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copied!<p>Your wireless chip/dongle/AP has to support both frequency bands (5Ghz and 2.4Ghz). The device specification would state if they support 802.11a/b/g/n. Most new smartphones and AP support both 2.4GHz and 5Ghz bands. This is implemented by 2 different radios within the chip. 2.4GHz is the initial frequency band allocated for WiFi (or by it's specification name IEEE 802.11). This frequency band is limited to ~14 channels (in some countries it's limited to 11) but effectively you usually only use channels 1,6,11 as the signal has a spread over several channels and using 1,6,11 prevents overlapping. 5Ghz was added later on in 802.11a (and can also be used in 802.11n) and has more spectrum available. The meaning of more spectrum is that you can have more APs which aren't interfering each other. Also, in 5GHz you can usually use 40Mhz channels which are twice the 20Mhz channels usually used in 2.4GHz. This translates to a much higher potential throughput. The new WiFi standard (802.11ac) works only in 5Ghz and can use even 80 or 160Mhz channels.</p> <p>Advantages for using 5Ghz:</p> <ul> <li>Currently it's usually more quiet (less people have APs configured in this band) so less interference</li> <li>Wider channels possible It all translates to higher throughput</li> </ul> <p>Disadvantages:</p> <ul> <li>Devices with dual band may be more expensive. This is more relevant in case you're a smartphone or a sensor maker where a couple of cents difference may make a difference. For APs it's becoming less of an issue.</li> <li>For some applications with low throughput requirements (e.g. sensors connected WiFi) there's no real need for 5Ghz</li> <li>5Ghz wouldn't go as far as 2.4Ghz. It doesn't traverse walls as good as 2.4Ghz.</li> </ul> <p>For more info on 802.11: <a href="https://en.wikipedia.org/wiki/IEEE_802.11" rel="nofollow">https://en.wikipedia.org/wiki/IEEE_802.11</a></p>

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