We know, we know, Google has the whole hot air balloon thing covered. But this idea is a bit different. It consists of a group of "helikites," or small load-bearing balloon-kite hybrids, which can quickly be launched to form a network of LTE or WLAN masts up to an altitude of 2.5 miles, providing data coverage following an earthquake or tsunami. A standalone rugged suitcase, or "Portable Land Rapid Deployment Unit," contains everything needed for activation in tough conditions. Researchers behind the project, including German R&D firm TriaGnoSys, have even found a way to integrate the temporary network with existing cell towers that remain in tact on the ground -- a feature that makes the system suitable not only for emergencies, but also for expanding mobile coverage during planned events in remote locations. Of course, the helikites would eventually drift apart and lose connectivity, probably after around four days depending on the wind, but these things never travel quite as far as you'd expect.
Source:EAI PSATS (PDF download)