L AND S BAND
Satellite Communications Glossary
Satellite Communications — Satellite Frequencies — L and S Band
Information on L and S Band
The L and S band frequencies from 1-4 GHz
become increasingly useful for satellite communications because the high frequencies
allow high capacities (although still much less than C and
Ku band), and propagation is line-of-sight with little man-made noise
and relatively low absorption by the atmosphere (although ionospheric scintillation
and polarisation rotation must be taken into account). In a
similar manner to P band, however, the frequencies are still
low enough to use relatively simple antennas such as Yagi
and helical antennas as well as to reduce the cost
and design of receivers.
L and S band are shared
with terrestrial services such as industrial and educational television and
studio-to-television transmitter links, and other space links such as radio
astronomy applications and NASA’s space probes. These bands are therefore
not very suitable for GEO operation as they still do
not have enough capacity and are very difficult to coordinate
with terrestrial services over large areas.
The first major use
of L band was by Marisat for ship-to-shore satellite communication
as an adjunct to the UHF payload carried for the
US Navy. While there is some limited use of S-band
frequencies for BSS in India and the Arab countries, L
and S band are allocated predominantly for MSS and
particularly for satellite personal communications services. For example, the Globalstar
system uses L-band frequencies (approximately 1.6 GHz) for the satellite-to-mobile
link and S-band frequencies (approximately 2.5 GHz) for the mobile-to-satellite
link. Iridium uses frequencies of approximately 1.6 GHz.
Other topics in our resources on Satellite Communications related to L and S Band include:
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