Wireless routers have fourteen different channels they can use for 2.4 GHz Wi-Fi, but three of them are off limits. Channels 12 and 13 are allowed in low-power mode, while channel 14 is bannedand only allowed in Japan. While the USA restricts 2.4 GHz Wi-Fi to eleven channels, channels 12 through 14 are available elsewhere in the world. You might even be able to activate them by changing your router settings, although you should not do so. Channel 14 is the most tempting to people, as it would have even less interference—but it’s illegal to operate your router on this channel in the USA.