The devolution effects of flat fading on connected wireless networks under shadowing

This paper studies how Rayleigh flat fading causes partitioning of wireless ad-hoc networks which already satisfy the connectivity achieving conditions under macro-scale log-normal shadowing. The devolving effects of fading are investigated by analyzing the network-wide link outage, time-based connectivity, node degree loss and average lifetime of emergent connected components. The study reveals that fading severely impairs the connectivity of sparser networks where the network connectivity rate drops to below 40%. Shadowing is found to immunize the network against the devolving effects of fading by introducing a link-diversity gain. A slight tolerance to the spatial connectivity requirement yields considerable gains in the network robustness against further partitioning; 90% of the network can be kept connected at 50% less node density or shadowing. A high rate of change of the graph structure is observed. This results in short component lifetime that exponentially decays with component size.