Luke,
Not in five lines... and I'm not sure I entirely understand
your question... but let me take a stab at it.
CDMA (Code Division Multiple Access) is one of the three
approaches to "multiple access"... that is, means for
multiple uses to share the airwaves at the same time.
The other two approaches are TDMA (Time Division Muliple
Access) and FDMA (Frequency Division Multiple Access).
In TDMA, each user gets his own assigned time slice when
he is allowed to transmit. In FDMA, each user gets his own
assigned frequency band in which he is allowed to transmit.
In CDMA, each user gets his own assigned "code" which he
uses to transmit... although the various users transmit
at the same time and in the same frequency band, they
use different "codes" and this minimizes mutual interference.
There are various pros and cons to these different multiple
access technologes... and their use can be mixed in various
ways as well... but in the end, they are all just different
methods of slicing up the same pie. [One can also consider
SDMA (Space Division Multiple Access) as a fourth approach
whereby user transmit signals are geographically separated,
either through clever beamforming techniques or simply by
being in different well-separated locations, so that they
don't interfere with one another.]
Anyway, CDMA is popular for use in mobile phone networks
and it appears it will supplant TDMA eventually.
Mobile phone networks are one of the three major markets
for STXN; see my transcript (Part 3) of the recent conference
call in which Chuck Kissner reviews their major markets.
In these networks, the user's voice signal must first
be carried to a cell base station (using CDMA or TDMA
or whatever)... then the signal must be carried from
the cell base station to the central office. STXN's
products are used for this latter "backhaul" purpose
where they compete with land-lines... the advantages
of wireless over land-lines include (1) faster network
build-out, and (2) lower capital cost. The fact is, its
terribly time-consuming and expensive to install land-lines.
One must obtain rights-of-way, dealing with numerous local
authorities, and then dig trenches or whatever to install
land-lines... for wireless backhaul, you simply install
a transmitter/receiver pair and turn the switch to "on".
Of course, STXN's products also carry the voice (and, more
recently, data) signals in the other direction, from the
central office to the base station, as well.
So as network operators expand their mobile networks,
whether they use CDMA or TDMA or whatever, and as the
capacity requirements of these networks grows (due to
adding data transmission to voice transmission), their
backhaul requirements grow and they rush out to buy
STXN's high-capacity spectrally-efficient products
to meet these growing needs.
Hope that helps,
Rob |
