Narrow Band Version; Applications For Narrow Band Devices - Siemens SWT-3000 Equipment Manual

Functional Description

Narrow band version

Application:
Frequency space:
SWT unit:
Multi-purpose:
Alternate multi-purpose: Use in conjunction with PLC transmission is not possible in alternate
Channel 4:

Applications for narrow band devices:

4-wire connections
Page - 14
Equipment in the narrow band version can be operated on VF links and
over CF and radio relay routes. Security against impulse noise and inter-
ference voltages is somewhat lower than with the broadband version.
The wanted frequencies are closer together in this equipment version. As
a result up to three of the 4 possible channels (channel 1, 2, 3) can be
operated simultaneously within an ITU-T voice band of 3.1 kHz band-
width (0.3 ... 3.4 kHz).
Each of these channels requires a separate SWT 3000 unit. There is
space for accommodating two SWT 3000 units in an equipment frame.
These two units are totally independent from one another and no compo-
nents are shared.
Use in conjunction with PLC transmission is possible in multi-purpose
operation. However, a smaller range (transmit level distribution for all
services) and less security against interference must be expected com-
pared with the broadband version.
multi-purpose operation.
Channel 4 can be used with a 4 kHz frequency space. Its position in the
VF frequency band is defined so that it is operated in the upper half of the
transmission bands 2.67 ... 3.7 kHz (voice band limitation 2.4 kHz with pi-
lot 2.58 kHz) and 2.1 ... 3.6 kHz (voice band limitation 2.0 kHz with pilot
3.78 kHz). In the second case another four 50 Bd WT channels can be
accommodated between the voice band and channel 4.
The operation of several units in parallel at a connection is possible by
using narrow band devices.
SWT 3000
NB1
T
R
SWT 3000
NB2
T
R
Figure 6: Parallel connection of several SWT 3000 units at one connection
Edition p3_3_2x 08/09
SWT 3000 Equipment Manual
SWT 3000
NB1
R
T
SWT 3000
NB2
R
T
© SIEMENS AG 2008