Harmonic channel detection and prevention

A first access point (AP) comprising:

• at least one processor;
• and
• a memory coupled to the at least one processor, the memory storing instructions to cause the at least one processor to:
• receive a beacon frame transmitted by a second AP;
• parse the beacon frame to obtain information of a second channel indicated in the beacon frame;
• determine a plurality of candidate harmonic channels based on a first frequency of a first channel on which the first AP working and a scan channel bandwidth of the first AP by:
• determining a sampling rate of the first AP based on the scan channel bandwidth of the first AP;
• and
• determining frequencies of the plurality of candidate harmonic channels by adding a non-zero integer multiple of the sampling rate of the first AP to the first frequency of the first channel, wherein at least a part of signals transmitted on the plurality of candidate harmonic channels is scanned by the first AP as a result of sampling aliases;
• validate that the second channel is one of the plurality of candidate harmonic channels based on the information of the second channel;
• validate that the beacon frame is transmitted on the second channel based on a sequence number and a target beacon transmission time (TBTT) indicated in the beacon frame;
• and
• discard the beacon frame.

A non-transitory computer-readable medium comprising instructions stored thereon which, when executed by a first access point (AP), cause the first AP to:

• receive a beacon frame transmitted by a second AP;
• parse the beacon frame to obtain information of a second channel indicated in the beacon frame;
• determine a plurality of candidate harmonic channels based on a first frequency of a first channel on which the first AP works and a scan channel bandwidth of the first AP by:
• determining a sampling rate of the first AP based on the scan channel bandwidth of the first AP;
• and
• determining frequencies of the plurality of candidate harmonic channels by adding a non-zero integer multiple of the sampling rate of the first AP to the first frequency of the first channel, wherein at least a part of signals transmitted on the plurality of candidate harmonic channels is scanned by the first AP as a result of sampling aliases;
• validate that the second channel is one of the plurality of candidate harmonic channels based on the information of the second channel;
• validate that the beacon frame is transmitted on the second channel based on a sequence number and a target beacon transmission time (TBTT) indicated in the beacon frame;
• and
• discard the beacon frame.