—In this paper, we study link properties over dynamic radio channels based on analytical models and simulations. Specifically, channel variability and mobility are investigated through two quantities: effective transmission range and nodepair distance, respectively. We find that the PDF of link lifetime can be approximated by exponential distribution with parameter characterized by the ratio of average node speed to effective transmission range. Moreover, we show that average link lifetime for slower mobile nodes is mainly determined by radio channel characteristics, whereas for faster mobile nodes, it is dominated by node mobility. Through analysis and simulations, we find that the impacting factors on residual link lifetime are in the decreasing order of average node speed, effective transmission range, and node-pair distance on the fly. We further present the implication and application of link properties to path lifetime, network connectivity, and routing performance.