Internet connectivity is made possible through a wireless router. When you access Wi-Fi, you're connecting to a wireless router, which allows your compatible devices to access the internet.

Modulation and data transmission :
The process of transmitting Wi-Fi data begins with signal modulation. The digital data to be sent is converted into modulated radio frequency signals. This modulation can use different techniques, such as phase modulation (PSK) or amplitude (ASK), to represent data bits.

Frequencies and channels :
Wi-Fi networks operate in the unlicensed radio frequency bands, primarily in the 2.4 GHz and 5 GHz bands. These bands are divided into channels, which are specific frequency ranges that Wi-Fi devices can communicate on. Wi-Fi channels allow multiple networks to coexist without excessive interference.

Multiple Access :
To allow multiple devices to share the same channel and communicate simultaneously, Wi-Fi uses multiple access techniques, such as Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA). Before transmitting data, a Wi-Fi device listens to the channel for activity. If it does not detect any activity, it can transmit its data. Otherwise, it waits for a random moment before trying again.

Encapsulation and protocols :
The data to be transmitted over a Wi-Fi network is encapsulated in frames, in accordance with Wi-Fi protocol standards (such as IEEE 802.11). These frames contain information such as the MAC address of the sender and receiver, the type of frame, the data itself, and so on. Different types of frames are used for different types of communication, such as management, control, and data frames.

Authentication and Linking :
Before a device can communicate over a Wi-Fi network, it must authenticate and pair with a Wi-Fi access point (AP) or router. This typically involves an exchange of authentication and association messages between the device and the access point, where the device provides credentials (such as a password) to prove its authorization to access the network.

Encryption and security :
Encrypting data in a Wi-Fi network is essential to prevent unauthorized persons from intercepting and reading sensitive information. Security protocols, such as Wi-Fi Protected Access 2 (WPA2) and WPA3, are designed to provide this protection by using robust encryption methods.

WPA2 has long been the primary security standard for Wi-Fi networks. It uses advanced encryption protocols, such as AES (Advanced Encryption Standard), to secure data in transit over the network. However, with the evolution of computer attacks and technologies, new encryption and security methods have become necessary.

That's where WPA3, the latest iteration of Wi-Fi security protocols, comes in. WPA3 brings several improvements over its predecessor, including more robust encryption techniques and better protection against brute force attacks. It also introduces features such as Individualized Data Protection that improve the security of Wi-Fi networks, especially in environments where many devices connect simultaneously.

In addition to encryption, Wi-Fi networks can also use authentication techniques to verify the identity of users and devices. For example, corporate networks can implement certificate-based authentication systems or usernames and passwords to ensure that only authorized users can access the network.

Wi-Fi technology, which is therefore standardized, has seen its characteristics and speeds evolve over time and with use. Each WiFi standard with the identifier 802.11 is followed by a letter expressing its generation.
Aujourd’hui, on considère que les normes 802.11 a/b/g sont quelques peu dépassées. Depuis ses origines en 1 9 9 7, les normes Wi-Fi se sont succédées pour laisser place tout récemment, fin 2019 à la norme Wi-Fi 6E (802.11ax).

There are different modes of networking :

The "Infrastructure" mode
A mode that allows computers with a Wi-Fi card to be connected to each other via one or more access points (APs) that act as hubs. In the past, this method was mainly used in companies. In this case, the installation of such a network requires the installation of "Access Point" (AP) terminals at regular intervals in the area to be covered. Terminals, as well as machines, must be configured with the same network name (SSID = Service Set IDentifier) in order to be able to communicate. The advantage of this mode, in companies, is that it guarantees a mandatory passage through the Access Point : it is therefore possible to check who is accessing the network. Currently, ISPs, specialty stores, and big box stores provide individuals with wireless routers that work in "Infrastructure" mode, while being very easy to configure.

The "Ad hoc" mode
A mode that allows computers with a Wi-Fi card to be connected directly, without using third-party hardware such as an access point. This mode is ideal for quickly interconnecting machines with each other without additional equipment (e.g. exchanging files between mobile phones on a train, in the street, in a café, etc.). The implementation of such a network consists of configuring the machines in "Ad hoc" mode, the selection of a channel (frequency), a network name (SSID) common to all and, if necessary, an encryption key. The advantage of this mode is that it does not require third-party hardware. Dynamic routing protocols (e.g., OLSR, AODV, etc.) make it possible to use autonomous mesh networks in which the range is not limited to its neighbors.

Bridge Mode
A bridge access point is used to connect one or more access points together to extend a wired network, such as between two buildings. The connection is made at the OSI layer 2. An access point must operate in "Root" mode ("Root Bridge", usually the one that distributes Internet access) and the others connect to it in "Bridge" mode and then retransmit the connection over their Ethernet interface. Each of these access points can optionally be configured in "Bridge" mode with client connection. This mode allows you to build a bridge while welcoming customers like the "Infrastructure" mode.

The "Range-extender" mode
An access point in "Repeater" mode allows a Wi-Fi signal to be repeated further. Unlike Bridge Mode, the Ethernet interface remains inactive. Each additional "hop" increases the latency of the connection, however. A repeater also has a tendency to decrease the speed of the connection. Indeed, its antenna must receive a signal and retransmit it through the same interface, which in theory divides the throughput by half.

WiFi 6E, also known as 6GHz WiFi, represents a significant advancement in the field of wireless networking. This new standard, based on the 802.11ax standard, offers a multitude of possibilities and benefits that revolutionize the capabilities and performance of WiFi networks.

First of all, the transition from the 802.11ax WiFi standard to WiFi 6E marks a clarification and simplification in the terminology used to describe the different generations of WiFi. This standardization allows a better understanding of WiFi technologies for users and professionals.

One of the main features of WiFi 6E is the introduction of new frequencies, specifically in the 6 GHz band. This harmonisation opens up new possibilities for the use of the radio spectrum, thus offering more channels and reducing interference. The new 6 GHz frequency band, ranging from 5945 to 6425 MHz, offers considerable space for the deployment of high-speed WiFi networks.

In terms of performance, WiFi 6E brings several innovations. MiMo (Multiple Inputs, Multiple Outputs) is a technique that allows multiple antennas to be added to a WiFi device, increasing its ability to handle multiple data streams simultaneously. This results in a significant improvement in the speed and reliability of wireless connections.

In addition, WiFi 6E offers major performance benefits with features such as OFDMA (Orthogonal Frequency-Division Multiple Access) and Mu-MIMO (Multi-User, Multiple Input, Multiple Output). OFDMA enables more efficient use of radio spectrum by dividing channels into smaller sub-channels, allowing for better management of network traffic and increased network capacity. Mu-MIMO, on the other hand, allows a WiFi access point to communicate with multiple devices simultaneously, improving overall network performance, especially in densely populated environments.

Finally, the battery life of connected devices is also improved thanks to TWT (Target Wake Time) technology. This feature allows devices to determine when they need to be on standby and when they need to wake up to communicate with the WiFi hotspot, reducing power consumption and extending battery life.