How Does Wi-Fi Work?

Wi-Fi has become an indispensable part of our daily lives. By providing a wireless internet connection, it allows devices to connect to each other and to the internet. 

Wi-Fi is an abbreviation for "Wireless Fidelity" and is a technology standard used for wireless local area networks (WLAN). Wi-Fi allows devices to exchange data wirelessly using radio waves. This technology enables computers, smartphones, tablets, printers, smart home devices, and many other devices to connect to the internet or to each other. 

History 

The foundations of Wi-Fi technology were laid in 1985 when the United States Federal Communications Commission (FCC) released the unlicensed frequency band. In 1997, the Institute of Electrical and Electronics Engineers (IEEE) developed the 802.11 standard, which is considered the birth of modern Wi-Fi technology. The first commercial Wi-Fi devices were launched in 1999 and have since rapidly become widespread. 

How Does Wi-Fi Work? 

Wi-Fi transmits data using radio frequencies. These frequencies are typically in the 2.4 GHz and 5 GHz bands. Wi-Fi networks enable devices to connect to the internet wirelessly by transmitting data packets via radio waves. Several key components play a role in this process. 

Access Point 

An access point is the center from which the Wi-Fi signal is broadcast. It is commonly known as a Wi-Fi router or modem. The access point is connected to the internet and sends a wireless network signal to devices. 

Devices (Clients) 

Bilgisayarlar, akıllı telefonlar, tabletler ve diğer cihazlar, erişim noktasının yayımladığı Wi-Fi sinyalini alır ve bu sinyal üzerinden internete bağlanır.

Radio Waves 

Wi-Fi uses radio waves for data transmission. These waves are used to send and receive data by converting it into digital signals. Radio waves act as a bridge carrying data between the access point and devices. 

Working Principle of Wi-Fi 

The working principle of Wi-Fi is based on data transmission over radio waves, and to understand how this process works, we need to examine a few key steps. 

1-) Data Packaging and Encoding  

Every piece of data to be sent over Wi-Fi is divided into small packets before transmission. This packaging process ensures that data is transmitted more efficiently and securely. When data leaves a computer or another device, it is in a digital format. This digital data has a binary encoding system consisting of zeros and ones. 

2-) Converting to Radio Waves 

The Wi-Fi adapter converts these digital data packets into radio waves. Radio waves are electromagnetic waves that allow data to be transmitted through the air. The frequencies used for Wi-Fi are generally in the 2.4 GHz and 5 GHz bands. These bands provide high-speed data transmission and are the backbone of Wi-Fi networks. 

3-) Modulation Techniques 

Modulation techniques play a critical role in the working principle of Wi-Fi. Modulation is used during the conversion of digital data to radio waves. Wi-Fi uses several different methods to modulate data into radio waves. 

3.1 DSSS (Direct Sequence Spread Spectrum): This technique allows data to be spread over a wide frequency band, reducing signal distortion. 

3.2 OFDM (Orthogonal Frequency Division Multiplexing): OFDM allows data to be divided into multiple subcarriers and transmitted in parallel. This method offers high efficiency in data transmission and enables faster operation of Wi-Fi. 

4-) Communication with the Access Point 

The radio waves emitted from the device reach the Wi-Fi access point (e.g., a router). The access point converts these radio waves back into digital signals. This conversion process is necessary for transmitting data to the internet network or a local network. The access point communicates with multiple devices simultaneously and assigns a specific channel for each device. Channel management plays a critical role in preventing data collisions and signal interference in Wi-Fi networks. 

5-) Data Routing and Internet Access 

The access point receives the data and transmits it to the internet via the internet router. The router ensures that the data reaches the correct destination and sends the data from the internet back to the access point. At this stage, the Wi-Fi device's internet access process is completed. 

6-) Data Retrieval and Reception 

Data coming from the internet is transmitted to the access point via the router. The access point receives this data, converts the digital signals back into radio waves, and sends them to your device. The device then converts these radio waves back into digital data and displays the information requested by the user on the screen. 

7-) Data Security 

Wi-Fi networks use various encryption protocols to ensure data security during transmission. The most commonly used encryption types are: 

WEP (Wired Equivalent Privacy): An older encryption standard that is no longer considered secure today. 

WPA (Wi-Fi Protected Access) and WPA2: More secure encryption methods. WPA2 is widely used in modern Wi-Fi networks and ensures data encryption. 

WPA3: The latest encryption standard offering advanced security features. 

These encryption techniques ensure that data transmitted over Wi-Fi is protected from unauthorized access. 

8-) Coverage Area and Signal Strength 

The coverage area of a Wi-Fi signal depends on the power of the access point and environmental conditions. The access point can broadcast radio waves up to a certain distance, but walls, metal surfaces, and other obstacles can reduce signal strength. To extend the coverage area, range extenders or mesh network systems can be used. 

9-) Roaming and Handover 

When a device moves between different access points within a Wi-Fi network, "roaming" and "handover" processes occur to ensure the device maintains an uninterrupted connection. This process automatically connects the device to the access point that provides the strongest signal. 

Wi-Fi and Future Technologies 

Wi-Fi technology is constantly evolving. Next-generation Wi-Fi standards like Wi-Fi 6 and Wi-Fi 7 promise higher speeds, broader coverage, and more device support. Additionally, the integration of Wi-Fi technology with other wireless technologies like 5G will create faster and more reliable wireless networks in the future.