1. Modem description
The Sigrand SG-16G2 modem is a SНDSL-modem. It features two E1
system interfaces (ITU-T G.703/G.704, 2048 kbps) and is intended to be
used as a line termination unit of TDM-based communication equipment.
The modem allows to make connections between devices equipped with E1
interfaces such as telco equipment, routers and access servers.
The key feature of the modem is the capability to transmit two Е1 trunks
through a single SHDSL interface.
Features of the ТСРАМ line coding:
The ТСРАМ line coding used by G.991.2 (G.SHDSL) compatible modems
has a few modes. The modes differ in complexity of coding algorithm. The
modes with larger number of modulation positions (ТСРАМ16, ТСРАМ32)
are applicable for higher rates, the modes with less number of modulation
positions (ТСРАМ4, ТСРАМ8) are applied for lower rates. Respectively, the
more complicated the coding algorithm the worse the channel noise
immunity and vice versa.
So take special attention to the ТСРАМ line coding algorithm selection while
configuring the line rate. It may be necessary to change the line coding to
achieve the best result.
Table 1 shows the line coding options and respective data rate ranges.
Table 1
Line coding
Data rate range (kbps)
TCPAM32
256 – 4096
TCPAM16
192 – 3840
TCPAM8
192 – 1216
TCPAM4
64 – 704
Manual line coding selection is available only in the console
management mode – see chapter 3 of this Guide.
Compatibility:
The Sigrand SG-16G2 modem line coding is compatible with all Sigrand
SG-16 series and Granch SBNI16 series modems.
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