3.3.3 Line coding selection
As mentioned above, different TСРАМ line coding modes are used to
transmit data with different rates.
Chart 1
256 Kbps
192 Kbps
192 Kbps
64 Kbps
6016 Kbps
3840 Kbps
1216 Kbps
704 Kbps
0
1000
2000
3000
4000
5000
6000
7000
TCPAM32
TCPAM16
TCPAM8
TCPAM4
The
code cccc
option of the
dsl
command provides a way to select a
line coding mode of 4 available (ТСРАМ32, ТСРАМ16, ТСРАМ8 and
ТСРАМ4). It allows to select a proper mode in according to ratings of the
line.
: dsl code tcpam8
DSL: Rate=512 kbit/s Code=TCPAM8 MASTER – OFFLINE
:
As follows from Chart 1, many data rates allows to use
multiple line coding modes. Rule: apply a coding mode with
less positions (ТСРАМ8, ТСРАМ4) on a line exposed to high
level of noise; apply a coding mode with more positions
(ТСРАМ32, ТСРАМ16) if bandwidth is limited.
For automatic rate selection only the TCPAM16 line code is allowed.
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