Reaching out with wireless

The application of wireless for humanitarian relief can be greatly enhanced by circumventing the range limitations of current technologies, without requiring bulky transceivers with very large antennas. In this talk, we discuss two broad approaches to this problem, and give some preliminary results that illustrate the promise of these approaches. The first approach is the use of distributed antenna arrays using cooperation among neighboring nodes. Promising results over the past few years, both in terms of theory and prototyping, indicate that such distributed arrays have the potential of providing order of magnitude range improvements, along with enhanced spatial reuse. Such distributed arrays are easy to set up and tear down, since they can be realized with nodes with compact form factor, and allow operation over large carrier wavelengths (for which conventional centralized antenna arrays would be too bulky), thus significantly enhancing propagation. The second approach is the use of autonomous mobile agents such as Unmanned Aerial Vehicles (UAV) as an integral part of the sensing and communications infrastructure., which can, providing connectivity in disconnected networks and for tracking survivors using radio frequency (RF) beacons. We discuss promising recent results on providing adaptive UAV-based data collection and processing for disconnected sensor networks, and on robust algorithms for following RF beacons despite large spatial fades (which apply, for example, for tracking survivors in a disaster situation).