Cable
Modem Theory
Written by: Rolf V. Østergaard |
InfoRanger
Cable Modem by Samsung
|
CMI & CMZ
3Com Cable Modem |
DCM105
Cable Modem by Thompson |
UBR904
Cable Modem by Cisco |
PCX-1000
Cable Modem by Toshiba
|
SB2100
Cable Modem by General Instrument |
This
Cable Modem tutorial is designed to answer most questions about Cable Modems and the
associated technology. Somehow I just got tired explaining the same stuff again and again.
Now it is on-line and we can start our conversation at a level past the most basic stuff.
Assumptions
This presentation deals mainly with what I term
2nd generation Cable Modems. As from the following definition:
- 1st generation
Proprietary systems. Not based on widely
accepted standards. Cable Modems from different vendors does not work on the same
CMTS/Head-End. This includes among others the first Com21 systems.
- 2nd generation
Systems based on standards. MCNS/DOCSIS 1.0/1.1
(US etc.) and DVB/DAVIC 1.3/1.4/1.5 (Europe). Cable Modems from different vendors work
together (or can be made work together). This is the systems that are shipping right now
(98/99).
- 3rd generation
Time will tell. Maybe IEEE will play a role
here.
- Also this presentation deals only with "real" Cable
Modems (as in "real men" :-), that does two-way communications on the cable.
That excludes the telephone modem return systems, although most of the presentation
applies to these systems as well. I do accept that telephone return systems are quite
important as a step on the migration path towards "real" Cable Modem systems.
But from my (very) technical viewpoint, they are not quite as interesting.
|