Analog transmission

Analog transmission

Analog transmission is a method of conveying voice, data, image, signal or video information using a continuous signal which varies in amplitude, phase, or some other property in proportion to that of a variable.

Description

Modes of transmission

Analog transmission can be conveyed in many different fashions:

* twisted-pair or coax cable
* fiber-optic cable
* Via air
* Via water

There are two basic kinds of analog transmission, both based on how they modulate data to combine an input signal with a carrier signal. Usually, this carrier signal is a specific frequency, and data is transmitted through its variations. The two techniqes are amplitude modulation (AM), which varies the amplitude of the carrier signal, and frequency modulation (FM), which modulates the frequency of the carrier.The Froehlich/Kent Encyclopedia of Telecommunications By Allen. Kent, Froehlich E. Froehlich.1991 Marcel Dekker. ISBN 0824729005]

Types of analog transmissions

Most analog transmissions fall into one of several categories. Until recently, most telephony and voice communication was primarily analog in nature, as was most television and radio transmission. Early telecommunication devices utilized analog-to-digital conversion devices called modulator/demodulators, or modems, to convert analog data to digital data and back.

Benefits and drawbacks

Analog transmission is still very popular, in particular for shorter distances, due to significantly lower costs and complex multiplexing and timing equipment is unnecessary, and in small "short-haul" systems that simply do not need multiplexed digital transmission.Telecommunication System Engineering By Roger L. Freeman.2004 John Wiley and Sons. ISBN 0471451339]

However, in situations where a signal often has high signal-to-noise ratio and can't achieve source linearity, or in long distance, high output systems, analog is unattractive due to attenuation problems. Furthermore, as digital techniques continue to be refined, analog systems are increasingly becoming legacy equipment.

Recently, some nations, such as the Netherlands, have completely ceased analog transmissions on certain media, such as television, [http://www.dslreports.com/shownews/80237 Netherlands Ends Analog Transmission - Goodbye antenna, hello digital... - dslreports.com ] ] for the purposes of the government saving money.http://www.nytimes.com/aponline/technology/AP-Netherlands-TV.html?_r=2&oref=slogin&oref=slogin]

ee also

*Analog signal
*Analog television
*Analog to digital converter
*modulation
*signal

References


Wikimedia Foundation. 2010.

Игры ⚽ Поможем написать курсовую

Look at other dictionaries:

  • analog transmission — analoginis perdavimas statusas T sritis automatika atitikmenys: angl. analog transmission vok. Analogübertragung, f rus. аналоговая передача, f pranc. transmission analogique, f …   Automatikos terminų žodynas

  • analog transmission — WikiB The broadcasting of a signal using an analog recording. Examples of use include radio …   Audio and video glossary

  • analog transmission —    A signaling technology in which sound waves or other information are converted into electrical impulses of varying strengths. See also digital signal …   IT glossary of terms, acronyms and abbreviations

  • Analog — or analogueref|cwe may refer to: * (1): Analog signal, a variable signal continuous in both time and amplitude (as opposed to digital or discrete, e.g. analog wristwatch vs digital wristwatch) **Analog circuits, circuits which use analog signals… …   Wikipedia

  • Analog television — Analog (or analogue) television encodes television picture and sound information and transmits it as an analog signal: one in which the message conveyed by the broadcast signal is a function of deliberate variations in the amplitude and/or… …   Wikipedia

  • transmission analogique — analoginis perdavimas statusas T sritis automatika atitikmenys: angl. analog transmission vok. Analogübertragung, f rus. аналоговая передача, f pranc. transmission analogique, f …   Automatikos terminų žodynas

  • analog/digital converter —    A device that converts an analog transmission signal into digital format …   IT glossary of terms, acronyms and abbreviations

  • Analog Rebellion — Background information Origin Aledo, Texas, United States Genres …   Wikipedia

  • analog — [an′ə lôg΄, an′əläg΄] adj. 1. of a system of measurement in which a continuously varying value, as sound, temperature, etc., corresponds proportionally to another value, esp. a voltage 2. of or by means of an analog computer 3. of or having to do …   English World dictionary

  • Analog high-definition television system — Historically the term high definition television was first used to refer to television standards developed in the 1930s to replace early experimental systems with as few as 12 lines. Not so long afterwards John Logie Baird, Philo T. Farnsworth… …   Wikipedia

Share the article and excerpts

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