Many of you may have seen the newer Wi-Fi router, the hottest Wi-Fi 6 right now. Another label on the router box might say 802.11ax. These new routers are backward compatible with 802.11 b/a/g/n/ac. This article will share with you about 802.11ax or Wi-Fi6.
- Wi-Fi 6, as the name suggests, is the sixth generation of Wi-Fi.
- The first generation of Wi-Fi was Wi-Fi 0 or 802.11. Wi-Fi 0 is 1-2 Mbps. The standard is technically beta and works on the 2.4 GHz wireless band.
- Wi-Fi 1 or 802.11b uses 1-11 Mbps in the 2.4 GHz range.
- 802.11a or Wi-Fi 2 only uses the 5GHz band, which does not allow backward compatibility. It runs at 6-54 Mbps. But this generation shows that the standard needs to be backward compatible, because it does cause objections from many users.
- Wi-Fi 3, also known as 802.11g, uses the 2.4 GHz band and has a speed range of 6-54 Mbps.
- Wi-Fi 4 is 802.11n and uses the 2.4 GHz band with speeds of 72-217 Mbps.
- Wi-Fi 5 or 802.11ac uses the 2.4 and 5 GHz bands at speeds of 2.43-1733 Mbps. (The version with the most users at the moment)
- 802.11ax or Wi-Fi 6 with speeds of 600-2401 Mbps.
Multiple input multiple output (MIMO)
Multiple Input Multiple Output is a process that uses multiple antennas. There can be two (2×2) or four (4×4) on the sending and receiving devices.
Think of bandwidth as a highway. A highway can have multiple lanes, each lane is a sub-channel. MIMO works like a multi-lane highway going up. If your device is 2×2, it has two channels, one on top of the other. A 4×4 MIMO would be four channels stacked on top of each other. Multiple “layers” simultaneously allow for greater throughput.
NOTE: Multiple Input Multiple Output can be thought of as a system with multiple network interface cards connected to the same network at the same time. The throughput of each NIC can be combined with the overall speed.
A router that supports 4×4 Mu-MIMO can talk to four devices at once. Likewise, a 2×2 router can talk to two devices at once. If the number of devices exceeds the specified number, the devices will be shared. Remember that routers switch data streams between two or more devices very quickly. From the device’s point of view, it has a constant connection. Switching is similar to a hardwired network, where only one system can transmit packets over the network at a time. Data speeds can be high even when multiple systems are sending and receiving at the same time.
Note: For MIMO to work properly, both the device and the router must support MIMO at the same time for multiple devices to communicate with the router at the same time. Otherwise, each device talks to the router one at a time.
MU-MIMO was introduced in 802.11AC and is ideal for allowing subchannels to communicate with multiple systems simultaneously.
Many factors are attributable to physical speed. Of course, router speed is just as important as modem speed. Ultimately, you may be limited by the bandwidth you get from your Internet Service Provider (ISP). For example, if you purchased 1000 Mbps of bandwidth and your modem or router only supports 850 Mbps, you will lose 150 Mbps of bandwidth.
Take an AC2300 device (Wi-Fi 5 or 802.11ac) as an example. The speed is 2300, but it’s actually 1625+600. This means that the 5 GHz band allows 1625 Mbps, while the 2.4 GHz band supports up to 600 Mbps. Throughput totaled 2225 Mbps, rounded up to 2300.
Take a look at the specs of the Asus AX6000 router. The router is tri-band, which means there are three antennas. The three bands are used for 2.4 GHZ (AC speed of 4333 Mbps), 2.4 GHz (AX speed of 1148 Mbps), and 5 GHz (AX speed of 4804 Mbps). The total speed of the AX band is 5952. The AC band has an additional 4333 Mbps for backward compatibility. Each AX band supports 4×4 MIMO.
Throughput is not realistic for a given speed. Remember that TCP/IP has a lot of overhead in packets. Each packet will of course contain a data payload. There is a good chance that the data payload will require a large number of packets to hold all the data. A packet is a set size, which in most cases is smaller than the data to be sent. Each packet must be received at the receiving end system, and the data will be removed from the packet and put back in place. In addition to the data itself, each packet contains a lot of information. These include IP addresses, MAC addresses, routing information, packet numbers, and more information in the packets. You might be sending packets to the AX6000 router at 4804 Mbps on the 5 GHz band, and the actual amount of data being sent is much less. One might be thinking about sending a 1 GB file to the Internet. You perform a speed test and find that the reported speed is 4500 Mbps. Since speed is measured in megabits (Mb), you need to divide by eight to find the speed in megabytes (MB). 4500 Mbps is about 562 Mbps. The speed shows that if the speed is constant, the file sending takes about 1.8 seconds. In practice, the overhead can be more than 10 seconds (or more).
For TCP/IP transport, there is also the fact that after so many packets have been sent, the sending system waits for a message from the receiving system. The receiving system needs to verify that all packets have been received. If any packets are lost, the receiving system notifies the sending system and resends the necessary packets. These pauses, while small, can still slow down the overall transfer time.
The 5GHz band allows 500 MHz channels.
If you set each channel to 20 MHz, you can have 25 channels (20 x 25 = 500). If the channels are 40 MHz, you can have 12 channels. Each channel can be up to 160 MHz, but only 2 channels are allowed.
The physical components of the router may limit the number and width of channels. The larger the width, the more data can be sent through the channel. The problem is that having fewer channels will limit the number of devices that can communicate at one time. Using Wi-Fi 5 (802.11AC) you can talk to 25 devices at once if you use a 25 MHz channel. Of course, the device also needs to support MU-MIMO.
Make sure to check the device as described earlier in this article, otherwise, only one channel can be used.
If you have a Wi-Fi device that uses a pre-802.11AC standard (Wi-Fi 5), the device will use all channels because it can only use the entire band at a time. This is why you need to ensure that all devices are on the same standard in order to benefit from all the features of a specific standard.
802.11AX (Wi-Fi 6)
Now that we’ve covered a lot of Wi-Fi terms, we can take a look at Wi-Fi 6. Wi-Fi 6 allows multiple devices to share a channel. If you have multiple IoT devices, each requiring 1 MHz of space, you might have 20 IoT devices sharing a 20 MHz channel.
The smartphone may need to use 5 MHz to update apps when you are in the store. With 20 MHz channels, four people can share a channel.
The benefits of Wi-Fi 6 will greatly improve performance for multiple users.
In a home environment with a small number of devices, Wi-Fi 6 may not improve device throughput. Most people using Wi-Fi 5 in a home environment won’t have much of a problem. Most problems in the home are related to interference with other nearby routers or obstructions by walls.
There are many other aspects of Wi-Fi 6 that could really improve its capabilities, but most of these aspects are the domain of a large number of endpoints.
The main aspect is that the 802.11AX standard won’t be finalized until later in 2020. Until then, changes may be made (not known at this time).
No 802.11AX router will give you the full power of the new features unless your device also supports 802.11AX. Don’t buy right away because you expect a new product router to outperform your existing router. Even a router upgrade won’t change the status quo if all systems are still using 802.11AC.