romans establish postal services

first printing press

First daily news paper

recieves first patent for typewriter

invents morse code

invents the first long distance electric telegraph line

patents the electric telephone

invented the first telephone

patents the first fax machine

patents the direct dial telephone/automatic telephone exchange

first words from the telephone

improves wireless telegraphy

-transmits radio signals from cornwall to newfoundland
-first radio signal across atlantic ocean

electronic amplifying tube or triode

am radio broadcasting

-television or iconoscope (cathode ray tube)
-first television camera

radio astronomy discovered

FM radio

RADAR and SONAR perfected

inevented transistor

cable tv (community antenna) first appears

computers are first solf commercially

Integrated circuit

introduction to first communication satellite

the first internet started

floppy disk invented

first cellular phone comm network started in japan

-IBM PC first sold
-first laptop computers sold to public

IBM PC AT released

GPS used commercial and personal applications

Am govt releases controll of internet and www is born - making comm at light speed

30-300Hz

300-3000Hz

3-30khz

30-300khz

300-3000khz

3-30mhz

30-300mhz

300-3000mhz

3-30ghz

30-300ghz

300-3000ghz

3-30thz

30-300thz

300-3000thz

3-30Phz

30-300phz

300-3000phz

3-30Ehz

basic process of exchanging info

basic components of electronic communication

unwanted signal produced by atmsphre

to convert the info into a suitablr signal over a medium

to convert the sgnal back to original info

the medium by which the electronic signal is transmitted from 1 place to another

two types of comm

continiously varying signsal

has only two distinct levels high and low

transmission of orig signal wo modulation

portion of frequency range occupied by th signal