User’s Manual for Node C Network Elements
Page 72
PRELIMINARY M0121A1A_uc.doc
5.2 FEATURES OF THE NODE C
5.2.1 Filters
Filters are set automatically according to the channels set in “Setup Wizard” or
“Technician Setup”. For further information about these menus refer to chapters
4.2.4.1
and
4.2.4.3
.
Possible filters are:
5 10
15
5
5
5
MHz
and
,
,
One
WCDMA
channel
two adjacent
WCDMA
channels
three
adjacent
WCDMA
channels
two
WCDMA
channels;
intermediate channel
not used
5.2.2 Digital ICE (Digital Interference Cancellation Equipment)
Digital ICE has been developed to enhance antenna isolation. This feature enables
the Node C to provide coverage in areas where effectivity is decreased due to
physical site limitations which cause insufficient antenna isolation.
Antenna isolation is the RF loss measured between the donor antenna and the
coverage antenna. If the gain of the network element exceeds the path loss,
feedback in form of oscillation occurs. The isolation is usually dominated by the direct
path loss from one antenna to the other, but reflections can contribute to or even
affect antenna isolation. Digital ICE cancels the signal from the primary feedback
path, thus allowing the gain of the network element to be increased.
The required delay resulting from the on-site conditions is measured by the DCM
module and set accordingly.
For software setting commands please refer to the online help screens.
The Digital ICE function can be enabled or disabled in the “Technician Setup” page
(see chapter
4.2.4.3
). Isolation and gain margin* can be checked in the “Status and
Reports” menu accessible via the home page of the web interface (see
figure 4-4
).
* gain margin = antenna isolation minus Node C gain
