Setup guide
Acknowledgement Timeout 
AirOS has an auto-acknowledgement timeout algorithm which dynamically optimizes 
the acknowledgement timeout value without user intervention. This is a critical feature 
required for stabilizing long-distance outdoor links. The user also has the ability to 
enter the value manually, but this is not recommended. 
Distance: specify the distance value in miles using slider or enter the value manually. 
The signal strength and throughput falls off with range. Changing the distance value 
will change the ACK Timeout to the appropriate value of the distance. 
ACK Timeout: specify the ACK Timeout. This is the amount of time the subscriber 
station will wait to hear a acknowledgement response from the wireless device after 
the data packet is transmitted. If the timeout is set too short or too long, it will result 
poor connection and throughput performance. 
Changing the ACK Timeout value will change the Distance to the appropriate distance 
value for the ACK Timeout. 
Auto Adjust control will enable the ACK Timeout Self-Configuration feature. If enabled, 
ACK Timeout value will be derived dynamically using an algorithm similar to the 
Conservative Rate Algorithm described above. 
Antenna Settings 
AirOS based devices have a possibility to switch the antenna polarities with a single 
web management control. This is achieved by using Ubiquiti's patent-pending Adaptive 
Antenna Polarity (AAP) technology. 
AirOS devices often have multiple antenna options. In the case of the NanoStation, 
there are 4 antenna modes: 
1. Vertical Polarity 
2. Horizontal Polairty 
3. Adaptive: This mode chooses the best polarity dynamically. Adaptive – switches 
adaptive antenna polarity mode which allows for the beam polarities to be switched 
dynamically on the fly for improved performance in heavy noise environments. 
4. External: This allows a connection to an external port / higher gain antenna 
Antenna Alignment LED Thresholds 
The LED's on the back of the AirOS Device can be made to light on when received 
signal levels reach the values defined in the following fields. This allows a technician to 
easily deploy an AirOS CPE without logging into the unit. 
RSSI LED Thresholds specify the marginal value of RSSI which will switch on LEDs 
indicating signal strength: 










