Cisco Cisco Aironet 1310 Access Point Bridge Guida All'Installazione
41
Cisco Aironet 1300 Series Wireless Bridge Mounting Instructions
78-16136-02B0
Positioning a Directional Antenna
ENGLISH
Positioning a Directional Antenna
The goal when positioning a directional antenna is to align the local antenna for maximum received
signal strength using the LED indications. The LEDs are convenient and easy to use.
signal strength using the LED indications. The LEDs are convenient and easy to use.
Normally, you observe a single large peak as you pan the antenna across the signal path. However, if the
antennas are not well positioned during installation, you may observe two peaks of roughly equal
amplitude. Think of the receive signal as a target (see
antennas are not well positioned during installation, you may observe two peaks of roughly equal
amplitude. Think of the receive signal as a target (see
Figure 15
Signal Strength Target Showing Two-Peak Case
The target consists of concentric rings, with the strongest signal at the center, surrounded by a weak area,
and then a moderately strong side lobe. As you scan across the signal, you can miss the strong center
signal and encounter two peaks of roughly equal amplitude, as shown by the horizontal dashed line. If
you position the antenna on one of these weaker peaks and subsequently adjust the vertical position, you
miss the maximum signal area completely. Instead, you must locate the two peaks and center the antenna
between the peaks. The vertical scan then crosses the center point where the signal level is maximum.
and then a moderately strong side lobe. As you scan across the signal, you can miss the strong center
signal and encounter two peaks of roughly equal amplitude, as shown by the horizontal dashed line. If
you position the antenna on one of these weaker peaks and subsequently adjust the vertical position, you
miss the maximum signal area completely. Instead, you must locate the two peaks and center the antenna
between the peaks. The vertical scan then crosses the center point where the signal level is maximum.
Positioning the Antenna Using LED Indications
You can position the integrated antenna or a directional external antenna using the LEDs only after the
bridge successfully associates with the remote bridge. In installation mode, the Install LED is continuous
amber or green when the bridge has successfully associated. For the first 20 seconds following
association, the bridge reads the received signal strength indication (RSSI) levels from the received
packets and records the maximum value. After 20 seconds, the Ethernet, status, and radio LEDs on the
bridge indicate relative RSSI readings (see
bridge successfully associates with the remote bridge. In installation mode, the Install LED is continuous
amber or green when the bridge has successfully associated. For the first 20 seconds following
association, the bridge reads the received signal strength indication (RSSI) levels from the received
packets and records the maximum value. After 20 seconds, the Ethernet, status, and radio LEDs on the
bridge indicate relative RSSI readings (see
) compared to the maximum recorded during the
initial 20 seconds.
1
Medium signal level
3
Strong signal level
2
Weak signal level
4
Midpoint between peaks
Horizontal
Vertical
1
4
2
3
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