Edimax BR-6225N User Manual page 82

TIPS: You can try to change channel number to another one if you
think the data transfer rate is too slow, or keep having problem while
transferring the file over wireless network. There could be some other
broadband routers using the same channel, which will disturb the
radio communication between wireless client and the broadband
When you finished with the settings in this page, you can click 'Apply'
button to save changes you made in this page, or you can click 'Cancel'
to discard changes. After you click 'Apply' button, you'll see the
following messages:
Where you can setup Channel Width in "
Auto 20/40MHz " to get good wireless
signal.
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