Q2- Name and describe two examples of information,which are commonly
transmitted in digital form, but are pressented to users in analogue
form. use a diagram to show how this information is transformed and
transmitted as a digital signal.

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Request for Question Clarification by endo-ga on 09 Dec 2003 16:51 PST

Hi,

Are you looking specifically for answers in the wireless and mobile
world or would any domain be ok?

Thanks.
endo

Hi,

Thank you for your question.

Here are a couple of examples you are asking for.


1-) Digital phones such as DECT (Digital Enhanced Cordless
Telecommunications) use digital transmission methods, but present the
information to the user in analogue form. Analogue sound is generated
by the speaker, it goes through a microphone that transforms the sound
into electric signals, which are then processed by a DSP (Digital
Signal Processor) and transmitted digitally through air using
electromagnetic signals.

You can find more information about DECT here:

DECT forum
http://www.dect.org/

DECT DSP
http://www.dspg.com/dspg/dect.html

Phone diagram:
http://membres.lycos.fr/dbky/prankster/phonediagram.jpg



2-) A similar example is a wireless headphone. Sound is transmitted
digitally to the headphones and then transformed to analogue sound.

Amphony 2000 Digital Wireless Headphones 
http://shop.store.yahoo.com/hometheaterplus/am202wihe.html



3-) For Cable TV, analogue video tapes are digitized, then signals are
transmitted digitally over coaxial cable, then transformed using an RF
modulator within the digital tuner set-top box back into an analogue
signal, that can then be picked up by an analogue tuner and displayed
on an analogue TV.

TV Diagram:
http://membres.lycos.fr/dbky/prankster/TVdiagram.jpg


I hope this answers your question. If something is unclear, if you
require any more help or you require any clarifications, please do not
hesitate to ask.

Thanks.
endo