The growing demand for bandwidth intensive wireless applications and devices portend a future where millimeter-wave and sub-THz carrier frequencies will be used to provide massively broadband® bandwidths and many Giga-bits-per-second (Gbps) data rates in mobile environments . Concurrently, the importance of energy efficiency for communication systems incentivizes discovery of new routing and access techniques that work in conjunction with power saving protocols to maximize battery life and improve power consumption. Wireless channels, as well as the wireless devices themselves, play a major role in determining both achievable data rates and power requirements. In this paper, we use the consumption factor  framework to quantify the impact of channel characteristics on both data rate performance and power consumption in a wireless link. Based on recent 38 GHz cellular propagation measurements , we demonstrate how future (5G) millimeter-wave cellular channels will impact the data rates and power requirements for future millimeter-wave cellular systems having cell radii less than a km. Analysis results presented here show how to include frequency-domain representations of the channel for use in the consumption factor analysis. A key result from the analysis is that, as massively broadband systems become more prevalent, it will be important to assess the ideal cell size to achieve the lowest energy consumption per pit. Higher bandwidth systems generally benefit form shorter transmission distances. As futuristic cellular standards contemplate the use of millimeter-wave frequencies for greater bandwidths, the work here may offer insight into how to analyze energy efficiency and performance.