computer-network-chapter-5-satellite-network

Table of contents

Satellite network

Operation

• 케플러 법칙
• the signal from a satelllite is normally aimed to

Three Categories of Satellites

• GEO satellite: 정지 궤도 위성, 고도 $35,786\,km$에 위치해야 함.
  • van allen belt is a layer that contains charged particles
• MEO
• LEO MEO, LEO는 자전속도보다 훨씬 빠르게…

Frequency Bands for Satellite Communication

• transmission from the earth to the satellite is called uplink
• transmission from the satellite to the earth is called downlink

GEO Satellites

• Geostationary Earth Orbit (정지 궤도 위성)
• 지구 전체를 모니터링 하려면 세개를 쏘아 올려야 한다.

MEO Satellites

• Medium-Earch Orbit (MEO)
• One Example of a MEO satellite system is the Global Positioning System (GPS), 고도 18000km

GPS

• 24개의 위성, 6개의 궤도
• 한 궤도에 4개의 위성
• four satellites are visible from any point on Earth.
• GPS is based on a principle called trilateration
• On a plane,
• In space

LEO

• Low-Earth Orbit

Iridium System

• 66 satelites, orbit에 11개

Teledesic

• 288 satellites in 12 polar orbit