User's Manual

Installing and Connecting an MP-622
Installing an MP-622
MP-622 Installation Guide
3 – 14
Aligning Antennas for Bridge or Mesh Links
If you are installing MP-622 units for wireless bridge or Mesh Services operation, after the units
have been mounted, connected, and the radios are operating, the antennas must be accurately
aligned to ensure optimum performance on the bridge or mesh links.
This alignment process is particularly important for long-range point-to-point links. In a
point-to-multipoint configuration, the Mesh Portal AP uses an omnidirectional or sector antenna,
which does not require alignment, but Mesh APs still need to be correctly aligned with the Mesh
Portal antenna.
Point-to-Point Configurations – In a point-to-point configuration, the alignment process
requires two people at each end of the link. The use of cell phones or two-way radio
communication may help with coordination. To start, you can just point the antennas at each
other, using binoculars or a compass to set the general direction. For accurate alignment,
monitor the RSSI’s LED indicator as you move the antenna horizontally and vertically.
Point-to-Multipoint Configurations – In a point-to-multipoint configuration all Mesh APs
must be aligned with the Mesh Portal antenna. The alignment process is the same as for
point-to-point links, but only the Mesh AP end of the link requires the alignment.
The LEDs are viewed right to left as you look at the back of the MP. The range from 1 to 12 will
cover the signal range to accurately align the antenna. The signal strength LEDs indicate the
received radio signal strength for a particular bridge link. The more LEDs that turn on, the
stronger the signal. (RSSI level 1 should equate to the lowest useful signal). Alternatively, you can
monitor the Receive Signal Strength Indicator (RSSI) value directly from the management
interface. The higher the RSSI value, the stronger the signal.
When you move the antenna during alignment, the radio signal from the remote antenna can be
seen to have a strong central main lobe and smaller side lobes. The object of the alignment process
is to set the antenna so that it is receiving the strongest signal from the central main lobe.
Figure 3–8. Aligning the MP-622 Antenna According to Signal Strength
Main Lobe
Maximum
Horizontal Scan
Vertical Scan
RSSI
Value
Side Lobe
Maximum
RSSI Value
Remote
Antenna
Maximum Signal Strength Position
for Horizontal Alignment
Maximum Signal
Strength Position for
Vertical Alignment