A recent article on providing 2400 baud to Guinea using high-frequency (HF) radio and not 802.11. A followup to the Wired on Wireless article I posted a while back.
"If you have been making the move to wireless lately, most likely you are working with the microwave, high bandwidth frequencies of 802.11b. If so, you know that on a clear day you maybe can get a line-of-sight connection out 10 miles or so. That surely won't do for the vast distances and wild terrain we need to cover in rural Africa.
HF radio is another animal. Its longer waves roll out across the landscape, reflecting off the ionosphere to follow the curvature of the earth. This gives HF signals a range in the hundreds of miles. From Conakry to Nzerekore--IRC Guinea's most distant field office--HF easily covers a straight-line distance of over 375 miles (600 kilometers.) The road that sometimes connects these two points is, of course, much longer--a gut-slamming, spine-jamming, two-day punishment for the damned."