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© Tieline Research Pty. Ltd. 2020
Genie Distribution WNET Manual v3
13
About POTS Modules
The Tieline POTS G5 module can be used in the codec to stream
high quality audio over a POTS (PSTN) phone line. The codec has
two module slots available and it is possible to insert one or two
POTS G5 modules, or a mix of POTS G5 and ISDN G5 modules
as required. The Tieline Music algorithm can deliver 15 kHz
quality bi-directional audio at bit rates as low as 24kbps over a
POTS connection.
Modem Negotiation and Line Quality
The codec can send and receive high-speed digital information over a standard POTS telephone line
via the modem in the POTS G5 module.
G5 POTS modems initially attempt to establish a link at the lowest
Max Bit rate
setting configured
in the two modules being connected. If the POTS line doesn't support this bit rate, the modems will
attempt to connect at the highest possible bit rate to suit the prevailing line quality at each end of
the link. The modem then perform a process called ‘training’, during which the codecs at each end
of the link analyze the line. The codecs will then 'renegotiate' the link downwards to the highest
possible bit rate where line quality is greater than 70%.
The POTS G5 module contains a SmartDAA™ (Smart Data Access Arrangement) line interface,
which isolates the modem from voltages on phone lines. It is important to select the correct country
in the codec from which you are dialing. This allows the SmartDAA to automatically adjust for the
line voltage present in that country.
Important Note:
It is possible to connect two concurrent POTS connections, however the
codec will not bond two POTS connections.
Connecting to G3 Codecs using POTS
The codec will successfully connect to Tieline Commander G3 and i-Mix G3 codecs over POTS.
These Tieline G3 codecs may use:
·
POTS
modules (older superseded version)
·
POTS G3
modules (current version)
Connecting to POTS G3 Modules
POTS G3 modules operate in the same way as POTS G5 modules when connecting, e.g. they
establish a link at the default bit rate of 28.8kbps and then 'renegotiate' the link downwards to
the highest possible bit rate where line quality is greater than 70%.
Connecting to Legacy POTS Modules in G3 Codecs
These modules have slightly different characteristics when connecting. When dialing from a
POTS G5 module to these older POTS modules the codecs will attempt to connect initially at
19.2kbps. If line quality is above 80% at this bit rate then the codec will ‘retrain’ the connection
up to a maximum of 28,800bps (depending on modem handshaking). The codec will then
renegotiate the link downwards to the highest possible bit rate where line quality is greater than
70%.