Wireless Networking

A wired link has a cable that contains the signal. A wireless link sends the signal through shared radio spectrum. That change affects nearly every design and troubleshooting decision.

Wireless networking lets phones, laptops, sensors, and other clients reach a local network without a cable. Most workplace wireless local area networks use IEEE 802.11 technology, commonly called Wi-Fi. An access point bridges client traffic into the rest of the network.

The useful mental model is a conversation in a shared room. A client and an access point take turns using a channel. Other devices may hear the same channel, and non-Wi-Fi equipment may add noise. Distance, walls, antenna behavior, interference, and competing clients all affect the conversation.

The path through a wireless network

A connection begins before an application sends data:

1. An access point advertises a wireless network.
2. A client discovers available networks and selects one.
3. The client authenticates and associates with an access point.
4. Security controls establish protected communication.
5. The client obtains normal network configuration, such as an IP address.
6. The access point forwards traffic between the wireless client and the distribution network.