Wireless Roaming

i wanna walk around my house with epic amounts of internet

Clients can roam around an ESA using a mesh of APs around the premises. They have to be configured with the same ESSID and security configuration. They should be configured to use different channels so in areas that signal overlaps, there's no interference.

When a client isn't getting good signal anymore, it can search the area for a closer station with better signal. If it finds one, it disconnects from the old one to maintain optimal connection speeds.

 Depending on roaming infrastructure and security type, the client device might have to reauthenticate after switching APs. However, if 802.11r is supported, it can use it's old authentication settings to generate new ones for the new AP.

Flapping (Raw Lesson Content)

Roaming is supposed to be seamless, but in practice reestablishing the connection can often cause time-out problems for applications. To improve mobility, there needs to be a balance between determining what constitutes a "good" signal and the rate at which a client tries to associate with different APs. Many adapters support a roaming "aggressiveness" setting that can be configured to prevent a Wi-Fi adapter "flapping" between two APs or (conversely) to prevent a client from remaining associated with a more distant AP when it could achieve better bandwidth through one closer to it.

Wireless Network Broadcasting

This is done at a set interval (usually 100ms) using a special beacon frame. The interval can be changed, but higher/lower values either cause higher overhead or delays devices from quickly joining the network. This is how WAPs advertise the presence of a wireless network. The beacon frame contains:

• SSID/ESSID (unless broadcasting is disabled)
• BSSID
• supported data rates
• signaling
• authentication/encryption requirements

Wireless Distribution Systems (WDSs)

A mesh network of repeater nodes that forward all traffic to a base station connected to a cabled segment. All the mesh nodes must be wireless, and they all can broadcast the network. If implementing a WDS, make sure to use APs from the same vendor, since there are vendor specific support and implementation processes.