1. Satellite connectivity Skills: none IT concepts: geostationary orbit, low-earth orbit, satellite footprint, applications, latency (ping time) This work is licensed under a Creative Commons Attribution-Noncommercial- Share Alike 3.0 License.

2. Where does this topic fit? Internet concepts –Applications –Technology (communication) –Implications Internet skills –Application development –Content creation (images)

3. Satellite is slow and expensive, but may be the only possibility This dish will probably serve a village or rural Internet kiosk.

4. Geostationary orbit about 22,000 miles Low earth orbit about 500 miles 100 minutes 24 hours

5. A geostationary orbit for Internet connectivity

6. 1945: Arthur C. Clarke’s geostationary satellite Fig. 2. Typical extra-terrestrial relay services. Transmission from A being relayed to point B and area C; transmission from D being relayed to whole hemisphere.

7. Satellite footprint

8. Satellite latency Radius of the earth is approximately 4,000 miles 22,000-4,000 = 18,000 2 X 18,000 = 36,000 Light travels 186,000 miles per second 36,000/186,000 = 193 milliseconds

9. Low earth orbit (LEO) satellite constellations Animation Teledesic Animation GPS Iridium

10. Satellite connectivity Skills: none IT concepts: geostationary orbit, low-earth orbit, satellite footprint, applications, latency (ping time) This work is licensed under a Creative Commons Attribution-Noncommercial- Share Alike 3.0 License.