TP-Link Archer AX80

Netgear R7800 4x4 802.11ac "Wave 2" Wi-Fi 5 Router

But let's also be very realistic. If you have 400 Mbps (or less) Internet speeds, 2×2 MIMO Wi-Fi 5 to your router is almost always sufficient -- and IS fast enough -- even with an older high quality "wave 2" 4×4 MIMO 802.11ac router (an example of one is seen right).

KEY Wi-Fi concept: Client devices often limit speeds, not the router/AP.

AC5300 4×4 Router to 2×2 Client (at a distance of 32 feet) 5300 → 2166 → 1083 → 866 → 650 → 455

AC5300 4×4 Router to 4×4 Client (at a distance of 32 feet) 5300 → 2166 → 1733 → 1300 → 910

More on bands in the Beware tri-band marketing hype section far below.

Wi-Fi specifications for iPhone, iPad, or iPod. Virtually all newer iOS devices are 2×2 MIMO and older iOS devices are 1×1 (no MIMO).

Analogy: Understanding Modulation/Coding: Imagine that once a second, you hold up your arms in various positions to convey a message to someone else. If you were only ten feet away from that person, the number of arm positions reliably detected would be very high. But now move 100 feet away. The number of arm positions reliably conveyed would be reduced. Now move 500 feet way. The number of arm positions reliably conveyed might be reduced to just 'did the arm move at all'. The same thing happens in wifi. If you are close to the AP/router, a large number of bits can be conveyed 'at once'. But as you move away, a smaller and smaller number of bits can be reliably conveyed 'at once'. So 'modulation/coding' is simply how much information can be conveyed at once, and is directly related to distance from the AP/router.

Just Google 802.11ac MAC efficiency to understand this issue. In short, there are 'housekeeping' packets that MUST be sent at the SLOWEST possible modulation, and that takes time and slows everything down (along with other issues, see understanding Wi-Fi overhead)

Analogy: You are on a road going 60 mph, but every 100 feet you must slow down to 1 mph for 1.5 feet. Do the math - your average mph is deceptively much lower than you might think. Because what matters is not the (minimal) distance traveled at the slow speed, but the TIME that it takes.

An analogy for all of the above: What if I built a three lane toll road from Washington, DC to New York, NY, and sold passes for chauffeured rides with speeds "up to 74 mph" (AC5300). But after you pay for a ride, you discover that the speed limit is 30 mph (AC2166) on two of the lanes and 14 mph on the third lane. So you take the 30 mph lane, but find out your chauffeur is only driving at 10 mph (MIMO level and QAM) and worse yet, every 100 feet the chauffeur slows down to 1 mph for 10 feet (MAC efficiency). Your average speed is 5 mph. And yet, that is exactly what router manufacturers are doing to you -- AC5300 is really only 455 Mbps for most wireless devices -- just like 74 mph is really 5 mph.

• for Wi-Fi 3, 54 Mbps
• for Wi-Fi 4, 144 Mbps (20 MHz channel), or 300 Mbps (40 MHz channel) -- 64-QAM, 2×2 MIMO
• for Wi-Fi 5, 866 Mbps (80 MHz channel), or 1733 Mbps (160 MHz channel) -- 256-QAM, 2×2 MIMO
• for Wi-Fi 6, 1200 Mbps (80 MHz channel), or 2401 Mbps (160 MHz channel) -- 1024-QAM, 2×2 MIMO

KEY Wi-Fi concept: Client devices often limit speeds, not the router/AP.

Your device (not the router) is almost certainly limiting Wi-Fi speeds

Expect throughput anywhere from 60% to 80% of PHY speed. So use 70% (±10%) as a fair estimate.

In a real-world test, on a 2×2 866.6 Mbps PHY link, I measured 461 Mbps (53%) download speeds on one (very old) computer, 540 Mbps (62%) on a second computer, and 673 Mbps (78%) on a third (brand new) computer. All tested just feet away from the same R7800 router. So brand new client hardware seems to perform much better than years old client hardware.

PHY speed is an indicator of: (1) channel width, (2) modulation/coding (distance from router), and (3) minimum MIMO level support. Please note that the PHY speed displayed is not a static value, but changes over time, depending upon distance from AP/router, interference, etc.

PHY speed tables: If you don't find your PHY speed in the PHY tables in this paper below, look up the speed in the full PHY speed tables.

Windows PHY Speed

Example: Lookup 702 Mbps speed (right) in the PHY tables far below and it is not found. So, go to the full PHY speed tables and you will find various matches, but only one makes logical sense: 80 MHz channel, 2×2 MIMO, 256-QAM.

The PHY speed reported by Windows appears to actually be the maximum of both the Tx PHY and the Rx PHY speeds. Some tests showed the speed reported as the Rx PHY speed. Other tests showed the speed reported as the Tx PHY speed. Also, if Windows is getting the PHY speed from the wifi driver, this observation could be very wifi device (and vendor) specific. Running "netsh wlan show all" (from a DOS CMD prompt) displays a ton of wireless information, including both Tx and Rx speeds for the wifi interface, but on my test systems, both speeds are always the same Mbps value (which is not accurate). It might work better for you?

UPDATE: Here is a tip I received -- if you happen to use Apple's AirPort WiFi base station: "Install Apple's 'airport utility' and then open it. Click on the wifi base station. Click on 'wireless clients' and then click on your iOS device and then 'connection'. This will give you the iOS device 'PHY' connection speed."

Android PHY Network Speed

Example: Lookup 585 Mbps (right) in the PHY tables far below, and you will find it in multiple columns, but given the client, what makes the most sense is: 80 MHz channel width, 2×2 MIMO, and 64-QAM.

It appears that Android reports the "Tx PHY" as the 'link speed'. This is preliminary and needs more research.

Supporting 4×4 MIMO takes a lot more power, and for battery powered devices, runtime is FAR more important.

You will see the spec sheets for many modern phones that MIMO is 4×4, but look closely and notice that this is only for cellular, not Wi-Fi.

However, of note is that many (non-Apple) Wi-Fi 6/6E devices support 160-MHz channels (HE160), which instantly doubles throughput vs Wi-Fi 5 using 80-MHz channels (VHT80). So speed is increasing dramatically via wider channels, not increased MIMO levels.

A final wrench in the PHY puzzle: And PHY speed is not 'constant'. Unless you are right next to the router (with a fantastic signal strength and PHY speed is highest possible speed), PHY speed is actually constantly changing up and down between MCS levels, adapting to changing signal strength conditions. It is not uncommon with a single second to see 3 to 4 different MCS levels (PHY speeds) used. Are you highly technical? Then use the Router deep dive appendix below to determine exactly what MCS indexes are being used for both Tx PHY and Rx PHY.

KEY Wi-Fi concept: Expect Wi-Fi throughput to be around 70% (±10%) of PHY speed.

What I am beginning to realize is that the PHY speed reported by wifi devices is a best case value (and may not accurately reflect the actual PHY speed used). The MCS Spy tool has been invaluable in detecting and visualizing this during a throughput speed test. PHY speed also can fluctuate a lot up and down, and is not a 'fixed' single value. Also, the newer the device the better. There appears to be some issues with older 802.11ac devices (not achieving top rated speeds).

With both a modern client device and a modern router, and no one else using Wi-Fi -- so NO contention -- I regularly measure maximum throughput to be around 80% of PHY speed.

PHY speed in wifi is exactly like the speed limit (sign) on a local road. You can go that fast some of the time but clearly not all the time. Because you must take into account known slow downs: stop signs, turns, traffic lights, traffic, school zones, weather conditions, etc. And in Wi-Fi, there are a lot of slow downs that add up.

SSID overhead: The overhead per SSID (on one channel) can be anywhere from 3% to incredibly high. See this article (using a 802.11b 1 Mbps beacon rate) for details.

A striking analogy: You are on a road going 120 mph, but for 40 feet of every mile (or 0.75% of 5280 feet) you are required to slow down to 1 mph. What is your average mph for the entire mile? -- lower than you might expect. The answer is 5280/(5240/120+40/1), or 63 mph! It is not the distance that you slowed down that is important, but rather the time you spend slowed down that really matters (as compared to the time you spend going fast).

So when you are running that download throughput speed test, your device is mostly receiving, but it is also transmitting (acknowledging data sent)! Using the MCS Spy tool (Router deep dive appendix below), a PC downloaded at 120 Mbps, but was uploading at 1.8 Mbps at the same time. This is simply due to how TCP/IP works. And almost always, the client transmits back to the AP at a slower MCS than the MCS the router uses to transmit to the client. So because wifi is half duplex, there may be around 1% to 3% (relative) 'overhead' simply due to how TCP/IP works (acknowledgements).

Analogy: Wi-Fi spectrum is just like a narrow bridge. Cars (Wi-Fi traffic) can either go one way or the other, but not both ways at the same time. OR, like a walkie talkie, where you can either talk, or listen, but not both at the same time.

And if you have a lot to transmit, that 'wait for a random amount of time' over and over adds up. But that random wait is necessary to ensure 'fairness' to other wifi devices.

CSMA/CA works very well when there are not many devices all wanting to transmit at the same time (which IS typical in Wi-Fi, which is why it mostly works so well). But overhead can increase dramatically if there are too many devices all wanting to transmit at the same time (due to collisions; see below).

From a test AP, there were 1,519,932 packets transmitted and 48,878 packets retransmitted. So, around 3% of the data packets had to be retransmitted.

Wi-Fi hidden node problem

A mitigating factor is that even if your network has the hidden node problem, the hidden nodes will not impact each other, unless they attempt to use wifi and transmit at the exact same time. If both hidden nodes are sporadically using wifi, the problem will not happen that often.

How is Wi-Fi spectrum shared? By bandwidth? By time? By something else? In general, by TIME -- if 'N' users all want to use Wi-Fi at the same time, on average, they will all get to use the channel '1/N' of the time. For example, if two users want to use the same channel, and first user at a PHY of 6 Mbps, and the second user at a PHY of 866 Mbps, the first user will get to use the channel 50% of the time (so 6/2, or around 3 Mbps), and the second user will get to use the channel the other 50% of the time (so 866/2, or around 433 Mbps).

This 'a channel is shared' concept is easy to gloss over and not fully understand. But if you see (in a Wi-Fi analyzer app) that your wireless router and other wireless routers (neighbors) on the same channel (or overlapping channels), you are sharing the SAME wifi spectrum.

A striking example: A laptop in the same room as an AP (on the second floor of a house) with an unobstructed view of the AP gets real-world Tx average throughput of 92 Mbps (measured using TxRate). But when the laptop is moved downstairs (so now the Wi-Fi signal has to go through walls/floors), Tx throughput increases to a rock solid 116 Mbps. How is that possible? -- throughput should have decreased! The surprising answer is that downstairs, neighboring Wi-Fi signals were greatly attenutated, so the laptop transmitted more often. And yes, that means the laptop WAS actually transmitting at the same time as a far away station but all that did is raise the noise floor for those transmissions, which were still successfully received.

A prime example: A Windows laptop with an 'older' 802.11ac 2×2 MIMO four feet from the router reports (an expected) 'speed' of 866.6 Mbps (MCS9). A throughput tests shows download speeds of 475 Mbps. That is a MAC efficiency around 55%. But the MCS Spy tool (see Router deep dive appendix below) clearly shows that the router is transmitting to the PC using only MCS7 (650 Mbps), which is actually a much better MAC efficiency of around 75%. There is still the problem of why MCS9 is not being used, but MAC efficiency is much better than it initially appears.

• Wi-Fi Overhead, Part 1: Sources of Overhead (CWNP)
• Wi-Fi Overhead, Part 2: Solutions to Overhead (CWNP)
• RTS/CTS enhanced with bandwidth signaling (Cisco)

KEY Wi-Fi concept: There is a lot of marketing hype in the claims made by router companies.

iPhone XS Max

1. Band One: 750 is the maximum PHY speed for MIMO 3×3 in the 802.11an band, but for an unrealistic 1024-QAM (see PHY table far below). A much more realistic PHY speed for a 2×2 MIMO wireless device is 300 Mbps.
2. Band Two: 1625 is the maximum PHY speed for MIMO 3×3 in the 802.11ac band, but for an unrealistic 1024-QAM (see PHY table far below). A much more realistic PHY speed for a 2×2 MIMO wireless device is 650 Mbps (about 32 feet from the router).
3. Band Three: same as band two.

So upgrading to a faster router will increase your iPhone XS Max speeds, right? No! What about an AC5400 4×4 tri-band router? Same speed. What about a brand new ultra-fast Wi-Fi 6 AX6000 8×8 router, marketed as being 4x faster than Wi-Fi 5? Same speed. Understand router manufacturers' marketing hype.

4×4 MIMO illustration

Analogy: Think of MIMO as adding 'decks' to a multi-lane highway. More lanes (capacity) are added without using more land (spectrum). 2×2 MIMO is a highway with one more highway deck above it. And 4×4 MIMO is a highway with three more highway decks above it.

MIMO adds more capacity without using more spectrum!

The huge caveat, of course, is that BOTH the transmitter and receiver must support MIMO. And if each supports different levels of MIMO, the minimum MIMO level common to both devices will be used. For example, a 2×2 MIMO tablet connecting to an 8×8 MIMO router will only use 2×2 MIMO. But as a very significant bonus, the 'extra' antennas (if there is a mismatch in MIMO levels between the client and router) do not go unused, but are used for 'diversity' and 'beamforming', which extends range, and improves speed at range.

• 1×1 MIMO yields 433 Mbps
• 2×2 MIMO yields 866 Mbps (most wireless clients are 2×2)
• 3×3 MIMO yields 1300 Mbps
• 4×4 MIMO yields 1733 Mbps (most higher end routers are 4×4)
• 8×8 MIMO yields 3466 Mbps

FCC documents discuss that the 'maximum' gain when doubling antennas is 10×log(N_ANT/N_SS) dBi, which for a 2×2 client to a 4×4 access point, would result in a diversity gain of 'around' 3 dBi.

Comcast XB6 gateway - 8×8 MIMO

KEY Wi-Fi concept: It is easy to overlook and miss, but beamforming and diversity are the key reasons why you want a 4×4 MIMO router even though most clients are still only 2×2 MIMO. The extra antennas are actually used and offer significant value (a stronger signal, which translate to better connect speeds for far-away users)!

AX 'Stream' Deception: Router vendors' are now being incredibly deceptive when it comes to advertising in their new "AX" class of routers. Netgear is using "spatial streams" to describe their new AX routers (page), but this is NOT the same thing as "spatial streams" in MIMO in the 802.11ax standard -- which is what most people will (wrongly) conclude -- and that is outright deceptive, and Netgear knows it (because when I mentioned this in a Netgear forum post, a Netgear moderator deleted my post). Netgear claims their new RAX80 4×4 four-antenna (four spatial streams) router is "8 streams" [page]. So, do your research, and buyer beware. Netgear's "spatial stream" logic is provably wrong. The maximum number of streams in a router can not be larger than the number of antennas in the router. because "In the T×R configuration the maximum number of spatial streams is limited by the lesser of either T or R" [source Cisco]. A pattern emerges: Router vendors are incredibly 'creative' in their marketing of new routers. They are constantly figuring out creative ways to make new hardware sound 'so much better' than older hardware.

• EXCELLENT: 802.11ax Frequently Asked Questions (Aerohive)
• MIMO: Why multiple antennas matter (Cisco)
• FAQ: MIMO, MRC, Beamforming, STBC, and Spatial Multiplexing (Huawei)

Gen	Spec	Year	Speeds	Unofficial name	Band
First	802.11	1997	2 Mbps	Wi-Fi 1	2.4 GHz
Second	802.11b	1999	11 Mbps	Wi-Fi 2	2.4 GHz
Third	802.11a	1999	54 Mbps	Wi-Fi 3	5 GHz
Third	802.11g	2003	54 Mbps	Wi-Fi 3	2.4 GHz

802.11a/g PHY Speeds 20 MHz channel 800ns guard interval Modulation + Coding Mbps 0 BPSK 1/2 6.0 1 3/4 9.0 2 QPSK 1/2 12.0 3 3/4 18.0 4 16‑QAM 1/2 24.0 5 3/4 36.0 6 64‑QAM 2/3 48.0 7 3/4 54.0 More PHY tables

The router industry learned a hard lesson -- that any new router/AP must also be backward compatible (must support most, if not all, of the old client devices out there)! New routers today support ALL prior generations of Wi-Fi back to 802.11b.

★ The big advance in Wi-Fi 3 was the introduction of OFDM, instantly improving throughput nearly five times over the prior Wi-Fi 2 (from 11 Mbps to 54 Mbps; only for AP/clients that support OFDM).

A note about channels: In the U.S. there are 11 overlapping Wi-Fi channels in 2.4 GHz. The only way to get non-overlapping channels is for all routers/AP to cooperate and set their channels to either 1, 6, or 11. But when I use a wifi analyzer, I see routers operating on other channels all of the time. Be a nice neighbor and only use channels 1, 6, or 11. See the drawing in the next section for more details.

• Wi-Fi (802.11) PHY Data Rates (understand how PHY rates are computed)
• Different Wi-Fi Protocols and Data Rates (Intel)

Gen	Spec	Year	Speeds	New Name
Fourth	802.11n	2009	72 to 217 Mbps	Wi-Fi 4

802.11n is called "HT" for High Throughput

Let that sink in. Only 70 MHz of spectrum must be shared between you, and a bunch of neighbors.

2.4 GHz Wi-Fi has only THREE non-overlapping channels

An analogy: A router using channel 2, 3, 4, 5, or 7, 8, 9, 10 (instead of channel 1, 6, or 11) is exactly like a car on a three lane Intestate driving directly over the dashed lane divider lines and refusing to move over into a lane. That 'car' then impacts TWO lanes instead of just one lane.

In a very 'clean' wifi environment, I have seen throughput around 54.2 Mbps for a PHY speed of 72.2 Mbps, which comes out to 75% efficiency -- pretty good. Another time, when I was just feet from the router, I measured a peak throughput of around 118 Mbps for a PHY speed of 144.4 Mbps (82% efficiency) -- very good.

802.11n PHY Speeds (Mbps) 20 MHz channel, 400ns guard interval Modulation + Coding MIMO 1×1 2×2 3×3 4×4 0 BPSK 1/2 7.2 14.4 21.6 28.8 1 QPSK 1/2 14.4 28.8 43.3 57.7 2 3/4 21.6 43.3 65.0 86.6 3 16‑QAM 1/2 28.8 57.7 86.6 115.5 4 3/4 43.3 86.6 130.0 173.3 5 64‑QAM 2/3 57.7 115.6 173.3 231.1 6 3/4 65.0 130.0 195.0 260.0 7 5/6 72.2 144.4 216.6 288.8 - 256‑QAM 3/4 86.6 173.3 260.0 346.6 - 5/6 96.2 192.5 288.8 385.1 - 1024‑QAM 3/4 108.3 216.6 325.0 433.3 - 5/6 120.3 240.7 361.1 481.4 256-QAM and 1024-QAM are non-standard 802.11n PHY Speeds (Mbps) 40 MHz channel, 400ns guard interval Modulation + Coding MIMO 1×1 2×2 3×3 4×4 0 BPSK 1/2 15 30 45 60 1 QPSK 1/2 30 60 90 120 2 3/4 45 90 135 180 3 16‑QAM 1/2 60 120 180 240 4 3/4 90 180 270 360 5 64‑QAM 2/3 120 240 360 480 6 3/4 135 270 405 540 7 5/6 150 300 450 600 - 256‑QAM 3/4 180 360 540 720 - 5/6 200 400 600 800 - 1024‑QAM 3/4 225 450 675 900 - 5/6 250 500 750 1000 256-QAM and 1024-QAM are non-standard More PHY speed tables

Analogy: Think of channel width as how many 'lanes' you can use at once on a multi-lane highway. 20 MHz is a car using a single lane. 40 MHz is a 'wide' load trailer using two highway lanes.

I am curious if this issue had anything to do with why Netgear stopped getting their routers 'Wi-Fi Certified'?

Or, if there is a single 20 MHz only client that connects to the AP, the AP will (should) drop from 40 MHz operation to 20 MHz operation, disabling channel bonding. This situation is actually VERY likely to happen (for example, my daughter's very inexpensive laptop that is only two years old, but only supports 20 MHz channels).

Also, in the real world, things are MUCH more complicated, because many routers don't always follow 'good neighbor' standards.

Great article on the subject: "Bye Bye 40 MHz Mode in 2.4 GHz"

Of note is that 40 MHz channels in the 5 GHz band for 802.11n does work (very well).

The reason why 256-QAM and 1024-QAM are included in the PHY tables here is for reference/convenience -- because these PHY tables ARE ALSO the PHY speed tables for 802.11ac for 20 MHz and 40 MHz channel widths. The PHY speeds for an 80 MHz channel is far below in the next section.

Microwave ovens are licensed in the entire ISM (Industrial, Scientific and Medical) band from 2.4 GHz to 2.5 GHz, which covers all 2.4 GHz wifi channels. Example

How bad the interference is totally depends upon the specific microwave. Some microwaves are very bad, while others seem to have very little impact. At one house, using the microwave oven causes wifi clients to disconnect from the AP, while in another house, using the microwave oven only causes a slight slowdown in bandwidth to wifi clients.

Years ago I was testing a Wi-Fi security camera (base station and cam connected via 2.4 GHz), and just happened to use the microwave oven, and noticed the cam was unable to record any video. I learned my lesson and immediately returned the cam.

Is your house near a busy road? If so, you are likely getting interference from all the cars driving by that are operating a 'hotspot' (likely always enabled, although maybe not with Internet activated). And the worst part is, you can NOT plan for that channel usage, because the cars are mobile!

In a beach resort community, with homes very close to each other, a Wi-Fi analyzer app shows well over 15 2.4 GHz networks within range. At night, Wi-Fi performance (actual throughput) on the 2.4 GHz band was horrible due to contention (sharing bandwidth) with many neighbors. However, performance on the 5 GHz band was excellent.

Example: In mid-2023, Ring introduced a new $60 Ring Indoor camera that supports ONLY 2.4 GHz. And since it is plugged in all the time to an outlet, that seems very short-sighted (especially when I can find smart plugs for $8 that support 5 GHz). If the 2.4 GHz Wi-Fi band still works OK for you, then no problem, But if 2.4 GHz is too congested at your physical location, then this camera will not work well for you. Buyer beware.

Gen	Spec	Year	Speeds	New Name
Fifth	802.11ac	2013	433 to 1733 Mbps	Wi-Fi 5

802.11ac is called "VHT" for Very High Throughput

BEWARE: Many entry-level low-end routers only support 180 MHz of the 5 GHz spectrum (not all 560 MHz).

One 80 MHz channel in 5 GHz has more spectrum than ALL 2.4 GHz channels combined!

Channel Use Restriction: 16 (seen in red, right) of the 25 channels (or 64%) come with a critical FCC restriction (DFS - dynamic frequency selection) to avoid interference with existing devices operating in that band (weather-radar and military applications). Very few 'consumer-grade' access points support ALL of these 'restricted' channels, whereas many 'enterprise-grade' access points DO support these channels. More on this later in this section. 802.11h defines (1) dynamic frequency selection (DFS) and (2) transmit power control (TPC).

Channel 144: This channel was added as part of FCC changes in 2014. So this channel will be problematic for older devices that don't recognize this channel. Worst of all is that some brand new devices also mess up and don't support channel 144, so it is best to avoid selecting 144 as a 'primary' channel in most routers -- because if you do, a small subset of clients will not be able to connect to your router. Devices that don't recognize 20 MHz channel 144, also by definition don't recognize 40 MHz channel 142 and 80 MHz channel 138 (so a client device may have limited channel width when connecting to an AP using primary channels 132, 136, or 140).

For example, Ring video doorbell cams that operate in 5 GHz don't understand that channel 144 exists. The cam will NOT connect to an AP on channel 144, and will only connect to an AP on channel 140 using a 20 MHz channel (not 40 MHz).

120/124/128: Terminal Doppler Weather Radar (TDWR): If you are 'near' a major metropolitan airport, you might not be able to use 20 MHz channels 120, 124, or 128 (and hence 80 MHz channel 122) due to use of Terminal Doppler Weather Radar operating within 5600-5650 MHz at a peak power of 250,000 watts. TDWR locations and frequencies. See also wiki info and a Cisco blog post on the TDWR issue. Channels affected are in dark red (right).

New channels: In mid December 2019, the FCC voted to move forward on allocating an additional 45 MHz to the end of U-NII-3 in 5.9 GHz to wifi (seen in yellow in table right). This results in three NEW 20 MHz channels (169, 173, 177). See also FCC 19-129. This also creates two additional 40 MHz channels (167, 175), one new 80 MHz channel (171), and one new non-DFS 160 MHz channel (163). But, the big problem is that these new channels are for INDOOR USE ONLY. See FCC guidelines. Also, given that Wi-Fi 6E now exists (with 1200 MHz of new spectrum), the value of these new channels in 5 GHz is GREATLY diminished -- because existing Wi-Fi 5 devices don't know about these new channels (and will fail to connect to a router using them) and new devices capable of recognizing the new channels will just use the Wi-Fi 6E channels instead.

Center Frequency TIP: The 'center frequency' (in GHz) of any 5 GHz channel number is simply that channel number multiplied by five (and added to 5000). For example, the center frequency of channel 60 is 5000 + 60×5 = 5300 GHz. Or, reverse to compute channel number from center frequency.

Channel 165: ONLY select channel 165 when the router is configured for 20 MHz channel widths. Because if you select channel 165 when the router is configured to use 160/80/40 MHz channel widths, there are actually NO available 160/80/40 MHz channels -- NONE! Wi-Fi clients will ONLY be able to connect to 20 MHz channel 165! This behavior was first noticed on a Netgear R7800 router.

Other routers are smart enough to not show channel 165 (unless the router is configured to only use 20 MHz channels).

This 'automatic' selection of the appropriate 160/80/40 channel from a single 20 MHz channel that you select totally sidesteps the problem of one (misaligned) wide channel straddling two other wide channels.

With 5 GHz, neighbors can (often times) be on the same channel and typically not interfere with each other (nearly as much as 2.4 GHz), because with reduced range, neighbors can't see as many neighbors wifi anymore. Of course, all of this depends upon how 'close' your neighbors are.

• 802.11 Channel Plans New Rules v02 - This is just the chart above
• Code of Federal Regulations - The actual Federal Code governing the Wi-Fi spectrum
• Straddle channels - treatement of channels that straddle U-NII bands

Many residential routers have a transmit power around 995 mW. Many (battery powered) wifi clients have a transmit power anywhere from 90 mW to 250 mW. Client devices often transmit at power levels below the maximum power level permitted. More information

802.11ac PHY Speeds (Mbps) 80 MHz channel, 400ns guard interval Modulation + Coding MIMO 1×1 2×2 3×3 4×4 8×8 0 BPSK 1/2 32 65 97 130 260 1 QPSK 1/2 65 130 195 260 520 2 3/4 97 195 292 390 780 3 16‑QAM 1/2 130 260 390 520 1040 4 3/4 195 390 585 780 1560 5 64‑QAM 2/3 260 520 780 1040 2080 6 3/4 292 585 877 1170 2340 7 5/6 325 650 975 1300 2600 ↕ typical real-world Modulation/Coding at distance ↕ 8 256‑QAM 3/4 390 780 1170 1560 3120 9 5/6 433 866 1300 1733 3466 - 1024‑QAM 3/4 487 975 1462 1950 3900 - 5/6 541 1083 1625 2166 4333 1024-QAM is non-standard 802.11ac PHY Speeds (Mbps) 80 MHz channel, 800ns guard interval Modulation + Coding MIMO 1×1 2×2 3×3 4×4 8×8 0 BPSK 1/2 29 58 87 117 234 1 QPSK 1/2 58 117 175 234 468 2 3/4 87 175 263 351 702 3 16‑QAM 1/2 117 234 351 468 936 4 3/4 175 351 526 702 1404 5 64‑QAM 2/3 234 468 702 936 1872 6 3/4 263 526 789 1053 2106 7 5/6 292 585 877 1170 2340 ↕ typical real-world Modulation/Coding at distance ↕ 8 256‑QAM 3/4 351 702 1053 1404 2808 9 5/6 390 780 1170 1560 3120 - 1024‑QAM 3/4 438 877 1316 1755 3510 - 5/6 487 975 1462 1950 3900 1024-QAM is non-standard More PHY speed tables

Your mileage will vary depending upon construction materials. In one home (single level; sheetrock with aluminum studs), I saw a dramatic increase in speeds at range. But at an older second home with very thick brick walls, range improved just a little.

Buyer beware: Not all 'wave 2' products will support the restrictive 5 GHz DFS channels! WiFi certification for 'wave 2' only 'encourages' devices to support this -- so NOT required.

160 MHz channels: Support for 160 MHz channels in some routers reduces MIMO support. For example, in Netgear's R7800, there is 4×4 MIMO support for 80 MHz channels, but for 160 MHz channels, MIMO is reduced to 2×2.

MU-MIMO issues: There are a lot of issues with MU-MIMO. So it may or may not work for you. MU-MIMO (1) sometimes disables client MIMO (where a 2×2 client switches to 1×1; Broadcom chipset) (2) requires spatial diversity (physical distance) between clients (3) has significant sounding overhead (4) a client device must be MU-MIMO aware (many are not) (5) only works with high SNR (very strong signals) and (6) works best with completely stationary clients. For more details, read "A MU-MIMO Reality Check". Aruba Networks says "Experience from 802.11ac MU-MIMO in real-world deployments revealed some limitations". [source] [more info]

Another example: An older Dell laptop using Centrino Advanced-N 6230 dual-band wifi. The laptop 'sees' the 5 GHz SSID being broadcast from a 802.11ac router, but when the laptop connects to the router, it is only doing so using 802.11n, 2×2 MIMO, and 40 MHz channels (max PHY of 300 Mbps; no 256-QAM)

Technically, support for 160 MHz channels existed in Wi-Fi 5, but support in routers was spotty at best, and very rare in most client devices.

• O'Reilly '802.11ac: A Survival Guide' by Matthew S. Gast (154 page book)
• 802.11ac In-Depth (Aruba)
• Technical White Paper: "802.11ac: The Fifth Generation of Wi-Fi" (Cisco)
• 802.11ac (Wikipedia)
• Clients List - lists common Wi-Fi clients and the channels they do and don't support

Gen	Spec	Year	Speeds	New Name
Sixth	802.11ax	2019	600 to 2401 Mbps	Wi-Fi 6

802.11ax PHY Speeds (Mbps) 80 MHz channel, 800ns guard interval Modulation + Coding MIMO 1×1 2×2 3×3 4×4 8×8 0 BPSK 1/2 36 72 108 144 288 1 QPSK 1/2 72 144 216 288 576 2 3/4 108 216 324 432 864 3 16‑QAM 1/2 144 288 432 576 1152 4 3/4 216 432 648 864 1729 5 64‑QAM 2/3 288 576 864 1152 2305 6 3/4 324 648 972 1297 2594 7 5/6 360 720 1080 1441 2882 ↕ typical real-world Modulation/Coding at distance ↕ 8 256‑QAM 3/4 432 864 1297 1729 3458 9 5/6 480 960 1441 1921 3843 10 1024‑QAM 3/4 540 1080 1621 2161 4323 11 5/6 600 1200 1801 2401 4803 802.11ax PHY Speeds (Mbps) 80 MHz channel, 1600ns guard interval Modulation + Coding MIMO 1×1 2×2 3×3 4×4 8×8 0 BPSK 1/2 34 68 102 136 272 1 QPSK 1/2 68 136 204 272 544 2 3/4 102 204 306 408 816 3 16‑QAM 1/2 136 272 408 544 1088 4 3/4 204 408 612 816 1633 5 64‑QAM 2/3 272 544 816 1088 2177 6 3/4 306 612 918 1225 2450 7 5/6 340 680 1020 1361 2722 ↕ typical real-world Modulation/Coding at distance ↕ 8 256‑QAM 3/4 408 816 1225 1633 3266 9 5/6 453 907 1361 1814 3629 10 1024‑QAM 3/4 510 1020 1531 2041 4083 11 5/6 567 1134 1701 2268 4537 More PHY speed tables

802.11ax is called "HE" for High Efficiency

Multi-user support is baked into OFDMA: This is a critical concept to fully understand about Wi-Fi 6. In Wi-Fi 5, 'multi-user' was accomplished via MU-MIMO using multiple antennas. HOWEVER, in Wi-Fi 6, there is a SECOND (and now primary) 'multi-user' method 'baked' into the protocols called MU-OFDMA. Don't confuse MU-OFDMA with MU-MIMO! Also, see this interesting MU-OFDMA vs MU-MIMO article.

This multi-user support is a big deal, and will greatly improve wifi for all -- but it will take many YEARS before most clients are 802.11ax. So don't expect to see Wi-Fi 6 benefits for YEARS.

The goal of every prior version of wifi was dramatically increasing 'peak' speeds (for one user). And by looking at Wi-Fi generation Mbps speeds, you can see this: 2 -> 11 -> 54 -> 217 -> 1733 -> 2401, except for the last jump, which is Wi-Fi 6. Instead, by changing to MU-OFDMA in Wi-Fi 6, there will be dramatic (overall) capacity gains to a dense set of users (as a whole), but only when (all) clients fully support Wi-Fi 6.

160 MHz channels: Support for 160 MHz channels in some routers reduces MIMO support. For example, in Netgear's RAX120, there is 8×8 MIMO support for 80 MHz channels, but only 4×4 MIMO support for 80+80 channels. The other problem with 160 MHz channels is that there are currently only two channels, and they both intersect with DFS channels (making them both potentially unusable).

6 GHz spectrum: The FCC opened up the 6 GHz and for Wi-Fi (but this requires new hardware). See Wi-Fi 6E in the next section.

Very deceptive router manufacturer speed comparison

Analogy: It should be painfully obvious by now that router manufacturers are selling you on hype. They are selling you on a 'dragstrip' (the router), where you can 'legally' go '1000 mph' -- and that sounds fantastic, so you buy the dragstrip (router). But then you step back and realize that (1) all the vehicles (wifi devices) you own don't go over 120 mph, (2) you can buy faster cars but they are not legal for you (desktops have faster wifi than smartphones), and (3) 1000 mph was obtained by adding the speeds of multiple cars together (aggregating multiple wifi bands).

Is there really something that you can't do with 455 Mbps throughput in Wi-Fi 5 that you can all of a sudden do with the 500 Mbps that Wi-Fi delivers (10% more).

★ There is very little point in upgrading a Wi-Fi 5 4×4 router to a 4×4 MIMO Wi-Fi 6 router until many/most of the clients connecting to the router fully support Wi-Fi 6. Until that happens, upgrading a router to Wi-Fi 6 will have very little impact. Vendors are throwing around huge Mbps numbers that are meaningless (because it is client device capabilities that mostly limits throughput).

"The bottom line is until Wi-Fi 6 / 802.11ax clients reach critical mass, the benefits of 11ax are minimal and will have low impact" [source: Cisco]. "For [most enterprise customers], we recommend installing 802.11ac wave 2 access points today, because of the sheer value of 802.11ac wave 2" [source: Cisco]. Consumer Reports concludes that there is very little point in buying a new Wi-Fi 6 router, especially if your smartphone, TV, laptop, etc. only support Wi-Fi 5.

I have seen some reviewers show graphs showing a huge increase in Wi-Fi 6 speeds as compared to Wi-Fi 5, but that result was obtained by using 160 MHz channels in Wi-Fi 6 vs 80 MHz channels in Wi-Fi 5. When reviews show numbers too good to be true, scrutinize the details.

If your client device is in the same room as a Wi-Fi 6 wireless router, you may see a big speed boost using Wi-Fi 6 over Wi-Fi 5. But once you move to the next room, you will only see a very subtle speed boost.

Technically, Wi-Fi 5 also supported 160 MHz channels, but it was rare to see a battery powered client device support 160 MHz channels. For some reason, that appears to have changed in Wi-Fi 6, where support for 160 MHz channels (even in battery powered client devices) now appears very common (but not for Apple devices).

• 802.11ax High Level Overview (YouTube video by Ruckus)
• White paper on 802.11ax (Aruba Networks)
• Technical White Paper: "802.11ax: The Sixth Generation of Wi-Fi" (Cisco)
• White Paper: IEEE 802.11ax, The Sixth Generation of Wi-Fi (Broadcom)
• Dual-Band 11AX (Quantenna)
• 802.11ax (Wikipedia)
• 802.11ax Resource Units (Wikipedia)
• What is 802.11ax Wi-Fi (Ruckus)
• High Efficiency Wi-Fi- 802.11ax - WLPC US Phoenix 2017 (Youtube)

• FCC Opens 6 GHz Band to Wi-Fi and Other Unlicensed Uses (fcc.gov)
• FCC Technical Report and Order 20-51 (fcc.gov)

There is only 560 MHz of spectrum currently available to Wi-Fi in 5 GHz (and only 70 MHz in 2.4 GHz). So adding an additional 1200 MHz in 6 GHz is a very welcome and significant jump in spectrum.

And again, once Wi-Fi 6E routers come out, it will take a long time before most clients are Wi-Fi 6E capable, but you can bet that most higher-end client devices will immediately and fully switch over to and support Wi-Fi 6E.

Many entry-level Wi-Fi 5 routers (with no DFS support) only support 180 MHz of spectrum. But I expect entry-level Wi-Fi 6E routers (with no AFC support) to support all 1200 MHz of spectrum.

Also of note is that Wi-Fi currently has no 160 MHz channel that is not subject to DFS restrictions, meaning that currently, actually being able to use a 160 MHz channel today in 5 GHz is hit or miss. This new spectrum should (hopefully) make it much easier to find and actually use multiple 160 MHz channels.

Wi-Fi 6E access points in low-power mode are permitted to operate at 24 dBm EIRP (6 dB BELOW 5 GHz DFS power levels), and Wi-Fi 6E clients at 18 dBm EIRP (6 dB BELOW that of the AP). Many Wi-Fi 5 clients today already operate 'around' this power level, so Wi-Fi 6E range will be affected by the slightly higher operating frequencies, and the 6 dB power difference (below DFS). Namely, expect Wi-Fi 6E range (in low-power mode) to be around 42% of Wi-Fi 5 DFS channel range.

Wi-Fi 6E access points in normal-power mode are permitted to operate at 36 dBm EIRP (the same power levels of 5 GHz U-NII-1 power levels), and Wi-Fi 6E clients at 30 dBm EIRP (6 dB BELOW that of the AP). Most Wi-Fi 5 devices already operate below these levels, so Wi-Fi 6E range will be affected only by the slightly higher operating frequencies. Namely, expect Wi-Fi 6E range (in normal-power mode) to be around 83% of Wi-Fi 5 range.

Privacy mitigating factors: An access point can operate in 'low power mode' and then NOT be subject to AFC (but then signal range WILL suffer) OR, the access point can reduce the GPS quality and then report a larger general 'area' to the AFC instead of an exact location (but then frequencies and power levels that can be used might be reduced).

Incumbent Services: The FCC did not just have 1200 MHz of spectrum laying around unused. Instead, this spectrum is heavily used by 'incumbent services', such as:

1. Fixed Microwave Services (FS): You have probably seen these towers around (google microwave tower), with a 'dish' pointed in a fixed (horizontal) direction.
2. Fixed Satellite Services (FSS): Ground to satellite communication (and vice-versa).
3. Radio Astronomy: The study of celestial objects at radio frequencies.
4. Other miscellaneous services: Mobile services (etc).

Video showing FS usage in the US (YouTube)

The thinking is that with Wi-Fi 6E and 160 MHz channels, a reliable 2 Gbps PHY connection with 1 Gbps actual throughput becomes commonplace (instead of hit or miss) when are you in the same room as the access point -- with only a 2×2 MIMO client device.

• Low-power access points can use the entire 1200 MHz spectrum, but use is restricted to indoor use only, and range will be limited. These low-power devices cannot be weather resistant, must have permanently attached integrated antennas, cannot be battery powered, and must be labeled "for indoor use only".
• Normal-power access points can be used outdoors, but must use AFC, and are restricted to using U-NII-5 or U-NII-7.
• Client devices are prohibited from being used as a mobile hotspot.
• Access points are prohibited in moving vehicles such as cars, trains, ships, or small aircraft (but with an exception for large passenger aircraft operating over 10,000 feet, but may only use U-NII-5).
• Access points are prohibited on ships and oil platforms.
• Use is prohibited on unmanned aircraft systems.
• Devices using AFC must report geo-location, geo-location accuracy, antenna height above ground, device FCC ID, and device serial number to a centralized AFC database, which then returns frequencies and power levels that may be used. The device must contact the AFC database at least once per day (failure means stop working; with one day grace period)
• Assumes that there will be 17 dB in signal loss when the signal from an indoor access point travels outside through a building's walls.
• Sets a maximum channel width of 320 MHz.
• Client devices are prohibited from transmitting anything until the device hears something from an access point (so no probe requests).
• Client devices must operate at 6 dB below the power level of the access point power level.
• An underlying AFC presumption is that access points are at a fixed location (not mobile nor moving around).

Wi-Fi 6E products exist right now, but some are expensive. Just be patient. Prices will drop.

• 320 MHz channels (vs prior 160 MHz channel width)
• allows 16×16 spatial streams (vs prior 8×8 limit), but only expect 2×2 in virtually all client devices, and 4×4 in mid to higher end routers.
• 4096-QAM modulation (vs prior 1024-QAM)
• Multi-Link Operation, or MLO, uses multiple bands/channels at the SAME time -- for example using 2.4 GHz, 5 GHz, and 6 GHz all concurrently.
• Preamble Puncturing - if part of a 'wide' channel is being used by an old legacy client device, the rest of the channel can still be used by a modern Wi-Fi device
• plus other potential new features

802.11be is called "EHT" for Extremely High Throughput

UPDATE: Beware that some very inexpensive routers might only support a SINGLE 5 GHz channel. Just do your research before purchase!

DFS = Dynamic Frequency Selection

(1) Many Netgear Wi-Fi 5 routers do not support CH 144, and as such, can't support 80 MHz channel 138. This flaw was fixed in Newgear Wi-Fi 6 routers.

(2) The FCC added 20 MHz channels 169, 173, and 177 in 2019 (for indoor use only), which also creates a new 80 MHz channel 171. But don't expect support in very many devices (yet) for the new channels.

Also, this is especially important if you can see several other 5 GHz AP's, which happens when you (1) have close neighbors like in an apartment building, or (2) want to install multiple AP/routers. So, only consider AP/routers that support ALL the DFS channels.

See the Router Reference Appendix far below for examples. Some vendors have NO routers that support DFS channels.

Netgear ALERT: Most Netgear routers don't support 80 MHz channel 138. But this is slowly changing. The R7800 is a rare exception, supporting channel 138, but only via firmware 1.0.2.68. Also, it appears that Netgear is finally 'aware' of the issue as some of the newer 'AX' hardware also supports channel 138.

Most of the Netgear business access points (Netgear ProSafe Access Points) do NOT support the restricted 5 GHz channels. But I did find ONE that did. Just do your research.

For example, I was in a Drury Hotel and from my room, I could see the Drury SSID on channels 48, 64, 100, 104, 108, 140. So the hotel was clearly using DFS certified 5 GHz access points -- successfully.

FCC Operating Frequencies show DFS support

1. Google 'wikidevi' and the router company name and the router model number (eg: "wikidevi Netgear RAX80"). You should immediately find the wikidevi web page for that router.
2. On the wikidevi web page, find the "FCC ID:" for that router (eg: "PY318200414").
3. Google the FCC ID found and click on the first top hit, which should be https://fccid.io/PY318200414.
4. In the resulting web page, look for the "Operating Frequencies" section (seen right).
5. Look for frequencies that cover the DFS channel range (highlighted in yellow right). [Frequency ranges are usually based upon '20 MHz center' values]. If so, that router/AP HAS DFS channel support. Otherwise, there is NO DFS channel support. For the RAX80, notice that it appears that DFS channels are supported (except for channel 144), which then also excludes channels 142 and channel 138 -- because the GHz range stops at 5.7 GHz instead of 5.72 GHz).
6. Look for the 'DFS Test Report' and see if the device is a master or a slave, or both (see immediately below). You are looking for 'master' (router) support.

Netgear was plain lazy: Netgear got the R6700v3 certified as a DFS Master but failed to get the router certified as a DFS Slave. This matters if you use the R6700v3 as a 'wireless bridge' (to connect 'ethernet only' devices to your main wifi router), because all of a sudden, in that mode, the R6700v3 no longer supports DFS channels -- meaning that if you bought the R6700v3 to connect to your main router (broadcasting/using a DFS channel), the R6700v3 will NOT work!

I have even selected a DFS channel and seen it work for weeks, only for the router to then all of a sudden auto select a non-DFS channel (meaning the router detected a conflict). Was this a real radar signal detected, or a false alarm (most likely)? You just need to be patient finding a DFS channel that works long-term for you.

Often times, when a router automatically switches to a non-DFS channel, that change is temporary -- as simply power cycling the router will cause the router to once again use the (configured) DFS channel.

A wifi client not supporting DFS channels is very rare -- and is definitely incredible laziness on the part of the device manufacturer. Often times, you will never notice, because the problem device will just connect to the router's slower 2.4 GHz band (not the fast 5 GHz DFS band).

Multiple people have told me that Roku devices do not support DFS channels! A google search appears to confirm this (but this needs more research). If true, that is crazy laziness on their part.

Netgear R7800 wireless setup

You can use different SSID names, but then you don't get wifi roaming.

The problem with the 'same name' technique is that some client devices are 'dumb' and incorrectly connect to the 2.4 GHz band instead of the 5 GHz band (and then speeds are much slower than they should be). I had this problem with a laptop that would initially start out connected to the (fast) 5 GHz band, but after about 10 minutes, it would then switch to the (much slower) 2.4 GHz band (for unknown reasons). Yes, the 5 GHz RSSI signal was weaker, but throughput from 5 GHz was MUCH better. I fixed by appending a "-5G" to the 5 GHz band SSID.

The bottom line: Be practical. Just use whatever SSID naming method works best for you and your devices.

Because any client device connecting to your network must include the SSID name in the 'I want to connect' request, that any Wi-Fi sniffer can capture and then see.

80 MHz 5 GHz channel 42 is made by combining four 20 MHz channels (only one considered 'primary')

Analogy: A channel is like a lane on an Interstate highway. All cars (AP) can use the same lane (channel), but that is slow and inefficient (lanes go unused). Everything works best when cars (AP) use all lanes (channels) -- as evenly as possible.

Could you put 10 APs in your house and configure them to all use the same SSID and the same channel? Yes, and it would work (albeit slowly). But that would not be the best and most efficient way to use the available spectrum, since all 10 APs are attempting to use the same 'lane' of a superhighway. Instead, distribute all 10 APs across all available lanes (channels) of the superhighway. Just remember that 2.4 GHz wifi has overlapping channels and that the only real (non-overlapping) channels available are 1, 6, 11.

Channel Planning: A full discussion on channel planning is beyond the scope of this paper, but in short, always try to leave unused spectrum between active channels. In other words, if you have a main router on 80 MHz channel 42, never put another nearby AP on 80 MHz channel 58. Instead, you would select a higher channel for the nearby AP. If possible, you want a 'gap' between active channels.

Beware the 'automatic' channel: Some AP/routers improperly set the 2.4 GHz channel to some channel other than one of the three non-overlapping channels. This can be corrected by not using 'automatic' and instead manually selecting either channel 1, 6, or 11.

Another fast DNS service is provided by CloudFlare, with DNS servers 1.1.1.1 and 1.0.0.1.

1. Reboot ALL Internet connected devices. Start with your modem, router, and Wi-Fi network (extenders, AP, mesh, etc) and then wait 5 minutes (for all Wi-Fi bands to be fully operational). Next, reboot all other Wi-Fi connected devices (game consoles, smart TV's, tablets, phones, cameras, etc). In some rare cases, this may fix your problem and you are then done.
2. Check for proper placement of your existing Wi-Fi devices, especially your main router.
3. Otherwise, you are left with the easy way (immediately below; buy new hardware) or the hard way (further below; try to fix what you have).

1. Use Ethernet whenever possible
2. Improve wireless PHY speeds

For any device using Wi-Fi now (smart TV, game console, desktop PC, etc) that has a RJ45 jack, try to switch over to using Ethernet instead of Wi-Fi for that device. Your goal is to free up Wi-Fi for use by devices that can only connect wirelessly.

a) Best v1: Go direct wired: Gigabit ethernet via Cat 5/5e/6/etc is still the gold standard of speed and reliability. If you have a wifi device that also has ethernet/RJ45 (smart tv, game console, etc), find a way to run a wired Cat 5/6 from your main router to the device. Expect 1000 Mbps PHY and 940 Mbps throughput from 1 Gigabit Ethernet.

TIP: If you are out of ports on your main router, add a Gigabit switch. Be aware that while 1GbE switches are very common, there ARE switches that support 2.5GbE (Cat5e), 5GbE (Cat6), and even 10GbE (Cat6a) speeds. Interesting video on cheaply adding 10 Gigabit Cat6a/RJ45 to your home network.

MoCA adapter setup

b) Best v2: MoCA 2.5 Ethernet: If you can't use/run Ethernet wire, but have access to RG6 (CATV) in every room, MoCA adapters may be for you. These adapters integrate into the Cable TV wiring (RG6) that most rooms in a home have, to distribute Ethernet around your house (example right). Expect MoCA 2.5 speeds (rated at 2500 Mbps) to easily max out 1 Gbps Ethernet (940 Mbps throughput). But, test in your environment to confirm. More information: Wiki info on MoCA and this interesting MoCA 2.0 adapter review (YouTube).

TIP: Avoid older MoCA versions (that are rated at lower speeds) and instead only consider using "MoCA 2.5" adapters, many of which now also offer 2.5 Gbps ethernet ports as well (as opposed to just a Gigabit Ethernet port). For example, on Amazon, look at the Motorola MM2025.

WARNING: I have also seen disclosures stating that MoCA adapters should NOT be used in homes where the coax cable is already being used by satellite TV, or for AT&T services (as they already use MoCA internally for their own boxes). This need more research and verification (because different MoCA devices in the home should be able to just use different channels and easily coexist).

TIP: If you have an ISP provided gateway device providing internet service, investigate if there is already one MoCA adapter 'built-in' to the provided device (there often IS for Verizon FiOS and Comcast gateways; but likely only MoCA 2.0).

MoCA is a great way to add wired Ethernet to remote locations (up to 16) in a house that has cable TV wiring, but has no way to add/retrofit CAT5e.

If you decide to use MoCA, make sure that there is a MoCA filter on the cable line feeding your entire house. It is common to find an all-in-on 'grounding block' and 'MoCA filter' inside the cable demarc box. This filter prevents MoCA signals generated inside the house from feeding back into the cable network.

c) Fair: Wireless bridge: Many high-end routers can be configured as a 'wireless bridge', meaning that they use wireless to connect to the main router, and provide that Internet to ONLY all of the wired Ethernet LAN ports (does NOT allow for wireless clients). Best when a 4x4 bridge is connected to a 4x4 router. Under good conditions, expect 1500 Mbps PHY and 750 Mbps throughput.

Yes, you are trading one wifi (on the device), for another wifi (on the bridge). But the PHY speed of wifi on the bridge is (hopefully) several times faster than wifi on the devices you replaced. Only use this option if PHY speeds go up 2x or more.

d) OK to Bad: Powerline Ethernet: If you need wired Ethernet, but find it impossible to run a CAT5/6 cable, give powerline ethernet a try. Plug in one next to your router. Plug the others (yes, many are possible) exactly where they are needed. Look for 1000 Mbps (or higher) adapters. Actual throughput ranges from 20 Mbps to 300 Mbps for these devices (and you won't know until you install and test). And depending on what you need/want, that may be acceptable, or horrible.

So why mention powerline if it is potentially so bad: (1) because acceptable speed depends upon your situation and (2) powerline is cheap. So if you get the speeds you need remotely (even if slow) -- job done. If both powerline adapters are on the same circuit breaker, you can expect fast speeds. But as soon as powerline adapters are put on different circuits, which for most use cases is almost guaranteed, throughput may drop substantially.

TIP: Plug powerline adapters directly into the wall outlet (don't use power strips).

a) Move as many devices as possible from wireless to wired: Avoid spectrum usage and contention whenever possible (free up TIME on the spectrum). Is there a smart tv that is heavily used for streaming? If so, try to move that to a wired connection, freeing up wireless time for those devices that are forced to be wireless only (like tablets). See section above.

b) Try different channels and TEST: Wi-Fi is a shared resource. If you have neighbors you may actually be sharing spectrum with them. Especially important at night when people come home from work and start streaming.

In reality, selecting the 'right' channel is crazy hard to do (well) -- because a channel with many access points may actually be the 'most unused' channel, if those access points rarely transfer data (vs a channel with one other access point that is tranferring data all the time). Often times you just need to change the channel and test (a lot).

TIP: The non-DFS 5 GHz channels (at 80 MHz, there are only two) are allowed to operate at a higher power level than the DFS channels. You should see better (download) PHY speeds at distance from these non-DFS channels, but everyone (you, neighbors, etc) want to use those channels. Whereas on a DFS channel, you likely will have the channel to yourself.

So try to find an unused DFS channel, which will result in the channel being all yours! A DFS channel is a must if you are in an apartment/condo building.

Inexplicably low PHY speeds?: If you see PHY speeds from your client device (when standing right next to your router) that are strangely 'too low', that is a huge tip off that you may be running into some 'interference' -- try changing wifi channels on the AP/router.

c) Is your Wi-Fi router centrally located and unobstructed: Follow the router placement guide.

d) Use a modern 4×4 MIMO Wi-Fi 6 router: Are you using a 2×2 router or a an older router? If so, give a new recommended 4×4 MIMO Wi-Fi 6 router a try. While PHY speeds very close to the router may not improve at all (likely at maximum PHY speed already), the goal is to increase PHY speeds for all wifi clients out there 'at a distance'.

e) Add a 4×4 MIMO AP: If some of your wireless devices are too far away from your main router, add an access point (must be wired to the main router via Ethernet) where it does the most good.

f) Several low-PHY 'heavy' users can significantly slow down everyone else: Devices operating at a very low PHY speed, and using the channel a lot, can slow down an entire wifi channel. Because what is critical is TIME spent on a channel (which increases as PHY speed decreases). Adding an access point (and hopefully on a new unique channel), and greatly improving the PHY speed for those devices, can free up time needed by other wifi clients.

Analogy: Imagine a highway (wifi channel) where a car (smartphone) is going 5 mph (PHY 65 Mbps) when the speed limit is 55 mph (PHY 866 Mbps). That one car will drastically slow down all other cars (wifi devices) wanting to use the highway (wifi channel). Adding a new lane (via AP on new channel) to the road not only puts the slow car (smartphone) onto a new lane (channel), potentially causes the car to all of a sudden start driving 55 mph (PHY 866 Mbps).

g) Get a 4×4 MIMO network adapter: If on a PC with 2×2 MIMO, try using a 4×4 MIMO network adapter (to a 4×4 router). The expectation is that PHY speeds will increase (but not quite double).

With a PC, always try to find a way to use Ethernet wired to your main router.

h) Upgrade your client device: If your client device is 1×1 MIMO, get a brand new client device that supports at least 2×2 MIMO. The expectation is that PHY speeds should roughly double (moving from 1×1 MIMO to 2×2 MIMO).

Brand new hardware might help: I have also seen 2×2 MIMO devices made in the last year outperform (consistently stay on a higher PHY speed) than 2×2 MIMO devices that are five years old. This can not be overstated. If you are looking for top speeds, always use modern/new devices. Each generation of newer hardware performs just a little bit better than prior generations.

i) Investigate 160 MHz channels: If your 2×2 client devices support 160 MHz channels (this was rare, but it is becoming a lot more common for Wi-Fi 6), look into a router that also supports 160 MHz channels. This is not always possible, but when possible and there are no DFS channel conflicts (or spectrum conflicts with neighbors), this has the 'potential' to double your PHY speeds (when compared to 80 MHz channels) -- but for only the few devices that actually support 160 MHz channels. But 160 MHz channels require a high SNR (you may need to be very close to the router). Also, remember that wider channels have slightly less range (than smaller channel widths) - details -- so this works best when very close to the router/AP.

j) Reserve 5 GHz for true 802.11ac devices: A requirement of any device being able to call itself 802.11ac capable is that it must support 80 MHz channels in 5 GHz. However, dual-band 802.11n devices can see your 5 GHz SSID and connect to it using 20 MHz (or 40 MHz) channels. If that 802.11n device is a heavy Internet user, this could slow down all of your 80 MHz channel devices. Move that problem device to the 2.4 GHz band SSID. This frees up time on the much faster 80 MHz 802.11ac channel for 80 MHz capable devices.

Analogy: A 802.11n device operating at 20 MHz in 5 GHz is like a car using one lane of a four lane Interstate and simultaneously preventing the three other lanes beside it from being used.

But if the dual-band 802.11n device is a lightweight when it comes to wifi usage, then keep it on 5 GHz, as it is 'doing no harm'.

It is all a balancing act -- because if the 802.11n device does not work properly in 2.4 GHz (too slow or unreliable due to congestion) then you may need to keep the device in 5 GHz (eg: a Ring camera).

k) Update firmware: Make sure that your router/AP is running the lastest firmware. It is rare, but there have been times that a performance problem is found and corrected and new firmware is released that fixes the problem (eg: WAN to LAN performance bug).

l) Switch bands: Often times (but not always), PHY speed increases dramatically when there is a switch from 2.4 GHz to 5 GHz. This is because the noise floor for 5 GHz is often much better (lower) than the noise floor in 2.4 GHz. The result is a much better SNR. This improved SNR together with wider channels (20 MHz to 80 MHz) often results is a big speeed improvement. Confirm that your dual-band device is connecting to 5 GHz and using 80 MHz channels. If not, consider upgrading your client device and/or router.

First, analyze the client devices that download/upload the most data. They should be running at high PHY speeds; and if not, fix.

Don't confuse great signal (at range) with speed (at range). Just because you used a Wi-Fi extender and get a great signal 'at range' does not mean that you now have great speed at that extended range. Instead, you likely traded a more reliable signal for a slow speed (because there is still the 'extender to main router' path that packets must traverse).

Analogy: Wi-Fi range extenders are to Wi-Fi like 'hubs' were to Ethernet (Ethernet switches now dominate, which are much smarter, faster, and better than hubs). So if you want to go down the Wi-Fi "Range Extender" path, just use a mesh network instead (just like no one uses hubs anymore, only switches).

Many extenders 'on paper' are a 'zero-sum game'. Because they are (typically) located in the middle between the main router and a client device, they improve the signal strength between the two paths (extender to router and extender to client device) only enough to make up for doubling Wi-Fi utilization (packet transmitted twice), and no more. Packets are (often) re-transmitted on the same channel, band, and channel width. So not much (if anything) is gained speed wise other than possibly a more reliable (but slow) Wi-Fi path.

Where extenders may actually work and help a little bit is if the device connecting to the extender is using slow Wi-Fi 4, but the extender backhaul to the main router is using faster Wi-Fi 5. But at that point, again, just use a mesh network instead.

Namely, if you are standing right next to the Wi-Fi extender, the PHY speed will be fantastic, but remember that there is still a PHY speed between the extender and main router that comes into play and limits throughput.

So the huge advantage that a wired/Ethernet Access Point has over Range Extenders (and mesh networks with a wireless backhaul) is that (1) packets are only transmitted ONCE over Wi-Fi AND that (2) the AP can be placed exactly where needed most so that client devices near that AP now get maximum Wi-Fi speeds (no more need to place extender devices 'mid-way')!

Mesh networks do also re-transmit packets, but they (virutally always) use a 'backhaul' channel/band/width that (1) is different than the main channel and (2) much faster than the main channel (high end mesh networks use 4×4 MIMO for the backhaul). A huge bonus is if you can find a way to wire each mesh node back to the main mesh node/router via 2.5 Gigabit Ethernet (try to avoid using a wireless backhaul).

• Consumer Reports: "Should you buy a Wi-Fi Range Extender"
• YouTube: Techquickie: DON'T Buy A Wi-Fi Range Extender!
• YouTube: CNET: "Mesh Wi-Fi vs. range extenders: The best option for your home"

Configuring a TP-Link Router as an "Access Point"

Please note that while you can buy dedicated access points (can't be used as routers), that most consumer routers can be configured to run either in "Router" mode or "Access Point" (AP) mode. So you don't need to buy a dedicated 'access point'.

TIP: Buy a recommended router (or re-use and old router) and configure it in 'access point' mode (example seen right).

You can name access points uniquely if you want to, but then all of those SSID show up in Wi-Fi lists on client devices (creates a lot of name pollution).

The only time I have used a unique SSID name for an access point is when I added an AP dedicated to service a wireless Ring camera (and I wanted only the camera -- and no other clients in the home -- using that access point).

• For 2.4 GHz, only use non-overlapping channels 1, 6, or 11.
• For 5 GHz, only use channels that fall into different 80 MHz channels (for example, 36, 40, 44, 48 are all in the same 80 MHz channel). Also, try using DFS channels first.
• For 6 GHz, only use channels that fall into different 160 MHz channels.

For example, your 'main router' is in your living room, but you then also have an access point (wired ethernet back to your main router) in your home office.

In your office, you will get the fastest Wi-Fi speeds that are possible for your client devices, and because there is Ethernet back to the main router, packets are never re-transmitted twice (as they would be with extenders or mesh).

TIP: What Ethernet port should be used (on a router configured as an access point) to wire/Ethernet the 'access point' back to your wired network -- the WAN port or a LAN port? Technically, it should not matter at all -- as every port 'should' work equally well. However, be aware that some older routers have some bugs in properly routing ALL packets across the WAN to LAN interface (when the router is in AP mode). So, to be super-safe, after configuring a router in "Access Point Mode", only use the LAN ports on the router/AP (and ignore the WAN port).

At one house, I added an access point into the 'kids playroom' -- so that any streaming or game play in (or near) that room will go through that access point (and not impact Wi-Fi in the rest of the house). Plus, everyone in the kids playroom then has the fastest Wi-Fi speeds possible.

The kids can max out their Wi-Fi channel without impacting Wi-Fi speeds for any other users in the entire house.

Mesh networks often are only 2×2 MIMO for the backhaul and 2×2 MIMO to client devices. And if 4×4 MIMO is supported, most often that is only for the backhaul, with client device communication still only at 2×2 MIMO.

	Amazon Eero Pro 6E -- Wi-Fi 6E (2.5 Gbps WAN) $550
	Asus ZenWiFi AX XT8 -- Wi-Fi 6 (2.5 Gbps WAN; 4×4 backhaul) $550
	Google Nest WiFi Pro -- Wi-Fi 6E (1 Gbps WAN) $400
	Linksys MX8503 Atlas -- Wi-Fi 6E (5 Gbps WAN; 4×4 backhaul) $800
	Netgear Orbi RBK853 -- Wi-Fi 6 (2.5 Gbps WAN) $900
	TP-Link Deco X75 Pro -- Wi-Fi 6E (2.5 Gbps WAN) $400

But unlike Wi-Fi extenders (which typically operate on the same channel as the main router), mesh networks operate the wireless 'backhaul' on a different Wi-Fi channel (and often different band), which results in mesh networks being much faster then Wi-Fi extenders.

Admittedly, running Ethernet cable is not always possible or cost effective (often need to pay someone else to install it). But, it is cost effective for me because I am willing to do all of the installation work myself. For me, this maximizes Wi-Fi speeds and minimizes costs.

• Compare Eero models -- "Radio Frequency" section lists MIMO level for each band
• WSJ BuySide Article - "The Best Mesh Wi-Fi Systems for Your Home"
• More details on Eero

Router manufacturers' wireless speed claims are just like a used car salesman trying to convince you that a Formula 1 racecar will reduce the time of your morning commute to work. What really matters is not 'maximum' vehicle speed, but actual speed possible for the road you are on.

Other crazy examples of this are the Netgear R6120, Linksys E5400, and TP-Link Archer A54 -- all with advertised wireless speeds "up to 1200 Mbps". However, ALL Ethernet ports (including the WAN port!) are only Fast Ethernet -- meaning 100 Mbps maximum speed to/from the Internet.

Ethernet all of a sudden looks pretty cool when every smart TV in the house can RELIABLY stream at the same time because NO Wi-Fi is being used!

This observation was confirmed by using the MCS Spy tool, which shows that clients are often transmitting at a lower MCS level (than the MCS level an AP/router uses to transmit to the client).

Have you ever tried to connect to a weak wifi network, only to have your client device complain that it failed to connect? And then you wonder, 'but my device can clearly see the wifi network name, so why is a connect failing'? You move slightly closer to the AP/router and your device connects? This is almost certainly caused by the client transmitting at lower power levels than the AP/router (is transmitting).

The same principle applies to large homes, where you want everyone evenly connected to several different AP's, not everyone connected to one AP (when each AP is on its own unique Wi-Fi channel, this 'creates' more bandwidth).

And it even goes further. For example, QualComm makes 'reference designs' (actual working products), allowing other companies (like Netgear) to then use the reference designs to make their own routers. An example of this is the Netgear 7800, which is just a "Qualcomm Atheros AP161 reference board".

But also, each new wave/generation of hardware/chips does seem to perform just a little bit better than prior generations. So sometimes, just being 'newer' can be better.

When updating a router, verify that client device PHY speeds actually increase, especially for devices 'at range'.

• 4×4 MIMO - increases signal quality, reliability, and range for all 2×2 MIMO client devices. Do not buy a 2×2 or 3×3 MIMO router, you really do want a 4×4 router.
• DFS channels - you need a router that supports ALL 5 GHz 80 MHz DFS channels, to increase the liklihood of NOT sharing a channel (and therefore bandwidth) with a neighbor.
• beamforming - improves signal strength, which increases the range at which devices stay at fast speeds (should be a standard feature of any new mid-range router)
• A mid-range Wi-Fi 6 (802.11ax) router - this is the best VALUE today (September 2023) -- expect to spend 'around' $230 plus/minus $50 (avoid cheap and expensive routers).
• AP mode - look for a router that also has an 'access point mode' (most routers will). Because when you do upgrade to a newer version of Wi-Fi, you may want to reuse the old router as an 'AP' in your new network (and not have it sit on a shelf unused).
• Wi-Fi Certified - not absolutely required, but if the router is certified, this guarantees "interoperability, security, and reliability." Product Search. Also, watch out for routers certified to a lower specification than expected (eg: a 802.11ax router certified for only 802.11ac).

Best ($189-$250)	Best ($265-$299)	Good ($160-$250)
TP-Link Archer AX80 WAN: 2.5 Gbps Ethernet ✓ 2.4 GHz: 4×4 MIMO ✓ 5 GHz: 4×4 MIMO ✓ DFS channels	Asus RT-AX88U Pro WAN: 2.5 Gbps Ethernet ✓ 2.4 GHz: 4×4 MIMO ✓ 5 GHz: 4×4 MIMO ✓ DFS channels	Netgear Nighthawk RAX50 WAN: 1.0 Gbps Ethernet 2.4 GHz: 2×2 MIMO ✓ 5 GHz: 4×4 MIMO ✓ DFS channels

However, there is an 'honorable mention' -- the TP-Link Archer AXE75 deserves to be pointed out. It is an entry level router supporting ALL three Wi-Fi bands (2.4 GHz, 5 GHz, and 6 GHz), but it is not a 'recommendation' only because of 2×2 MIMO instead of 4×4 MIMO.

But let's also be realistic. If are you not looking for a 'whole house' router, but are only looking for a router for a small appartment, or for an access point (wired back to your main router) to greatly improve Wi-Fi in a single room or a small area, 2×2 MIMO is good enough, making the TP-Link Archer AXE75 ($170-$200) a GREAT value, due to support for the brand new 6 GHz band.

This is why I can't recommend any router over $300 -- because for the same money you can buy a router and access point (wired to the main router) that improves Wi-Fi signal quality far more than any single router ever could, especially where it needed most (in large homes).

Also, don't expect top notch performance (throughput) from a cheap router. While Wi-Fi specifications may be similar, run a speed test, and throughput results can be very disappointing.

But let's also be honest. If you lower throughput expectations (or don't want to spend hundreds), and you don't need a 'whole house' router, an entry level $40 Wi-Fi 5 router configured as an access point and wired (Ethernet) back to your main router, installed in a single room, to provide Wi-Fi only in that one room (like for a kids play room), should be able to provide at least 150 Mbps Wi-Fi connectivity to Wi-Fi 5 client devices.

Comcast XB6 Gateway Comcast TIP: If you have Comcast for your Internet and they are already providing you with a 'gateway', contact Comcast and say that you want their new best XB6 Wireless Gateway, which is an 8×8:8 MIMO (eight stream!) 802.11ac device, which supports data throughput of 1 Gbps. Please note that the XB6 comes in two models. The TG3482G, which does NOT support DFS channels (but later revisions do). And the CGM4140COM, which DOES support DFS channels. UPDATE: Comcast has come out with a newer 3rd generation version, called the XB7 supporting Wi-Fi 6 (FCC ID G954331X) -- you are eligible for the XB7 if you subscribe to Comcast 300 Mbps (or higher) Internet speeds. WARNING: But someone wrote to me stating that on the XB7 that it is no longer possible for the 'end-user' to select which Wi-Fi channel to use, as that is now all 'automatic' and behind the scenes. UPDATE: And now Comcast has the XB8 (support Wi-Fi 6E), so check that out!

For example, place the main router some place centrally located in the house -- and then add an access point (wired/Ethernet to the main router) in your home office.

TIP: The hidden YEARLY cost of electricity for 24x7 devices can really add up: As a very general rule, the yearly cost in electricity for any 'always on' device roughly equals wattage. Examples: An old Netgear WNR1000v3 uses 4 watts ($4/year). A Netgear R6250 uses 10 to 14 watts ($10-$14/year). A Netgear R7800 uses 7 to 14 watts ($7-$14/year). You can expect newer routers to use even more (Netgear RAX120 has a 60W power adapter, but how much is actually used?). A 100-watt light bulb uses 100 watts ($100/year)!

One example: Compare Netgear's R7800 (router) to the C7800 (router + cable modem). With the R7800, you have full control over firmware updates. But with the C7800, you have NO control and Netgear states "Firmware upgrades are pushed down by your ISP". But if your ISP is a small regional player, you might get NO firmware updates at all.

Worse yet is that some ISP's refuse to push any new firmware to customer owned cable modems! I know from from first hand experience with Spectrum outside of Orlando FL. I bought a Netgear CM1000V2 and noticed that it was still on V1.0 firmware. I contacted Spectrum and they refuse to do anything about it since the modem is 'customer owned'.

In another case, I was getting great PHY speeds, but very slow Internet speeds. A bunch of speed tests eliminated Wi-Fi and my router as the cause. This suggested the problem was with the only remaining hardware -- the (cable company provided) modem. So I rebooted (only) the modem and instantly had my fast speeds back. Frustrating.

At one location, ISP download speeds were sometimes OK, and sometimes bad. Rebooting the cable modem caused it to acquire a 'random' set of bonded download channels from the CMTS. As one particular channel was having issues, this reboot caused the modem to randomly use/avoid the problematic channel.

Also, walk to your router and stand about five feet (line of sight) away from the router, cause some Internet activity, and then re-check PHY speed. On a 2×2 Wi-Fi 5 client, I would expect to see a very strong signal with a PHY speed of 866 Mbps to a Wi-Fi 5/6 router.

Newer client devices (in the wifi settings) may tell you the 'Frequency' (2.4 or 5 GHz) your device is connected to. If not, the PHY speed you see on your device should be a huge tip off as to which band (and channel width) you are connecting to. Look up the speed in the PHY tables, which then reveals a ton of information about how you are connecting.

Try turning off the 'smart connect' feature of the router (that tries to push the client device to the 'best' band). Or, for testing, go to the router configuration and confirm that the 2.4 GHz SSID and the 5 GHz SSID are uniquely named. If they are the same, append a "-5G" to the 5 GHz SSID name temporarily. When you see the SSID for each band, connect to the 5 GHz SSID. If PHY speed increases dramatically, you likely have a problem with your device connected to the (slower) 2.4 GHz SSID, instead of (much faster) 5 GHz SSID.

WiFi Analyzer Access Points

Verify channel width: It is important to confirm that your 5 GHz SSID is operating at an '80 MHz' channel width. If you see '40 MHz' or '20 MHz' for your 5 GHz SSID (notice this for 'Goofy-5G' in example right?), go into your router configuration and fix the problem. The other possibility is that the router is only a dual-band Wi-Fi 4 (802.11n; not capable of 80 MHz channels) router and not actually a Wi-Fi 5 (802.11ac) router.

A: The most likely cause is that NOT all devices in your network are 1 Gbps capable. If there are any Fast Ethernet (100Mbps) devices between you and your ISP, that device becomes a 'choke point' that will very likely cause dropped packets and speed problems.

TIP: It is very common for ISP's to provision internet modems to 110% of the advertised speed. So if you sign up for 100 Mbps internet, your 100 Mbps network will not work, since the internet speed is more than likely actually 110 Mbps -- and any Fast Ethernet devices between you and the internet are a problem.

Another possibility is a bad Ethernet cable between two Gbps devices, causing that link to operate at the problematic 100 Mbps speed instead of the desired 1 Gbps speed. TIP: Many RJ45 jacks have tiny LED lights indicating speed.

A: Due to wifi protocol overhead, the expected throughput at the application level is around 60% to 80% of the physical (PHY) wifi speed. This is normal and sadly, the router industry has done a horrible job explaining this to the general public.

A: Blame router companies -- they love to advertise maximum speeds. Looking at the 5 GHz speed table far above, we can see that '1733' implies a 4×4 access point supporting 256-QAM. 650 is the PHY speed for a 2×2 device at 64-QAM. The conclusion is that your smartphone is a 2×2 MIMO device and that you are maybe 20 to 30 feet from your router. Expected application throughput will be around 70% of that, or 455 Mbps (±45 Mbps).

A: Maybe, but maybe not. Always try several different speed test programs, like speedtest.xfinity.com, fast.com, or cfspeed.com. The very nature of the internet is that everyone will not always be fast. I find that the xfinity speed test gives the most reliable results, almost all of the time (and it had better, since Comcast is the largest broadband provider in the U.S.).

A: Fast Ethernet (100 Mbps) maxes out at a throughput of around 94.92 Mbps within applications. So the most likely cause is that the router is only 'Fast Ethernet' and you will need to upgrade to a Gigabit capable router (modem is likely 1Gbps ethernet, but router is only 100 Mbps, causing the bottleneck). OR, if your router is Gigabit, is there a (slow) Fast Ethernet switch somewhere in the network between you and your router? OR, double check the color of LED lights for RJ45 connections (LED color should indicate 1 Gbps and not 100Mbps). You may need to replace a bad ethernet cable (as Gigabit requires all eight wires to be good; 100Mbps only uses four of the eight wires).

A: This can happen when 'WMM' (Wi-Fi Multimedia) is turned off in the router configuration. To fix, turn 'WMM' back on. WMM is actually required for any speeds past 54 Mbps.

A: The most likely cause (if your router is configured for 80 MHz channels) is that your client device does NOT support 802.11ac. Instead, your client device is likely only 802.11n (no 256-QAM support), and supports 'dual-band' and is connecting to the 5 GHz band using the maximum 40 MHz channel width of 802.11n.

Visit devicespecifications.com or phonescoop.com to research versions of wifi supported by your smartphone (802.11n vs 802.11ac, etc).

A: Wi-Fi speeds decrease with distance from the router, and especially decrease through obstacles (walls, floors, etc). Your maximum speed will be when you are just feet from the router (and line-of-sight), and speeds will slowly decrease the further away you move from the router. Sorry, but that is just how wifi signals work.

A: This can happen when a router is set to use channel 165. When channel 165 is selected, there are actually NO 40/80/160 channels available (so the router can only operate using 20 MHz channels). So even if the router is set to use 80 MHz channels, every wifi client connecting to channel 165 will only use 20 MHz channels. To fix, select a different channel.

A: Try a different channel on the router, or try updating wifi driver software on the client. The only time I have seen this is with an Intel AC-7260 laptop (channel 144 not supported) connecting to a Netgear R7800 router on DFS channel 140. The router transmitted to the laptop at 20 MHz speeds and the laptop transmitted to the router at 80 MHz speeds. Upgrading wifi drivers on the laptop resolved the problem.

A: First, can you connect wired/Ethernet to the Internet and confirm the problems go away (this confirms a wireless problem)? Try moving much closer to your wireless AP to maximize signal strength during the call. Try connecting to your router's Wi-Fi band (2.4 GHz to 5 GHz, or vise-versa). Try changing channels on the router. As a last resort, try setting your router to use 20 MHz channels in 5 GHz and try different channels (this will greatly reduce your maximum Internet speed, but hopefully in return, you will gain an ultra-reliable connection for your video calls).

A: If you see the SmartByte application installed (to check, go into 'Control Panel / Uninstall a program', search on 'SmartByte', and if you get a hit, it is installed), disable the SmartByte service, as that Dell service is the likely cause. Google "beware of SmartByte" for a discussion and instructions on how to disable. This Dell service, designed to give priority to video streaming, actually causes slow Internet speeds. Anything designed to 'speed things up' that actually 'slows things down' is pure garbage. I have personally experienced this problem on multiple brand new Dell laptops. Absolutely crazy.

A: The most likely cause of the modem diagnostic page showing that all "Channel ID" have very low 'uncorrectable' errors, expect for one Channel ID with a sky high 'uncorrectable' count -- is is a bad RG6 cable or connector. Try using a different RG6 cable.

A: Yes. I experienced this first-hand with a Netgear R7800 sitting right next to a Netgear CM1000V2 cable modem. The Internet would sporadically drop. The cable modem was seeing a fair amount of "Uncorrectable Codewords", and T3 errors in the events logs. Moving the R7800 over three feet away from the cable modem eliminated the problem. Your experience may be different, but in general, it is a good idea to keep 'transmitting' devices away from other devices as much as possible.

A: Check to see if your router/mesh device has something called "802.11r" (Fast Roaming) turned on. If so, turn off and see if that helps. Some older Wi-Fi client devices can't connect at all to networks with 802.11r enabled.

netsh wlan show interfaces

Description : Intel(R) Wi-Fi 6E AX210 160MHz Physical address : 2c:0d:a7:11:22:33 State : connected SSID : NETGEAR43-5G BSSID : 6c:cd:d6:11:22:33 Radio type : 802.11ax Authentication : WPA2-Personal Cipher : CCMP Band : 5 GHz Channel : 44 Receive rate (Mbps) : 2402 Transmit rate (Mbps) : 2402 Signal : 98%

netsh wlan show all

• Netgear: RAX20/RAX15, R8000/R7900, R7500v2, R7000/R6700
• Asus: GT-AC5300, GT-AC3100, RT-AC88U, RT-AC87U, RT-AC68U, RT-AC66R, Blue Cave
• TP-Link: Archer AX1500, Archer C5400X, Archer C5400, Archer C4000, Archer C3150V2
• Motorola: MR2600, MR1900, MR1700
• Linksys: MX5300, EA9500, EA9350, EA9200, EA8500, EA7500, EA7300
• D-Link: DIR-895L/R, DIR-890L/R, DIR-885L/R, DIR-882, DIR-879, DIR-878, DIR-867, DIR-859
• Amped Wireless: RTA2600-R2, RTA2600
• TRENDnet: TEW-829DRU, TEW-827DRU
• ZyXEL: Armor Z2
• Google: Google Wifi
• Eero: Pro 2nd gen (UPDATE: Eero now supports DFS with new firmware as of May 2020)

• Netgear: RAX40, R7000P/R6900P, Orbi RBR50, Orbi RBR40
• Ubiquiti: UAP-AC-PRO, UAP-AC-EDU
• Synology: RT1900ac
• Linksys: EA9300, EA8300, WRT32X, Velop
• TP-Link: AX3000
• Cisco: CBW140AC

• QCA9984 - Qualcomm 4×4 802.11ac Wave 2 + MU-MIMO + 160MHz
• BCM4366 - Broadcom 4×4 802.11ac + MU-MIMO
• MT7615N - MediaTek 4×4 802.11ac Wave 2 + MU-MIMO

• QCN5054 - Qualcomm 802.11ax
• BCM43684 - Broadcom 4×4 802.11ax
• WAV654 - Intel 802.11ax

Name	2.4 GHz		5.0 GHz		5.0 GHz
	MIMO	Mbps	MIMO	Mbps	MIMO	Mbps
N150	1×1	150
N300	2×2	300
N450	3×3	450
AC1200	2×2	300	2×2	866
AC1750	3×3	450	3×3	1300
AC1900	3×3	600	3×3	1300
AC2600	4×4	800	4×4	1733
AC3200	3×3	600	3×3	1300	3×3	1300
AC5300	4×4	1000	4×4	2166	4×4	2166
AX3000	2×2	574	2×2	2402
AX4300	2×2	459	4×4	3843
AX5400	2×2	574	4×4	4804
AX6100	2×2	400	2×2	2402	4×4	4804
AX11000	2×2	1148	4×4	4804	4×4	4804

2.4 GHz speeds are cited for a 40 MHz channel. 5 GHz speeds are cited for either an 80 MHz channel (802.11ac) or an 160 MHz channel (802.11ax).

TIP: Netgear 'Mode' means channel width.

• 1733: Lookup 1733 in the PHY tables far above and you find it under the 80 MHz PHY table with 256-QAM 5/6 modulation and 4×4 MIMO.
  
  
• 800: Lookup 800 in the PHY tables far above and you find it under the 40 MHz PHY table with 256-QAM 5/6 modulation and 4×4 MIMO.
  
  
• 347: Lookup 347 in the PHY tables far above and you find it (346.6) under the 20 MHz PHY table with 256-QAM 3/4 modulation with 4×4 MIMO. Note that this is because 256-QAM 5/6 is not available in 20 MHz mode (for most commonly used MIMO configurations).

• 1300: Lookup 1300 in the PHY tables far above and you find it under the 80 MHz PHY table with 256-QAM 5/6 modulation and 3×3 MIMO.
  
  
• 600: Lookup 600 in the PHY tables far above and you find it under the 40 MHz PHY table with 256-QAM 5/6 modulation and 3×3 MIMO.
  
  
• 289: Lookup 289 in the PHY tables far above and you find it (288.8) under the 20 MHz PHY table with 256-QAM 5/6 modulation with 3×3 MIMO.

• 300: Lookup 300 in the PHY tables far above and you find it under the 40 MHz PHY table with 64-QAM 5/6 modulation and 2×2 MIMO.
  
  
• 145: Lookup 145 in the PHY tables far above and you find it under the 20 MHz PHY table with 64-QAM 5/6 modulation and 2×2 MIMO.
  
  
• 54: This is the exception. In Netgear routers on the 2.4 GHz band, this sets the router to 802.11g (54 Mbps) operation only.

TIP: Reboot all of your test equipment before running a performance test. I have spent WAY too much time trying to track down the cause of a slow performance test (and not finding the problem), only to at the end, rebooting, and having the problem go away. Frustrating.

TIP: For the test, you only want ONE the computers on Wi-Fi, not both. Because if both are on Wi-Fi, you will get a bad result (as both computers are using Wi-Fi at the same time).

TIP: Run the speed test program LAN to LAN between two computers first, to confirm that both your computers and your LAN can handle 1 Gbps speeds. A result of around 940 Mbps for your 1 Gbps LAN would be a good result.

KEY Wi-Fi concept: A device's Tx and Rx PHY speeds are independent (and are often very different).

To the right is an unusual example of actual measured PHY speeds in real life between a router and a laptop computer. Notice that the laptop might report a 'good' 270 Mbps for the Link Speed (out of max possible of 300 Mbps), but that downloads from the Internet will only use a PHY speed of 216 Mbps! Admittedly, this example is unusual, as most often the (higher powered) router can transmit at a faster PHY to the PC than the PC can transmit to the router.

The best way to notice and see asymmetric PHY speeds is to place a client device 'at range' away from the AP/router being used. The closer a client device is to the AP/router, the less you will notice the asymmetry.

Asymmetric PHY (as seen at AP)

Most modern clients are capable of 80 MHz channel widths and 2×2 MIMO. If you are not seeing PHY speeds indicating that, then you have something to look into.

• mcsindex.com - an old resource, very recently redone and updated to include 802.11ax info
• Cisco's 802.11ac MCS rates - 802.11ac MCS rates
• SemFio Networks - includes a discussion of the math behind the numbers
• wlanpros.com - interesting as table also includes minimum SNR and RSSI values
• 802.11ac Missing MCS's - why some encoding combinations are not valid

First cut: Use scientific notation. 100 mW becomes 1E2, 0.001 mW becomes 1E-3 and 0.00001 mW becomes 1E-5. Well, we are on the right track because we don't have to count zeros, but 'E' notation is still awkward to use.

Second cut: Use only the exponent. Instead of 1E2, just say 2. Instead of 1E-5, just say -5. But we still need to account for the non-exponent (mantissa) part, so use logarithms. For example, log(100) is 2, log(0.00001) is -5,and log(0.00002) is -4.699. This is workable, but can we eliminate the decimal digit...

dBm solution: Multiply the log(mW) result (from step above) by 10 and round to a whole number (no remaining digits). The unit of the resulting number is dBm (decibel milliwatts; deci=tenth). The dBm scale is expressly based/referenced upon 1 mW (the 'zero' point). The (easy to use) result is the table seen upper right.

"dBm" (decibel milliwatts) still represents milliwatt values (in decibel units), but dBm is a MUCH easier way to represent "mW" (milliwatt) values that have 'too many zeros'.

dBm = 10×log(mW)

mW = 10(dBm/10)

Multiplying mW by 10 equals adding 10 dB to dBm Dividing mW by 10 equals subtracting 10 dB from dBm

We can actually deduce this from the table above. How many 'times 2' steps are there in going from 1 to 1000? 1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024? It turns out that 2¹⁰=1024, so there are (very close to) ten steps. And ten steps from 0 dBm to 30 dBm means the step size is 30/10 = 3 dB.

For those who want to know, the precise value is 10×log(2) = 3.0102999566...

• dBm - Wikipedia information on dBm

Seriously. Don't try to extend Wi-Fi signals wirelessly, because all that accomplishes is a 'very slow speed' at distance. Namely, after successfully extending Wi-Fi, you are then left with the problem of slow Wi-Fi speeds at that extended range -- and then you are back to square one -- how are you then going to improve Wi-Fi speeds?

TIP: Confirm that your main router is placed properly in your home.

KEY Wi-Fi concept: The best way to extend Wi-Fi is by adding an access point (wired/Ethernet back to your main router).

By splitting the Wi-Fi band names, you are taking an automated decision (of which band to connect to) away from Wi-Fi devices and manually deciding which band to use. The assumption is that you have tested and know which band is 'best'.

Think about it, if you could increase the transmit power in an AP by a thousand times, that certainly would improve 'AP to client' communication, but that power increase actually would do nothing to help 'client to AP' communication, right?

With an AP using a higher transmit power, the PHY speed (and range) from the 'AP to client' would be greatly improved. But the PHY speed (and range) from the 'client to AP' would remain unchanged (because the client Tx power level is unchanged). So 'at range', clients will see asymmetric PHY speeds.

TIP: To lookup the FCC ID for your phone, use phonescoop.com to find the web page for your phone, and the FCC ID is listed near the bottom of the web page. Then Google search the FCC ID and the search result at fccid.io should be what you want (displays power levels at various frequencies).

The key for understanding this idealistic model is noticing that what impacts received signal strength (in both directions) is: (1) transmit power, (2) transmit antenna, (3) path loss, and (4) the receive antenna.

2.4 GHz example: The Netgear R7800 router has a transmit power in 2.4 GHz of 975 mW and an antenna gain of 0.21 dBi (source). The Ring Video Doorbell Pro has a transmit power in 2.4 GHz of 82mW and an antenna gain of 1.08 dBi (source). Since both antennas are used in both directions, that is a essentially a 'wash' for comparison purposes. What becomes important is that the client has a rather large dB disadvantage of 10.8 dB (10×log(975)-10×log(82)). And that means that the Ring cam only has 29% (1/sqrt(975/82)) of the range that the R7800 router has.

This is why a Ring cam displaying the strong 'RSSI' ('AP to cam' signal) as an indicator of the connection quality is NOT very helpful, as the critical path for the Ring cam is the much weaker 'cam to AP' signal strength (uploading videos).

R7800 to Galaxy S6 long range

5 GHz example: The Netgear R7800 router has a transmit power in the upper 5 GHz of 969 mW. Likewise, for the Ring Stick Up Cam wired, the transmit power is 48.5 mW. The cam therefore has a 13 dB disadvantage -- or 22% of the range of the R7800 router!

5 GHz smartphone example: A Samsung Galaxy S6 is very similar, and results using the MCS Spy tool can be seen right, and confirm the very asymmetric PHY speeds (as 'router to client' power is much higher than 'client to router' power).

So on paper, the 2.4 GHz band has more range than the 5 GHz band, and in real-world testing, that happens most of the time, but not all of the time. Once in a while, the 5 GHz band provides just as much range (and much better throughput). You just need to test.

12 dB hit (6 dB DFS + 6 dB 5 GHz)

Example: The Netgear R7800 for DFS channels transmits with 243 mW. The Ring Stick Up Cam Wired for DFS channels uses 54 mW, a 6.5 dB disadvantage for the camera. So the camera ultimately limits range (not the AP).

Instead of thinking "How can I extend the range of my one router", the much better question is "How can I improve wifi signal strength and still maintain good bandwidth". The answer is: by installing another AP exactly where it is needed, wired/Ethernet to your main router.

Also, high-gain antennas are not without consequence. They work by altering the 'shape' of the signal. Namely, instead of sending the wifi signal out in all directions (think 'sphere'), a high-gain antenna 'flattens' the signal pattern, sending more of the signal out in one direction (eg: horizontally) and much less in the other direction (eg: vertically) -- think 'doughnut'. This change is likely OK for a single story house, but not for a multi-story house. There can be a 'dead zone' directly above/below the high-gain antenna.

It is not uncommon to find 9 dB or even 12 dB high-gain antennas on Amazon. However, I have no idea if they are quality antennas, or not.

Assume you do install high-gain antennas. What happens? All you have accomplished is adding several client devices at range at very slow PHY speeds, causing them to use the bunch of TIME on the channel, potentially slowing everyone else (on the same channel) down.

Also, I can not stress enough the need to test actual throughput in both Wi-Fi bands. The conventional wisdom and 'on paper' calculations show that 2.4 GHz has 'better range' than 5 GHz, but in the real world, this is NOT always the case! It may be true, but it may not be true. I frequently see a big jump in performance switching to the 5 GHz band. The ultimate cause is 'noise floor' differences. It does not matter if 2.4 GHz has a stronger signal strength if that also means a higher noise floor!

At one test location the 2.4 GHz band had a noise floor of -87 dBm, whereas the 5 GHz band had a noise floor of -108 dBm -- a huge difference of 21 dB -- explaining why 5 GHz at this location performed WAY better than 2.4 GHz. You simply won't know until you test both bands.

Every house around you (likely) has a Wi-Fi router, and there are a very limited number of unique non-overlapping Wi-Fi channels. So you are definitely sharing Wi-Fi frequencies with some neighbors. But most neighbor Wi-Fi activity won't impact you due to the fact that Wi-Fi signals attenuate rather quickly. Your router often only sees neighbor Wi-Fi activity as a slightly elevated 'noise floor'.

KEY Wi-Fi concept: The 'quick' attenutation of Wi-Fi signals is what actually allows 'everyone everywhere' to successfully use Wi-Fi 'all at once'.

Analogy: A great way to visually 'see' and understand this is to consider ever increasing spheres. Imagine an antenna at the center of the sphere and the surface area of the sphere is the radio signal as it travels outwards (in all directions). The (fixed) power output of the antenna must be distributed across the entire surface area of the sphere. Seen right are three spheres of radius 1, 2, and 3 (so a doubling and tripling of distance/radius). The formula for sphere surface area is 4×PI×r². The critical term to focus on is r². And you can confirm with your eyes that the sphere of radius 3 has a surface area that is not just three times larger, but 3² (nine) times larger (than the sphere of radius 1).

TIP: You don't have to memorize the Inverse-square law formula. Instead, just remember this 'sphere' analogy and you can easily mentally derive the relationship between distance and signal strength.


Image from Wikipedia.org

(new_dist/old_dist)2 = (new_pow/old_pow)-1

(new_dist/old_dist)2 = old_pow/new_pow

old_pow × old_dist2 = new_pow × new_dist2

TIP: The best way to use this final formula is to fill in the three terms that you do know, and then solve for the one remaining unknown term.

KEY Wi-Fi concept: The change in Wi-Fi signal strength (in mW) is inversely proportional to the square of the change in distance.

Unless you are working in a pure 'line of sight' environment, walls and other obstacles will have a far greater (negative) impact on signal strength than distance will.

BUT, if you have a wifi analyzer app on your smartphone, it is sure interesting to see this actually work in practice. Stand five feet from your router, cause internet activity, and then run the analyzer app and check the dBm value. Then exit all apps and double the distance from the router (try to remain 'line-of-sight') and repeat the process. At least in my testing of this, I do see a 6 dB drop in dBm every time I double my distance from the router (all dots were real measured values):

Netgear R7800 to Samsung Galaxy S6 on 2.4 GHz band

Notice how the power level is adjusted by 6 dB many times before we even get to 40 feet away from the router. And then the next 6 dB adjustment doubles that distance. The 'sweet spot' for most wifi connections is between -40 dBm (pretty close to a router) and -65 dBm (any further away and lower throughput may be very noticeable).

Almost all home access points use 80 MHz channels because speed ends up being far more important than range (and don't even notice, or just live with, the slightly reduced range).

TIP: Alternatively, some clients allow the 5 GHz channel width to be specified/forced to 20 MHz (normally a client would just use the channel width of the access point). This has the huge advantage of allowing you select an 80 MHz channel on the router (so most clients get 'fast speed'), and then only setting 20 MHz channels for those few (far away) clients that need 'extra range'.

If your client device is able to see a weak router SSID in the wifi list, but is unable to connect to it, the router-to-client signal strength may be OK, but the client-to-router signal strength may be too weak.

KEY Wi-Fi concept: The PHY speed (and throughput) you experience in Wi-Fi is determined not by RSSI, but by how far RSSI is above the 'noise floor' -- a value called SNR (signal to noise ratio).

I have seen the noise floor for a band vary by as much as 23 dB (-105 dBm to -82 dBm), and the only thing that changed is physical location (of my travel router; different State). That is rather interesting, because it implies that where you are located (actually how congested Wi-Fi is around you) can actually have a VERY measurable impact on the SNR (and Wi-Fi speeds) you experience.

Please note that the 'noise floor' is not a constant value, but is always fluctuating (and sometimes by a lot).

"Noise is defined as any signal other than the one being monitored" - Wikipedia

Technically, there are ways to communicate at signal levels below the 'noise floor' (like LoRa), but that is beyond the scope of this paper. Modern Wi-Fi relies upon a signal level well above the 'noise floor'.

RSSI stands for "Received Signal Strength Indicator" (wiki info). And while RSSI officially is a 'relative' number (to itself), with no (official) direct relationship to dBm, RSSI is often converted via formulas and displayed as just that (a negative number followed by "dBm").

Analogy: Talk normally in an empty room, and you can easily be heard (RSSI), because the 'noise floor' is so incredibly low (high SNR). But talk normally again (so RSSI signal level is the SAME) in a bar, and you won't be heard, because the 'noise floor' is so high (low SNR) relative to the signal level. The same thing applies to Wi-Fi. As long as the SNR for a Wi-Fi signal is 'good', that signal will be heard and understood.

The implication of this is that regardless of RSSI (even a poor RSSI), a high SNR at the same time means high throughput is very likely, but a low SNR means that high throughput is impossible.

I have seen discussions online state (but have not personally verified) that in industrial environments, large electrical motors running can cause the 'noise floor' to be so high (meaning SNR is always very low), that getting any wifi to work can be very challenging.

Because 5 GHz signals attenuate more through free space (and obstacles), that is providing a noise floor advantage for 5 GHz. I often see the 2.4 GHz noise floor at/around -86 dBm. Whereas for 5 GHz, the noise floor is often around -105 dBm.

When I travel, I run the Wi-Fi Analyzer on my smartphone to see how many access points my phone can see. I never saw a SSID with a RSSI in the mid -90's in the 2.4 GHz band, until one day I saw a RSSI of -95 (seen right). My take away from this is that the 'noise floor' at this location must have been VERY low in order for a signal at -95 dBm to not only be heard, but understood.

MacOS: An exception is that MacOS displays Noise dBm right next to Signal dBm. Very helpful. Use it.

TIP: What this means is that if a device is having trouble maintaining a Wi-Fi connection (and can't be moved closer to the router), and you would rather have a much slower PHY connection that stays up all of the time (than a faster connection to drops in and out) -- try reducing channel width (from 80 MHz to 40/20 MHz).

Now you know one key reason why many low-bandwidth IoT devices stuck to the 20 MHz channels of Wi-Fi 4 vs the 80 MHz channels of Wi-Fi 5 (they have no need for the higher throughput and would rather have increased range).

• 802.11ac Receiver Minimum Input Sensitivity Test
• 802.11ax receive sensitivity requirements
• IEEE 802.11-2012 Table that shows SNR requirements per modulation level
• IEEE 802.11 EVM specification

This has been invaluable to analyze the wifi behavior of a 'locked down' devices (what channel width, Tx and Rx PHY speeds, etc the cam uses).

TIP: When analyzing a device (like a Ring cam), only have that one device connect to the router via wifi (so all wifi stats on one wifi band must be from the device being tested). And then on your PC, telnet to the router via Ethernet (or the other wifi band).

WARNING: Telnet is a text based protocol (not encrypted). So only use it on 'research' networks (not production networks) where you trust everyone currently connected to the network.

wifi0 is the 5 GHz band and wifi1 is the 2.4 GHz band or vice-versa, use iwconfig (described below) to confirm.

This is a GREAT way to independently measure both Rx PHY and Tx PHY, with no cooperation needed on the part of the device being measured! The MCS index reveals the (approximate) PHY speed used (don't know guard interval differences), and quickly tells you if there are symmetric or asymmetric PHY speeds. Seen right is an example where both Tx and Rx PHY are 'mostly' using MCS 7.

In another example, all MCS numbers were pulled into Excel and produced the chart below -- which clearly indicates that the cam is able to receive from the router much better (ave 35 Mbps) than the cam is able to transmit to the router (ave 16 Mbps).

And by only changing wifi channels, cam upload speeds (the majority of everything the cam does) improved significantly (now averages 27 Mbps):

The TxRate and RxRate displayed appear to be kilo (1024) based numbers instead of bps (1000) PHY based numbers. So multiply by 1024/1000 to correct back to 'bps'.

RSSI displayed under Atheros is actually SNR, which is a very important number to know.

In one dual-band router tested, ath0 was the 5 GHz band and ath1 was the 2.4 GHz band. Use iwconfig (described below) to confirm the setup for your router.

OpenWRT: iwinfo wlan0|wl0|ath0 assoclist: source1 source2

This is incredibly useful to clearly 'see' the difference in transmit power (in dBm units) between the different bands/channels in 5 GHz (using DFS channels in 5 GHz have a 6 dB penalty). Also of note is that these power levels do NOT include antenna gain.

It becomes incredibly obvious after running this tool that not only are PHY speeds asymmetric, but that there is no single PHY speed in one direction. Rather, the PHY speed is constantly fluttering around. This is especially evident when the device being tested (eg: tablet) is moving around (with a person walking).

aid:1 rateset [ 1 2 5.5 6 9 11 12 18 24 36 48 54 ] MCS SET : [ 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 ] idle 10 seconds in network 183111 seconds state: AUTHENTICATED ASSOCIATED AUTHORIZED flags 0x1000e03a: WME N_CAP AMPDU HT caps 0x3c: GF SGI20 tx data pkts: 560610 tx data bytes: 80242252 tx ucast pkts: 277309 tx ucast bytes: 45807854 tx mcast/bcast pkts: 283301 tx mcast/bcast bytes: 34434398 tx failures: 246 rx data pkts: 217168 rx data bytes: 210097118 rx ucast pkts: 211051 rx ucast bytes: 209558247 rx mcast/bcast pkts: 6117 rx mcast/bcast bytes: 538871 rate of last tx pkt: 58500 kbps rate of last rx pkt: 117000 kbps rx decrypt succeeds: 1087298 rx decrypt failures: 0 tx data pkts retried: 5851 tx data pkts retry exhausted: 246 per antenna rssi of last rx data frame: -66 -57 0 0 per antenna average rssi of rx data frames: -64 -57 0 0 per antenna noise floor: -89 -92 0 0

qcsapi_sockrpc CMD wifi0 0

get_tx_mcs get_rx_mcs get_tx_phy_rate get_rx_phy_rate get_noise get_snr get_rssi_dbm

iw dev DEVICE station dump

signal: -73 dBm signal avg: -73 dBm tx bitrate: 162.0 MBit/s VHT-MCS 4 40MHz VHT-NSS 2 rx bitrate: 240.0 MBit/s VHT-MCS 5 40MHz short GI VHT-NSS 2 and lots more info...

1. Setup: Connect the AP via Ethernet to the local network/router. I then connect my laptop to the AP to confirm Internet access, and find the IP address of the AP (tip: use "ping routerlogin.net" -- and use that IP address in place of '192.168.1.222' in the steps below).
2. Enable telnet access: Visit "http://192.168.1.222/debug.htm" (use the router's web interface username/password) and ensure that "Enable Telnet" is checked.
3. Telnet to router: Use "telnet 192.168.1.222" and when asked for the password, use the router's web interface password. At this point, you should be successfully signed into a telnet session connected to the Netgear R7800 AP.
4. Start the packet capture: Type the command: "tcpdump -n -s 0 -i ath1 -w /tmp/output.pcap -v", using "ath1" to capture the 2.4 GHz band, or "ath0" to capture the 5 GHz band. Press 'CTRL-C' to end the packet capture.
5. Download the PCAP: I keep a micro USB thumb drive plugged into the AP at all times, and use "mv /tmp/output.pcap /tmp/mnt/sda1/output.pcap" to transfer the PCAP to the USB drive (use "df" to find your USB drive path), and then connect to the "\\192.168.1.222" network share (requires that network sharing is enabled for the USB drive on the AP; may need to use 'admin'/password to access) to download the PCAP file to my PC.
6. Analyze: I analyze the PCAP with WireShark.

The big advantage of using TCPDUMP on the R7800 itself (far above), is that the capture can be done 'remotely' (don't need to be physically next to the R7800).

Conversely, the big advantage of the port mirroring capture technique is that it is much easier for most people to use (and a lot less technical), but it requires your PC is plugged into port one on the R7800.

Dubious Netgear 802.11ad marketing

UPDATE: This is all but confirmed now that 802.11ax (Wi-Fi 6) -- the successor to 802.11ac (Wi-Fi 5) -- is out. Wi-Fi 6 effectively kills 802.11ad from ever being widely adopted for internet access. Instead it IS being used for very short distance point to point (laptop computer to dock).

Also, you know things are VERY BLEAK for 802.11ad in routers when Netgear has a tough time pointing out ANY client devices that actually support WiGig!

Linus video on tri-band (YouTube)

And since (virtually) all Netgear routers are missing support for channel 138, that may limit your options running 'dual 5 GHz'.

And physical separation between AP's make a lot of sense. Would you buy two AP's (same band) and place them literally on top of each other? Of course not. You would spread them around where they are needed. But with a tri-band router, that is exactly what you are doing (placing two AP's on top of each other).

LAN/Phone Structured Wiring Cabinet Gray Cat5e = 4-line Phone / room Gray Cat5e = spare Cat5e / room Blue Cat5e = LAN1+Internet / room Yellow Cat5e = LAN2+Internet / room Red Cat5e = Thermostats (not used) Orange = Modem/Router Internet CATV Structured Wiring Cabinet Black RG6 = CATV / room White RG6 = spare RG6 / room Red Cat5e = Internet to each TV

KEY Wi-Fi concept: Use wired/Ethernet connections whenever possible. Only use Wi-Fi when that is the only connectivity option.

When I built a new home in 2005-2006, my builder tried to convince me that installing Cat5e everywhere was not needed because everything was going 'wireless'.

I am sure glad now that I did not take his advice!

Ethernet is full duplex, and Ethernet 'switches' allow for full speeds between different ports on the switch.

Namely, a 16-port 1 Gbps switch allows for 32 Gbps of non-blocking bandwidth, and that is something that wifi simply can not do.

One room in a new home had two CATV jacks, but the structured wiring cabinet only had ONE run to that room. The installer accomplished this via a CATV splitter somewhere in the walls! He clearly did not understand 'structured wiring' (or was trying to hide a wiring mistake).

Every 'run' in 'structured wiring' home MUST be a 'home run'.

• telephone jack
• CATV
• wired LAN
• thermostat
• doorbell
• security camera
• Wi-Fi access point
• desks
• game console
• any other location you can think of

Possible alternative?: Consider adding strategic 'smurf cable' (empty conduit) runs to many locations.

TIP: Avoid CCA: There is a lot of wire coming out of China that is CCA (copper clad aluminum) that is pure JUNK, and actually violates U.S. building codes. Make sure the wire you install in the walls is quality 'solid bare copper' wire (not CCA) and not stranded (you want solid wire).

So when you have spare CAT6 in every room, that allows you to make changes 'down the road' that you can't foresee today.

• Every room/desk 'phone location' got one Cat5e (four phone lines) and one spare Cat5e.
• Every room/desk 'Internet/LAN location' got two Cat5e (each connected to a different switch in the structured wiring cabinet - for redundancy).
• Every 'CATV location' got two RG6 and one spare Cat5e.
• Every 'thermostat location' got a spare Cat5e.
• The 'CATV demarc location' got one RG6 and one spare RG6.
• The 'phone demarc location' got one Cat5e and one spare Cat5e.
• The (potential) 'satellite dish demarc location' got two RG6.

1. I should have run spare Cat5e to: (a) doorbell locations, (b) security camera locations, (c) security alarm base station location, and (d) all potential Wi-Fi AP locations.
2. Run more spare CAT5e to ALL the utility demarc locations (where phone/CATV/etc enter the home) at the side of the house, because I have already repurposed all of the CAT5e there for other purposes (PoE security cams) and need more.
3. Plan on more electrical outlets in the structured wiring cabinet than you think you need, and place onto a dedicated electrical circuit. You don't want it on a shared bedroom circuit, overloading (hair dryer + something else), tripping, and taking down Internet for the entire house.
4. Plan on having 'expansion room' in the structured wiring cabinets for future changes. Over the years, I added (a) Internet to all TV locations (b) VoIP telephone, (c) six PoE security cameras, (d) etc.

Place the Main Router centrally in a home

• Distances are minimized: Often times, this means placing your router in as 'centralized' a location as possible in the house, and often near where you spend a lot of time, like in a living room.
  
  
• Obstacles are avoided: You want all of the imaginary lines to all Wi-Fi client devices to avoid as many obstacles as possible (appliances, furniture, walls, bookcase, etc). Ideally, all you want the Wi-Fi signal hitting is walls and air, and nothing else.

KEY Wi-Fi concept: Place your 'main router' centrally located in your home, and out in the open.

I was once at a rental house where the Wi-Fi router was in a piece of furniture, in a closet (with a door), in a bedroom, located along an outside wall of the house. So half the house had only OK Wi-Fi signal and the far half of the house had NO Wi-Fi signal. The solution would have been to move the main router to the middle of the house (like the living room), and place the router out in the open.

The "1/2 rule" for supporting Wi-Fi 5 devices: Discovering the PHY speed of the two paths may be very hard, so as a 'general rule', place a mesh/extender node roughly half way between the main router and the furthest modern Wi-Fi 5 client that you must support -- but also place to minimize obstacles! Take advantage of long hallways where there are no obstacles to degrade the Wi-Fi signal.

The "2/3 rule" for supporting older Wi-Fi 4 devices: If you are trying to improve Wi-Fi for a far away Wi-Fi 4 device (eg: many Ring cameras), try placing a modern mesh/extender node 2/3 of way from the main mesh router to the device (camera). This is because you want the 'device to mesh' link to have great connectivity (a PHY of around 72 Mbps, which is the max), and you want the 'mesh/extender to router' link to have OK connectivity (PHY max around 866, but you want anything above 72 Mbps).

OR, just place the AP's where they provide the maximuim value for the most client devices, most of the time. Namely, in the living room, in a kids playroom, or in the home office.

So if you can place a router so that the Wi-Fi signal avoids a wall or two for a far away client device, that will help a lot.

KEY Wi-Fi concept: Don't place routers on or near metal objects.

I replicated the performance problem by placing a non-mesh Netgear RAX50 router on top of the stool. Wi-Fi performance was bad, but as soon as the stool was removed (replaced by a chair made of wood), Wi-Fi performance was great.

The lesson learned: The objects near/around your router can and will impact your Wi-Fi signal.

Using the MCS Spy tool (to confirm MCS indexes used in real-time), I was able to change the MCS level used by a far away device from MCS index 1 to MCS index 2 (doubling the speed) simply by moving the antennas on my AP slightly.

• The Ars Technica semi-scientific guide to Wi-Fi Access Point placement
• ASUS guide on placement of mesh nodes

And marketing hype is directly to blame. It is just another marketing ploy to make new routers sound 'so much better' than prior generation routers.

• 2.4 GHz / 5 GHz / 6 GHz / 60 GHz: Refers to the wireless frequency (spectrum/band) used by wifi.
• 8fs02.11n: Wi-Fi 4: The specification for HT (High Throughput) Wi-Fi (mainly) in the 2.4 GHz band (also operates in the 5 GHz band).
• 802.11ac: Wi-Fi 5: The specification for VHT (Very High Throughput) Wi-Fi in the 5 GHz band.
• 802.11ad: The specification for Wi-Fi around the 60 GHz band.
• 802.11ax: Wi-Fi 6: The specification for HE (High Efficiency) Wi-Fi 6.
• 802.11be: Wi-Fi 7: The specification for EHT (Extremely High Throughput) Wi-Fi 7.
• AFC: Automated Frequency Coordination. A part of Wi-Fi 6E that allows an access point to obtain a "list of available frequency ranges in which it is permitted to operate and the maximum permissible power in each frequency range".
• AP: AP is the acronym for (Wireless) Access Point. This allows your wifi devices to connect to a wired network (which is connected to the Internet).
• AC####: AC refers to support for 802.11ac (Wi-Fi 5) and #### is the sum of the 'maximum PHY network speed' for ALL bands in the router (like dual-band or tri-band). This naming convention is very deceptive because it can imply faster speeds where no faster speeds exist.
• AX####: AX refers to support for 802.11ax (Wi-FI 6) and #### is the sum of the 'maximum PHY network speed' for ALL bands in the router (like dual-band or tri-band). This naming convention is very deceptive because it can imply faster speeds where no faster speeds exist.
• Backhaul: Refers to how a node in the network communicates with the main router in the network -- is it 'wiress' or 'wired' (Ethernet).
• Beamforming: A standards-based (802.11ac/802.11ax) signal-amplification technique that results in increased range and speed to a device. Beware (avoid) earlier (proprietary) 802.11n beamforming implementations.
• Client: Refers to any wifi device (phone, tablet, console, TV, etc) that connects to an access point (AP).
• Dual-band: Two access points in one. Often band one is 2.4 GHz and band two is 5 GHz.
• DFS: Dynamic Frequency Selection. Routers that use DFS channels in 5 GHz must scan for conflicts (TDWR) and get off the channel if a conflict is found.
• IoT: Internet of Things. A future where every device is connected via Wi-Fi to the Internet.
• LAN: Local Area Network (eg: the wired network in your house, often Ethernet)
• MAC: Media Access Control. See Wikipedia.
• MIMO: Multiple-input and multiple-output on the same frequency, where 'multiple' refers to antennas. Also known as SU-MIMO (single user MIMO).
• MU-MIMO: MIMO to "multiple users" at the same time.
• 'N' Spatial Streams: Refers to T×R:N MIMO, where both 'T' and 'R' equals 'N'. For example, 4 spatial streams means 4×4:4.
• OFDMA: Orthogonal Frequency-Division Multiple Access, a proven technology that comes from cellular 4G LTE.
• PHY: PHY is an abbreviation for physical. For example, 'PHY speed' refers to the physical speed at the raw network layer. For every wifi device, there is not just one PHY value, but both a Tx PHY and a Rx PHY.
• PoE: Acronym for 'Power over Ethernet'. Uses an Ethernet cable to send both Ethernet and electrical power to a device. See Wikipedia.
• QAM: Quadrature amplitude modulation (details). A method of converting and sending digital information (0's and 1's) over wires using analog signals.
• Quad-Stream: Often refers to 4×4 MIMO in Wi-Fi 5 devices. But beware that in Wi-Fi 6, router companies are starting to 'add' the streams for each individual band, and publish that total number.
• SNR: Signal to Noise Ratio. The difference (in dB) between the signal level and the noise level.
• TDWR: Terminal Doppler Weather Radar. Important due to DFS channel restrictions.
• Tri-band: Three access points in one. Often band one is 2.4 GHz, band two is 5 GHz and band three is 5 GHz (or 6 GHz Wi-Fi 6E, or 60 GHz 802.11ad).
• WAN: Wide Area Network (the WAN port on your router is connected to a modem, which in turn is connected to the Internet).
• WAP: Wireless Access Point. A device that provides wireless access to a wired network.
• "Wave 2": An 802.11ac term used to define chipset and feature level. "Wave 1" was the first generation, supporting core basic features. "Wave 2" was the next chipset that added many optional advanced features.
• Wi-Fi: A 'brand name' for wifi created by an alliance of companies for IEEE 802.11 wireless technologies, to ensure that wireless products from different vendors all work with each other.
• WLAN: Wireless LAN

• How Does 802.11ax Address Common Problems With Wi-Fi?
  
• What Are The Goals of The 802.11ax Standard?
  
• What Does 802.11ax Change About The WLAN Standard?
  
• What Is BSS Coloring In 802.11ax?
  
• How Will Target Wake Time Help Mobile Devices And IoT In 802.11ax?
  
• Why Is OFDMA One Of The Most Important Features In 802.11ax?
  
• 802.11ax Frame Aggregation Enhancements
  
• What Does Multi-User (MU) Mean?
  
• How Do 20 MHz-Only Clients Operate In 802.11ax?
  
• 802.11ax and Medium Contention
  
• What is BSS Color in 802.11ax?
  
• How Does BSS Coloring Work in 802.11ax?
  
• Dueling NAVs in 802.11ax
  
• Will 802.11ax Make 80 MHz and 160 MHz Channels Usable in the Enterprise?
  
• Does The Number of Spatial Streams in 802.11ax Really Matter?
  
• What Benefits Does Dual 5 GHz Bring To 802.11ax?
  
• The Main Ingredient of 802.11ax: OFDMA
  
• What are OFDMA Resource Units in 802.11ax?
  
• How Does an 802.11ax AP Allocate OFDMA Resource Units?
  
• OFDM and OFDMA Subcarriers - What Are the Differences?
  
• How Does DL-OFDMA Work in 802.11ax?
  
• Unsolicited Buffer Status Reports in 802.11ax and Wi-Fi 6
  
• What is UL-OFDMA Random Access (UORA)?
  
• What is UL-OFDMA Random Access (UORA)? - Part 2
  
• 6 Things to Expect from 802.11ax (Wi-Fi 6)
  
• Why OFDMA is the Secret Sauce for Wi-Fi 6
  

• SmallNetBuilder - Lots of interesting information (but not updated much recently)
• DeviWiki.com - mirror of discontinued 'WikiDevi'
• TechInfoDepot - great site for router FCC numbers; chipsets, etc
• DeviceSpecifications.com - great site for finding smartphone wifi capabilities
• PhoneScoop.com - tons of specification information on phones (like FCC ID)
• FAQ - Basic Wireless Concepts - TP-Link (PDF)

• Ubiquiti FCC ID for all products
• Netgear notice of FCC compliance (but there are DFS support errors in this doc)
• Eero

• ASUS FCC filings
• Netgear FCC filings
• TP-Link FCC filings
• Ubiquiti FCC filings
• Apple FCC filings
• Linksys FCC filings
• D-Link FCC filings

• Interesting videos on their YouTube channel

• TP-Link

• 2023/07/05: Changed ASUS recommendation to RT-AX88U Pro
• 2023/05/20: Added 'metal object' issue to router placement
• 2023/04/10: Added section on the changing meaning of 'stream'
• 2023/02/23: Added 'the easy way' to How to improve Wi-Fi speeds
• 2023/02/20: Added sections on Mesh Networks and Access Points
• 2023/02/19: Changed TP-Link recommendation from Archer AX73 to Archer AX80
• 2023/02/12: Added section on Router/AP placement
• 2023/02/08: Emphasize need for 4×4 MIMO router in recommendation section
• 2023/02/06: Added this version history appendix
• 2023/01/29: Added section on Wi-Fi Range Extenders
• (tons of changes over the years)
• 2018/01/??: created this paper