Synopsis:
Small, inexpensive, hand-held satellite terminals, similar to older cellphones (flip-phones) in size, configuration and cost, can bring literacy-training to all corners of the world. The devices would function in a text-only mode with twitter-like limitations on message-size and message-frequency. A small LCD screen and a small keyboard would be used by students to play games and take lessons and tests involving vocabulary, spelling, syntax, grammar and other elements of literacy. The short message-length will enable large populations of users to be supported without requiring excessive bandwidth or power. The small size of these hand held devices will facilitate private training of students, including girls, in locations where public training might be controversial.

More detail:
The satellites would be a galaxy of Low Earth Orbit L- or C-band devices which talk both to the ground and to each other using a subset of conventional cellular communications technology. The satellite-to-satellite communication would be for the purpose of storing, processing and forwarding messages, as well as supporting the database functions needed for maintaining users and lesson-plans. Thus a message received by one satellite might be processed and responded to by a different satellite farther around the chain.

The twitter-like, text-only restriction means that each terminal can be supported by very low data-rates on very narrow-bandwidth channels. Communication would be half-duplex, further limiting bandwidth and power requirements.

These terminals will, of course, find other uses besides literacy training. Communication in third-world countries will be possible where neither land-line nor terrestrial cellphone technology is feasible. The experience with twitter-like facilities in industrialized countries has proven the feasibility and value of a severely-constrained, text-only, half-duplex communication medium.

The hand-held terminals would be battery-powered and would be recharged using integral solar-cells.

The galaxy of satellites supporting these small terminals would also be of value in providing remote communications for the very-low-cost laptop- and tablet-computer projects that are also targeted at third-world countries.