15-6 Sensors and Sensor Technology
15.2.9 Message
A message is the fundamental, indivisible unit of information that is exchanged between stations. User-
meaningful
in
formation
wi
ll
be gr
ouped
in
to
on
e
or mo
re
me
ssages
by th
e
OS
I
ne
twork
re
ference
mo
del
.
15.2.10 Multiplexing
Multiplexing refers to the ability to use the media in a network to carry multiple messages or infor-
mation
st
reams
“si
multaneously
.” Mu
ltiplexed
sy
stems
al
low
se
veral
co
mmunication
ch
annels
to us
e
th
e
sa
me
ph
ysical
wi
re
or me
dia
. Ea
ch
me
ssage
or in
formation
st
ream
ma
y
ha
ve
di
erent
so
urces
an
d
de
stinations
. Mu
ltiplexing
ma
y
be ac
complished
usi
ng
a va
riety
of me
ans
. Ti
me
di
vision
mu
ltiplexing
(T
DM)
in
volves
br
eaking
ac
cess
to th
e
me
dia
in
to
a se
ries
of ti
me
qu
anta
. Du