network architectures to better-utilize the available radio resources are being considered. One such method is network-assisted device-to-device (NA-D2D) communications, where the network instructs a pair of communicating nodes in close proximity to exchange information directly with each other, instead of via the network as done traditionally. Using software-defined radio (SDR) we prototype a practical implementation of a novel point-to-point power-control mechanism which demonstrates the power-saving benefits of this new topology. We subsequently further exploit the nonlinear power-distance relationship by introducing a relay node between the original communicating endpoints and illustrate how this new layout further reduces total "energy in the air", thereby paving the way for resource-reuse opportunitites.