FACTOID # 180: Mali and Niger have 7 children born per woman, yet their populations grow at less than 3% per year.
 
 Home   Encyclopedia   Statistics   Countries A-Z   Flags   Maps   Education   Forum   FAQ   About 
 
 
 
WHAT'S NEW
RECENT ARTICLES
More Recent Articles »
 

SEARCH ALL

FACTS & STATISTICS    Advanced view

Search encyclopedia, statistics and forums:

 

 

(* = Graphable)

 

 


Encyclopedia > Duplexing

Duplex is the having of two principal elements or parts.


A duplex home is the US name for a particular type of housing; see Semi-detached.


A Duplex Lamp is a type of oil lamp.


Telecommunications

In telecommunications, duplex means "two-way" when referring to communications channels.

  • A simplex channel is a one-way channel.
  • A half-duplex channel is one that can carry information in both directions, but not at the same time.
  • A full-duplex channel is a channel which can carry information in both directions at once.

These terms also apply to early PC sound cards, however almost all are now full-duplex.


Where channel access methods are used for dividing forward and reverse communication channels on the same physical communications medium, they are known as duplexing methods, such as:

Usage in point-to-multipoint networks

In point to multipoint networks such as cellular networks, both TDD and FDD are used in communication between the base station and the mobile transmitter.


Time division duplex has a strong advantage in the case where the asymmetry of the uplink and downlink data speed is variable. As the amount of uplink data increases, more bandwidth can be allocated to that and as it shrinks it can be taken away. Another advantage is that the uplink and downlink radio paths are likely to be very similar in the case of a slow moving system. This means that techniques such as beam forming work well with TDD systems.


Frequency division duplex is much stronger in the case of symmetric traffic. In this case TDD tends to waste bandwidth during switchover from transmit to receive, has greater inherent latency, and may require more complex, more power-hungry circuitry.


  Results from FactBites:
 
Duplex (telecommunications) - Wikipedia, the free encyclopedia (678 words)
Duplex systems are employed in nearly all communications networks, either to allow for a communication "two-way street" between two connected parties or to provide a "reverse path" for the monitoring and remote adjustment of equipment in the field.
Time division duplex has a strong advantage in the case where the asymmetry of the uplink and downlink data speed is variable.
Frequency division duplex (FDD) is the application of frequency-division multiplexing to separate outward and return signals.
Intro to Duplex Stainless Steel; Tubing, pipe, fittings, flanges, round bar & plate (559 words)
Duplex Stainless steels were developed more than 70 years ago in Sweden for use in the sulfite paper industry.
Called Duplex because of its mixed microstructure with about equal proportions of ferrite and austenite, duplex stainless steels are a family of grades, which range in corrosion performance depending on their alloy content.
Duplex alloys are essentially a compromise possessing some of the ferritic stress corrosion cracking resistance and much of the superior formability of the common austenitic stainless alloys, at a cost saving over the high nickel alloys.
  More results at FactBites »


 
 

COMMENTARY     


Share your thoughts, questions and commentary here
Your name
Your comments

Want to know more?
Search encyclopedia, statistics and forums:

 


Lesson Plans | Student Area | Student FAQ | Reviews | Press Releases |  Feeds | Contact
The Wikipedia article included on this page is licensed under the GFDL.
Images may be subject to relevant owners' copyright.
All other elements are (c) copyright NationMaster.com 2003-5. All Rights Reserved.
Usage implies agreement with terms, 1022, m