— Reducing energy consumption has been a recent focus of wireless sensor network research. Topology control explores the potential that a dense network has for energy savings. One such approach is Geographic Adaptive Fidelity (GAF) [1]. GAF is proved to be able to extend the lifetime of self-configuring systems by exploiting redundancy to conserve energy while maintaining application fidelity. However the properties of the grid topology in GAF have not been fully studied. In this paper it is shown that there exists an unreachable corner in the GAF grid architecture. Using an analytical model, we are able to calculate the unreachable probability and analyse its impacts on data delivery. After investigating a couple of lossless topologies, we propose to use the Honeycomb virtual mesh (GAF-h) to replace the square grid. GAF-h is proved to be able to achieve zero loss with little extra cost compared to the original GAF scheme. An efficient honeycomb cell placement and node association al...