Wireless Local Area Networks (WLANs) are a type of network that allows devices to connect and communicate without the need for physical cables. Unlike traditional wired networks, WLANs use radio waves to transmit data between devices. This wireless approach provides increased flexibility and mobility for connected devices.

Frequency Bands
WLANs operate within two main frequency bands: 2.4 GHz and 5 GHz. The 2.4 GHz band, though more crowded, offers a better range, making it suitable for environments with obstacles. On the other hand, the 5 GHz band provides higher data rates but has a shorter effective range.

IEEE 802.11 Standard
The foundation for WLANs is the IEEE 802.11 standard, which outlines the specifications for the implementation of these networks. This standard has evolved over time with various amendments, each introducing improvements and new features. Amendments include 802.11a, 802.11b, 802.11g, 802.11n, 802.11ac, among others.

The various amendments to the IEEE 802.11 standard, namely 802.11a, 802.11b, 802.11g, 802.11n, 802.11ac, and more, represent the evolution of wireless LAN technology with distinct improvements. 802.11a operates in the 5 GHz band, providing faster data rates but with shorter range compared to its predecessors. 802.11b, on the other hand, operates in the 2.4 GHz band, offering greater range but at the expense of lower data rates. 802.11g combines the best of both by utilizing the 2.4 GHz band while delivering higher speeds. 802.11n introduces Multiple Input Multiple Output (MIMO) technology for improved throughput and coverage. 802.11ac takes a significant leap forward by operating exclusively in the 5 GHz band, supporting wider channels, and achieving higher data rates. Each amendment builds upon the strengths and addresses the limitations of its predecessors, showcasing the continuous evolution of wireless LAN standards to meet the growing demands of connectivity in diverse environments.

Basic Components

• Access Points (APs): These are central devices in WLANs that facilitate wireless communication between connected devices and link the wireless network to a wired one.
• Wireless Clients: Devices such as laptops, smartphones, and tablets that connect to the WLAN

Wireless Modes

• Infrastructure Mode: In this mode, devices connect to the WLAN through an access point, forming a centralized network structure.
• Ad-hoc Mode: Devices in an ad-hoc network connect directly to each other without the need for an access point, creating a decentralized network.

Security Protocols

• WEP (Wired Equivalent Privacy): An early encryption protocol designed to secure wireless communication. However, WEP is now considered insecure and susceptible to attacks.
• WPA (Wi-Fi Protected Access): A more robust security protocol with various versions (WPA, WPA2, WPA3) providing improved encryption and authentication.
• WPA3: The latest iteration of WPA, offering enhanced security measures to protect against evolving threats.

Channels and Interference:
WLANs use channels to transmit data. However, overlapping channels can lead to interference, impacting performance. The selection of channels and their widths plays a crucial role in optimizing network reliability.

Multiple Input Multiple Output (MIMO)
MIMO technology utilizes multiple antennas to improve data rates and enhance the reliability of wireless communication. Common configurations include 2×2, 3×3, or 4×4 MIMO, depending on the number of antennas employed.

Roaming
Roaming is a crucial feature that enables devices to switch between access points seamlessly as they move within a WLAN. This ensures uninterrupted connectivity for devices in motion.

Future Trends
The future of wireless LANs involves ongoing advancements in technology. This includes the exploration of higher frequency bands, such as the 6 GHz band, and continuous improvements in efficiency, security, and overall network performance.

Self Assessment

• Define Wireless Local Area Networks (WLANs) and explain how they differ from traditional wired networks.
• Discuss the advantages and disadvantages of operating in the 2.4 GHz and 5 GHz frequency bands in wireless LANs.
• Elaborate on the role of Access Points (APs) in wireless networks. How do they facilitate communication between wireless clients and wired networks?
• Compare and contrast WEP, WPA, and WPA3 security protocols in wireless LANs. Highlight the importance of securing wireless communications.