Line of sight

from Wikipedia, the free encyclopedia
First Fresnel zone ("n = 1", black) over the hilly terrain of a radio link  D (green)

The term line of sight ( direct wave , English: line-of-sight , LOS for short ) is used in communications technology for radio transmission with direct visual contact between the transmitter and receiver . In contrast to the no line of sight  (NLOS) there is no obstacle in the first Fresnel zone .

A line of sight should be aimed for for the best possible radio connection, since the technical effort and the transmission power can be reduced compared to a non-line of sight connection .

The advantage of the line of sight is that through the use of parabolic antennas with very narrow opening angles , the effect of multipath ( multipath ) and interference minimized or can be excluded. In addition, the laws of wave propagation and free space attenuation apply . All these factors must be taken into account when developing a communication concept and when installing a radio transmission link.

literature

  • Ralf Gessler, Thomas Krause: Wireless networks for the local area. Embedded radio systems, 2nd edition, Springer Fachmedien, Wiesbaden 2015, ISBN 978-3-8348-1239-1 .
  • Jörg Eberspächer (Ed.): DFG Priority Program Mobile Communication. Herbert Utz Verlag, Munich 2000, ISBN 3-89675-937-X .
  • Armin Schöne: Measurement technology. Springer Verlag, Berlin / Heidelberg 1994, ISBN 978-3-540-54629-0 .

See also

Web links