What is WiFi?
Wi-Fi is a wireless networking technology that uses radio waves to create Wireless Local Area Network (WLAN), the name of Wi-Fi doesnât stand for anything, it just a logo and trademark chosen by Wireless Ethernet Compatibility Alliance (now Wi-Fi Alliance, renamed itself in 2002).
Factors of Wi-Fi
WiFi generations/IEEE standards
Wi-Fi indeed base on IEEE 802.11, but Wi-Fi not totally equal to that standard, because not all sub standards under IEEE 802.11 are using by Wi-Fi, for example, IEEE 802.11c is an amendment to the IEEE 802.1D MAC bridging standard.
In 2018, Wi-Fi Alliance change the naming rule for easier to understand and recognize, now Wi-Fi Alliance not call Wi-Fi standards for IEEE 802.11b, a, g, n, x anymore, but simply naming like Wi-Fi 1,2,3â¦n, and change their certification trademark also.
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 Name |
Protocol |
Year |
Frequency |
Actual speed |
Theoretical speed |
Indoor range |
Outdoor range |
|
Wi-Fi 1 |
802.11b |
1999 |
2.4-2.5 GHz |
6.5 Mbit/s |
11 Mbit/s |
about 30 meters |
about 100 meters |
|
Wi-Fi 2 |
802.11a |
1999 |
5.15-5.35/5.47-5.725/5.725-5.875 GHz |
25 Mbit/s |
54 Mbit/s |
about 30 meters |
about 45 meters |
|
Wi-Fi 3 |
802.11g |
2003 |
2.4-2.5 GHz |
25 Mbit/s |
54 Mbit/s |
about 30 meters |
about 100 meters |
|
Wi-Fi 4 |
802.11n |
2009 |
2.4 GHz or 5 GHz bands |
300 Mbit/sï¼?0MHz*4 MIMOï¼?/p> |
600 Mbit/sï¼?0MHz*4 MIMOï¼?/p> |
about 70 meters |
about 250 meters |
|
Wi-Fi 5 |
802.11ac |
2011.11 |
5 GHz |
433Mbit/s, 867Mbit/sï¼Optional 80MHzï¼?60MHzï¼?/p> |
867Mbit/s, 1.73 Gbit/s, 3.47 Gbit/s, 6.93 Gbit/sï¼? MIMOï¼?60MHzï¼?/p> |
about 35 meters |
|
|
Wi-Fi 6 |
802.11ax |
2018.12 |
2.4/5 GHz |
|
10.53Gbps |
10 meters |
100 meters |
Note: Wi-Fi 1 to 3 also called Legacy Wi-Fi since they are not widely in use today.
Differences between 2.4GHz and 5GHz
2.4 GHz and 5 GHz are most common radio frequencies used for Wi-Fi today, although you use them everyday even for now, but you may not complete know the differences between them, hit to the point, 2.4 GHz has long range and strong penetrability for wall, but low transfer speed and more signal interference(micro-wave), on the other hand,5 GHz has high transfer speed, but less short range and weak penetrability.
Frequency channel
2.4 GHz
IEEE 802.11 have total fourteen channels defined for the 2.4 GHz ISM band, but not all of these Wi-Fi channels are available in all countries, In USA, there are 11 channels allowed by the FCC, and 13 are allowed in Europe where channels have been defined by ETSI. The WLAN / Wi-Fi channels are spaced 5 MHz apart (with the exception of a 12 MHz spacing between the last two channels).
[/et_pb_text][et_pb_image src=”https://homeautotechs.com/wp-content/uploads/2019/10/ISM-Band.png” _builder_version=”3.26.6″][/et_pb_image][et_pb_text _builder_version=”3.26.6″ custom_padding=”0px|||||”]|
Channel |
Center Frequency |
USA |
Canada |
Most Countries |
|
1 |
2412 |
Y |
Y |
Y |
|
2 |
2417 |
Y |
Y |
Y |
|
3 |
2422 |
Y |
Y |
Y |
|
4 |
2427 |
Y |
Y |
Y |
|
5 |
2432 |
Y |
Y |
Y |
|
6 |
2437 |
Y |
Y |
Y |
|
7 |
2442 |
Y |
Y |
Y |
|
8 |
2447 |
Y |
Y |
Y |
|
9 |
2452 |
Y |
Y |
Y |
|
10 |
2457 |
Y |
Y |
Y |
|
11 |
2462 |
Y |
Y |
Y |
|
12 |
2467 |
N |
N |
Y |
|
13 |
2472 |
N |
N |
Y |
|
14 |
2484 |
N |
N |
N |
With the use of IEEE 802.11n, there is the possibility of using signal bandwidths of either 20 MHz or 40 MHz. 2.4 Ghz Transmission can be on a 22MHz (802.11b), 20MHz (802.11g/n), or 40MHz (802.11n) wide channel. When 40 MHz bandwidth is used to gain more than twice data transfer speed compares to 20MHz bandwidth, this obviously speed up the data throughput, but reduces the number of channels that can be used.
[/et_pb_text][et_pb_image src=”https://homeautotechs.com/wp-content/uploads/2019/10/width-22-20-40MHz-channels-for-2.4-GHz.png” _builder_version=”3.26.6″ custom_padding=”|446px||||”][/et_pb_image][et_pb_text _builder_version=”3.26.6″ custom_margin=”-13px|||||”]|
Channel |
Or Channel |
Center Frequency |
USA |
Canada |
Most Countries |
|
3 |
1+5 |
2422 |
Y |
Y |
Y |
|
11 |
9+13 |
2462 |
N |
N |
Y |
5 GHz
Transmission can be on a 20 or 40MHz (802.11a/n), 80 or 160MHz (802.11ac) wide channel
[/et_pb_text][et_pb_image src=”https://homeautotechs.com/wp-content/uploads/2019/10/5GHz-channels-allowed-by-FCC.png” _builder_version=”3.26.6″ min_height=”285px”][/et_pb_image][et_pb_text _builder_version=”3.26.6″]- U-NII: Unlicensed National Information Infrastructure
- TDWR = Terminal Doppler Weather Radar
Note: Devices must be professionally installed when operating in the U-NII-2C(5470 â?5725 MHz band)
|
Channel |
Frequency (MHz) |
 |
||
|
Lowest |
Center |
Highest |
Available in North America |
|
|
36 |
5170 |
5180 |
5190 |
Y |
|
40 |
5190 |
5200 |
5210 |
Y |
|
44 |
5210 |
5220 |
5230 |
Y |
|
48 |
5230 |
5240 |
5250 |
Y |
|
52 |
5250 |
5260 |
5270 |
DFS |
|
56 |
5270 |
5280 |
5290 |
DFS |
|
60 |
5290 |
5300 |
5310 |
DFS |
|
64 |
5310 |
5320 |
5330 |
DFS |
|
100 |
5490 |
5500 |
5510 |
DFS |
|
104 |
5510 |
5520 |
5530 |
DFS |
|
108 |
5530 |
5540 |
5550 |
DFS |
|
112 |
5550 |
5560 |
5570 |
DFS |
|
116 |
5570 |
5580 |
5590 |
DFS |
|
120 |
5590 |
5600 |
5610 |
DFS |
|
124 |
5610 |
5620 |
5630 |
DFS |
|
128 |
5630 |
5640 |
5650 |
DFS |
|
132 |
5650 |
5660 |
5670 |
DFS |
|
136 |
5670 |
5680 |
5690 |
DFS |
|
140 |
5690 |
5700 |
5710 |
DFS |
|
144 |
5710 |
5720 |
5730 |
DFS |
|
149 |
5735 |
5745 |
5755 |
Y |
|
153 |
5755 |
5765 |
5775 |
Y |
|
157 |
5775 |
5785 |
5795 |
Y |
|
161 |
5795 |
5805 |
5815 |
Y |
|
165 |
5815 |
5825 |
5835 |
Y |
DFS - Dynamic Frequency Selection is a WiFi function that enables WLANs to use 5 GHz frequencies that are generally reserved for radars
MIMO and MU-MIMO
[/et_pb_text][et_pb_image src=”https://homeautotechs.com/wp-content/uploads/2019/10/Mimo-toepassing.jpg” _builder_version=”3.26.6″][/et_pb_image][et_pb_text _builder_version=”3.26.6″ min_height=”107px”]MIMO is a short for Multiple-Input Multiple-Output, which is a wireless technology that uses multiple transmitters and receivers to transfer more data at the same time. Wi-Fi CERTIFIED devices make use of multiple antennas to send and receive more than one communication signal simultaneously. This multiplies the performance of the Wi-Fi signal, and is reflected in the two, three, or even more antennas found on some Wi-Fi CERTIFIED n AP (access point) devices or routers. All wireless products with Wi-Fi 4(802.11n) protocol support MIMO. The technology helps allow Wi-Fi 4 to reach higher speeds than products without it.
[/et_pb_text][et_pb_image src=”https://homeautotechs.com/wp-content/uploads/2019/10/MU-MIMO.png” _builder_version=”3.26.6″ custom_padding=”|398px||0px||”][/et_pb_image][et_pb_text _builder_version=”3.26.6″]MU-MIMO is short for Multi-user, multiple-input, multiple-output technology simultaneously, it is part of the Wi-Fi 5 (802.11ac) standard, MU-MIMO allows an AP or Router to communicate with multiple devices, increasing the speed of the data transfer without congestion.
[/et_pb_text][/et_pb_column][/et_pb_row][et_pb_row _builder_version=”3.26.6″][et_pb_column type=”4_4″ _builder_version=”3.26.6″][et_pb_text _builder_version=”3.26.6″]WiFi Beamforming
[/et_pb_text][et_pb_image src=”https://homeautotechs.com/wp-content/uploads/2019/10/WiFi-Beamforming.jpg” _builder_version=”3.26.6″ width=”22.3%”][/et_pb_image][et_pb_text _builder_version=”3.26.6″]Beamforming is a process that allows you to focus your WiFi signal. … WiFi beamforming narrows the focus of that router signal, sending it directly to your devices in a straight line, thus minimizing surrounding signal interference and increasing the strength of the signal that each device. Beamforming is a process that allows you to focus your WiFi signal. … WiFi beamforming narrows the focus of that router signal, sending it directly to your devices in a straight line, thus minimizing surrounding signal interference and increasing the strength of the signal that each device.
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