Telecommunications link

From Wikipedia, the free encyclopedia

 This article has no lead section.
To comply with Wikipedia's lead section guidelines, one should be written.
Please discuss this issue on the talk page and read the lead section guide to make sure the introduction summarizes the article.
This article does not cite any references or sources. (April 2007)
Please help improve this article by adding citations to reliable sources. Unverifiable material may be challenged and removed.


"Uplink" redirects here. For the 2001 computer game by Introversion software, see Uplink (computer game). For the Half-Life demo, see Half-Life: Uplink.

Contents

[edit] Uplink

Look up uplink in
Wiktionary, the free dictionary.

An uplink (UL or U/L) is the portion of a communications link used for the transmission of signals from an Earth terminal to a satellite or to an airborne platform. An uplink is the inverse of a downlink. An uplink or downlink is distinguished from reverse link or forward link (see below).

  • Pertaining to data transmission from a data station to the headend.
  • Pertaining to GSM and cellular networks, the radio uplink is the transmission path from the Mobile Station (Cell Phone) to a Base Station (Cell Site). Traffic and signalling flows within the BSS and NSS may also be identified as uplink and downlink.

[edit] Downlink

Look up downlink in
Wiktionary, the free dictionary.

A downlink (DL) is the link from a satellite to a ground station.

[edit] Forward link

A forward link is the link from a fixed location (e.g., a base station) to a mobile user. If the link includes a communications relay satellite, the forward link will consist of both an uplink (base station to satellite) and a downlink (satellite to mobile user).

[edit] Reverse link

The reverse link (sometimes called a return link) is the link from a mobile user to a fixed base station.

If the link includes a communications relay satellite, the reverse link will consist of both an uplink (mobile station to satellite) and a downlink (satellite to base station) which together constitute a half hop.

See also: Backhaul (telecommunications) and Return channel

[edit] Sources