Abstract
This chapter focuses on satellite mega-constellations, as mega-constellations raise several technical issues from telecommunication to launching these huge sets of satellites. Through an overview of basic signal science (periodic waves, types of modulation) and a discussion about telecommunication systems, actual 4G and future 5G networks, the chapter aims at giving without prior scientific background, sufficient material to better understand mega-constellation from its basic functioning to sophisticated satellites systems on orbit providing wide communication services all around the Earth. Major topics are evoked about such constellations be it on launching, space debris, challenges, and technologies used from a technical point of view.
TopTheory Of Telecommunication
Telecommunication comes from ‘tele’ meaning ‘far’ and ‘communicare’ meaning ‘sharing’, it brings the idea of an exchange of information between remote/distant protagonists. According to the article 1.3 of the International Telecommunication Union (ITU), telecommunication is defined by any transmission, emission or reception of signs, signals, writings, images and sounds or intelligence of any nature by wire, radio, optical or other electromagnetic systems (ITU Radio Regulation, 2016).
The section addresses different notions dealing with actual issues such as frequency bands, the sharing of the radio frequency spectrum, telecommunication networks and the 4G/5G transition.
Key Terms in this Chapter
Outer Space: The area above the Von Karman line (approximately between 80 to 100 km).
Frequency: Number cycle repetitions that occur within one second.
Satellites: A system placed in orbit around a celestial body, mainly Earth, carrying instrumentation in the purpose of fulfilling a determined mission such as telecommunication, Earth observation, or science.
Mega-Constellation: A constellation that is composed of several hundreds and thousands of satellites orbiting the Earth.
Telecommunication: The means to convey information using emitting and receiving features be it using writings, signs, waves, or other transmission way.
Internet: Interconnection network born in the 60s that is connecting people through electronic devices using internet protocol.
Modulation: A means to encode or decode a signal in the purpose to convey information, most often binary words.
Signal: A signal is a means to convey and to remotely transmit information.