There is a colony of 1000 people on the moon. Estimate the bandwidth needed. How would you provide internet to them?
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it will be important to understand the composition of the 1000 people on Moon and what they might be using internet for. Lets assume the people in moon are self sufficient and are an organized unit i.e they have their source of power, their friends are in moon, their social circles are in moon, and they dont have anyone to contact heavily at earth. Since its a colony, it will have households with people belonging to different subsection of society i.e. Utilities, education, Food, basic service providers and Law and Order.
Lets assume each of the groups identified have an administrator, and workers. Education will have a larger subsection of students.
- Utlities - 20% * 1000 = 200
- Education - 30% * 1000 = 300
- Food - 30% * 1000 = 200
- Basic service providers = 10% * 1000 = 100
- Law & Order = 10% * 1000 = 100
So if I were to break out their jobs into low, medium, high , very high bandwidth usage
utilities | 20% | 25% | 50% | 20% | 5% | 0.2*1000(.25*0.1mbps + 0.5*0.5mbps + 0.2*2mbps + 0.05*4mbps) = 200*(0.025+0.25+0.4+0.2) = 0.875*200 = 175 mbps |
education | 30% | 10% | 40% | 40% | 10% | = 300* (0.01+0.02+0.8+0.4)=369mbps |
Food | 30% | 10% | 70% | 10% | 10% | = 300*(0.01+0.35+0.2+0.4) = 288 mbps |
Basic Service | 10% | 100% | = 100* 0.5 = 50mbps | |||
Law & Order | 10% | 10% | 10% | 30% | 50% | = 100 * (0.01+0.05+0.6+0.2) = 86 mbps |
Total bandwidth needs = 968 mbps ~~ 1 GBPS
how to make internet available.
A few things we know about Moon, it doesnt rotate at the same speed as earth does i.e. the days & nights arent evenly broken out, its not always at the same position w.r.t earth.
There are a few options
- Have a router provisioning internet to the colony. The router has a satelite link to a remote desktop in earth. This is how ISS gets internet. The problem here would be very slow internet.
- Have an LEO satelite strategically positioned on earth and a dish receiver on the colony. The problem here would be there wont be a continuous line of sight between the satelite and receiver, since 2 times a year the sun is between the earth and the moon, not to mention RF signals will be face constant interference with cosmic radiation
- have laser based transmission from earth to moon via an uplink. I read recently that NASA has provided a 14.1 b contract to Nokia to provide 4G connectivity in Moon
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