When the first 802.11ax routers appeared in 2019, it was like a breath of fresh air for wireless home networking. Dubbed High-Efficiency Wi-Fi, or HEW for short, Wi-Fi 6 was a significant evolution in how wireless data traveled through the air and was a big step up from 2012's Wi-Fi 5 iteration of the technology, the 802.11ac standard.
The Wi-Fi Alliance announced the Wi-Fi 6E designation in 2020 for any IEEE 802.11ax (Wi-Fi 6) products that support 6 GHz wireless spectrum. This new iteration of wireless networks means Wi-Fi 6E will enable faster speeds and lower latencies than Wi-Fi 6 and earlier iterations. Wi-Fi 6E creates a "fast lane" for compatible devices and applications. The result is faster wireless speeds with lower latency, allowing more devices to connect with better wireless experiences.
Wi-Fi 6 and Wi-Fi 6E hardware are entering the market. But what does this mean for MSPs who deploy wireless networks to their customers? First, let's explore the differences between Wi-Fi 6 versus Wi-Fi 6E.
Q: What exactly IS Wi-Fi 6 (and what happened to Wi-Fi 1 through 5)?
A: Two primary technical organizations define Wi-Fi standards and device interoperability – the Institute of Electrical and Electronic Engineers (IEEE) and the Wi-Fi Alliance (WFA.) The IEEE is responsible for developing the technical standard through a public interchange of ideas and debate in a working group (802.11xx), codifying the requirements, ratifying them with a public vote, and publishing the results. WFA is an industry group comprised of manufacturers who initially aligned to ensure the interoperability of wireless devices. As the IEEE developed additional standards and augmented existing ones, the WFA developed platforms for testing and certification to ensure that a device met the requirements outlined in the IEEE's 802.11xx standard.
In October 2018, the WFA announced Wi-Fi 6 as the designation for products supporting the 802.11ax standard. Before this, the industry used the IEEE standard's nomenclature (802.11ac). Thus, Wi-Fi 1 through 5 only exists from a historical perspective. The WFA changed how Wi-Fi versions are named to create a consumer-friendly nomenclature.
Q: What is the difference between Wi-Fi 6 and Wi-Fi 6E?
A: In April 2020, the FCC voted to allow the entire 6 GHz radio spectrum for Wi-Fi use. Before that, Wi-Fi was limited to 11 non-overlapping channels in the 2.4 GHz frequency range (in the US) and 22 channels in the 5 GHz frequency range. The 6 GHz spectrum offers 59 non-overlapping channels. Countries outside the United States are beginning to follow the US's lead and are slowly opening some or all the 6 GHz spectrum for Wi-Fi use. Wi-Fi products that operate in the 6 GHz frequency band are referred to as Wi-Fi 6E products.
Allowing Wi-Fi to utilize more channels is critical to the future of Wi-Fi. The WFA estimates that there are currently 38.5 million devices using Wi-Fi today. Client connection and throughput speeds are affected by many factors, principally channel width, signal-to-noise ratio, and interference. While all these factors are essential, channel width determines the maximum transmission speed possible for a client connection.
802.11ac and Wi-Fi 6/6E offer channel widths of 20, 40, and 80 MHz. In addition, Wi-Fi 6/6E also allows for 160 MHz channels. The tricky part is that increasing the channel width requires multiple channels to be bonded together, reducing the number of available channels for additional APs to use.
Because Wi-Fi is a "polite" communication medium, APs listen for other devices transmitting on the same frequency before allowing connected clients to send or receive. This will slow the communication speed for connected client devices in environments with multiple APs or existing Wi-Fi networks (for example, neighbors).
Additional channels allow many of these challenges to be mitigated. While 5 GHz and 2.4 GHz-only devices (clients and APs) will still need to utilize only 20 MHz channels in most cases, Wi-Fi 6E-capable devices will create the opportunity to use 40 or 80 MHz channels in many environments. This will potentially yield far greater network throughput than is available today.
Another benefit of the additional 6 GHz channel availability is the opportunity to design networks capable of a higher density of users. More available channels translate to the possibility of positioning Wi-Fi 6 non-interfering APs near each other. This increases the number of simultaneously connected user devices in a smaller area without co-channel interference.
Q: How does Wi-Fi 6 differ from 802.11ac and 802.11n?
A: Wi-Fi 6 differs from previous IEEE standards in many ways. The focus of Wi-Fi 6 development was to find ways to increase the efficiency of Wi-Fi. 802.11a/b/g/n/ac clients and APs are suffering from excessive overhead at the MAC sublayer. This is because most Wi-Fi data payloads tend to be small, but the management frames are the same whether there is a lot of data in the payload or a small amount. This leads to less efficient use of the limited airtime available to a client. Wi-Fi 6 can reduce management frame overhead in Wi-Fi transmissions, yielding more efficient traffic management.
Q: Is Wi-Fi 6 backward compatible with previous standards?
A: Yes, clients using older chipsets and earlier standards will be able to communicate with Wi-Fi 6 APs. However, these clients will not experience the improved efficiency offered by Wi-Fi 6. In addition, the clients will not be able to take advantage of the security improvements that are integral to Wi-Fi 6.
Q: There are Wi-Fi 6 products in the market today. Should I upgrade now or wait for Wi-Fi 6E?
A: All existing clients will be able to communicate with Wi-Fi 6 APs. However, only newer clients that support 6 GHz can utilize Wi-Fi 6E.
Many client devices (phones, laptops, etc.) support Wi-Fi 6 but not Wi-Fi 6E. These devices will be able to take advantage of the improvements available in Wi-Fi 6. Still, they will remain constrained by the network deployment challenges associated with the 2.4 GHz and 5 GHz channel limitations.
Q: What is OFDMA and why does it matter?
A: OFDMA is how Wi-Fi 6 improves access efficiency. It allows an AP to allocate a channel to one or multiple users simultaneously. Because most data payloads are small, allowing the channel to be subdivided, that lets payloads be delivered to multiple clients simultaneously, improving the broadcast's overall efficiency. The AP manages this by communicating with the client and communicating that the packet it wants to receive will be included in a subdivided channel.
Q: Isn't OFDMA the same as MU-MIMO? Is one better than the other?
A: The concept of MU-MIMO (Multi-User Multiple Input Multiple Output) was first introduced with the 802.11ac standard release and Wave 2 APs. Operationally, MU-MIMO requires spatial diversity (using different spatial streams of data), with clients distant from the AP and each other. In addition, MU-MIMO must be paired with beamforming, which adds considerable overhead to the Wi-Fi broadcast. To make matters worse, beamforming in 802.11ac is just one way – from the AP to the client. Finally, very few client devices support MU-MIMO, requiring two radios and two antennas.
OFDMA provides multi-user support by subdividing the broadcast channel. No beamforming is required. Clients can be next to each other or far apart. Another benefit is that both the AP AND the client can support OFDMA. The AP coordinates timing using a trigger frame, allowing the client transmission to be scheduled (as opposed to the random method used in 802.11ac). In this battle for multi-user Wi-Fi access, OFDMA is expected to be declared the winner, but this determination will not be possible until more Wi-Fi 6-capable client devices are in the marketplace.
Q: Articles about Wi-Fi 6 mention resource units (RUs). What are RUs and how will they be used?
A: RUs are the term that is applied to the subcarrier units of a channel used by OFDMA. The channel can be subdivided into 26, 52, 106, or 212 resource units. These RUs create subchannels of 2 MHz, 4 MHz, 8 MHz, or the full 20 MHz. The Wi-Fi 6 specification allows for up to four clients to be simultaneously supported. For example, one client can be allocated 2 MHz, while three others are allocated 4 MHz.
Q: What is BSS color?
A: BSS color stands for Basic Service Set color. It is a feature that is designed to help minimize co-channel interference caused by a client. BSS color allows an AP to ignore client transmissions on the same channel but with a different color assigned from the AP. Note that the AP would communicate its color to a client during the association process.
Q: What are the chances I can use 80 MHz or 160 MHz channels in Wi-Fi 6/6E?
A: Successful deployment of large channel sizes will always depend on the environment in which the access points are deployed. In 5 GHz environments, the same restrictions that are encountered today will continue to exist in Wi-Fi 6 environments. In other words, these channel sizes will not be possible.
However, Wi-Fi 6E will offer a real opportunity to deploy the larger channel sizes. This is due to the dramatic increase in available broadcast channels in the 6 GHz frequency. However, it is unlikely that 160 MHz channels will be deployed in any enterprise environment.
Q: Are Wi-Fi 6 and 6E faster than 802.11ac?
A: While increased performance (throughput) in Wi-Fi 6/6E networks will be possible, this will only occur with clients that support Wi-Fi 6/6E.
Q: Why are we often told to ignore 2.4 GHz? Will Wi-Fi 6 solve the problems with 2.4 GHz?
A: Many of the problems experienced with 2.4 GHz networks stem from the essential characteristics of the environment - through walls, floors, and ceilings, which causes interference. Additional features that create a poor network design include excessive broadcast power or the use of overlapping channels. Wi-Fi 6 will not solve those problems.
However, there is an area where Wi-Fi 6 will assist in 2.4 GHz – Internet of things (IoT) devices. The majority of IoT devices deployed today utilize 2.4 GHz. This is expected to continue for the foreseeable future. Wi-Fi 6 allows (for supported devices) scheduled "awake" time to communicate with the network.
Many IoT devices are powered via batteries. Wi-Fi consumes a lot of power. By allowing devices to coordinate scheduled transmission time with the access point, energy for these devices can be conserved.
Q: I am confused by the terms 2x2:2, 3x3:3, 4x4:4, and 8x8:8. What do they mean and is 8x8:8 better?
A: The first portion of the term (e. g. 2x2) describes the number of transmitting and receiving antennas the device contains. The second term (:2) represents the number of spatial (data) streams the device can transmit.
Each antenna is connected to a separate radio. The more receiving antennas, the better the AP can "hear." This is referred to as diversity. The number of spatial streams helps determine the maximum theoretical transmission speed for the device. The more transmitting antennas, the more data the device can transmit at one time. Keep in mind that more antennas mean more radio chains, which means more power consumption.
Most Wi-Fi networks have some areas that are high density (higher education lecture halls or large conference rooms, for example), where an 8x8:8 may be warranted. The general-purpose deployment will most likely utilize 4x4:4 devices.
Q: Do I need different cabling and switches for Wi-Fi 6 and 6E?
A: Cat6 or better cabling and 802.3at (PoE+) switches are required for most Wi-Fi 6 products. While it is device and manufacturer dependent, the industry expects that the more significant power requirements for Wi-Fi 6E may require 802.3bt PoE, thereby driving switch upgrades.
Q: Will I need to throw away my existing 802.11ac APs to deploy Wi-Fi 6?
A: No. 802.11ac and Wi-Fi 6 APs can work together in a mixed environment. In fact, given that it will take some time to reach the needed client density, deploying Wi-Fi 6 APs in high-density areas initially while retaining 802.11ac APs in other sites may be appropriate.
Q: Are Wi-Fi 6 and 6E more secure than 802.11ac?
A: Potentially. Wi-Fi 6/6E AP certification requires support for WPA3. WPA3 fixes several security weaknesses present with WPA2-PSK (and to a much lesser extent, WPA2-Enterprise) and open authentication used by captive portals. However, WPA3 will not be available for non-Wi-Fi 6 clients. This means that Wi-Fi 6 APs will be required to operate in mixed mode, leaving legacy clients as vulnerable as they have always been.
Connect with WatchGuard if you’re looking to solve complex network security issues with simplified Cloud-managed secure Wi-Fi 6 access points.
Guest blog courtesy of WatchGuard Technologies. Read more WatchGuard guest blogs here. Regularly contributed guest blogs are part of ChannelE2E’s sponsorship program.
