AS W i p LL 900 MHz
Quick In stallation & Co nfigu ration Gu id e
13070311-02
Airspan Networks Inc.
23
Analyzing the RF Spectrum
Before setting up your wireless link between Base Station and subscribers, Airspan recommends analyzing
the RF spectrum at the
Base Station
to select only clear frequency channels (i.e. without interferences) for
building a frequency table for the wireless transmission.
Airspan recommends using frequencies that are approximately
28
,
20
, and
12
dB
above interference levels to
effectively operate in
8-
(4 Mbps/3 Mbps),
4-
(2 Mbps), and
2-level FSK
(1.33 Mbps/1 Mbps), respectively.
Notes:
1) Airspan’s Spectrum Analyzer feature, which plugs into WipConfig, is license-dependant.
2) Ensure all other ASWipLL devices are powered off, except the device whose spectrum you are analyzing.
3) Mount the ASWipLL device prior to commencing the spectrum analysis.
4) The spectrum analysis should be performed in continuous mode for at least 20 times. The longer you
perform the sweep, the more reliable results are obtained as interference in the ISM band can change
throughout the day or change rapidly (e.g. in frequency hopping systems).
5) To ensure locating clear frequencies, continually narrow down the sweep frequency range. For example,
first sweep a large frequency range. Once you have selected a clear area from this initial sweep, run another
batch of sweeps concentrating on these selected frequencies. The fewer frequencies the more reliable the
analysis for capturing bursty, intermittent transmitters (e.g. pagers).
6) When using external antenna, ensure correct Antenna Gain is defined with consideration to RF cable loss.
7) As interference depends on geographical locations, it is recommended to perform spectrum analysis at the
CPE location when installing the ASWipLL IDR device.
9.1. Accessing the Spectrum Analyzer
You can access the Spectrum Analyzer through either a serial or an IP network communication mode.
To access the Spectrum Analyzer:
1. Start WipConfig and then connect WipConfig to the BSR by performing one of the following:
Serial mode:
on the toolbar, select the
Serial
option, and then click
Connect
.
IP mode:
on the toolbar, select the
Network
option, and then in the
Remote Agent
field, enter the
ASWipLL device's IP address, and then click
Connect
.
2. In the Outlook bar, click the
Spectrum Analyzer
button; A message box appears informing you that
the device will lose connection with all other devices.
3. Click
OK
.
9.2. Setting up the Spectrum Analyzer
Before you can start analyzing the spectrum, you need to define various parameters in the Spectrum Analyzer.
To set up the Spectrum Analyzer:
1. Ensure the
Setup
tab (located in the top-right pane) is selected.
2. In the
Refresh Rate
field, enter the rate (in seconds) for polling the BSR/PPR. (The default is 3 sec;
maximum is 3600 sec.)
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