TDMA
TDMA is the access method used by the
Electronics Industry Alliance
and the
Telecommunications Industry Association
for
Interim Standard 54
(IS-54) and
Interim Standard 136
(IS-136). Using TDMA, a
narrow band
that is 30 kHz wide and 6.7 milliseconds long is split time-wise into
three time slots.
Narrow band means "channels" in the traditional sense. Each conversation
gets the radio for one-third of the time. This is possible because voice
data that has been converted to digital information is compressed so
that it takes up significantly less transmission space. Therefore, TDMA
has
three times the capacity
of an analog system using the same number of channels. TDMA systems
operate in either the
800-MHz
(IS-54) or
1900-MHz
(IS-136) frequency bands.
|
TDMA splits a frequency into time slots. |
To read about any of the technologies click on the blue links
2G cell-phone networks
for transmitting information (we'll discuss
3G technologies in the 3G section):
·
Frequency division multiple access
(FDMA)
·
Time division multiple access
(TDMA)
·
Code division multiple access
(CDMA)
