Distribution frame: Difference between revisions
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{{Short description| | {{Short description|Location at which telecommunications cables interconnect}} | ||
{{ | {{Primary sources|date=July 2008}} | ||
[[File:Distribution-frame-0a-messy.jpg|thumb| | [[File:Distribution-frame-0a-messy.jpg|thumb|upright|Unshielded twisted pair (copper) and optical fiber distribution frame]] | ||
[[File:Optical-fiber-distribution-frame-0a.jpg|thumb | [[File:Optical-fiber-distribution-frame-0a.jpg|thumb|An optical fiber distribution frame]] | ||
In [[telecommunications]], a '''distribution frame''' is a passive device which terminates cables, allowing arbitrary interconnections to be made. | In [[telecommunications]], a '''distribution frame''' is a passive device which terminates cables, allowing arbitrary interconnections to be made. | ||
For example, the | For example, the [[main distribution frame]] (MDF) located at a [[Telephone exchange|telephone central office]] terminates the cables leading to [[subscribers]] on the one hand, and cables leading to active equipment (such as DSLAMs and [[telephone switch]]es) on the other. Service is provided to a [[subscriber]] by manually wiring a [[twisted pair]] (called a jumper wire) between the telephone line and the relevant [[DSL]] or [[Plain old telephone service|POTS]] line circuit. | ||
In [[broadcast engineering]], a | In [[broadcast engineering]], a distribution frame is a location within an apparatus room through which all signals ([[Sound|audio]], video, or data) pass, with the ability to arbitrarily route and connect sources and destinations between studios and other internal and external points. Connections can either be [[Solder|soldered]], or made using terminal blocks. Because the frame may carry live broadcast signals, it may be considered part of the [[airchain]]. | ||
In [[data communication]], a '''building distribution frame''' (BDF) houses data switches, etc. | In [[data communication]], a '''building distribution frame''' ('''BDF''') houses data switches, etc. | ||
==Types== | ==Types== | ||
Distribution frames for specific types of signals often have specific | Distribution frames for specific types of signals often have specific initialisms: | ||
* DDF '''–''' [[Digital data|digital]] distribution frame | * DDF '''–''' [[Digital data|digital]] distribution frame | ||
* IDF '''–''' [[Intermediate distribution frame]] | * IDF '''–''' [[Intermediate distribution frame]] | ||
* MDF '''–''' [[Main distribution frame]] | * MDF '''–''' [[Main distribution frame]] | ||
* ODF or OFDF '''–''' [[optical fiber]] distribution frame<ref> | * ODF or OFDF '''–''' [[optical fiber]] distribution frame<ref>{{cite patent |country=US |number=7142765 |title=High Density Optical Fiber Distribution Frame }}</ref> | ||
* VDF '''–''' [[voice]] distribution frame | * VDF '''–''' [[voice]] distribution frame | ||
==Modernization== | ==Modernization== | ||
Distribution frames may grow to extremely large sizes. In major installations, audio distribution frames can have as many as 10,000 incoming and outgoing separate copper wires ([[balanced audio]] signals require two wires plus [[earth ground]] for each signal). Telephone signals do not use a separate earth ground wire, but some urban [[Telephone exchange|exchanges]] have about 250,000 wires on their | Distribution frames may grow to extremely large sizes. In major installations, audio distribution frames can have as many as 10,000 incoming and outgoing separate copper wires ([[balanced audio]] signals require two wires plus [[earth ground]] for each signal). Telephone signals do not use a separate earth ground wire, but some urban [[Telephone exchange|exchanges]] have about 250,000 wires on their MDF. Installing and rewiring these jumpers is a labour-intensive task, leading to attempts in the industry to devise so-called active distribution frames or [[Automated Main Distribution Frame]]s. The principal issues which stand in the way of their widespread adoption are cost and reliability. | ||
Newer [[Digital data|digital]] [[mixing console]]s can act as control points for a distribution frame or [[ | Newer [[Digital data|digital]] [[mixing console]]s can act as control points for a distribution frame or [[Router (computing)|router]], which can handle audio from multiple studios (even for multiple co-located [[Radio station|radio]] or [[Television station|TV]] stations) at the same time. Multiple smaller frames, such as one for each studio, can be linked together with fibre-optics (which also helps eliminate [[Ground loop (electricity)|ground loops]]), or with [[gigabit Ethernet]]. This has the advantage of not having to route dozens of feeds through walls (and sometimes floors and ceilings) to a single point. | ||
==See also== | ==See also== | ||
* | * {{Annotated link|66 block}} | ||
* | * {{Annotated link|Patch panel}} | ||
* {{Annotated link|Splicebox}} | |||
* | * {{Annotated link|Wiring closet}} | ||
* | |||
==References== | ==References== | ||
{{ | {{Reflist}} | ||
{{ | |||
==External links== | |||
* {{Commons category-inline|Distribution frames}} | |||
{{Authority control}} | {{Authority control}} | ||
[[Category:Broadcast engineering]] | [[Category:Broadcast engineering]] | ||
[[Category:Telephony equipment]] | [[Category:Telephony equipment]] | ||
Latest revision as of 23:10, 19 June 2025
Template:Short description Script error: No such module "Unsubst".
In telecommunications, a distribution frame is a passive device which terminates cables, allowing arbitrary interconnections to be made.
For example, the main distribution frame (MDF) located at a telephone central office terminates the cables leading to subscribers on the one hand, and cables leading to active equipment (such as DSLAMs and telephone switches) on the other. Service is provided to a subscriber by manually wiring a twisted pair (called a jumper wire) between the telephone line and the relevant DSL or POTS line circuit.
In broadcast engineering, a distribution frame is a location within an apparatus room through which all signals (audio, video, or data) pass, with the ability to arbitrarily route and connect sources and destinations between studios and other internal and external points. Connections can either be soldered, or made using terminal blocks. Because the frame may carry live broadcast signals, it may be considered part of the airchain.
In data communication, a building distribution frame (BDF) houses data switches, etc.
Types
Distribution frames for specific types of signals often have specific initialisms:
- DDF – digital distribution frame
- IDF – Intermediate distribution frame
- MDF – Main distribution frame
- ODF or OFDF – optical fiber distribution frame[1]
- VDF – voice distribution frame
Modernization
Distribution frames may grow to extremely large sizes. In major installations, audio distribution frames can have as many as 10,000 incoming and outgoing separate copper wires (balanced audio signals require two wires plus earth ground for each signal). Telephone signals do not use a separate earth ground wire, but some urban exchanges have about 250,000 wires on their MDF. Installing and rewiring these jumpers is a labour-intensive task, leading to attempts in the industry to devise so-called active distribution frames or Automated Main Distribution Frames. The principal issues which stand in the way of their widespread adoption are cost and reliability.
Newer digital mixing consoles can act as control points for a distribution frame or router, which can handle audio from multiple studios (even for multiple co-located radio or TV stations) at the same time. Multiple smaller frames, such as one for each studio, can be linked together with fibre-optics (which also helps eliminate ground loops), or with gigabit Ethernet. This has the advantage of not having to route dozens of feeds through walls (and sometimes floors and ceilings) to a single point.