Check this URL:
 
        http://www.teleport.com/~samc/cable5.html
 
The first paragraph says:
 
There's a battle going on. It's ISDN vrs Cable Modems. Cable Modems are a
tricky engineering challenge. Noise is a big deal on the upstream; apparently
someone with a hair drier and a bad hair day could bring down the block.
Spread spectrum rather than dedicated frequencies might be one answer.
Standards need to happen, costs need to come down and guts for a $500 price
point might be as elusive as that of the $300 digitial settop. And, of
course, you
need two-way plant. But 28 Mb/s beats 28Kb/s (even with 100 people sharing
the line). Cable operators have committed to buying 500,000 modems. Already.
Plant upgrades are underway.
 
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Have fun moving bits (oops..., packets or datagrams) around...
 
+---------------+
|               |
|            r  |  Alfredo                     [log in to unmask]
|          e    |                           http://www.adager.com
|        g      |  F. Alfredo Rego               Tel 208 726-9100
|      a        |  Manager, Theoretical Group    Fax 208 726-2822
|    d          |  Adager Corporation
|  A            |  Sun Valley, Idaho 83353-3000            U.S.A.
|               |
+---------------+