Narrowband interference avoidance for dynamic channel assignment

An apparatus comprising:

• a receiver configured to receive energy in a plurality of channels of a frequency band;
• a spectrum analysis unit configured to analyze energy received in the plurality of channels for occurrence and type of interference in each channel;
• and
• a controller coupled to the spectrum analysis unit and configured to:
• generate a quality metric for each channel based on the occurrence and type of interference detected in the channel;
• assign for each channel a bias value against selection of the channel based on whether narrowband interference is present in the channel, wherein to assign the bias value the spectrum analysis unit is further configured to:
• determine if a channel has characteristics of narrowband interference based on one or more of strength, duty cycle, or bandwidth of energy in the channel;
• when energy in a channel has the characteristics of narrowband interference, generating a bias value for that channel so as to more severely weight the corresponding quality metric of that channel as compared to a bias value applied to a different channel that comprises ambient noise;
• applying the respective bias value for each channel to the quality metric for the respective channel to produce an adjusted quality metric for each channel that weights the channel against the selection of the channel for use based on the presence of narrowband interference in the channel;
• and
• select a channel based on the adjusted quality metric for each of the plurality of channels.

A system comprising:

• a plurality of wireless devices configured to serve wireless client devices in a wireless network in a frequency band comprising a plurality of channels, each wireless device configured to receive energy in the plurality of channels, analyze the received energy for occurrence and type of interference in each channel, and generate a quality metric for each channel based on the occurrence and type of interference detected in the channel;
• and
• a controller apparatus configured to control the assignment of channels to the plurality of wireless devices, wherein the controller apparatus is configured to:
• for each of the plurality of wireless devices, assign for each channel a bias value against selection of the channel based on whether narrowband interference is present in the channel, wherein to assign a bias value the controller is further configured to:
• determine if a channel has characteristics of narrowband interference based on one or more of strength, duty cycle, or bandwidth of energy in the channel,
• when energy in a channel has the characteristics of narrowband interference, generating a bias value for that channel so as to more severely weight the corresponding quality metric of that channel as compared to a bias value applied to a different channel that comprises ambient noise;
• applying the respective bias value for each channel to the quality metric for the respective channel to produce an adjusted quality metric for each channel that weights the channel against the selection of the channel for use based on the presence of narrowband interference in the channel;
• and
• select a channel based on the adjusted quality metric for each of the plurality of channels.