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The Evolution of Home Wi-Fi: Hertz, Bands, Streams, Channels, Range, and More

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This is an umbrella post on Wi-Fi, the familiar name of the 802.11x networking standards. For the past two decades, Wi-Fi has been an essential cord-cutting invention. Imagine how your smartphone or tablet would be without this wireless connection.

In a nutshell, Wi-Fi is an alternative to network cables, allowing devices to connect to a network wirelessly. However, the world of Wi-Fi can be confusing due to its many speed standards, frequency bands, features, etc.

This post will help you understand Wi-Fi at least as well as the next guy without getting overwhelmed by the networking jargon. It's a good place to start for anyone new to the topic.

Dong's note: I originally published this piece on February 15, 2018, when Wi-Fi 6 wasn't a thing. It's one of my first posts on Dong Knows Tech. Much has changed since then. This latest update, published on July 28, 2023, aims to provide an up-to-date overview of home Wi-Fi.

Home Wi-Fi: Asus RT-AXE7800 vs. Netgear RAXE300: Though smaller in physical size, the firmware has everything the latter has and much more.
The port side of two Wi-Fi 6E routers, the Asus RT-AXE7800 and Netgear RAXE300.

Wi-Fi hardware

We need a signal broadcaster and a receiver to have a Wi-Fi connection. They are the two ends of a network connection. Specifically, the former emits Wi-Fi signals for the latter to catch on to form a wireless link.

For this to happen, the broadcaster can make the Wi-Fi an open network to which any client can connect or create a secure network where only authorized clients can connect via a password. (More Wi-Fi security is in this separate post on Wi-Fi Settings.)

A Wi-Fi broadcaster is typically called a wireless access point (WAP) or access point (AP) for short. However, you more often run into Wi-Fi routers. These are standard routers with a built-in AP. Most home routers nowadays are presumed to have Wi-Fi, though you can still find non-Wi-Fi routers.

The receiver is always a Wi-Fi adapter. In most cases, you do not see an adapter since it resides inside a larger device, such as a laptop or a smartphone. But if you have a computer that doesn't have built-in Wi-Fi (or Wi-Fi of the standard you want), you can upgrade or swap out the adapter fairly easily.

A device—a computer or a mobile phone—with a built-in Wi-Fi adapter is called a Wi-Fi client or just a Wi-Fi device.

Wi-Fi typically works in the "infrastructure" mode in which one broadcaster can host multiple receivers, but a receiver can connect to just one broadcaster at a time. Technically, two receivers can connect directly in the rarely-used "ad-hoc" mode.

All Wi-Fi broadcasters and receivers have antennas. If you don't see them, they are hidden inside or blended with the device's other (metal) parts, like the chassis.

A quick refresher: Wi-Fi signals use the same principle as radio. The cabinet below includes some highlights

How Wi-Fi works

Wi-Fi uses radio frequencies, measured in Hertz, to transmit data from one party to another. It shares the same principle as any other technologies that use radio waves, including the radio itself.

One Hertz vs. lots of Hertz

To understand Wi-Fi radio frequencies, we need to know what constitutes one Hertz.

Heinrich Hertz is a German physicist who conclusively proved the existence of electromagnetic waves in the late 19th century.

As shown in the GIF below, in the simplest terms, Hertz is the number of radio wave crests—or wave cycles—in 1 second. How frequently a wave crests per second is its frequency. It's simple enough.

Wave frequency
How Wi-Fi works: The demo of frequencies

The higher the frequency, the closer the distance between two consecutive wave crests, which translates into a shorter length the wave itself can travel. However, in radio transmission, that also means the more information you can put on it.

FM and AM radio broadcasting stations use frequencies measured in megahertz (MHz), kilohertz (kHz), or even lower frequencies. At these frequencies, a broadcasting station can cover a large area, like a big city.

Signal coverage also depends on the station's broadcasting power. At the same broadcasting power level, signals travel further using lower frequencies than higher ones.

Traditional Wi-Fi broadcasters (routers or access points) use much higher frequencies measured in Gigahertz (GHz), including 2.4 GHz, 5 GHz, and 6 GHz frequency bands. Additionally, per regulation, they use no more than 1 watt (or 30 dBM) of broadcasting power. As a result, generally, a single Wi-Fi broadcaster can only blanket a modest home in physical size.

Wi-Fi is also available on two unique frequencies: the short-lived 60 GHz band (802.11ad), which has an extremely high bandwidth at an extremely short range, and the upcoming 900MHz band (Wi-Fi HaLow), which has mile-long ranges but extremely low bandwidth.

How Wi-Fi works: Radio signals are similar to the ripples of water when a pebble hits the water's surface.
How Wi-Fi works: Radio signals are similar to the ripples caused by a pebble hitting the water's surface.

Real-life Wi-Fi visualization and interference

You can visualize how Wi-Fi, or any wireless radio transmission, occurs by dropping a rock in a still pond and watching the ripples move outwards on the water's surface.

The size of the rock and how hard you throw it equal the "broadcasting power".

Pick a particular ripple and count the number of times it reaches its highest point in one second. If it crests only once per second, you get one Hertz, twice equals two Hertz, and so on. That's the idea.

Radio wave crests can't be counted with the naked eye—we can't see them to begin with—and, as mentioned, Wi-Fi uses frequencies in GHz. For example, 5GHz means there are 5,000,000,000 wave crests in a second. So, I'd leave the counting to the science!

Now, if you drop another pebble at a different spot, that'd be your neighbor's Wi-Fi signal. Toss a rubber duck in the water! That's a microwave. See what happens when the ripples collide? Those are signal distortions—it's when your Wi-Fi signals drop, disconnect, or degrade.

Here's the thing: the pond was never entirely serene. Wind, insects, fish, debris, the liquid's viscosity, etc., are always there to affect the ripples. Similarly, visible and invisible stuff around us can adversely affect Wi-Fi signals. The point is that at any given time, there are more things in the air that hinder a router's Wi-Fi signals than those that don't. And there's always something in the air.

Signal distortions and degradations are part of radio transmission. As radio waves travel through the air, their integrity is degraded by distance and other factors—the fact that Wi-Fi works at all is remarkable.

Netgear A8000 Wi-Fi 6E Adapter in ActionWi-Fi 6E Laptop
A Wi-Fi 6E USB adapter (left) and a Wi-Fi 6 internal adapter (installed) next to a loose Wi-Fi 5 adapter inside a laptop. Note the black antenna wires of the latter.

Once we have a broadcaster and receiver, a Wi-Fi connection's speed depends on their Wi-Fi standard.

Home Wi-Fi and their standards

Wi-Fi standards are how we manipulate the frequencies mentioned above using specific spectrums determined by the Institute of Electrical and Electronics Engineers (IEEE). We have a new standard each time a spectrum is available for Wi-Fi use.

These standards are necessary partly because we can't use just any frequencies. They are regulated—the hardware you buy is restricted to a specific spectrum. Additionally, devices must agree on standardized procedures to communicate via radio successfully.

Since 1999 there have been seven major Wi-Fi standards: 802.11b, 802.11a, 802.11g, 802.11n, 802.11ac, 802.11ax (with an 802.11axe extension), and 802.11be.

There are some non-major standards, too.

The first three standards (802.11b, 802.11a, and 802.11g) are now obsolete. Generally, we only need to care about Wi-Fi 4 (802.11n) and later.

And if you're confused by those cryptic names above, here's good news: you don't have to remember them.

Wi-Fi naming convention

On October 3, 2018, the Wi-Fi Alliance introduced a new Wi-Fi naming convention using simple numbers.

Specifically, 802.11ax is called Wi-Fi 6—it's the 6th generation—802.11ac is now Wi-Fi 5, and 802.11n is Wi-Fi 4, etc.

Later, newer standards are called similarly. The 802.11axe, an extension of Wi-Fi 6, is called Wi-Fi 6E. After that, we have Wi-Fi 7 for the latest 802.11be standard.

This new naming convention is a welcome change. And it makes sense that a higher number of Wi-Fi means a newer and faster standard.

Many Wi-Fi clients nowadays show their connection with this new convention. Specifically, you might see a tiny number of the standard next to the Wi-Fi symbol on your devices, allowing users to pick one that best matches your device.

Faster Wi-Fi doesn't necessarily translate into a speedier Internet because Wi-Fi and the Internet are two different things.

Wi-Fi Symbols
Here's a screenshot of a smartphone's partial Wi-Fi page. Note the little numbers next to the Wi-Fi symbols that indicate the Wi-Fi standards of each network, including Wi-Fi 6 and Wi-Fi 6E in this case.

Wi-Fi’s connection rules and its backward compatibility

Generally, newer standards are faster than the older ones but are backward compatible if they use the same frequency. Consequently, for the most part, you can use Wi-Fi devices of different generations together.

Wireless devices connect using the standard they support, and you can't tell which one they use unless you test the speed, use specific equipment, or view their status via an application. Wi-Fi signals are invisible, and there's no way to tell them apart by looking at the air.

A Wi-Fi connection's speed between two direct parties shares the same principle of a network connection—always that of the slowest party. Also, up to Wi-Fi 6e, a Wi-Fi connection occurs in a single band, using a fixed channel, at a given time.

Wi-Fi 7's new MLO feature allows combining multiple bands into a single link.

For example, if you use a Wi-Fi 6 client with a Wi-Fi 5 router, the connection speed will be that of the latter. And when you use a dual-band client with a dual-band (or tri-band) router, the connection will use one 5GHz or 2.4GHz band at a time.

A Wi-Fi broadcaster's band also has lots of overhead, and generally, its real-world bandwidth is just half or two-thirds of its theoretical speed. That bandwidth, by the way, is shared between all of its connected devices.

Network connection: Wi-Fi vs. Wired

Fundamentally, Wi-Fi can never replace Ethernet.

Wi-Fi: Partial bandwidth and always Half-Duplex. Data moves in one direction at a time using a portion of a band (spectrum) called a channel. You can think of Wi-Fi as the walkie-talkie in voice communication.

Wired: Full bandwidth and (generally) Full-Duplex. Data travel using the entire cable's bandwidth and in both ways simultaneously. That's similar to a phone call in voice communication.

While Wi-Fi is super-convenient, it's only relevant when operating on top of a reliable and fast wired connection.

Wi-Fi standards in brief

The table below includes all current Wi-Fi standards and their brief specifications.

AvailabilityChannel Width
(in MHz)
and Theoretical Speed (in Mbps)
per Stream
(rounded numbers)
Max Number Streams
Used in Clients
(Max Speed Theoretical(•)/Real-word)
SecurityBands (frequency)Status
(in 2024)
802.11b199920MHz/11MbpsSingle-stream or 1x1
802.11g200320 MHz/54Mbps1x1
(Wi-Fi 4)
Quad-stream or 4x4
(Wi-Fi 5)
(Phasing out)
60 GHzLimited use,
(Wi-Fi 6)
Dual-stream or 2x2
(Wi-Fi 6E)
(Wi-Fi 7)
2023 20MHz/225Mbps
(Wi-Fi HaLow)
(85Mbps to 150Mbps)OWE
Wi-Fi standards' real-world theoretical speeds
(•) The absolute best theoretical speed of a real-world connection in an ideal connection before interference, signal degradation, and hardware incompatibility are taken into account. Among the mainstream standards, depending on the number of streams and channel width in use, this theoretical ceiling speed is lower, often by half. In any case, you need to discount this ceiling number by another 30% or 50% to get the real-world sustained rates.
(••) The 5GHz band is split into two portions as sub-bands.
(•••) The 5GHz or 6GHz band is split into two portions as sub-bands.

802.11ad and Wi-Fi HaLow

You'll note in the table above the two "odd" Wi-Fi standards, 802.11ad and Wi-Fi Halow. They are indeed different from the rest and opposite of each other.

802.11ad, often known as WiGig, was first introduced in 2009 and didn't become part of the Wi-Fi ecosystem until 2013.

This standard operates in the 60 GHz band and offers super-fast wireless speeds of up to 7 Gbps. However, it has a super-short range that maxes out at less than 10 feet (3m). It also can't penetrate walls or objects, making it impractical as a wireless networking standard.

Linksys EA9300
The Linksys EA9300 is the first and one of a few 802.11ad routers on the market.

The 802.11ad was briefly available as a docking solution for a laptop—a quick way to connect devices close to each other within a line of sight. However, the standard suffered from low adoption rates and has become obsolete.

An 802.11ad router, such as the Netgear Nighthawk X10, always includes 802.11ac and 802.11n access points to work with existing Wi-Fi clients.

Wi-Fi HaLow, on the other hand, is an upcoming standard that operates in the 900MHz band to deliver signals over a vast distance—over a mile—with limited connection speeds. It's a standard design for low-bandwidth IoT devices.

Wi-Fi HaLow, explained: Low power, passable bandwidth, extreme range

With that, let's dig deeper into the details of Wi-Fi.

Wi-Fi bands and their intricacies (range, channels, and streams)

Wi-Fi bands are the radio frequencies on which the Wi-Fi signals travel between an AP and a client. When it comes to Wi-Fi, we generally need to know the following bands: 2.4GHz, 5GHz, and 6GHz.

There's the 60GHz band, but it's hardly useful or used at all—more in the 802.11ad standard below.

Besides the base speeds mentioned in the table above, each of these bands' most significant and common attributes is their ranges. Let's find out!

Wi-Fi range in theory: It’s “clean” and generous

The way radio signals work is that the lower the frequency, the longer the wave can travel. AM and FM radios use frequency measured in kilohertz and megahertz—you can listen to the same station in a vast area, like an entire region or a city.

Wi-Fi uses 2.4GHz, 5GHz, and 6GHz frequencies—all are incredibly high. As a result, they have much shorter ranges compared to radios. That's especially true when considering the broadcasting power of Wi-Fi broadcasters is limited by regulations.

The highest allowed broadcasting power for Wi-Fi—in the case of the U.S.— is 1 watt or 30 dBm. Wi-Fi 7's AFC might increase this, but only enough to compensate for the fact the 6GHz is inherently short in range.

But, regardless of Wi-Fi standards, these bands generally share the following: The higher frequencies (in Hz), the higher the bandwidth (speeds), the shorter the ranges, and the more bandwidth progressively lost over increasing distance.

Generally, physically larger Wi-Fi broadcasters tend to have better ranges than smaller ones—they use all the allowed broadcasting power and have enough processing power to deliver the most bandwidth at the far end of the signals. Still, it's impossible to accurately determine each's actual coverage because it fluctuates wildly and depends heavily on the environment.

That said, here are my estimates of a home Wi-Fi broadcaster's ranges in the best-case scenario, specifically:

  • Outdoor environment
  • On a sunny day
  • No interference or broadcasters in close proximity
  • Maximum broadcasting power (30 dBm)

Note that Wi-Fi signals don't die abruptly but gradually degrade as you get farther away from the broadcaster. The distances mentioned below are when a client still receives signals strong enough for a meaningful connection. Wi-Fi performance also depends on hardware and Wi-Fi standards—a Wi-Fi 7 router is not better than a Wi-Fi 5 one, in range and whatnot, if the network consists mainly of Wi-Fi 5 and older clients.

  • 2.4GHz: This band has the best range, up to 200 ft (≈ 60 m). However, this is the most popular band. It's also used by non-Wi-Fi devices like cordless phones or TV remotes. Its real-world speeds suffer severely from interference and other things. As a result, for years, this band has been considered a backup, applicable when the range is more important than speed.
  • 5GHz: This band has much faster speeds than the 2.4GHz band but shorter ranges, maxing out at around 150 ft (≈ 45 m).
  • 6GHz(*): This is the latest band available, starting with Wi-Fi 6E. It has the same ceiling speed as the 5GHz band but with less interference and overheads, so its actual real-world rate is faster. However, due to the higher frequency, it has just about 70% of the range, which maxes out at approximately 115 ft (≈ 35m).

(*) Wi-Fi 7 has a new feature called Automated Frequency Coordination (AFC). When implemented, AFC increases the broadcasting power of the 6GHz band enough to make its range comparable to that of the 5GHz band.

Some might consider these numbers generous, and others will argue their router can do more, but you can use them as the base to calculate the coverage for your situation.

Wi-Fi range in real life: The devil is in the little and big details

In real-world usage, Wi-Fi broadcasters in the same frequency band and broadcasting power generally deliver the same coverage. Specifically, they are all the same if you measure the signal reach alone.

What differentiates them is their sustained speeds and signal stability, or how the quality of their Wi-Fi signals changes as you increase the distance. And that generally varies from one model or Wi-Fi standard to another.

Your router's Wi-Fi range is always much shorter than the theoretical number mentioned above. That's because Wi-Fi signals are sensitive to interference and obstacles.

While the Wi-Fi range doesn't depend on the channel width, the wider the channel and the higher the frequency, the less stable it becomes. It's more susceptible to interference and obstacles, and its range is more acutely hindered. So, within the same standard, more bandwidth generally equals higher fragility.

Below are the items that will affect Wi-Fi ranges.

It's worth noting that the new 6GHz band generally doesn't suffer from same-band interference other than when you use multiple broadcasters nearby. On the other hand, the 2.4GHz and 5GHz bands have a long list of other non-Wi-Fi applications that can harm their ranges, and there are always many broadcasters in close proximity using these bands when you live in an urban neighborhood.

Common 2.4 GHz interference sources: Impossible to measure
  • Other 2.4 GHz Wi-Fi broadcasters in the vicinity
  • 2.4GHz cordless phones and other appliances
  • Fluorescent bulbs
  • Bluetooth devices
  • Microwave ovens
Common 5 GHz interference sources: Impossible to measure
  • Other nearby 5GHz Wi-Fi broadcasters
  • 5GHz cordless telephones and other appliances
  • Radars
  • Digital satellites
Common signal blockage for all Wi-Fi bands: Measurable, albeit challenging, walls and large objects

Physical objects, such as appliances or elevators, hinder all Wi-Fi bands. However, among obstacles, walls are the most problematic since they are everywhere. Different types of walls block Wi-Fi signals differently, but no wall is good for Wi-Fi.

Here are my rough real-life estimations of how much a wall blocks Wi-Fi signals—generally use the low number for the 2.4GHz and the high one for the 5GHz, add another 10%-15% to the 5GHz's for the 6GHz band:

  1. A thin, porous wall (wood, sheetrock, drywall, etc.) will block between 5% and 30% of Wi-Fi signals—a router's range will be much shorter when placed next to it.
  2. A thick porous wall: 20% to 40%.
  3. A thin nonporous wall (concrete, metal, ceramic tile, brick with mortar, etc.): 30% to 50%.
  4. A thick nonporous wall: 50% to 90%.

#2 and #3 apply to most walls in residential homes. #4 is the case of condos in high rises or walls around bathrooms.

Again, these numbers are just ballpark, but you can use them to know how far the signal will reach when you place a Wi-Fi broadcaster at a specific spot in your home. A simple rule is that more walls equal worse coverage, and generally, a single wall will reduce the signal by approximately 30%.

That said, in real life, when all adverse elements are taken into account, and depending on the situation and where you stand from the broadcaster, we need to discount the theoretical ranges mentioned above between 40% and 90% to get a broadcaster's realistic coverage.

Wi-Fi channels

Wi-Fi channels, in a nutshell, are a small portion (section) of each Wi-Fi band. If a Wi-Fi band is a freeway, the channels are lanes.

A Wi-Fi connection must use a particular channel at a given time. (Just like a car must use a specific lane at any given time.)

The channel width (or bandwidth) decides how fast a link is—the amount of bandwidth it can deliver. That's like a bike lane can handle less traffic than a car lane but is still more capable than the sidewalk for pedestrians.

In return, a wider channel also tends to suffer more from interference and is hence less stable than a narrower one. But the specificity of that depends on the environment. In an ideal air space, wider is always better.

wi fi 6E Bands
How channels work in different Wi-Fi bands.

Channels are measured in Megahertz (MHz)—the higher the number, the wider, hence, the more bandwidth.

Depending on the frequency, there are four popular channel width levels. The 2.4GHz band can only have 20MHz and 40MHz channel widths; the 5GHz band adds 80MHz and 160MHz. The latest 6GHz band has even wider channels.

In all cases, we need to combine multiple contiguous channels to make up a wider one. So a 40MHz channel includes two consecutive 20MHz channels, an 80MHz channel requires two contiguous 40MHz channels (or four 20MHz ones), etc.

As a result, a Wi-Fi band can include more narrower or fewer wider channels. On the 5GHz, there can be at most two 160MHz channel widths (or three if you count the UNII-4 portion). Most importantly, both require the use of DFS channels.

What's DFS, exactly?

Dynamic Frequency Selection (DFS) channels

Only available on the 5GHz band, DFS channels are special ones that share the air space with radar signals which have the right-of-way. So a DFS channel is like a bike lane on which you can drive your car, but only when there's no cyclist around.

Normally, these channels work just like any other channel. However, when radar signals are present, often if you live within tens of miles of an airport or weather station, the router will move its signals to the next unoccupied DFS channel.

During this channel-switching process, your device might briefly get disconnected. That said, using the 160MHz channel width, which requires DFS, is not always a good idea.

Not all clients support DFS, so most routers don't use these channels by default for compatibility reasons.

160MHz vs. 160MHz (80+80) channels

To avoid DFS, some Wi-Fi chips have the 160MHz (80+80) mode by combining two non-contiguous 80MHz channels into a single one—like in the case of the Netgear RAX120.

The 160MHz (80+80) approach is a hack and doesn't deliver the same performance as a natural 160MHz channel. It hardly works in real-world testing and is considered abandoned, especially with the subsequent availability of the UNII-4 portion.

Over-lapping channels

Overlapping channels are those that multiple types of traffic can use—like a bike can go on a lane designed for cars—and tend to be more susceptible to interference.

On the other hand, non-over-lapping channels are like lanes explicitly intended for a type of traffic, such as a railroad or a carpool lane.

Wi-Fi streams

Wi-Fi streams—often referred to as spatial or data streams—are how a Wi-Fi signal travels. A stream determines the base speed of a frequency band in a Wi-Fi standard. The more streams a band can handle, the faster its rate is.

You can think of streams as vehicles that use the road. Depending on the cargo space's size (or the number of trailers it can pull), a vehicle can move more or fewer goods per trip.

Depending on the hardware specs, a Wi-Fi connection uses a single-stream, dual-stream (2x2), three-stream (3x3), or four-stream (4x4). Right now, 4x4 is the highest, though there might be even more in the future.

Note that we're talking about the number of streams of a single band here. Starting with Wi-Fi 6—more below—many networking vendors combine the streams of all bands in a broadcaster into a larger number, like 8 or 12 streams.

That's misleading since a Wi-Fi connection takes place in one fixed channel of a particular band at a time, similar to the fact that a vehicle can use only one lane of a road at a time. Therefore, it's irrelevant to use the number of lanes found on all roads to insinuate the performance of one particular lane, road, or vehicle.

As you can see in the table above, each Wi-Fi band and standard has a different base single-stream speed. But in all cases, the concept of multiple streams remains the same.

While both a car and a bike can tow a trailer, the sizes of their trailers are different.

Important note: In a particular Wi-Fi connection, the fewer streams used, the fewer parties involved. For example, if you use a 4x4 router with a 2x2 client, you'll have a 2x2 connection.

Bands vs. Channels vs. Streams

Wi-Fi uses three frequency bands, including 2.4GHz, 5GHz, and 6GHz. The width of each band is measured in MHz—the wider the band, the more MHz it has.

The 6GHz band is the widest of the three and has 1200MHz in total width, ranging from 5.925GHz to 7.125GHz. Depending on the local regulations, only a portion or portions of this entire spectrum is available for Wi-Fi applications.

In real-world usage, each band is divided into multiple portions, called channels, of different widths. Depending on the Wi-Fi standards and hardware, a channel can be 20MHz, 40MHz, 80MHz, 160MHz, or 320MHz wide. The wider a channel is, the more bandwidth it has. Depending on the channel width, the number of channels in each Wi-Fi band varies, but there can be only so many.

The 6GHz band has enough space for three 320MHz channels or seven 160MHz channels.

Data moves in one channel of a particular band at a time, using streams, often dual-stream (2x2), three-stream (3x3), or quad-stream (4x4). The more streams, the more data can travel at a time.

Here's a crude analogy:

If a Wi-Fi band is a freeway, channels are lanes, and streams are vehicles (bicycles vs. cars vs. buses). On the same road, you can put multiple adjacent standard lanes (20MHz) into a larger one (40MHz, 80MHz, or higher) to accommodate oversized vehicles (higher number of streams) that carry more goods (data) per trip (connection).

A Wi-Fi connection generally occurs on a single channel (lane) of a single band (road) at a time. The actual data transmission is always that of the lowest denominator—a bicycle can carry just one person at a relatively slow speed, even when used on a super-wide lane of an open freeway.

The evolution of Wi-Fi

Over the years, as Wi-Fi progresses over different standards, it also has more and more features. Below are a few big milestones.

Again, since the older standards are obsolete, we'll start with Wi-Fi 4.

Wi-Fi 4 (802.11n)

Wi-Fi 4, also known as Wireless-N, uses 20MHz and 40MHz channel widths and up to four streams (4x4). A single stream delivers 150Mbps (40MHz).

Wi-Fi 4 is when we also have:

  • Dual-band
  • The designations of combined speeds
  • MIMO
  • The popular use of WPS and Wi-Fi Protected Access (WPA) security methods.

This is when a Wi-Fi broadcaster operates in 2.4GHz and/or 5GHz at a time.

Dual-band is a compatibility necessity. Some Wi-Fi devices only use the 2.4GHz band, and others use the 5GHz. So for devices to work interchangeably, regardless of their standard, dual-band support is necessary.

A dual-band broadcaster has two access points, one for each band. A dual-band client similarly has two wireless receivers.

Keep in mind that "dual" doesn't mean you'll see two hardware units. Instead, one physical access point (or router or adapter) has two hardware components on the inside.

Dual-band broadcasters (routers, access points) are generally concurrent (or true) dual-band, meaning they can work on both bands simultaneously. There were once selectable dual-band broadcasters—supporting the obsolete 802.11a and 802.11b/g standards—that operated on one band at a time.

All receivers (adapters/clients), dual-band or not, can only connect to a broadcaster using one band at a time. This is like a car can only use one lane of a road at a given time.

Combined speed designation

With Wi-Fi 4, networking vendors use the N designations, where N is short for 802.11n.

For example, they called a dual-band dual-stream (2x2) Wi-Fi 4 router an N600 router. The number following N is the combined ceiling speeds of both bands (300Mbps on the 2.4Ghz and 300Mbps on the 5Ghz). Similarly, three-stream (3x3) routers are now classified as N900.

This type of naming continues with newer Wi-Fi standards.


MIMO stands for multiple inputs and multiple outputs. It allows a pair of broadcasters and a receiver to handle multiple data streams simultaneously. The more streams there are, the faster the connection is.

Again, MIMO started with Wi-Fi 4 (802.11n) and works on both 2.4GHz and 5GHz frequency bands. Later, thanks to the introduction of MU-MIMO, or multi-user multiple-input and multiple-output, in Wi-Fi 5, it is often referred to as single-user MIMO or SU-MIMO.

Wi-Fi Protected Setup (WPS)

First introduced in 2006 by Cisco, WPS became popular with Wi-Fi 4. It is a quick way for a client to connect to a Wi-Fi network by pressing a button on the router and then on the client.

WPS saves you from the hassle of manually typing in the Wi-Fi password, but it could pose security risks in some instances. Nonetheless, it remains in later standards.

Wi-Fi Protected Access (WPA)

Wi-Fi 4 is also when the new Wi-Fi protected setup Wi-Fi Protected Access (WPA) became widely adopted.

Officially available in 2003, WPA replaced the Wired Equivalent Privacy (WEP) security method laden with vulnerabilities.

WPA uses a common configuration called WPA-PSK (Pre-Shared Key). The security keys this method uses are 256-bit long, much better than the 64-bit and 128-bit keys of WEP.

Initially, WPA uses the Temporal Key Integrity Protocol (TKIP) for encryption, which employs a dynamic per-packet key system that's more secure than WEP's fixed key system. Later, WPA gets an even better encryption standard called the Advanced Encryption Standard (AES).

WPA allows users to choose between TKIP and AES throughout its lifetime. In addition to WPA, Wi-Fi 4 hardware also supports WEP for backward compatibility since some legacy clients don't support WPA.

While secure, WPA is vulnerable to hacking, especially via the Wi-Fi Protected Setup (WPS) mentioned above.

Asus RT-AC88U
The Asus RT-AC88U is one of the best Wi-Fi 5 routers on the market.

Wi-Fi 5 (802.11ac)

This standard operates only on the 5GHz band and the base single stream speed of around 433Mbps (80MHz) and can deliver up to four streams at a time (4x4), hence up to around 1733Mbps (4 x 433Mbps) speed.

Some Wi-Fi 5 broadcasters support the new 160MHz to deliver even faster speed. However, very few Wi-Fi 5 clients support this channel width.

On the 5GHz band, the standard is backward compatible with Wi-Fi 4. Also, a Wi-Fi 5 router/access point always includes a Wi-Fi 4 access point on the 2.4GHz band. For this reason, any Wi-Fi 5 broadcaster will support all existing Wi-Fi clients.

With Wi-Fi 5 comes:

  • Traditional Tri-band
  • Beam Forming
  • The adoption of the WPA2 security method
  • Wi-Fi mesh system
Traditional tri-band

Generally, this means a broadcaster has three access points of different bands.

Traditionally, this means it has one 2.4GHz band and two of 5GHz bands, all working simultaneously. A tri-band broadcaster can serve more 5GHz clients simultaneously than a dual-band router before slowing down.

There's now a new type of tri-band with the introduction of Wi-Fi 6E—more below.

Dual-band vs. Tri-band vs. Quad-band: That burning bandwidth question

Wi-Fi 5’s AC designations

Similar to the N designations above, networking vendors now combine the speeds of all bands into new names for Wi-Fi 5 routers. These names start with AC, where AC is short for 802.11ac.

As a result, you'll find many variables such as AC3100 (like the Asus RT-AX88U), AC5400 (TP-Link C54X), AC2200 (Synology MR2200ac), and a lot more.

Different vendors might use different numbers depending on how they decide to round up (or down) the total bandwidth, mostly for marketing purposes. So, they are not consistent throughout the industry.

Keep in mind that the numbers following AC are not the top speed of a single connection but the total bandwidth of all bands.

That's like calling your flying car (when you have one!), which can run at 60 miles per hour and fly at 120Mph, a 180Mph vehicle. That is misleading since the car can only run or fly at a time. But networking vendors love to use this as a marketing ploy.


Beamforming is a feature where the broadcaster automatically focuses its signals in a specific direction of a receiver to increase efficiency and speed.

Beamforming is only available on the broadcaster side, and it's generally hard to gauge its effectiveness.


Commercially available in 2006, the WPA2 is an improved version of WPA. The Biggest change is the mandatory use of the AES encryption method and the introduction of the Counter Cipher Mode with Block Chaining Message Authentication Code Protocol (CCMP) as the replacement for TKIP.

Wi-Fi 5 hardware still supports WPA for backward compatibility. The support for WEP was also available initially but slowly phased out in newer hardware.

While WPA2 is much more secure than WPA, it's not 100% hack-proof and is also susceptible to hacking, again via WPS. The chance of getting a WPA2 security method hack is minimal, however.


This feature is part of Wi-Fi 5 Wave 2—an enhanced version of 802.11ac. MU-MIMO allows multiple devices to receive various data streams at the same time.

More specifically, in a MIMO network, the broadcaster handles just one Wi-Fi client at a time, first come, first served. So if you have multiple clients, they must stay in line and take turns receiving data packages. It's like when there's just one bartender in the club.

On the other hand, in an MU-MIMO network, the broadcaster can simultaneously serve up to four (possibly more in the future) Wi-Fi clients. It's like having a few bartenders in the club.

That said, it's important to note that even in a MIMO network, a router can switch between clients quite fast, and most of the time, you won't experience any delay or slowdown.

Consequently, unless you have many—a dozen or so—simultaneously active clients, you won't see the benefit of MU-MIMO. Also, this feature only works on the downlink and the 5GHz band.

Most routers, if not all, new routers and access points support MU-MIMO.

Wi-Fi mesh system

Wi-Fi mesh systems use multiple broadcasters to form a seamless network to cover a large property. This Wi-Fi solution type starts with Wi-Fi 5, specifically with the eero, first introduced in 2016.

Mesh systems come in all different flavors to deliver different speeds and coverage grades to fit different needs. You can read more about them in this post.

Ubiquiti UniFi Dream Machine vs. AmpliFi Alien Wi-Fi Routers Front
The AmpliFi Alien Wi-Fi 6 router is next to the Dream Machine Wi-Fi 5 counterpart.

Wi-Fi 6 (802.11ax)

Wi-Fi 6 is the latest generation of Wi-Fi and became commercially available in early 2019. Details of this new standard can be found in this post about Wi-Fi 6.

Wi-Fi 6, explained: Real Speeds, Range, DFS channels, and More

But briefly, this new standard operates in both 5GHz and 2.4GHz bands. On the former, it supports the 160MHz channel and has a base single-stream speed of 600Mbps.

Wi-Fi 6 adds the following to Wi-Fi:

The current Wi-Fi 6E Routers on the market
The current collection of all Wi-Fi 6E routers on the market

Wi-Fi 6E (802.11axe)

Wi-Fi 6E is the extension of Wi-Fi 6 and uses the 6GHz band to do away with DFS channels at the cost of a shorter range. The standard became commercially available in 2021.

The biggest change of Wi-Fi 6E is it mandates the use of WPA3.

Details of the new standard can be found in this post on Wi-Fi 6E.

Wi-Fi 6E, explained: The 6GHz novelty

Wi-Fi 7 (802.11be)

Wi-Fi 7 is the latest and the biggest improvement, with the first supporting routers available in 2023.

Besides inheriting all the features of the previous standard, it's slated to improve the connection speed by supporting multiple features, including combining various bands into a single link and using extra broadcasting power in certain situations to make the 6GHz range comparable to that of the 5GHz.

Wi-Fi 7 is the first standard that can deliver true muti-Gigabit connections, with a big focus on Multi-Gig wired standards. More about it is in the separate post linked below.

Wi-Fi 7, explained: How it's slowly becoming a game changer

Netgear NIghthawk RS700 Wi-Fi 7 Router out of Box
The Netgear Nighthawk RS700 is one of the first Wi-Fi 7 routers on the market

The takeaway

For the past two decades, Wi-Fi has become one of the essential technology in our daily life. Over the years, it has evolved so much, delivering connection speeds tens of times faster than when it first became available to the masses.

And Wi-Fi 7 is likely not the last revision.

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20 thoughts on “The Evolution of Home Wi-Fi: Hertz, Bands, Streams, Channels, Range, and More”

  1. With 802.11ad, you say:

    However, it has a concise range of fewer than 10 feet (3m).

    What is a “concise” range ?

  2. Dong, thanks for the useful info. I’m reasonably technical but still haven’t quite got my head around streams. Specifically I’m trying to understand the relative benefits between a 4×4 stream operating with 80MHz channels vs a 2×2 stream with a 160MHz channels. Presumably the trade-off is in maintaining speed for a larger number of supported clients (more streams) vs having a higher max speed for those clients than can actually support the wider channel (2×2 at 160MHz). I’d interested in getting your take on it?

  3. ##It allows a pair of broadcaster and receiver to handle multiple data streams at a time##
    But again on a single band at a time?

  4. Is there a way to find out if I have radar signals present in my home?
    I live in Lisbon and we have an airport here so I suppose that I have radar signals, but anyway I would like to verify somehow. The distance from my home to the airport is about 5-6km.

    • No, not without some special equipment, but 6km is very close so you sure have it. This post is for the US region, by the way, I don’t know about EU regulations on this matter. Again, make sure you pay attention when reading.

  5. Hi,

    Why is dual-stream called 2×2, three-stream called 3×3, and four-stream called 4×4? It’s easy to think that this means there are 4 streams, 9 streams and 16 streams respectively even though its just dual, three , or four stream.

    Why is it not more intuitively labeled as dual-stream (2 x 1) , three-stream (3 X 1) and four-stream (4 X 1) ??

    • How is your way more intuitive, Shane? Among other things, that can be understood as 2,3,4 respectively, the x1 is redundant. But to answer your question, the streams are working in *both* directions, sending and receiving.

      • Because I read it as 2 times 1 = 2 , 3 times 1 = 3 , and 4 times 1 = 4 . Is it because I’m reading the pronunciation of “×” wrong? I should pronounce “×” as “of” , rather than pronounce/read “×” as “times”?

        So, 4×4 does not mean 4 X 4 = 16 streams , but 4 of 4 streams – meaning: 4 antennas capable of transmitting (i.e. sending and receiving) 4 streams .

        and 2×2 simply means “2 streams of 2 antennas” (not “2 streams of 2 streams” or “2 streams times/multiply 2 streams”)

        • I think you’re confusing yourself by overanalyzing, Shane. It’s just a way folks have agreed on. My previous comment was just to say that your way could be confusing for others, too, if they wanted to be confused.

  6. Hi Dong. I’ve enjoyed your reviews on that other site and am happy to just now find you on your own site!

    My Linksys WRT3200ACM purchased in late 2017 is now having issues on the 5GHz band. I first noticed it when my Netflix streams would stop suddenly, and then when my Macbook Pro could no longer connect to that band.

    So it seems I am in the market for a new router. Your articles are helping, but I would love to have a top 5 list or something similar. Presently I am very hisitant to buy another Linksys, and my ASUS before this router only lasted about 3 or 4 years. Which router should I buy!

    We don’t do gaming, we stream a movie several times per week, and otherwise just use the internet mostly on the weekends. Our phones (2 of them) are both older (iPhone 7 and Samsung S7.)

    Any help is much appreciated!


    • Glad you found me here, Brock. For your needs, I’d recommend the Asus RT-AC86U or the Blue Cave (pick the design you like). If the Linksys WRT3200ACM worked out for you at one point, either of the Asus will do really well.

  7. If I use a WiFi 6 wireless adapter on a WiFi 5 router, am I going to lose any WiFi 5 speed? Comparing to using a WiFi 5 adapter. WiFi 6 and WiFi 5 adapters are in the same price range now, so buying a WiFi 6 adapter should be more future proof. I am not planning to upgrade my WiFi 5 router. So I want to use a WiFi 6 adapter on my WiFi 5 router.

    • Yes, Carlos. It’s safe to upgrade to WiFi 6 on the client side without doing so on the router side. And vice versa.

  8. Thanks for your prompt reply Dong! I was able to resolve my problem by going into the main router’s configuration page and clicking on the “Aimesh Node” button at the bottom of the Network Map and then clicking on the “Search” button on the “Find Aimesh node” section that appears on the upper right corner of the page. Then I selected the found node and “voila”.


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