WLAN Components

1. Wireless NICs

🔍 To communicate wirelessly, your device needs a Wireless Network Interface Card (NIC). Most modern laptops, smartphones, and tablets have built-in wireless NICs that include a radio transmitter and receiver.

But what if your device doesn’t have a built-in NIC? Don’t worry—you can use a USB wireless adapter that adds wireless capabilities in seconds.

💡 Did you know? Many wireless NICs have hidden antennas. That’s why you don’t see any visible antenna on your smartphone or laptop, but it’s still connecting seamlessly to Wi-Fi!

2. Wireless Home Router

When you set up Wi-Fi at home, the heart of your network is the wireless router. It does more than just provide Wi-Fi—it’s a multi-purpose device.

Here, for example, it’s a TP-Link AX1800 wireless router.

✅ Functions of a Wireless Router

• Access Point (AP): Provides Wi-Fi connectivity using one standard from the 802.11a/b/g/n/ac/ax family.
• Switch: Offers Ethernet ports for wired connections.
• Router: Acts as the default gateway, allowing your devices to connect to the internet.

This little device broadcasts a Service Set Identifier (SSID)—the name of your Wi-Fi network—so your devices can discover and connect to it.

⚠️ If you have a big house, you may have “dead zones” where you’re too far away from your wireless router to connect to the Wi-Fi. You may need to extend your wireless coverage by using a Wi-Fi range extender. Extenders repeat the router’s signal to cover a wider area, but they’re not the most efficient solution—more on that soon!

3. Wireless Access Points (AP)

An Access Point (AP) extends your Wi-Fi network and allows wireless devices to connect seamlessly. While home routers have built-in APs, professional setups like offices or enterprise campuses use dedicated APs to ensure optimal coverage.

Access points broadcast a Service Set Identifier (SSID), which is the network name, so your devices can detect and connect to them. Once your device connects, the AP authenticates it and provides network access.

💡 In enterprise environments, APs are essential for creating a reliable wireless network that can handle multiple devices across large areas. You may have already seen APs mounted on walls or ceilings in your office or school—they’re often placed strategically to ensure full coverage throughout the building.

AP Categories

🔍 Autonomous APs

Autonomous APs are standalone devices that require individual manual configuration using a web interface or command-line tools (CLI). They’re commonly used in small networks where only a few APs are needed.

This setup is simple when you only need to configure a few APs. However, imagine needing to configure hundreds of APs in a large campus network—managing each AP individually would be unrealistic and time-consuming.

✅ Key Points:

• Each AP is configured independently and doesn’t rely on a central system.
• Manual configuration is required for settings like transmit power, channel selection, security policies, and Quality of Service (QoS).
• No centralized monitoring or management.

🔍 Lightweight APs

Lightweight APs are designed for large networks and do not need to be configured individually. Instead, they are centrally managed by a Wireless LAN Controller (WLC), which automatically configures each AP when it joins the network.

✅ How It Works:

• The AP handles real-time tasks like sending/receiving RF traffic, encryption, and broadcasting SSIDs.
• The WLC manages advanced functions such as RF management, client authentication, security policies, and client roaming.

In summary, autonomous APs work well for small networks where only a few independent APs are needed. Lightweight APs are ideal for enterprise networks where centralized management is crucial. Well-placed APs, managed by a WLC, provide strong and consistent wireless coverage throughout any space.

4. Wireless LAN Controller (WLC)

A Wireless LAN Controller (WLC) is the “brain” of your wireless network in enterprise environments.

The WLC provides centralized control over all lightweight APs in the network, simplifying management and improving efficiency.

Key Responsibilities of the WLC:

• Centralized Control: All configurations are managed from the WLC and applied to APs automatically.
  
• Automatic Configuration: When a new AP is added, the WLC configures it automatically based on the predefined settings.
  
• RF and Security Management: Handles channel selection, transmit power, security policies, and client roaming.

The communication between the WLC and the AP uses CAPWAP (Control and Provisioning of Wireless Access Points), an IEEE standard protocol that encapsulates and forwards wireless client traffic between the AP and WLC. CAPWAP builds upon the older LWAPP protocol and provides better security and flexibility.