Subscriber Alignment: Monitoring and Evaluating RSSI Readings

When installing a subsciber unit or point-to-point node, proper antenna alignment is paramount for optimal system performance.  This article discusses some the key wireless parameters and tools to monitor during alignment and how to interpret their readings.

Where to Monitor

Wireless metrics may be monitored on the Home and Monitor Wireless GUI pages or in the eAlign tool (located at Tools eAlign).  


  • Operating Frequency:  The current frequency at which the SM is transmitting and receiving
  • RSSI (Received Signal Strength Indication):  The power level of the received signal
  • MCS (Modulation and Coding Scheme):  The dynamic rate adjustment based on radio conditions.  MCS1 is the lowest rate and MCS15 is the highest. 

Evaluating Readings

To initially determine the quality of the alignment, evaluate the readings of the SM's RSSI (also referred to as Downlink RSSI or Current RSSI).  Compare the readings to the tables below to determine if an acceptable MCS will be achieved based on system specifications.  Operators may also reference the ePMP Capacity Planner Tool located here.  For a listing of data rates for each MCS, see the ePMP User Guide here, section "Data Throughput Capacity".

5 GHz threshold

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2.4 GHz threshold

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eAlign Tool

The eAlign tool (located in the web management GUI at Tools eAlign) features a graphical display of the current and
historical RSSI measurements.  A valid link to an AP is required to provide meaningful measurements.




Operating Frequency

The current frequency at which the SM is operating.

Registered AP SSID

The SSID of the AP to which the SM is registered.

Current RSSI

Current RSSI value measured on the downlink by the SM’s receiver.  Attempt to achieve the highest RSSI possible with subtle antenna adjustments.


Peak RSSI value measured by the SM’s receiver from the time the user navigated to the eAlign page.  This provides a reference point for the best RSSI achieved during the session.

Reset Measurements

Click this button to reset all current measurements.