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Inside IEEE 802.11 Wireless Networks: Wi-Fi Architecture and Signaling

Inside IEEE 802.11 Wireless Networks: Wi-Fi Architecture and Signaling

Vincenzo Miccoli : 18 October 2025 09:20

IEEE 802.11 wireless networks, better known as Wi-Fi, are the beating heart of modern connectivity. From a niche solution for home use to a technological cornerstone for the Internet of Things (IoT), smart cities, and enterprise infrastructure, Wi-Fi has evolved unstoppably. Today, in 2025, the arrival of Wi-Fi 7 (IEEE 802.11be) brings theoretical speeds of over 46 Gbps and latencies of less than a millisecond, but with it comes new challenges: security, interference, and spectrum management.

In this article, part of Red Hot Cyber’s Wi-Fi series, we analyze the fundamentals of IEEE 802.11 networks, exploring their architecture, signal behavior, advantages, and limitations. The goal is to understand not only the potential of Wi-Fi 7 but also the emerging challenges, particularly those related to cybersecurity and spectrum management.

Why Wi-Fi Dominates (and Where It Stumbles)

Imagine a world without Wi-Fi: no connected smartphones, no smart homes, no offices without tangled cables. Wi-Fi has conquered the planet thanks to four strengths:

  • Pure mobility : You move, you stay connected. From robotic warehouses to university campuses, it’s a game-changer.
  • Reduced costs : No wiring means quick installations and savings of 30-40% compared to Ethernet [1] . Perfect for historic buildings or temporary structures.
  • Blazing-fast speeds : With Wi-Fi 7, Multi-Link Operation (MLO) simultaneously uses the 2.4, 5, and 6 GHz bands, pushing throughput to unprecedented levels.
  • Extreme Flexibility : From a home LAN to a business with thousands of devices, Wi-Fi adapts.

But all that glitters is not gold. Transmission via radio waves makes it vulnerable: an attacker with a directional antenna can intercept signals from a distance, and even WPA3 isn’t immune to sophisticated exploits. Then there’s interference—microwaves and Bluetooth congest the 2.4 GHz band, while the 6 GHz band requires advanced strategies to avoid overlap. Finally, range: regulations like those of the ETSI (20-30 dBm) limit coverage to 100-200 meters outdoors, and indoors a concrete wall can halve that.

How It Works: Wi-Fi Architecture

Wi-Fi is based on a cellular architecture, the Service Sets , which define how devices talk to each other:

IBSS (Ad Hoc): Direct communication between devices

In an Independent Basic Service Set (IBSS) network, there is no Access Point (AP): devices connect directly to each other. This scheme, also known as Ad Hoc mode , is useful for emergency scenarios or temporary networks.

Example : Industrial sensors in a factory or remote drilling site can use IBSS to exchange data directly, without the need for a complex network architecture.

  • Scenario : A toxic gas monitoring system in a mine or refinery, where sensors need to share real-time readings with a mobile station without fixed infrastructure.

Operation : The sensors connect in Ad Hoc mode , transmitting critical information to each other to generate a local alert in case of danger.

BSS: Networks with centralized Access Point (AP)

In the Basic Service Set (BSS) , an AP acts as a coordinator , managing Wi-Fi clients and optimizing communication. This model is standard for home and business environments.

Example : Wi-Fi 6 network for small offices , with a single AP that uses OFDMA (Orthogonal Frequency-Division Multiple Access) and MU-MIMO to handle multiple simultaneous connections, assigning portions of spectrum more efficiently.

ESS: Extended coverage networks with seamless roaming

The Extended Service Set (ESS) connects multiple BSSs through a Distribution System (DS) , usually via Ethernet or wireless backhaul. It is the model used to ensure uninterrupted coverage over large areas.

Example :

  • In a hospital with fast handoff , APs use 802.11r (Fast Roaming) to ensure clients can seamlessly switch from one AP to another without having to perform a full re-authentication (thanks to Key Caching).
  • In industrial environments with AGVs (Automated Guided Vehicles), Wi-Fi must ensure latency-free roaming . Protocols like 802.11k/v allow devices to know in advance which AP is best to connect to, reducing transition times.

In 2025, Wi-Fi 7 raises the bar: MLO allows you to use multiple bands in parallel, reducing latency and increasing reliability. The result? A device can switch from 2.4 GHz (long range) to 6 GHz (high capacity) without you even noticing. Add 320 MHz channels and bidirectional MU-MIMO, and you have a network that can handle up to 50 devices in a room without a hitch.

After seeing how Wi-Fi architecture with IBSS, BSS and ESS works to ensure connectivity and seamless roaming, the natural question is: what physically happens to the signal as we move from one Access Point to another?

The Wi-Fi Signal: Physics at Work

Wi-Fi isn’t just software and networks, but electromagnetic waves that must overcome distances and obstacles to connect devices. Its frequencies operate in the ISM (2.4 and 5 GHz) and U-NII (6 GHz) bands, and their propagation is governed by precise physical laws. Frequency dictates everything: at 2.4 GHz, the wavelength is 12.5 cm, ideal for passing through walls; at 6 GHz, it drops to 5 cm, perfect for speed but fragile against obstacles.

The received power drops with distance according to the inverse square law:

Pr​=(4πR)2Pt​​

Add absorption (10-15 dB for a concrete wall) and reflections, and you understand why the signal drops out at 50 meters indoors. But there are tricks: beamforming focuses the waves like a lighthouse, and OFDM splits the data into subchannels to avoid interference. Wi-Fi 7 takes things further, with 4096-QAM that crams more bits into each symbol, increasing throughput by 20% compared to Wi-Fi 6.

Wi-Fi 7: The Future is Now

In 2025, Wi-Fi 7 is the new gold standard, taking wireless connectivity to new heights:

  • 320 MHz channels : Twice as wide as Wi-Fi 6, for a data highway.
  • MLO : Multi-band real-time, latency under 1ms.
  • 6 GHz : Clean spectrum, but requires higher AP density for coverage.

The result? You can stream 8K, manage an army of IoT devices, and work remotely without lag. But there’s a price: more APs mean more costs, and security must keep pace with increasingly sophisticated threats.

Security Challenges and Prospects

Wi-Fi is powerful, but it’s also vulnerable if not properly secured. WPA3 represents a step forward, but threats persist:

  • Deauthentication flood attacks , which forcibly disconnect devices.
  • Exploitation of vulnerabilities in chipsets , as demonstrated by FragAttacks (2021) .
  • IoT is growing exponentially – Every connected device is a potential weak point in the network.

MLO helps distribute traffic and reduce risks, but without encryption and proper segmentation, a compromised access point can act as a Trojan horse . Furthermore, the spread of the 6 GHz band will lead to increased device density, necessitating the adoption of AI algorithms for dynamic interference management and real-time channel optimization .

Conclusion: a Precarious Balance

The IEEE 802.11 protocol is an engineering masterpiece that has made Wi-Fi synonymous with speed, flexibility, and ubiquity . With Wi-Fi 7 , the future of connectivity enters a new era, but not without compromises:

  • Cybersecurity and threats remain a constant challenge.
  • Interference and spectrum management will require intelligent solutions.
  • Cost and scalability may slow adoption in certain environments.

For those involved in cybersecurity and network management , the message is clear: design with foresight, secure every layer, and prepare for an increasingly wireless – and increasingly risk-prone – world.

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References :

[1] IEEE (2024). Wi-Fi 7 Technical Overview .

[2] Higher Order Feature Extraction and Selection for Robust Human Gesture Recognition using CSI of COTS Wi-Fi Devices https://www.mdpi.com/1424-8220/19/13/2959

Immagine del sitoVincenzo Miccoli
Since childhood I have nurtured a deep passion for information technology, discovering over time an even more fascinating and surprising branch, computer security. Graduated with honors from the University of Bari Aldo Moro in Information Security. Currently, I hold the position of Cyber Security Analyst, constantly motivated by the desire to deepen my knowledge and constantly progress.

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