Fechar
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
