Airspan AS4000, Installation Manual

Page: 125 / 193

Setup and Test
121
Setting RX sensitivity using DACU 2.0-2.3GHz & 3.4-3.6GHz
Band
(Test 6) If a DACU is not available use Setting RX Sensitivity without DACU
Preparation for commissioning at the Central Terminal
1. The DACU should be powered up and allowed to warm up for 30 mins to achieve
stability prior to setting the RX sensitivity. For details on setting up the DACU see
Connecting the DACU
2. Enter the loss values in the DACU calibration chart for the relevant frequency See
chart below.
3. Calculate/determine total path loss and required DACU output power and hence
power meter reading.
4. Connect cables and equipment as per diagram below
5. Ensure that the commissioning button is off. This should have been done at the end
of the TX Gain set-up but it is prudent to ensure that it has been switched off. Switching off
resets the DTU card, reactivates RW14&15 for link acquisition, and sets all RWs in service.
Note: The DTU card view shows all of the RW codes, and their current state within the system
(i.e. OOS or IS).
6. Create an ST on Netspan. See Netspan Section
7. Configure test ST using AS7020STMON according to modem shelf properties to the
correct frequency, PN code and ID number.
8.
Allow test ST to acquire link and net enter to “warm” state
9. Using the ST Line List, set loopback mode on both lines to enable 160k high rate
operation.
10. Measure the DACU o/p level
11. On Modem Shelf Properties, set RX gain to achieve required ST o/p level as
calculated in step 4 for
–
98dBm receiver sensitivity Adjust the 'RX Gain' by increasing and
decreasing the values.
12. Note: To start with, set the RX gain to around 2200. ( if value is reduced power goes
UP). The values may be set by typing in a new value or by using the up and down arrows at
the side of the box. The ST power changes in steps of approximately 0.7dB and the nearest
value to the required value. A single step on the gain value may not produce any change so
start with larger values and through a number of iterations home in on the correct setting.
Note: Levels are updated only when the OK button is clicked. Check the output power of the
DACU, and repeat until the output power matches that in the DACU Calibration Table.