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Multi-Link Operation, or MLO, is arguably the most exciting and promising feature of Wi-Fi 7 on paper. In reality, its real-world usefulness can be subdued.
This post will explain this feature in detail and set the right expectations, including when you can expect MLO from your hardware. All that is based on my years-long real-world testing and serious use of Wi-Fi 7 hardware.
Unfamiliar with Wi-Fi 7? Check out the primer post on this Wi-Fi standard first.
Multi-Link Operation: A close look at the first bonded Wi-Fi link
To understand Multi-Link Operation (MLO), we first need to be aware that up to Wi-Fi 6E, a Wi-Fi connection between two direct devices occurs in a single band at a time. Specifically, no matter how many bands a broadcaster (router or access point) has—dual-band, tri-band, or even quad-band—a particular client will only connect to one band at any given time.
Multi-Link Operation changes by combining two or more bands into a single wireless link via a bonded SSID, allowing a client supporting this feature to use multiple bands at the same time. You can think of MLO as Link Aggregation in the world of wired connections.
That said, MLO is possible as long as the hardware has more than one band, which is always the case with Wi-Fi 7: the broadcasters are always dual-band, tri-band, or quad-band, and the receivers, such as the Intel BE200 or Qualcomm NCM865, are always tri-band.
So, the idea of MLO is simple enough.
Multi-Link Operation: The complicated details
Unfortunately, the devil is always in the details.
The first thing to note is that MLO is firmware-based and not a required feature, meaning it may or may not be supported by a particular device. Some Wi-Fi 7 broadcasters may not have this feature initially, and if so, the feature can be added via a firmware update or not at all.
Secondly, with simplification, there are two main MLO operation modes:
- Enhanced Multi-Link Multi Radio (EMLMR): It’s a multi-link aggregation using all available bands (2.4GHz, 5GHz, and 6GHz) to deliver higher throughput, lower latency, and better reliability.
- Multi-Link Single Radio (MLSR): It’s a multi-link using dynamic band switching between 5GHz and 6GHz to deliver load balancing and lower latency. (For dual-band hardware, this mode switches between the 2.4GHz and 5GHz bands.)
Thirdly, it’s worth noting that the EMSR (#2) is more popular, especially on the receiving end. So far, there is no end-device that supports EMLMR (#1) on the market.
As a result, no matter which mode is used, from an end device’s perspective, MLO increases or improves the bandwidth. The fastest link a client can get from an MLO SSID is still the speed of the fastest band at any given time, which is likely the 6GHz or 5GHz.
The point is that MLO affords supported clients the best probability of connecting successfully at the highest possible speed using the fastest band at any given time. It doesn’t give the user an actual faster rate of the bands’ combined bandwidth, which has been consistently the case in my testing.
Finally, how MLO pans out in the real world varies depending on many factors, such as the hardware specs of involved devices and the distance between them. As a result, keep the following in mind about MLO in consumer-grade hardware:
- By nature, link bonding is more complicated than single-band connectivity—there are just too many variables.
- MLO only works with supported Wi-Fi 7 clients. (To support MLO, a Windows computer must run Windows 11 24H2 or later.)
- Wi-Fi 6 and 6E and older clients will still use a single band at a time when connecting to an MLO network (SSID) and will pick whichever is available in the bonded link.
- An MLO SSID requires the WPA3 encryption method and won’t allow legacy clients to connect.
- The reach of the bonded wireless link (the range) is as far as the range of the shortest band involved (often the 6GHz).
Wi-Fi coverage can be tricky. Since the 6GHz band has just about 75% of the range of the 5GHz when the same broadcasting power is applied, MLO is truly meaningful with the help of Wi-Fi 7’s other optional feature, the Automated Frequency Coordination (AFC). Per my experience with the first official AFC-ready hardware, the Ubiquiti UniFi E7, at best, MLO’s effective range is that of the 5GHz band.
And there’s more to note about MLO in real-world usage.
Multi-Link Operation in real-world usage
In my real-world experience, MLO can be quite fastidious. It’s not as rosy as it’s cracked up to be by hardware vendors.
The gist is that this feature is great in a fully wireless mesh system and relatively insignificant, if not a drawback, in serving clients.
Multi-Link Operation on broadcasters: A game-changer in wireless mesh backhaul, when available
For those who need to extend their Wi-Fi coverage without running network cables, which is common in most homes, MLO can play a significant role. It helps improve the wireless backhaul link between a Wi-Fi system’s broadcasters.
Not sure what backhaul is? The cabinet below holds a quick refresher.
Backhaul vs. fronthaul
When you use multiple Wi-Fi broadcasters—in a mesh Wi-Fi system or a combo of a router and an extender—there are two types of connections: fronthaul and backhaul.
Fronthaul is the Wi-Fi signals broadcast outward for clients or the local area network (LAN) ports for wired devices. It’s what we generally expect from a Wi-Fi broadcaster.
Backhaul (a.k.a backbone), on the other hand, is the link between one satellite Wi-Fi broadcaster and another, which can be the network’s primary router, a switch, or another satellite unit.
This link works behind the scenes to keep the hardware units together as a system. It also determines the ceiling bandwidth (and speed) of all devices connected to the particular satellite Wi-Fi broadcaster.
At the satellite/extender unit, the connection used for the backhaul—a Wi-Fi link or a network port—is often called the uplink. Generally, a Wi-Fi broadcaster might use one of its bands (2.4GHz, 5GHz, or 6GHz) or a network port for the uplink.
When a Wi-Fi band handles backhaul and fronthaul simultaneously, only half its bandwidth is available to either end. When a Wi-Fi band functions solely for backhauling, often available traditional Tri-band hardware, it’s called the dedicated backhaul.
Generally, for the best performance and reliability, network cables are recommended for backhauling—wired backhauling, which is an advantage of mesh Wi-Fi hardware with network ports. In this case, a satellite broadcaster can use its entire Wi-Fi bandwidth for front-hauling.
Via my testing method, I’ve seen sustained MLO backhauling links with over 5Gbps of bandwidth at 40 feet away with a line of sight. In modest cases, this link can still sustain at Gig+ or low multi-Gigabit.
It’s worth noting that in a mesh setup, vendors have the option to use the MLMR MLO if the chipset supports it, which truly helps increase the bandwidth. (Again, this mode is generally not yet supported by any end client.)
Still, wireless backhaul is always problematic. With a wall in between, the signal will be reduced significantly. Additionally, just because you use a Wi-Fi 7 mesh system doesn’t mean MLO is available.
Indeed, to have MLO as the backhaul link of a mesh, all broadcasters within the system must use the same Wi-Fi specs. In other words, you should expect MLO only when you use the same hardware units (the same model) or units of a purpose-built MLO-enabled mesh pack throughout the entire system.
If you mix Wi-Fi 7 broadcasters of different tiers, bands, or sometimes even hardware models, MLO is highly unlikely to be available as the backhaul link.
Furthermore, you need to arrange the hardware in the star topology, with the satellites placed around the primary router. If you place them in a linear (daisy-chain) arrangement, MLO is not available as backhaul starting at the second hop.
Since the MLO backhaul can be finicky, some vendors have opted not to use it for now—such as Ubiquiti with its UniFi Express 7, likely due to the currently lack of MLSR MLO support in the chipset—in an attempt to simplify the system and improve its reliability.
So, MLO is excellent for a wireless mesh system, but only when it’s available, which is not always the case. The point is: don’t assume that it’s there!
Multi-Link Operation on clients: Comparably unimpressive real-world data rates, no backward compatibility
If you think MLO as mesh backhaul is unfulfilling, you’ll be disappointed to learn about its effect on end-clients.
In my experience, MLO has proven ineffective as the fronthaul. In fact, with it, you trade the sure lack of backward compatibility for (almost) no impact on performance.
That’s my general experience when using a single Wi-Fi 7 broadcaster or a system via wired backhauling. In this case, devices with built-in Wi-Fi 7 adapters, such as the Intel BE200 or Qualcomm NCM865 chips, both of which are MLO-enabled when used with Windows 11 24H2 or later, do not enjoy improved data rates via an MLO link—likely due to the lack of MLMR support.
Specifically, despite the high negotiated speed shown in the bonded link’s status, an MLO-enabled SSID often yields a lower real-world rate than a 6GHz or 5GHz SSID from the same broadcaster. In other words, as mentioned above, an MLO connection can give you a good feeling when checking the link’s status, but it won’t actually improve real-world data rates of any particular application.
As for the “low latency” notion, that’s completely presumptuous. I’ve never seen an MLO do better in terms of lag compared to a pure 6GHz or 5GHz connection. Considering the airspace can be temperamental, though, the ability to automatically switch between these two bands never hurts.
As such, MLO seems more of an enhanced version of the finicky “Smart Connect“, where a single SSID is used for all of the broadcaster’s bands, than a performance upgrade. In fact, to use MLO with a broadcaster’s primary SSID, you need to either enable Smart Connect or at least use the same network name (SSID) for the bands you want to be part of the bonded link.
Aside from all that, the use of MLO can be problematic, considering the security requirements mentioned above. Putting a band in an MLO SSID means you must use it with WPA3 as the authentication method. As a result, millions of legacy devices that support WPA2 or lower can’t connect to this SSID.
Here’s the kicker: Many home-grade broadcasters, such as those in the Netgear Orbi or Amazon eero family, do not have generous virtual SSID options beyond the primary one, further complicating the support for legacy clients.
In any case, keep the following in mind when considering MLO for the fronthaul:
- Turn MLO off and get the most flexible SSID configuration options for each band, including support for legacy clients.
- Turn MLO on and:
- Use the primary SSID with MLO, but be aware that it may not support legacy devices. Or
- When possible, use the bands’ primary SSID(s) without MLO, and use a virtual SSID with MLO for Wi-Fi 7 clients. Or
- When possible, use the primary SSID with MLO and separate non-MLO virtual SSID(s) with lower requirements for legacy clients.
That said, for the fronthaul, MLO is best used when you have only Wi-Fi 6 and newer clients, which won’t be the case for years. Until then, this feature should be turned off when using a single Wi-Fi 7 broadcaster or a mesh with wired backhaul, unless you have the option to create (enough) additional virtual SSIDs with lower security requirements for existing clients.
Top 5 best Wi-Fi 7 mesh Wi-Fi systems
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| Name | Asus ZenWiFi BT10’s Ratings | Asus ZenWiFi BQ16 Pro’s Rating | Netgear Orbi 870 Series’s Rating | TP-Link Deco BE85’s Rating | Linksys Velop Pro 7’s Rating |
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The takeaway
The idea of Wi-Fi 7’s Multi-Link Operation is great, but its practical application in the real world is nuanced.
It’s safe to say that when you use a mesh system that features MLO, the wireless backhaul link is excellent. But just because you use a Wi-Fi 7 mesh system doesn’t mean MLO backhaul is a given.
The point is that Multi-Link Operation is more of a marketing ploy than a real-world benefit, at least for now. If you can use it, it doesn’t hurt, but your feelings might get seriously hurt if you assume it will be there for you in your particular situation. Consider yourself warned!
Hello Dong,
I recently upgraded my AiMesh to BE98 Pro as main router and two BQ16 pro as nodes in full wireless setup. However I found that MLO backhaul is not available. After searching, I found the ASUS website states MLO backhaul is only available between same models.
I am wondering if it’s technically difficult to add MLO backhaul feature between different models. How likely will ASUS add the feature in a future firmware?
That’s to be expected, Wei. More here. That particular combo only makes sense, financially among other things, when you use it via wired backhauling.
> despite the high negotiated speed shown in the bonded link’s status, an MLO-enabled SSID often yields a lower real-world rate than a 6GHz or 5GHz SSID from the same broadcaster.
omg I thought I was doing something wrong. especially when I switched to dedicated 6ghz and got better speeds and signal strength too. why is that though? even tplink mentions on all FAQ that this could happen with MLO. will existing MLO APs do ok with better client implementation in the future? the faq from tplink seemed to suggest the issue was mostly down to implementation as the standard is so new. or is MLO as standard itself flawed and we’ll never see things like the negotiated phy rate as actual speed or better stability or something?
That happens in Link Aggregation, too. Its bandwidth vs. speed, similar to the case of dual-WAN. So, it’s not flawed, it’s just physics.
oh interesting. Sorry, I missed that where you said that, i see it now:
> client’s particular application still uses one band at a time.
But let me ask you then, what is the “best case future scenario” you see for MLO? Like let’s say we have the best Wifi7 broadcasters from today and some future wifi7 device that implements MLO in a good way, what can i *hope* to see as an improvement over non MLO, just using 6ghz wifi? Or, if i could put it a bit bluntly: what is the point of MLO, ultimately? (beyond the marketing hype etc)
As mentioned above, that would be when you use MLO as the backhaul in a mesh system. In my experience, the satellite unit can use the link as its backhaul which had more (and more reliable) bandwidth than when one band is working as such at a time. For clients, the point of MLO is convenience and the chance of the best-possible given the airspace. It doesn’t mean it’s *always* the best in data rates, but it’s collectively the best. And of course, it’s also a nice marketing ploy (again, as mentioned in the post).
In any case, make sure you read the entire post first. Else, you’ll miss a lot more. One of the rules is that you need to first read before leaving a comment.
Hello Dong,
My question is about the two MLO options I have with my ASUS BQ16 twin set.
One option is to use “2GHz, 5GHz and 6GHz” bands as MLO, and the other (Default) is “5GHz-1, 5GHz-2 and 6GHz”.
I wonder what would be the recommendable choice, having in mind I plan to use MLO only as a backhaul.
Thanks for your help and commitment.
Those are two different modes as mentioned above, Steve. In my experience, they are similar in terms of performance at a certain range. You can use either and it’s no the end of the world to switch between them when you change your mind.
Well, of course I switched the MLO bands several times and didn’t see any notable difference.
In fact, my curiousity to ask such a question, was inspired by the presence of this snail-slow, obsolete and trimmed 2.4GHz band, as a part of the top-of-the-tier, ultra modern and speedy Wi-Fi 7 feature, as MLO is.
In other words – how can this archaic slow 2.4 GHz band play any role at all in the super-speed world of Wi-Fi 7?
2.4 GHz is mainly a legacy band for Wi-Fi 7; it’s mostly used by older devices that weren’t made for 5 GHz (like IoT devices not made for true “wireless mesh” networks like Z-Wave, Zigbee, Matter or Thread), or for extended range (greater than the other two frequencies). The Wi-Fi 7 protocol alone only slightly boosts speeds at 2.4 MHz, and may actually be a hindrance to devices expecting older Wi-Fi protocols. There’s not a lot of benefit for 2.4 GHz in future years.
As far as MLO, my guess is you have more than enough bandwidth & signal that your 6 GHz band plus one of your 5 GHz bands is all the wireless backhaul you can use; it makes no difference if you add the other 5 GHz band or the 2.4 GHz band. (Probably best to avoid the 2.4 GHz band for MLO in that case.) If you’re still not getting most of your Internet speed to your satellite BQ16, try wired backhaul.
Thank you for your opinion and advice. In fact I don’t have any connection issues, BQ16 AiMesh is doing fine, speeding right to the top.
I was just wondering what has to do granny old and slow 2.4 GHz band amongst the WiFi-7 MLO standards. Simply I can’t find any technical logic and explanation for 2.4 GHz participation in MLO tier bands.
It’s obvious why Wi-Fi 7 routers still have a 2.4 GHz band in general — backwards compatibility; some of them retain Wi-Fi 6 protocols on that band while others support Wi-Fi 7 protocols there as well. And though including 2.4 GHz in MLO can slow down performance especially for backhaul (as my latest Deco firmware update appears to acknowledge), my guess is it’s included to help Wi-Fi 7 clients on the edge of the AP’s range more easily maintain a connection; even though 2.4 GHz will never be as fast as the other two bands, it can’t be beat on range.
As mentioned in the post, Steve, it’s part of what that makes MLO the “enhanced version” of Smart Connect. When you’re at a distance out of the 6GHz and 5GHz’s range, you’ll still get connected without having to manually switch the SSID. There’s more in a connection than just speed.
Great info on the MLO. I hooked this up on a mesh, wired network, between an Asus BE7200 and an AX89X. Had been informed previously that the AX89X supported MLO, but when signals began to drop repeatedly I did some further investigation and found that that information on the AX89X was incorrect. It just didn’t work at all. Needless to say, had to turn the MLO off, and once I rebooted everything, the mesh was good again.
From what I read in your post, it sounds like the concept is good but the functionality will only benefit when everything is perfect, and I think that is still going to be a stretch for most of us.
Appreciate the great research and write up, as always.
MLO is only available in Wi-Fi 7, John. Whoever told you the RT-AX89X had it had no idea what they were saying or simply lied to you.
I should note that TP-Link Decos with Wi-Fi 7 treat their “Backhaul Aggregation” feature as separate from MLO, as it potentially aggregates all Wi-Fi bands plus even a wired connection as backhaul — though I can’t see what benefit adding Wi-Fi to 2.5GbE wired backhaul can bring to my BE63 (perhaps Decos with faster WAN ports can use it), and its newest firmware update defaults to disabling 2.4 GHz backhaul as they say it can impair legacy clients. That does sound a lot like MLO, but maybe just slightly different? It did allow me to move my two BE63s from my old house to a small apartment where my 1 gig fiber Internet is in the back while my TV is in the front; they’re close enough that wireless backhaul alone delivers nearly full speed to my wired streaming boxes & a few Wi-Fi 6E/7 clients.
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