What Is a WiFi Adapter & How Does It Work?

What Is a WiFi Adapter & How Does It Work
What Is a WiFi Adapter & How Does It Work

What is a WiFi Adapter and How Does It Work?

Ever wonder how you can surf the web on your PC or laptop without a hard-wired connection? Almost everyone who has home Internet uses WiFi, which enables users to go online by communicating with their wireless Internet router/modem/gateway via radio waves. So, what is a WiFi adapter and how does it work?

Laptops for at least the past 10 or 12 years include built-in (integrated) WiFi adapters. Most of us use them without ever thinking of how they work. A WiFi adapter is essentially a combined radio transmitter and receiver, tuned to unlicensed radio frequencies of either 2.4 GHz or 5 GHz (or both). A laptop uses a WiFi adapter to wirelessly send and receive data from a DOCSIS/DSL router. When combined with a modem, the device is called a gateway.

If you upgraded to a wickedly-hot data speed (say, 100 Mbps or greater) service tier offered by your Internet Service Provider (ISP) but have an older laptopone that relies on a legacy Institute of Electrical and Electronics Engineers (IEEE) standardyou may wonder why your device still operates at the same speed as before.

The solution is twofold; one, you need a newer router capable of transmitting and receiving 5 GHz bandwidth and/or your laptop needs a newer WiFi adapter to more rapidly process data speed. Trust us—a new WiFi adapter is much cheaper than buying a new laptop or PC.

WiFi Bandwidth Primer

Faithful IAG readers will recall our rant denouncing 5G millimeter waves (MMWs). MMWs are extremely-high frequency (EHF) radio bandwidths, operating between 30-300 GHz. These bandwidths carry lots more data (viz, greater data speeds) than lower bandwidths but can’t travel very far without attenuation or penetrate material thicker than clothing.

By contrast, WiFi uses two unlicensed portions of the radio spectrum: 2.4 GHz and 5 GHz. 2.4 GHz lies near the top of ultra-high frequency (UHF30 MHz-3 GHz) bandwidths while 5 GHz ranks among the lowest super-high frequency (SHF3 GHz-30 GHz) bandwidths. If you deduce that 5 GHz carries more data than 2.4 GHz, doesn’t travel as far and can’t penetrate material as easily as 2.4 GHz does, you reason correctly.

“Wi-Fi,” an IEEE trademark, refers to a family of wireless standards called IEEE 802.11. Older standards802.11b and 802.11g—use only the 2.4 GHz portion of the radio spectrum. 802.11a uses just 5 GHz. In 2009, the IEEE released 802.11n, which operates on either (not both) 2.4 GHz and 5 GHz. 2013 saw the release of 802.11ac, deployed on 5 GHz frequencies. The latest improvement is 802.11ax aka WiFi 6, operating across all ISM bands from 1-6 GHz.

Many laptops manufactured before 2015 aren’t compatible with 802.11ac. 5 GHz bandwidths, as a rule, have less congestion than 2.4 GHz bandwidths. 802.11ac also has greater throughput than earlier IEEE standards. If you’re using a laptop or PC with 802.11g or 802.11n standards and an 802.11g or 802.11n wireless router, you’ll be lucky to attain data speeds higher than 50 Mbps.

Comparing IEEE 802.11 Standards

The first 802.11 standards802.11a (for 5 GHz) and 802.11b (for 2.4 GHz)first appeared at the end of the 1990s. Since then, the IEEE has released amendments to the original IEEE 802.11 standard that reflect improved technology and data throughput. Each new amendment released is backward-compatible with previous versions. Major IEEE 802.11 amendments built into OEM computing devices include:

  • 802.11g aka “Wi-Fi 3” (2003)—2.4 GHz; max throughput 54 Mbps.

  • 802.11n aka “Wi-Fi 4” (2009)—both 2.4 GHz and 5 GHz; max throughput 72 Mbps on a 1 x 20 MHz channel. If 2 x 20 MHz channels are used (i.e., channel bonding, creating a 40 MHz channel), max throughput increases to 150 Mbps. According to forbes.com, the fastest “real world” 802.11n speeds are 240 Mbps.

  • 802.11ac aka “Wi-Fi 5” (2013)—5 GHz; according to forbes.com, the fastest “real world” 802.11ac speed ever tested was 720 Mbps.

  • 802.11ax aka “Wi-Fi 6” (2019)—2.4 GHz, 5 GHz and all ISM bands between 1-6 GHz; using a 160 Mhz channel and 8 (TX) x 8 (Rx) antenna array, max throughput reaches a possible 14 Gbps. Don’t expect to receive anywhere close to this speed at home. You probably don’t even receive 1 Gbps from your ISP.

Types of WiFi adapters

Depending upon the device, computers can utilize several categories of wireless adapters. These include:

1. Integrated adapters

Found on laptops, tablets and smartphones, these built-in devices offer unsurpassed convenience with functionality. Yet, since it’s a factory-installed component and not easily accessible (if at all without voiding the manufacturer’s warranty), they usually can’t be updated to the latest IEEE standards. Moreover, antennas (see below) on integrated adapters don’t transmit/receive radio signals as efficiently as external adapter antennas outside a computer’s housing.

2. USB adapters

Available for all devices save smartphones, they’re (usually) easy to install and use. A USB port, of course, must be dedicated to its use. This can pose problems for those of us who connect several peripherals to our computer; some adapters are large enough to block off more than one port. Fortunately, there’s always a USB port hub. Note that a PC’s rear USB ports are preferred for adapters, as they deliver more power to WiFi antennas.

Many USB adapters are called “dongles“—a catchall term for any small plug-and-play hardware device, such a receiver used with a USB infrared wireless mouse. Remember that smaller or “nano” USB adapters usually require stronger WiFi signals than adapters with external (if unsightly) antennas. But bear in mind that “mobile dongles” refer to USB cellular modems, used to pull in LTE or 3G frequencies instead of WiFi. Know the difference between the two.

Ease of USB adapter installation largely depends upon the availability of software drivers. Some may be as simple as plug and play, with software drivers already available from your computer. Others may need the driver’s software downloaded. While most USB WiFi adapters come with a software CD, it’s a fact that nowadays many laptops lack optical drives.

If you’re beset by this issue, you can either copy the software to a flash drive for later installation, use an external USB optical drive or go online via a wired connection and download the adapter driver software from the manufacturer’s website. In any case, always visit the manufacturer’s website to ensure you have the latest driver version.

3. Peripheral Component Interconnect Express (PCIe) adapters

This WiFi card fits into a slot on a desktop PC’s motherboard. This means that to install it, one must gain access to the PC’s electronic innards. Most PCIe adapters have external antennas that extend from the back of the card to improve the wireless signal range. “Mini-PCIe” wireless cards are used for laptops and notebooks.

PCIe WiFi adapter cards using MIMO spatial multiplexing with multiple antennas generally offer much greater throughput than UBS wireless adapters. But to take advantage of the faster data transfer rates these PCEi cards offer, your router or gateway must support MIMO.

If you’re not comfortable cracking open your computer’s housing, PCIe adapters are not for you.

4. Desktop PC Motherboard adapters

Similar to a PCIe, this adapter is built directly into the motherboard (not a card slot) and integrated into the board as a non-factory accessory. Most use external antennas routed outside the desktop PC housing for better signal strength and less interference.

Another option is to replace your old PC motherboard with a WiFi-enabled motherboard available from Amazon or newegg.com. But you’ll be doing a “PC build.” If soldering irons, heat sinks and EPROMs are alien concepts to you, we advise you to consider either option 2 or 3.

No matter what option you choose, ensure that your adapter is compatible speed-wise with your router/gateway, viz, 802.11g, 802.11n or 802.ac.

Best WiFi Adapters According to GamingScan

Look at GamingScan’s Best Wireless Adapters for 2019 in the video below:

WiFi Adapter Antennas

Wireless adapters can also be categorized by their antennas. Some are omnidirectional (equal Tx and Rx in all directions); others are directional. An antenna’s strength is manifested in decibels over isotropic (dBi). Directional WiFi adapter antennas, like HD TV antennas, are more powerful than omnidirectional ones.

Since 5 GHz signals don’t travel as far in strength as 2.4 GHz, often a WiFi adapter will need an external antenna to communicate with a router/gateway. If you’re using a USB WiFi adapter for 5 GHz, to take full advantage of 802.11ac data speeds you need to be close to the router/gateway to receive a strong signal for a reliable connection and to prevent data packet loss.

Similarly, you’ll need a high-gain external antenna on your WiFi adapter to send and receive WiFi signals if multiple floors or walls separate you from your router/gateway. Remember, even with a high-gain external antenna, distance and multiple obstacles may preclude the use of 5 GHz frequencies for WiFi.

When using a USB WiFi adapter from a desktop PC’s rear port, the presence of electrical interference may necessitate the use of a USB extension cable. Use a high-quality cable, preferably as short as possible, to prevent voltage loss. Otherwise, you may need to invest in an active USB extender to regenerate the USB’s signal.

USB 2.0 vs USB 3.0

We would be remiss if we didn’t mention these two very crucial elements when using a USB WiFi adapter. Older laptops have USB 2.0 ports while newer ones use USB 3.0 ports. USB 2.0 has a max speed of 480 Mbps; USB 3.0 is theoretically capable of 5 Gbps. Also, remember 802.11n speeds top out at 56 Mbps.

So, let’s hearken back to the beginning of today’s article. You recently upgraded to a 100 Mbps data package from your ISP and need a USB WiFi adapter. To take full advantage of its greater speeds, you need:

  • 1) a USB 3.0 port

  • 2) an 802.11ac router/gateway

  • 3) an 802.11ac WiFi adapter

If your laptop uses USB 2.0, then we suggest you replace your factory Mini-PCIe WiFi adapter card with an updated WiFi adapter card on your device’s motherboard.

Security Protocols

An often overlooked consideration when upgrading USB adapters is the security protocol of the router. Since we at the IAG just know you’re diligent about your wireless network security, we’re sure that you’re using a WiFi Protected Access 2 (WPA2) password with 16 random (mixed-case alphanumeric and special) characters. Whatever security standard you use, ensure your adapter uses the same protocol as your router/gateway.

We’ll rant about Wired Equivalent Privacy (WEP) and legacy WPA another time. For now, we’ll just mention that if you’re not using WPA2 or (even better) WPA3 security standards, you’re putting your WLAN at risk of unauthorized intrusion.


As always, how one uses the Internet determines the desired functionality of one’s network elements. Hardcore gamers, if they deign to use WiFi at all, need extreme throughput and very low latency. For them, USB 3.0, an 802.11ac router and an 802.11ac WiFi adapter are more or less de rigeur.

Those of us who don’t need such high-powered networking heft can get by on an 802.11n router to take advantage of its dual-band capability when combating endemic 2.4 GHz network congestion. Just remember to align 802.11 compatibilities with your WiFi adapter, wireless router/gateway and USB release.

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