Motorola 2.1 Manual De Usuario

Appendix A: 

 

•  When the scan concludes, the decision on how a channel is chosen is based on the strength and 

number of beacons on each channel. Also, non-overlapping channels are weighted as highly 
preferred channels.  

•  This scan can occur through three different methods:  

o

  Upon the Boot-up  

o

  Through a manual channel rescan command via Wireless Manager  

o

  Through a scheduled channel rescan command via Wireless Manager 

 
High Interference and channel scan on the 2.4GHz radio 

•  High interference can be defined as the Duo node being incapable of receiving or transmitting 

due to an extremely high noise floor.  

•  In this case, the Duo node will initiate a reboot if it is in this state for an extended amount of time.  

•  The reboot will force the node to execute an Auto Channel Rescan where it is expected to select 

a channel that is cleaner.  

•  If this still exists, the Duo node will keep rebooting until it finds a cleaner channel.  

•  An operator of the network has the ability to monitor this behavior through Wireless Manager. If a 

Duo node is rebooting due to extreme interference, a threshold alarm can be set that will indicate 
a frequent node that is rebooting. Through this threshold alarm, a network operator will be notified 
that a node has had a high number of reboots which would highlight further investigation of that 
node. 

•  High interference can be defined as the Duo node being incapable of receiving or transmitting 

due to an extremely high noise floor.  

•  The behavior for the 5.4GHz radio is similar to the behavior of the 2.4GHz radio during high 

interference.  However, the channel scan on a 5.4GHz radio is different. It is also different 
between IAP’s an MWRs.  

•  When an MWR initiates a channel rescan, it will look for an IAP.  

•  If there are multiple IAP’s that are within range, it will choose the IAP based on the best link 

metric.  

•  When an IAP disappears, the MWR will prefer to stay on the current channel rather than rescan 

on other channels.  

•  It will scan the current channel for other IAP’s and once again choose the IAP that has the best 

link metric.  

•  If it does not find an IAP on that channel, it will trigger a channel rescan.  

•  After this channel rescan concludes, it will have chosen a new channel and a new IAP on that 

channel.  

 

:  

The impact of interference avoidance in the network is similar to the impact of radar avoidance. The 
exception is that the channel in which the interference is detected is not blacklisted for 30 minutes when a 
scan is initiated. 

 

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