WiFi 7 vs WiFi 6: What's the Difference?
Written by Don Schultz, trueCABLE Senior Technical Advisor, Fluke Networks Copper/Fiber CCTT, BICSI INST1, INSTC, INSTF Certified
WiFi technology is advancing pretty quickly in recent years as compared to the lull (read: rut) we were all in for more than a decade. This rapid evolution has to do with the FCC (Federal Communications Commission) opening up previously unavailable operating bands. Of course, nothing is free and without “gotchas”. WiFi is a technology where advances forward usually come with steps backward due to how the electromagnetic spectrum operates. Increased bandwidth and higher frequencies carry a penalty, which we will discuss further in this blog. First, though, let’s recap all of the WiFi flavors you are likely to encounter out there and compare them quickly side by side. We will explain the terms that frequently make discussing them confusing as well.
Oh, and we will revisit a question I first asked in What is WiFi 6?, Is Ethernet dead now? We shall see!
WiFi Versions Compared
Biggest changes from WiFi 6 through WiFi 7 are noted in bold and underlined.
Multi-AP: Multi-AP means multiple access points (if you have them) ganging up and transmitting and receiving to a single client device as a virtual unit. This theoretically increases speeds, assuming you have more than a single WiFi router and make use of multiple access points instead. This is likely to benefit MESH setups where multiple access points can be utilized to serve a single client, but those multiple access points need to be in range of the client in order to be of any benefit.
Multi-RU Puncturing: This rather intimidating term is easy to explain. It is a “testing the water” strategy to keep one WiFi device from stepping on another, while attempting to provide as much bandwidth to the device as it needs. Multi-RU Puncturing is designed to assess how much bandwidth the device wants, what channels are already in use, where the interference is, and then allocate the signal for that client to non-interfering channels. This technology can literally shape the channels used, depending on the required amount of bandwidth, around busy channels.
MU-MIMO / DL MU-MIMO / UL & DL MU-MIMO: MU-MIMO stands for Multiple User Multiple Input Multiple Output and has evolved to the point where we need to subdivide the terms used to describe it.
- When the term MU-MIMO is used by itself, it typically means DL MU-MIMO where the WiFi Router/access point can transmit to a number of clients in the downward direction simultaneously. It is unidirectional in nature. WiFi 5 allowed for up to four client devices to take advantage of DL MU-MIMO at a time. WiFi 6 increased that to eight. WiFi 7 takes this to a staggering sixteen.
- UL & DL MU-MIMO means the client stations can also transmit back to the WiFi router/access point and have their signals accepted simultaneously. This is semi-simultaneous bidirectional WiFi communication. Only WiFi 7 allows for this. All previous versions of MU-MIMO are in one direction only (DL).
- It should be noted that even UL/DL MU-MIMO in WiFi 7 still requires separate data bursts to be processed one at a time. That is where OFDMA comes in.
OFDMA: Orthogonal Frequency Division Multiple Access. OFDMA significantly enhances both variations of MU-MIMO. This technology allows the WiFi router to transmit to more than one client at a time in the same signal burst by dividing up the signal into frequency units. In short, a single signal can contain data meant for more than one client at a time. When combined with WiFi 7, you now have true simultaneous bidirectional WiFi communication. Now multiple devices can be addressed simultaneously during a single data burst, and in both directions. This was a major breakthrough.
OFDMA compared to the older method. One signal burst to serve multiple clients.
TWT: Target Wake Time. This means your WiFi router and/or client device will switch off the transmitter to save battery and air time. This greatly benefits IoT devices that infrequently pass data like light bulbs and temperature sensors.
xxx-QAM: QAM is the modulation scheme used to actually put bits of data into a signal burst. The QAM number refers to the density of the data present in the signal. As the number increases, the amount of data present in the signal is higher. WiFi 4 has a paltry 64-QAM compared to the new WiFi 7 which is 4096-QAM. So, for each signal sent, the efficiency dramatically increases with higher QAM and this requires less signal pulses to send the same amount of data as before. Higher QAM also frees up more signal time for more client devices, too.
4096-QAM packs more data into one signal burst
Essentially WiFi 6 and WiFi 6E are identical except WiFi 6E has the ability to operate at 6 GHz. This addition alone is not enough to make WiFi 6E desirable over “standard” WiFi 6, considering you would need to buy all new devices to take advantage of a feature that has a significant drawback--range. WiFi 7 takes everything WiFi 6E has and adds a lot of fancy new functionality that attempts to address dense operating environments with the new technology practically doing handstands in order to keep one device from stepping on another and ruining your on-line game experience or even basic web surfing. This makes WiFi 7 much more promising, assuming it is implemented correctly on every manufacturer’s device.
None of these advancements actually increase your range, however, and that is a big problem. In fact, it is a problem that cannot be solved due to physics and the current technology of using radio waves to transmit data over the air.
So, you walk into your local store or shop online and come across a box just plastered with pretty pictures and marketing points extolling the virtues of the device inside. WiFi 7, incredible speeds, unparalleled reliability, and perhaps even the solutions to the world’s problems. What is not to like?
- In order to take advantage of WiFi 7, all of your devices need to support it. This means changing out your WiFi router and all your client devices at once to get any meaningful and immediate benefit. Can we say “cha-ching”?
- Not all manufacturers will implement all the new features. Some of the features are optional. Case in point: WiFi 6 is present in many smartphones and is becoming prevalent. Most smartphones have exactly two antennas inside. WiFi 6 supports eight antennas for eight spatial streams. So much for advertising. Well, that is a downer, right?
- 6 GHz has horrible object penetration, limiting usefulness to the same room or perhaps to an adjacent room. It is not a whole-house technology unless you have a MESH setup or multiple access points. 5 GHz is better, and can usually penetrate several drywall clad rooms before becoming unusable. 2.4 GHz has the best object penetration of all, but is very prone to interference and offers very few actual discrete channels (it only has three, actually). With wire mesh backed plaster or concrete walls, forget about 6 GHz or even 5 GHz as neither will make it past that kind of material--it will be confined to a single room. Suffice it to say, you won’t be using 6 GHz outside your home regardless.
- Stable and correct implementation of WiFi 7 will take a considerable amount of time. This new technology is dependent on not only new hardware but also new firmware (software inside the router). Each manufacturer will have to get everything right in order for devices to communicate with each other without problems. Case in point: It took years for Apple, Qualcomm, Intel, MediaTEk, and Broadcom to get their act together on WiFi 5 in regards to combining multiple channels together to increase bandwidth in the same frequency range much less across frequencies.
On the Ground Conclusions
- Don’t rush out and buy the latest technology and expect it to work correctly or with all of your devices. Given historical precedent, this movement to WiFi 7 will be a mess for a while.
- WiFi 6 is just starting to get stable, making it the most desirable technology right now
- Wait. As you buy new products over time that support WiFi 7 out of the box you will realize any benefits it may bring. Or not. WiFi 7 is not a panacea.
Is Wired Ethernet Dead Yet?
Ah! So now we come to the big question. Did WiFi 7 kill the wired Ethernet party? No. That is a simple and succinct answer and here are the reasons:
- Wired Ethernet technology is finalized and very stable
- Wired Ethernet is extremely fast and a network constructed with it will not have any overlap issues or interference issues nor constant updates to keep one manufacturer’s device working and playing nicely with the others
- The cost of implementing actual stable 10 Gb/s networking in your home has dramatically decreased in the last five years. Most modern computer motherboards and pre-built systems come with at least a 2.5 Gb/s Ethernet port thanks to NBASE-T. 2.5 Gb/s Ethernet is supported even by lowly Cat5e, which won’t require you to change out our wiring if you are strapped for cash or time. See Just What is NBASE-T?
- The speeds of Ethernet are not theoretical. They are real. When you use WiFi of any flavor, your actual speed is going to be much lower than the advertised “pie in the sky” speed due to a myriad of factors.
Of course wired Ethernet has to be installed, which is the main downside. It requires some sweat and maybe even getting on ladders. You certainly cannot plop it onto a desk in your living room and expect it to work right without effort. The old adage of “no pain, no gain” comes to mind. Nothing worthwhile comes free and easy. Don’t confuse any variation of WiFi by itself as a shortcut to a well planned and well functioning network. You are likely to be disappointed.
And there you have it. WiFi 6 through WiFi 7 explained, all in one spot and compared. WiFi technology is of great benefit to mobile devices and will remain inextricably linked to wired Ethernet for the foreseeable future. Both technologies have their pros and cons and a properly implemented modern network makes use of both wired and wireless technology to serve you, the human. With that I will say…
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