Wireless beyond the third generation-facing the energy challenge

After a stellar growth over the last decade driven by voice as the killer app, wireless communications is now rapidly moving into a new era propelled by data networking. For a wide host of devices, wireless will serve as the "last interconnection hop" to the high data-rate wired networks. The basic trends in these devices can be best summarized under the following two headers: "ubiquity" and "more bits/sec". Both of these have some important ramifications on energy dissipation. We outline the predominant trends in wireless, analyze the energy challenge of those trends, and examine a number of emerging solutions.