Anritsu Spectrum Master MS2720T User Manual page 855

ООО "Техэнком" Контрольно-измерительные приборы и оборудование
3-6 EVDO Over-The-Air Measurement Setup
3-6 EVDO Over-The-Air Measurement Setup
OTA (over-the-air) testing provides field technicians with the ability to monitor hard-to-reach
pole-top base stations. Traditionally, the repair process for pole-top base stations entailed
pulling down the failed base station, then installing a new one. The failed base station was
then returned to the manufacturer or repair depot for service. If a base station was
determined to be healthy (a no trouble found (NTF) event), then the cost of the process was
incurred unnecessarily. OTA testing provides information about the health of the base
station, thereby improving the likelihood that a correct decision will be made with regard to
the base station. The result is fewer NTFs and elimination of their associated costs.
If you choose to measure EVDO performance over the air with an antenna, then additional
setup is required, as explained in the setup section. The instrument needs a timing reference
in order to determine PN Offset and timing errors. This reference comes from the base station
GPS when it is connected to the instrument, or it can be recovered from GPS when a GPS
antenna is connected.
To make EVDO OTA measurements, connect the instrument to the base station and perform
the following setup procedure:
1. Press Freq main menu key then press the Channel submenu key and use the Up/Down
arrow keys, the keypad, or the rotary knob to select a channel number for the selected
signal standard. The center of the channel is tuned to the center of the display.
2. Press the Setup main menu key to open the Setup menu.
3. Press the PN Setup submenu key and choose GPS. Follow the setup instructions
"GPS Setup" on page
4. Press the PN Search Type submenu key and select Auto.
5. Press the Setup main menu key then press the Walsh Codes submenu key to toggle
between 64 codes and 128 codes depending upon the transmitting signal.
64 Walsh Codes can be displayed when the unit is in 128 code mode. The Walsh
Note
Codes will be repeated on the measurement screen.
6. Press the Measurements key to open the measurements menu.
7. Press the OTA submenu key to activate Over-The-Air measurements.
3-12
2-3.
PN: 10580-00235 Rev. D
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EVDO Signal Analyzer
3GPP2 MG