Wireless - Wi-Fi 5 GHz frequency bands and channels
The 5 GHz frequency band used by Wi-Fi technologies defines a specific range of frequencies that can be leveraged for wireless communications. This frequency range is separated into specific channels as illustrated in the following table:
| Channel | Frequency Range (GHz) | Center Frequency (GHz) |
|---|---|---|
| 32 | 5.150 - 5.170 | 5.160 |
| 36 | 5.170 - 5.190 | 5.180 |
| 40 | 5.190 - 5.210 | 5.200 |
| 44 | 5.210 - 5.230 | 5.220 |
| 48 | 5.230 - 5.250 | 5.240 |
| 52 | 5.250 - 5.270 | 5.260 |
| 56 | 5.270 - 5.290 | 5.280 |
| 60 | 5.290 - 5.310 | 5.300 |
| 64 | 5.310 - 5.330 | 5.320 |
| 68 | 5.330 - 5.350 | 5.340 |
| 72 | 5.350 - 5.370 | 5.360 |
| 76 | 5.370 - 5.390 | 5.380 |
| 80 | 5.390 - 5.410 | 5.400 |
| 84 | 5.410 - 5.430 | 5.420 |
| 88 | 5.430 - 5.450 | 5.440 |
| 92 | 5.450 - 5.470 | 5.460 |
| 96 | 5.470 - 5.490 | 5.480 |
| 100 | 5.490 - 5.510 | 5.500 |
| 104 | 5.510 - 5.530 | 5.520 |
| 108 | 5.530 - 5.550 | 5.540 |
| 112 | 5.550 - 5.570 | 5.560 |
| 116 | 5.570 - 5.590 | 5.580 |
| 120 | 5.590 - 5.610 | 5.600 |
| 124 | 5.610 - 5.630 | 5.620 |
| 128 | 5.630 - 5.650 | 5.640 |
| 132 | 5.650 - 5.670 | 5.660 |
| 136 | 5.670 - 5.690 | 5.680 |
| 140 | 5.690 - 5.710 | 5.700 |
| 144 | 5.710 - 5.730 | 5.720 |
| - | 5.730 - 5.735 | - |
| 149 | 5.735 - 5.755 | 5.745 |
| 153 | 5.755 - 5.775 | 5.765 |
| 157 | 5.775 - 5.795 | 5.785 |
| 161 | 5.795 - 5.815 | 5.805 |
| 165 | 5.815 - 5.835 | 5.825 |
| 169 | 5.835 - 5.855 | 5.845 |
| 173 | 5.855 - 5.875 | 5.865 |
| 177 | 5.875 - 5.895 | 5.885 |
There are a couple of things to keep in mind when looking at the above table:
- Each channel is defined by its center frequency. This is the frequency at the very center of the channel width.
- The channel width is the range of frequencies that each channel encompasses. From the Frequency Range column, you can see that each channel is 20 MHz in width.
- Unlike the channels that have been defined for the 2.4GHz frequency band, these channels are non overlapping.
- The range 5.730 to 5.735GHz is undefined as far as a specific channel is concerned. In some areas of the world this is defined as "unknown" while for others it is usable, but isn't actually defined. For all intents and purposes, this small slice of frequency remains unused.
- Notice also that the channel numbers are not sequential, but
Channel bonding can take place between channels in the 5GHz frequency range depending upon the Wi-Fi standard being used. Bonding of 2, 4, or 8 20 MHz channels can result in bonded channels of 40, 80, and 160 MHz in width respectively.
Links:
https://networklessons.com/cisco/ccna-200-301/introduction-to-wireless-networks
https://commons.wikimedia.org/wiki/File:Channels5GHzWLAN-da.svg
https://en.wikipedia.org/wiki/List_of_WLAN_channels#5_GHz_(802.11a/h/n/ac/ax)