sender receiver medium
communications network
signals
telephone audio
analog
analog loud
greater quieter
frequency
Hz
frequency
kHz
Hertz
kHz
cycles second
lower less
on
digital binary
analog
digital
demodulation digital
duplex
does not
half-duplex
second receive
simplex half-duplex full duplex
binary
synchronous
synchronization character
data
frame
asynchronous
stop
start stop
16
500000
40
1004
16
64
32064
eight bits 256512
106.88
asynchronous
asynchronous
media
telephone twisted pair
Ethernet twisted pair
coaxial
802.11g