Air Based Communication Platforms

A balloon or circling plane high in the air is a very interesting communications platform. A bunch of these can make a nice network. The advantages are:

They are at fixed locations relative to the users on the earth (like Geostationary satellites but not like LEOs) so customers could use directional antennas
Can be rolled out gradually. Do not need whole system to up to start, so capital investment is easier
Cost of the platform may be far less than a satellite
The systems can be easily taken down and repaired.
At 10 to 100 miles it much closer to customers than GEO (23,000 miles) and even well closer than LEO (say 400 to 1000 miles) so the customers transmitter power can be far less.

Systems in the works

Overview
General Atomics planes
Angel Technologies planes
SkyStation balloons
Platforms International planes
HALE - research
Skysat Communications - SKATA previous company by same guy later started platforms international

Note that solar powered planes with fuel cells are another alternative for communication platforms in the sky.