Egli model

The Egli model is a terrain model for radio frequency propagation. This model, which was first introduced by John Egli in his 1957 paper,[1] was derived from real-world data on UHF and VHF television transmissions in several large cities. It predicts the total path loss for a point-to-point link. Typically used for outdoor line-of-sight transmission, this model provides the path loss as a single quantity.

Applicable to/under conditions

The Egli model is typically suitable for cellular communication scenarios where one antenna is fixed and another is mobile. The model is applicable to scenarios where the transmission has to go over an irregular terrain. However, the model does not take into account travel through some vegetative obstruction, such as trees or shrubbery.

Coverage

Frequency: The model is typically applied to VHF and UHF spectrum transmissions.

Mathematical formulation

The Egli model is formally expressed as:

Where,

= 50th percentile receive power [W]

= Transmit power [W]

= Absolute gain of the base station antenna.

= Absolute gain of the mobile station antenna.

= Height of the base station antenna. [m]

= Height of the mobile station antenna. [m]

= Distance from base station antenna. [m]

= Frequency of transmission. [MHz]

Limitations

This model predicts the path loss as a whole and does not subdivide the loss into free space loss and other losses.

Further reading

Introduction to RF propagation, John S. Seybold, 2005, John Willey and Sons Inc.

gollark: One thing I miss from void is systemd-like journalctl.
gollark: ```nimproc makeFilePath(basepath, page, filename: string): string = # putting tons of things into one directory may cause issues, so "shard" it into 256 subdirs deterministically let pageHash = getMD5(page) let hashdir = pageHash[0..1] # it is possible that for some reason someone could make two files/pages which normalize to the same thing # but are nevertheless different files # thus, put the hash of the ORIGINAL file/pagename before the shortened version let pagedir = pageHash[2..31] & "-" & normalizeFilename(page) let filenameHash = getMD5(filename) discard existsOrCreateDir(basepath / hashdir) discard existsOrCreateDir(basepath / hashdir / pagedir) basepath / hashdir / pagedir / (filenameHash & "-" & normalizeFilename(filename))```<@319753218592866315> is this ↑
gollark: There might also be a ROT13 button, if I feel like it.
gollark: Well, I was considering an option where you could use SQLCipher for data storage instead of SQLite.
gollark: Of course it does. It's important to know how susceptible your document is to frequency analysis if enciphered in certain ways.

References

  1. Egli, John J. (Oct 1957). "Radio Propagation above 40 MC over Irregular Terrain". Proceedings of the IRE. IEEE. 45 (10): 1383–1391. doi:10.1109/JRPROC.1957.278224. ISSN 0096-8390.

See also

Longley–Rice model

ITU terrain model

International telecommunication union

This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.