How a Wi-Fi router works: an analysis of the internal circuitry and operating principles

When you connect to your home Wi-Fi, you rarely think about what's going on "under the hood" of your router. Yet, it's a complex device with its own operating system, processor, and even memory—essentially a mini-computer optimized for routing traffic. Understanding Wi-Fi router devices It helps not only choose the right one, but also diagnose problems: why the speed drops, why the device overheats, or why the signal doesn't reach the farthest room.

In this article we will look at physical design router (case, ports, indicators), its internal circuit (chipset, antennas, power supply) and we will explain how the signal is converted from the provider to the wireless network. You will also learn which components are responsible for 2.4 GHz And 5 GHzWhy do some routers support Wi-Fi 6, while others don't, and how firmware affects performance. If you've ever opened your router settings and gotten lost in terms like NAT, DHCP or QoS, here you will find explanations linked to real hardware components.

This material will be useful for both beginners and those who want to delve deeper into technical nuances. We avoid complex terminology, but if we encounter it, we provide explanations. For clarity, we'll provide A comparative table of chipsets for popular routers (TP-Link, ASUS, Keenetic) and we will show how their characteristics affect the actual operation of the network.

1. The router's external structure: what is visible from the outside

Even without disassembling a router, you can tell a lot about its capabilities from its external components. Manufacturers include everything necessary for connection and diagnostics on the case—you just need to understand what each connector or indicator does.

Main external components:

• 📡 Antennas — their number and location affect the coverage area. External antennas are usually removable (connector RP-SMA), internal ones - soldered into the board. Routers with MIMO (For example, ASUS RT-AX88U) use multiple antennas for parallel data transmission.
• 🔌 LAN/WAN ports - usually 1 port WAN (blue, for provider cable) and 4 ports LAN (yellow, for wired devices). Gigabit ports are marked as 10/100/1000 Mbps.
• ⚡ Power connector - can be standard (DC 12V/1A) or proprietary (for example, Apple AirPort). The power supply capacity affects the stability of operation under high load.
• 🔄 Reset button — reset to factory settings. For some models (for example, Keenetic) there is a separate button to turn it on WPS.
• 💡 Indicators — show internet connection status, Wi-Fi activity, and connected devices. Green/red blinking indicates errors.

Please note ventilation holes — their absence or clogging with dust leads to overheating. Routers with passive cooling (for example, TP-Link Archer C6) get hotter than models with an active cooler (for example, ASUS RT-AX86U).

⚠️ Caution: If the power indicator is red and the router doesn't respond to a reset, this may indicate a faulty power supply. Do not attempt to disassemble the device while it's live!

2. Internal diagram of the router: the “brain” and “heart” of the device

If you remove the router's cover, you'll find a printed circuit board (PCB) underneath the plastic casing, containing microchips, heatsinks, and antenna cables. The key components that determine performance are:

Central processing unit (CPU) — processes data packets, manages routing and security. In budget routers (for example, TP-Link TL-WR841N) there is a single-core processor with a frequency 600–800 MHz, in flagships (for example, ASUS RT-AX89X) - quad-core 1.8 GHzThe more powerful the CPU, the better the router handles a large number of connected devices.

Random Access Memory (RAM) — temporarily stores data about sessions and routes. Minimum volume for modern tasks — 128 MB (For Wi-Fi 5), optimal - 256–512 MB (For Wi-Fi 6). Insufficient RAM leads to freezes when downloading torrents or playing online games.

Flash memory — stores firmware and settings. The size varies from 8 MB (obsolete models) up to 256 MB (flagships). Important: some routers (for example, MikroTik) allow you to install firmware on a removable microSD.

Wi-Fi chipset — responsible for wireless communication. Popular manufacturers:

- Qualcomm Atheros (used in Netgear Nighthawk),

- Broadcom (found in ASUS And Apple),

- MediaTek (budget models TP-Link And D-Link).

The chipset determines the standards support 802.11ac (Wi-Fi 5) or 802.11ax (Wi-Fi 6), as well as the maximum speed. For example, Qualcomm IPQ8074 provides up to 6000 Mbps, A MediaTek MT7621 — to 1200 Mbps.

⚠️ Attention: When replacing the firmware (for example, on DD-WRT or OpenWRT) Make sure your router model is supported. Incompatible firmware can brick your device!

3. How a router converts a provider's signal into Wi-Fi

The process of data transfer from the provider to your smartphone can be divided into several stages. Let's look at them using a typical home network as an example:

1. Receiving a signal from the provider

The signal comes through the cable (Ethernet, GPON or DOCSIS (for cable internet) to the port WANIf you have PPPoE- connection, the router sends the login/password to the provider for authentication. This process is processed CPU using data from flash memory.

2. Traffic routing

The router analyzes data packets and determines where to forward them:

- To a local network (via cable or Wi-Fi),

- To the external network (Internet),

- To a specific device (for example, when Port Forwarding).

Responsible for this firmware, which sets out the rules NAT (network address translation) and DHCP (automatic assignment of IP addresses to devices).

3. Convert to wireless signal

To transmit data over Wi-Fi, the chipset encodes the data into a radio signal. This involves:

- Antennas (determine coverage area and speed),

- Signal amplifiers (increase transmission power, but increase energy consumption),

- MIMO technology (allows you to use multiple antennas simultaneously to increase throughput).

For example, when transmitting video from YouTube on smartphone:

1. The router receives data packets from the provider.

2. Determines that the request comes from a device with an IP 192.168.1.100.

3. Encodes data into a radio signal at a frequency 5 GHz (if the smartphone is connected to this network).

4. Transmits the signal through antennas using the standard 802.11ac.

Why might a router slow down when there are a large number of devices?

When connecting 10+ devices, cheap routers with a small amount of RAM (64 MB) can't process packets quickly, which leads to delays. The problem could also be a weak processor that can't handle NAT or QoS (traffic prioritization).

4. Antennas and Frequencies: How Wireless Transmission Works

Antennas are the most visible component of a router, but their role is often underestimated. They determine not only the coverage area, but also signal quality, interference resistance, and even connection speed. Let's look at the key aspects:

Antenna types:

• 📶 External removable - allow replacement with more powerful ones (for example, antennas with amplification) 9 dBi instead of standard ones 5 dBi). Suitable for large apartments or offices.
• 🏠 Internal — compact, but less effective in interference conditions. Often found in budget models (for example, Xiaomi Mi Router 4A).
• 🔄 MIMO antennas - work in pairs (for example, 2×2 MIMO or 4×4 MIMO). The more antennas, the higher the throughput. Routers with Wi-Fi 6 (For example, TP-Link Archer AX6000) are used 8×8 MIMO.

Frequencies 2.4 GHz And 5 GHz:

Modern routers operate on two frequencies, each of which has its pros and cons:

• 📻 2.4 GHz — passes through walls better, but is susceptible to interference from other devices (microwaves, Bluetooth). Maximum speed — 600 Mbps (standard 802.11n).
• 🚀 5 GHz - less interference, higher speed (up to 1300 Mbps V 802.11ac), but has poorer penetration through obstacles. Ideal for online gaming and 4K video.

Signal enhancement technologies:

• 🔋 Beamforming — focuses the signal toward the connected device (e.g., a laptop), rather than dispersing it in all directions. Supported by most modern chipsets.
• 🌐 Mu-MIMO — allows the router to communicate with multiple devices simultaneously (unlike traditional MIMO, where communication occurs one at a time). This is important for networks with multiple devices.
• 🔗 OFDMA - technology Wi-Fi 6, which divides the channel into subchannels, reducing latency. Useful for smart homes with sensors and cameras.

5. Firmware and software: the “brains” of the router

A router's hardware is useless without its software. firmwareIt manages all processes, from authentication with the provider to distributing IP addresses to devices. The firmware consists of several key components:

1. Kernel

The main part of the OS responsible for operating the hardware. Most routers use the kernel. Linux (For example, OpenWRT built on its basis). The kernel controls:

- Memory allocation,

- The work of the processor,

- Interaction with the Wi-Fi chipset.

2. Protocol stack

A set of rules for processing network packets. Includes:

- TCP/IP — the main protocol of the Internet,

- DHCP — automatic assignment of IP addresses,

- NAT — address translation for Internet access,

- QoS — traffic prioritization (for example, for games or video calls).

3. Web interface

A graphical interface for configuring a router. It varies by manufacturer:

- TP-Link - simple interface with basic settings,

- ASUS - advanced features (eg AiProtection for safety),

- Keenetic — cloud management support.

4. Additional services

The firmware may have the following built in:

- VPN server (For example, OpenVPN or WireGuard),

- Parental Control (restricted access for children),

- Guest network (isolated Wi-Fi for visitors),

- USB server (for connecting a printer or hard drive).

The firmware can be updated via the web interface or manually (by downloading the file from the manufacturer's website). Updates fix vulnerabilities, add new features, or improve stability. For example, ASUS RT-AX88U After the update, support appeared Wi-Fi 6E (frequency 6 GHz).

⚠️ Please note: Some manufacturers (eg. Xiaomi) block the possibility of installing third-party firmware (like DD-WRT) at the bootloader level. Check model compatibility before experimenting!

6. Power and cooling: why does the router overheat?

A router operates 24/7, and its components (especially the processor and Wi-Fi chipset) become hot. Overheating leads to:

- Reducing speed,

- Spontaneous reboots,

- Reduction of the service life of the device.

Causes of overheating:

• 🔥 Poor ventilation — the router is located in a closed cabinet or near heat sources (for example, behind a TV).
• 💻 High load — Simultaneous operation of a torrent client, IP cameras, and online games forces the processor to work at its limit.
• ⚡ Poor quality power supply - cheap units do not provide stable voltage, which leads to additional heating.
• 🛠️ Dust inside the case — accumulates on radiators and impairs heat dissipation.

How to cool a router:

• 🌬️ Move it to an open space (for example, on a shelf).
• 🔧 Regularly clean the ventilation openings from dust (you can use a vacuum cleaner on minimum power).
• 🔄 If your router supports it, install alternative firmware with optimized power consumption (for example, OpenWRT with unnecessary services disabled).
• ❄️ For emergency cooling, you can use a USB cooler (if the router has a USB port).

The router temperature should be normal. 40–60°CYou can check it:

- Via the web interface (in some models, for example, ASUS, there are temperature sensors),

- Using applications like WiFi Analyzer (indirectly, by signal stability),

- Tactile - if the case is hot (more 70°C), this is critical.

7. How to choose a router based on its internal specifications

When buying a router, most people focus on price and appearance, but the real performance lies within. Here's what to look for first:

1. Processor and memory

• For an apartment with 5-10 devices: 2 cores, 1.2 GHz, 256 MB of RAM (For example, TP-Link Archer C20).
• For the office or smart home: 4 cores, 1.5 GHz+, 512 MB of RAM (For example, ASUS RT-AX86U).
• For gaming and 4K streaming: a chipset with hardware acceleration QoS (For example, Netgear Nighthawk Pro Gaming XR500).

2. Wi-Fi chipset

• For basic use: MediaTek MT7621 (supports Wi-Fi 5, speed up to 1200 Mbps).
• For high speeds: Qualcomm IPQ8074 (Wi-Fi 6, to 6000 Mbps).
• For stability: Broadcom BCM4906 (works well with a large number of connections).

3. Antennas and technologies

• For a small apartment: 2×2 MIMO (2 antennas).
• For a large house: 4×4 MIMO + Beamforming (For example, TP-Link Archer AX90).
• To minimize interference: support 160 MHz on frequency 5 GHz (doubles the speed compared to 80 MHz).

4. Firmware and support

• If you need flexibility: models with support OpenWRT or DD-WRT (For example, GL.iNet).
• If simplicity is important: routers with cloud management (for example, Keenetic or Google Nest WiFi).
• If security is required: built-in antiviruses and firewalls (for example, ASUS AiProtection).

Examples of optimal models for different tasks:

Frequently asked questions about Wi-Fi routers

Is it possible to boost Wi-Fi signal by replacing antennas?

Yes, if the router has removable antennas with a connector RP-SMAFor example, replacing standard antennas 5 dBi on 9 dBi can increase the coverage radius by 20-30%. However, it is important to consider:

• Antenna gain works both ways: it "hears" devices better, but they also need to "hear" it. If a smartphone has a weak antenna, the effect will be minimal.
• Too powerful antennas (for example, 15 dBi) may break the law (in some countries the maximum transmitting power is limited).
• For frequency 5 GHz High antenna gain is less effective due to the peculiarities of signal propagation.

It is better to combine the replacement of antennas with channel tuning and use MIMO.

Why do cheap routers slow down when connected to a large number of devices?

Main reasons:

1. Low RAM — when connecting 10+ devices 64–128 MB of RAM There is not enough space to store routing tables, which leads to delays.
2. Weak processor - single-core CPU with a frequency 600 MHz can't handle packets from multiple gadgets.
3. Lack of hardware acceleration - budget chipsets (for example, MediaTek MT7620) do not support NAT acceleration, which causes the CPU to be overloaded with unnecessary calculations.
4. Outdated firmware — Manufacturers of cheap routers rarely release updates, so vulnerabilities and bugs appear over time.

Solution: Limit the number of devices connected at the same time or upgrade your router to a model with 512 MB of RAM and a multi-core processor.

What's the difference between Wi-Fi 5 and Wi-Fi 6 routers?

Main differences:

Characteristic	Wi-Fi 5 (802.11ac)	Wi-Fi 6 (802.11ax)
Maximum speed	3.5 Gbps	9.6 Gbps
Number of devices	Up to 30–40 (with delays)	Up to 100+ (thanks to OFDMA)
Technologies	MU-MIMO (up to 4 streams)	MU-MIMO (up to 8 streams) + OFDMA + BSS Coloring
Energy efficiency	No optimization	Target Wake Time (TWT) extends the battery life of gadgets

Wi-Fi 6 is better suited for smart homes, offices, and networks with a large number of devices. However, for it to work fully, it also requires Wi-Fi-enabled client devices. 802.1