Telecommunications link

Telecommunications link
"Uplink" redirects here. For other uses, see Uplink (disambiguation).

A telecommunications link is generally one of several types of information transmission paths such as those provided by communication satellites to connect two points on earth.

Contents

Uplink

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.

This is similar to the general computer network concept of the upstream direction.

Downlink

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

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

This is similar to the general computer network concept of the downstream direction.

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).

Reverse link

The reverse link (sometimes called a return channel) 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

Sources

See also


Wikimedia Foundation. 2010.

Игры ⚽ Поможем написать реферат

Look at other dictionaries:

  • Link — may refer to:ComputingInternet* Links (web browser), a web browser for Unix like systems * Reciprocal link, two way links to and from websites, also known as link swaps , link exchanges and link partners * Hyperlink, a reference in a hypertext… …   Wikipedia

  • TÉLÉCOMMUNICATIONS - Téléactivités — La notion de téléactivité englobe toute forme de travail à distance «médiaté», c’est à dire opéré par voie de télécommunications. Elle concerne les activités du secteur tertiaire dont l’objet est de manier, traiter, produire et/ou transmettre de… …   Encyclopédie Universelle

  • Telecommunications — Télécommunications Alexander Graham Bell Les télécommunications sont définies comme la transmission à distance d’informations avec des moyens à base d électronique et d informatique. Ce terme a un sens plus large que son acception équivalente… …   Wikipédia en Français

  • Telecommunications in East Timor — Telecommunications Democratic Republic of Timor Leste …   Wikipedia

  • Telecommunications in Mauritius — Telecommunications had an early beginning in Mauritius, with the first telephone line installed in 1883, seven years after the invention of the telephone. Over the years, the network and telephony improved. By the late 20th century, the rapid… …   Wikipedia

  • Telecommunications in South Africa — Telecommunications infrastructure in South Africa provides modern and efficient service to urban areas, including cellular and internet services. In 1997, Telkom, the South African telecommunications parastatal, was partly privatised and entered… …   Wikipedia

  • Telecommunications in Uzbekistan — Telecommunications Republic of Uzbekistan …   Wikipedia

  • Telecommunications Services of Trinidad and Tobago — Limited (generally known as TSTT) is the largest telephone and Internet service provider in Trinidad and Tobago. The company, which is jointly owned by the Government of Trinidad and Tobago and Cable Wireless, was formed out of a merger of Telco… …   Wikipedia

  • Link adaptation — Link adaptation, or adaptive coding and modulation (ACM), is a term used in wireless communications to denote the matching of the modulation, coding and other signal and protocol parameters to the conditions on the radio link (e.g. the pathloss,… …   Wikipedia

  • Telecommunications in Cuba — consists mainly of NTSC analog television, analog radio, telephony, AMPS, D AMPS, and GSM mobile telephony, and the Internet. Telephone service is provided through ETECSA, mobile telephone service is provided through the Cellular Telephone… …   Wikipedia

Share the article and excerpts

Direct link
… Do a right-click on the link above
and select “Copy Link”