Differences between current version and predecessor to the previous major change of BroadBand.
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Newer page: | version 6 | Last edited on Sunday, August 17, 2003 12:58:42 pm | by zcat(1) | |
Older page: | version 4 | Last edited on Saturday, August 16, 2003 4:10:42 pm | by zcat(1) | Revert |
@@ -1,24 +1,13 @@
-A Frequency Division Multiplex'd
communications channel.
+A frequency division multiplexed
communications channel, ie one that uses different parts of the frequency spectrum for different signals
.
-See also Dictionary:Broadband
+Normal phone service uses approximately 300Hz-3.2KHz for voice signal, 75V at 20Hz for ringing, and a DC loop current to signal on/offhook and supply a small amount of power to subscriber equipment. However, a pair of copper wires can carry frequencies far above 4KHz. [ADSL] exploits this extra [Analog] BandWidth to carry analog-encoded data between the subscriber and telco without interfering with normal phone service.
-Compare BaseBand
+U.S.Robotics also has a good description of [how ADSL works|http://www.usr.com/education/bb2.asp]
+and a glossary of [broadband related terms|http://www.usr.com/education/broadbandglossary.asp]
-----
-(From old Broadband node)
-A nice fast connection to the [Internet], for some reason defined as 128kb by [TelecomNZ].
-Technically BroadBand
means that the signals are converted
to analog then transmitted then converted back to digital signals at the other end
. BaseBand is defined as signals being transmitted digitally. The technical definition has no limits on speed. A "56k modem" would be BroadBand while
[10BaseT
] is BaseBand. Of course this has somehow been corrupted by general use, so everyone thinks "!BroadBand" means >
128k. People are weird
.
+The term has long become synonymous with fast, high-bandwidth networking, regardless of the
means to achieve it
. [TelecomNZ
] uses it to describe
128k connections
.
-----
-Sorry to nitpick, but most of the references I've seen (Network Engineering stuff, the dictionary link above, [WikiPedia|http
://www.wikipedia.org/wiki/
Broadband], etc..) say that broadband refers to using different parts of the frequency spectrum for different signals.
+See also Dictionary
:Broadband
-They also acknowledge that BroadBand has become synonymous with fast, high-bandwidth networking.
-
-Normal phone service uses approximately 300Hz-3.2KHz for voice signal, 75V at 20Hz for ringing, and a DC loop current to signal on/offhook and supply a small amount of power to subscriber equipment.
-
-A pair of copper wires, however, can carry frequencies far above 4KHz. ADSL uses this extra Analog BandWidth to carry analog-encoded data between the subscriber and teleco without interfering with normal phone service.
-
-
-
-You could argue that POTS is already broadband since it uses loop current to signal when the line is in use.. but that's really stretching the definition.
+Compare BaseBand