Wireless Networks

Modulation Techniques and How They Work

In short, the process of modulation is the varying in a signal or a tone called a carrier signal. Data is then added to this carrier signal in a process known as encoding. Imagine that you are singing a song. Words are written on a sheet of music. If you just read the words, your tone is soft and does not travel far. To convey the words to a large group, you use your vocal chords and modulation to send the words farther. While you are singing the song, you encode the written words into a...

The Layer 2 Roaming Process

As previously discussed, Layer 2 roaming happens when a user moves to another AP but stays on the same VLAN and the same IP subnet. As far as the user is concerned, nothing special has happened. The client isn't notified that he is roaming. He also keeps his IP address, and all active transmissions stay active. This process is handled within a single controller. This process is called intracontroller roaming and takes less than 10 ms. Behind the scenes, the client, when roaming to a new AP,...

Using the CLI to Configure the Controller

To configure the Cisco Mobility Express solution, you need a console connection to the Cisco 526. You do not need to do anything on the AP because the controller takes care of it. After you have a console connection, you can power on the device and view the boot process. In Example 15-1, notice that if you press the Esc key, you are presented with multiple boot options. The normal selection is to run the primary image. Example 15-1 Booting the Cisco 526 Controller Booting Primary Image Press...