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airMAX - Improving SNR/CINR


This article aims to assist the user in obtaining the proper CINR for every deployment. If you are suffering from low throughput or instability, please follow these guidelines to improve your overall wireless link health.

Table of Contents

  1. Introduction
  2. Factors to Assess
  3. Related Articles


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The CINR is Carrier to Interference+Noise Ratio which is basically "signal to noise ratio" in dB. Having the proper CINR means having a much stronger signal over the noise in an environment. In most cases, wireless links that suffer from poor throughput or instability do not have the proper CINR to maintain a stable link. Having a greater CINR is paramount for a proper link stability. This article mentions seven factors that will affect stability. 

Increasing SNR and CINR values by following the steps to assess the factors below should result in improved capacity and throughput on the dashboard. Using iPerf3 across the link before and after these steps will help track the results of any improvements. See our Related Article below for more.

Factors to Assess

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Physical alignment of devices is a crucial determining factor of signal strength. It is important to ensure that the center of the radiation patterns meet as directly as possible. How To Align airMAX Antennas

Line of Sight

Obstructions between the devices will greatly affect the signal strength of the link. While some frequencies can penetrate some obstructions, all signals will suffer when line of sight is blocked in any way.

Fresnel Zone

The Fresnel Zone is like a bubble around the beam in which radio waves travel. At least 60% of this zone should be clear of all obstructions in order to ensure strong and stable signal levels; the clearer this zone remains, the better the signal can become.


Competing signals from other devices can introduce noise on the spectrum that will disrupt your link's ability to capture and filter its signal in isolation. Use airView to scan the spectrum and select the clearest channel that meets your needs with respect to output power regulations. In addition, reducing your channel width will help to limit interference. Selecting the Best Channel Width


A narrower beamwidth device will intercept less noise from competing and neighboring frequencies.

Output Power

Some channels have different EIRP limits. If there are more available channels clear of interference, higher output power may become available.

Antenna Gain

Higher gain antennas provide better signal strength by increasing efficiency of conversion between electrical power and radio waves.

Related Articles

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airMAX - How to Align airMAX Antennas

airMAX - Testing Throughput with iPerf3

airMAX - Selecting the Best Channel Width

airMAX - Using airView to Find the Best Channel

airMAX - Troubleshooting Weak or Fluctuating Signal

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