Basic Telecommunication

8/9/2019 Basic Telecommunication

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Telecommunication


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Simplex: A paeris a wireless telecommunications device that

receives and displays numeric or text messaes, or receivesand announces voice messaes. !ne-way paerscan only

receivemessaes,


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HA"F-#$%"&' A half-duplex(H#') system provides communication in both directions,

but only one direction at a time (not simultaneously). Typically, once a

party beins receivin a sinal, it must wait for the transmitter to stop

transmittin, before replyin (antennas are of trans-receiver type in these

devices, so as to transmit and receive the sinal as well).

An example of a half-duplex system is a two-party system such as awal*ie-tal*ie, wherein one must use +!ver+ or another previously

desinated command to indicate the end of transmission, and ensure that

only one party transmits at a time, because both parties transmit and

receive on the same freuency.


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F$"" - #$%"&' A full-duplex(F#'), or sometimes double-duplexsystem, allows

communication in both directions, and, unli*e half-duplex, allows this

to happen simultaneously. "and-line telephone networ*s are full-

duplex, since they allow both callers to spea* and be heard at the

same time, the transition from four to two wires bein achieved by a

hybrid coil. A ood analoy for a full-duplexsystem would be a two-lane road with one lane for each direction.

n full-duplex mode, data you transmit does not appear on

your screen until it has been received and sent bac* by the other

party.


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/&""$"A0 1& 2!03S

Overview

Data Rates

1G(


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/ellular networ*s: From 45 to 65

1G! "irst #e$erati$ wire%ess &e%%'%ar! ar% 1980s *$a%# tra$s+issi$, pri+ari% spee&! *M/ (*va$&e

Mbi%e $e /ste+s) a$ ters

2G! /e&$ #e$erati$ wire%ess &e%%'%ar! ate 1980s Di#ita% tra$s+issi$

ri+ari% spee& a$ %w bit-rate ata (9.6 Kbps) i#-tier! G/M, /-95 (DM*), et& w-tier (/)! w-&st, %w-pwer, %w-+bi%it e.#. */

2.5G! 2G ev%ve t +ei'+ rate (< 100bps) ata 3G! 't're 7raba$ +'%ti+eia

144 bps - 384 bps r i#-+bi%it, i# &vera#e 2 Mbps r %w-+bi%it a$ %w &vera#e

7e$ 3G! resear& i$ 4G


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OMM:;*

'b%i&/wit&ee%ep$e

;etwr(/;)

Mbi%ee%ep$e/wit&i$#

e$ter(M/)

7ase ra$s&eiver /tati$ (7Mbi%e :ser

e%% 1

e%% 2

r%ess &$$e&ti$

ire &$$e&ti$

R R

R = +e &ati$ Re#ister

R = isitr &ati$ Re#ister


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"re>'e$& Re'se

e%%s wit tesa+e $'+berave te sa+e

set re>'e$&ies


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Freuency Spectrum

Focus !n:

HF 7 Hih Freuency(3-30MHz

) 8HF 7 8ery Hih Freuency (30-300 MHz)

$HF 7 $ltra Hih Freuency (300MHz - 3 GHZ)

"ower 9icrowave Freuencies

Basic Telecommunication

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