802.11 WiFi devices claim so many different amazing wireless speeds, especially with the introduction of 802.11ac, that it is sometimes hard to make sense of them. We'll try to explain below.
Generally, 802.11n devices use 150Mbps per spatial stream (in the 2.4GHz band), so theoretical maximum speeds are in multiples of 150, i.e. 150, 300, 450, depending on the number of concurrent streams that the device supports.
Similarly, 802.11ac technology uses 433Mbps per spatial stream (in the 5GHz band), so 802.11ac theoretical maximum speeds are 433Mbps, 866 Mbps, etc., in multiples of 433.
To add to the confusion, manufacturers often rate their devices in combined theoretical maximum speed in both the 2.4GHz (802.11n) and 5GHz (802.11ac) frequency bands, adding them all together and sometimes generously rounding up. So what does a router that claims 1900ac speeds actually mean ? How much speed can your 2.4Ghz N clients get from it ? Is it going to provide more or less than your 900N access point ?
Below is a table of commonly used wireless speeds, along with their 802.11ac and 802.11n composition that may help wade through some of this confusion:
3200 Mbps (1300ac+1300ac+600n)
2350 Mbps (1743ac+600n)
1900 Mbps (1300ac+600n)
1750 Mbps (1300ac+450n)
1600 Mbps (1300ac+300n)
1350 Mbps (867ac+450n)
1300 Mbps (802.11ac)
1200 Mbps (867ac+300n)
1000 Mbps (433ac+600n)
900 Mbps (433ac + 450n)
900 Mbps (802.11n)
750 Mbps (433ac+300n)
750 Mbps (802.11n)
600 Mbps (433ac+150n)
600 Mbps (802.11n)
450 Mbps (802.11n)
300 Mbps (802.11n)
150 Mbps (802.11n)
108 Mbps (802.11g or 802.11a)
54 Mbps (802.11g or 802.11a)
22 Mbps (802.b)
11 Mbps (802.b)
Notes:
802.11n can use either only the 2.4GHz band, or both the 2.4GHz and 5GHz bands. Devices that support over 450Mbps N speeds sum up the throughput in both bands.
802.11ac devices that claim 600 Mbit/s in the 2.4GHz N band use 3 spatial streams at 200Mbps each (instead of the standard 150Mbps N spatial streams). Achieving these speeds requires the use of 256-QAM modulation, which can be considered a proprietary 802.11n extension.
See Also:
What is the actual real-life speed of wireless networks ?
