airMAX - How to Align airMAX Antennas


Overview


This article will provide the basic steps to deploy and align a new airMAX Point to Point (PtP) or Point to Multi-Point (PtMP) installation.


Table of Contents


  1. Introduction
  2. How to Align an airMAX PtMP Deployment
  3. How to Align an airMAX PtP Deployment

Introduction


Back to Top

Having a perfectly aligned link is crucial for a well-performing link. Without proper alignment, less than desirable throughput, high latency, or just overall stability issues will be perceived. Follow the steps in this article to maximize link performance.


How to Align an airMAX PtMP Deployment


Back to Top

Step 1: Ensure the plan is viable with our link planner.

  • Visit this link and select the AP location and desired Station locations.
  • Set the real height of each location.
    • airLink does not account for trees, building, or other obstructions; only ground elevation. If deployment is in a wooded area, the obstructions will have to be judged by sight: either by looking at the satellite imagery or by going on site.
    • For PtMP deployments, the AP is generally higher, Stations will be closer to the ground.
  • Select the antennas that will be used at each location.
  • Select the total EIRP that you are allowed to use. 
  • Change the channel width until the desired capacity is reached.

If the signals are not close to -50, consider using higher gain antennas.

Step 2: Install the Access Point.

  • For longer links, it can be easier to use the satellite imagery to pick out a landmark that is visible from the AP location and point the AP in that direction.
  • Be mindful of the tilt. It is very easy to point the AP too far up or down. Most sector antennas have a 2-degree electrical down-tilt already.

Step 3:  Install the Station or Stations.

  • Find a high ground high above all reflective surfaces to mount the Client's CPE.
    • Never install and point a CPE across the surface of a roof.
    • Be sure to install the antenna two or three meters above the ground.
  • Point the CPE in the general direction of the AP, then log into it.
    • Once logged in, open the scan list and select the AP's SSID. 
    • Once the connection has been established, open the alignment tool and start very slowly panning the antenna from the left to the right keeping in mind the best signal that appears. Once the signal starts dropping dramatically, pan back from right to left until the signal starts dropping again. Pan one more time from left to right and stop once again at the best signal seen so far.
    • Repeat for elevation.
  • The signals should now match the expected signal from airView.

Step 4: After several CPEs have been installed, go back to the AP and adjust the alignment as needed.


How to Align an airMAX PtP Deployment


Back to Top

1. Use this link to find landmarks near both ends of the link for the installers to aim at.

2. Mount the Access Point and slave radios with installers at both sides.

3. Have both installers use the previously found landmarks to establish a link. This can take quite a while depending on the experience of the installers. Each installer may need to change the azimuth and elevation a few degrees at a time in order to establish the initial link. Be sure only one antenna is being moved at a time!

4. Open up the alignment tool in the AirOS WebUI and have one installer slowly adjust the azimuth on one antenna until the signal gets better, and then it begins to worsen.

5. Once you notice you're losing signal, start backing up the azimuth until you reach the peak signal.

6. Repeat step 5 for the elevation.

7. Do the same for the second installer: have the second installer slowly adjust the azimuth on one antenna until you see the signal improve, then get worse again, then again for elevation.


We're sorry to hear that!