User Guide for FibeAir® IP-20 All-Outdoor Products, CeraOS 10.5
Page 486 of 825
Ceragon Proprietary and Confidential
To disable XPIC, enter the following commands:
root> radio-groups
radio-groups>
radio-groups> xpic set admin disable
14.5.4
Performing Antenna Alignment for XPIC (CLI)
To configure the antennas:
1 Align the antennas for the first carrier. For a 2+2 XPIC configuration (or a 4x4
MIMO configuration), align the antennas for the first carrier on the upper IP-
20C or IP-20C-HP units. While you are aligning these antennas, mute the
second carrier. See
Configuring the Radio Parameters (CLI)
. For a 2+2 XPIC
configuration (or a 4x4 MIMO configuration), mute all the carriers except the
first carrier on the upper IP-20C or IP-20C-HP units.
2 Adjust the antenna alignment until you achieve the maximum RSL for the first-
carrier link (the “RSL
wanted
”). This RSL should be no more than
+/-2 dB from the expected level. Record the RSL of the first carrier as the
RSL
wanted
.
3
Measure the RSL of the second carrier and record it as the “RSL
unwanted
”.
Note:
To measure the second carrier, leave the Voltmeter connected to the
BNC connector. In the Radio Parameters page of the Web EMS
(
), change the
RSL Connector Source
field from
PHYS1
to
PHYS2
(or vice versa). The BNC connector will now measure RSL from
the other carrier.
4 Determine the XPI, using either of the following two methods:
◦
To calculate the XPI, subtract RSL
unwanted
from the RSL
wanted
.
◦
Read the XPI by going to radio view and entering one of the following
commands:
radio [x/x]>modem pm-xpi show interval 15min
radio [x/x]>modem pm-xpi show interval 24hr
5 The XPI should be between 25dB and 30 dB. If it is not, you should adjust the
OMT assembly on the back of the antenna at one side of the link until you
achieve the highest XPI, which should be no less than 25dB. Adjust the OMT
very slowly in a right-left direction. OMT adjustment requires very fine
movements and it may take several minutes to achieve the best possible XPI.
Note:
As an extra step, to check the veracity of the initial measurements, you
can mute the first carrier and unmute the second carrier on the upper
IP-20C or IP-20C-HP units on both sides of the link. Then measure the
RSL of the second carrier link (the “RSL
wanted
”), measure the RSL of the
first carrier (the “RSL
unwanted
”) and determine the XPI. The XPI should
match the XPI with the second carriers muted.
6 Unmute all the carriers and check the RSL levels of all the carriers on both
sides of the link. The RSL of the horizontal carrier of the local unit should
match the RSL of the vertical carrier of the remote unit, within ±2dB. The RSL
of the vertical carrier of the local unit should match the RSL of the horizontal
carrier of the remote unit, within ±2dB.
