Introduction to Wireless LANs (WLANs)

What is a Wireless LAN (WLAN)?

A Wireless Local Area Network (WLAN) is a type of network that allows devices to connect and communicate wirelessly over a short distance using radio waves. It eliminates the need for physical cables, providing flexibility and mobility within a defined area such as a home, office, or public space.

How WLANs Work

WLANs use Wi-Fi technology, based on the IEEE 802.11 standards, to transmit data between devices and a central access point (AP). The AP connects to a wired network (such as an internet router), enabling wireless devices to access the network.

Components of a WLAN

1. Access Point (AP): The central device that transmits and receives wireless signals.
2. Wireless Clients: Devices such as laptops, smartphones, tablets, and IoT gadgets that connect to the WLAN.
3. Router: Often combined with an AP, it provides internet access and network management.
4. Network Interface Card (NIC): A wireless adapter in client devices that allows communication with the WLAN.

Types of WLANs

1. Infrastructure Mode:
   • Most common setup.
   • Devices connect through a central AP, which connects to a wired network.
2. Ad-Hoc Mode:
   • Devices communicate directly without an AP.
   • Used in temporary or small-scale setups.

Advantages of WLANs

✔️ Mobility: Users can move freely within the coverage area.
✔️ Scalability: Easy to expand by adding more devices or APs.
✔️ Cost-Effective: Reduces the need for physical cabling.
✔️ Easy Installation: Faster and simpler setup compared to wired networks.

Challenges of WLANs

❌ Security Risks: Prone to hacking and unauthorized access.
❌ Interference: Signals can be disrupted by other wireless devices and physical obstacles.
❌ Speed & Reliability: Wireless connections may be slower than wired connections.
❌ Coverage Limitations: Performance degrades with distance from the AP.

Common WLAN Standards (IEEE 802.11 Family)

• 802.11a: 5 GHz, 54 Mbps
• 802.11b: 2.4 GHz, 11 Mbps
• 802.11g: 2.4 GHz, 54 Mbps
• 802.11n: 2.4/5 GHz, up to 600 Mbps
• 802.11ac (Wi-Fi 5): 5 GHz, up to 6.9 Gbps
• 802.11ax (Wi-Fi 6): 2.4/5 GHz, higher speeds & better efficiency

Future of WLANs

With the rise of Wi-Fi 6, Wi-Fi 7, and IoT (Internet of Things), WLANs are becoming faster, more reliable, and more secure. Technologies like Mesh Wi-Fi, AI-driven network optimization, and 5G integration will further enhance wireless connectivity.