Can WiFi 5 and WiFi 6 routers be used interchangeably? Don't rush to throw away your old router—I've tested all three connection methods

last month, my main router at home was switched to a Xiaomi AX3000T and WiFi 6 machine. Before switching, I even did a thorough calculation of the WiFi 6 and WiFi 7 accounts (see this article ). I replaced it with a TP-Link WDR7660 that's been in service for over four years, a veteran of WiFi 5. It's a shame to throw it away, and it's only a few dozen yuan for second-hand use. I thought about mixing the two, but found that the term 'mixed' was too vague—the way they mix is different, and the experience is worlds apart. I've written down the three connection methods I've tried and tested the data, for reference to others who still have old routers.

leave the conclusion here: you can get through, but there are three tiers of ways to do it

"WiFi 5 and WiFi 6 mixed" actually hides three completely different scenarios, and many people argue for a long time but find they are not the same:

The first is device —you have a WiFi 6 router at home, but your phone, tablet, and old laptop still have WiFi 5, so you can connect together. The second is wired cascaded hybrid —old WiFi 5 routers are connected by cables under the main router as an AP, each managing a piece of land. The third is wireless relay hybrid —old routers have no network cables to pull and rely on wireless relay to the main router's signal.

the first method basically comes at no cost; the second depends on your needs; the third type I advise you to think twice. Let's talk about them one by one.

"Old devices connected, the whole network turns into WiFi 5"? I tested it specifically—it's fake, but there's a bit of authenticity

Before

upgrade, I saw a forum saying: if a WiFi 5 device connects to a WiFi 6 router, the entire network will be dragged back to WiFi 5, so everyone should slow down. This rumor made me feel uneasy, so I spent the whole night testing myself.

let's start with the test environment: 500Mbps broadband, AX3000T 5G band, dual-band integration turned off, router placed on the living room coffee table. The WiFi 6-supporting phone tested speeds at 487Mbps, near the bandwidth limit. Switching to that old phone that only supports WiFi 5, connected to the same WiFi at the same location, the negotiated speed next to the status bar is 867Mbps—this is typical WiFi 5 at 2x2 antennas with 80MHz bandwidth, no 160MHz, and no WiFi 6 new features, measured downlink speed of 398Mbps.

key point: then I tested with a WiFi 6 phone, 487Mbps, and it didn't change at all. two devices connect at their own speeds, there is no such thing as "downgrading the entire network to the lowest one."

where is that 'even a bit of truth'? During the idle time. Only one device can speak at the same time on the same frequency band over a wireless network, which is determined by the queue mechanism (I drew a queue chart in OFDMA ). I took my old WiFi 5 phone to the corner of the bedroom, with a signal of -75dBm, set it to download at full speed, and tested the WiFi 6 phone in the living room — dropping from 480 to around 310. Slow devices with weak signals hoarded the microphone, forcing others to wait. This effect is even more pronounced in 2.4G, while 5G is better due to its abundant bandwidth.

the correct explanation is: older devices won't "drag down the protocol," but weak signal slow devices will "take up more space." Putting old equipment in a signal area is better than anything else.

old WiFi 5 router when the AP is cascaded: it only has WiFi5

the second mixing method was what I ultimately adopted. Run a network cable from the AX3000T LAN port to the bedroom, connect it to the WDR7660 LAN, turn off DHCP on the old router, and use it purely as an AP. I covered the specific wiring methods and pitfalls I wrote about router AP before.

after that, the WiFi in the corner of the bedroom was WDR7660 to be delivered. When a WiFi 6 phone connected, the negotiated speed capped at 867Mbps—since the AP itself is WiFi 5, your phone supporting WiFi 7 doesn't matter; the lower limit of the link is up to you. Actual tests of 500 Mbps broadband running 370 to 400 Mbps in a bedroom.

sounds like a loss? Let's see who you're competing against. 370MB means downloads of tens of MB per second, 4K streaming requires only 25Mbps, and gaming costs just a fraction. Unless your home uses gigabit broadband and your bedroom is running at full speed, you won't notice this loss at all. If you really care, there's only one option: switch to a WiFi 6 AP or Mesh node, which is a different budget story.

one thing you must mention: the WiFi names of both routers are the same. At first, I chose the same name for convenience: when my phone moved from the living room to the bedroom, it stuck to the weak signal in the living room and wouldn't switch—whether roaming switches or not is up to the phone, which tends to favor the old connections that 'still work,' which is the same thing I complained about in my Mesh roaming sticky . Later, I changed the old AP's name to include the "bedroom" suffix, so whichever signal works best, manual selection is the most reliable.

Wireless Relay Mixed: The Worst Cost-Effective Tier

study room didn't have a pre-installed network cable, I tried a third option: WDR7660 wireless relay AX3000T. This account is both the easiest to calculate and the ugliest to look at.

relay mode naturally folds in half first—the same machine must receive signals from both the main router and the underlying devices, with both transmitting and receiving queued on a single antenna. I previously tested relay with two AX3000T, and the 280MB main link was down to 110MB (the process is described in the wireless relay setup ). This time, using an old WiFi 5 device as the relay was even worse: the backhaul ran on the WiFi 5 AC protocol, and the phone only got 70 to 80 Mbps after passing through.

What does

70 Zhao mean? When two or three people watch HD videos at the same time, they start dragging each other out. So the conclusion is straightforward: if you have a network cable at home, even if it's just an exposed cable running along the corner, don't mix it with wireless intermediate storage. If you installed network cables during renovation, just look at how to choose between AC+AP and Mesh —that's the right approach.

old equipment: 2.4G IoT private networks are perfect for waste utilization

tried three connection methods, the final position I assigned to WDR7660 was a bit unexpected: dedicated to maintaining 2.4G smart devices.

IoT devices at home—robot vacuums, speakers, temperature and humidity sensors—only recognize 2.4G, but the main reason for network failure is frequency band issues ( only recognize 2.4G I only realized it after five explosions). These devices have very little data per unit, but they have no requirements for WiFi 5 or WiFi 6—2.4G runs on old protocols, and the new features of WiFi 6 routers on 2.4G are meaningless to them.

so the old AP only released 2.4G, with WiFi named specifically for IoT, and the main router's 2.4G and 5G bands kept separated. There are two benefits: the storm of collective connection of smart devices does not reach the main network; The main router's 2.4G channel is also quiet. A four-year veteran is more than capable of handling this job.

Conclusion: One Comparison Table and Three Rules

three mixing methods to look at together:

three rules: if you have a network cable, use cascading; relay is the only solution; Name the two routers separately; don't pretend to be an integrated Mesh; 2. 4G old equipment is dedicated to old routers for separate maintenance, while the main network is reserved for new devices.

mixing is not shameful; think carefully which machine to manage which stall; old routes can still last a few more years.