Consider a satellite network consisting of a constellation of S satellites placed at an altitude of 1,000km
Question:
Consider a satellite network consisting of a constellation of S satellites placed at an altitude of 1,000km above the Earth (Earth’s diameter is ?12,750km) and G ground stations connecting both customers and Internet exchange points. Each orbit of the constellation consists of 50 satellites (20 orbits total). Each satellite is equipped with five communications laser-receivers; one to communicate with the ground and four to communicate with the nearest neighbour satellites. The satellites are not geostationary. You may assume each satellite only communicates with its nearest neighbours at any time. Each node—satellite, or ground station—has a unique identifier of 16 bytes which it knows. Design a topology-discovery protocol than can identify the shortest path among any two ground stations using the 1,000 satellites in orbit. Symmetric paths may be presumed.
(a) Outline a protocol (including message formats) for a node to learn about its immediate neighbours. [3 marks]
(b) Design a protocol (including message formats) for distributing this information across the network. [7 marks]
(c) Give a bound on the total amount of non-redundant information which is transmitted to ensure that every node acquires complete topology information. [5 marks]
Physics
ISBN: 978-0077339685
2nd edition
Authors: Alan Giambattista, Betty Richardson, Robert Richardson