WIFi Roaming terminologies and project problem statement - sharmasadhna/mylearnings GitHub Wiki

WPA : Wireless protected Access,

STA : station (client, mobile, laptop etc...)

AP : Access Point (switch, router)

supplicant : 1 end in WLAN which is waiting for authentication from other end

ESS : Extended service set (set of 1 SSID and more than 1 BSSID), a device within 1 ESS can roam freely between BSSID's/AP's w/o explicitly changing the network

SSID : service set identifier

BSSID : basic service set identifier (can be many within 1 SSID, roaming happens between BSSID's)

re-associate : changing from 1 AP to another APP --> happens when roaming between BSSID's

SignalToNoiseRatio ?

wifi analyzer tool used?

Facts about Wifi Frequencies, Bands, Channels

Radio Frequency--> consider like natural resource, allotted in bands for specific purpose, ex: Band1 for submarine, Band2 for sattelite TV etc...

Bands are further divided to channels--> can overlap in a band (always try to use non-overlapping channels (range of freq) for low interference)

Channels within 2.4 and 5 GHz, are controlled by nations, i.e we cannot use all the channels within a Band, only available channels after government authorization for a Band can be used

Wi-Fi routers often use two bands to provide dual band Wi-Fi, the 2.4GHz (primary band) and 5GHz Wi-Fi band.

2.4 Ghz : can have max of 3 non-overlapping channels, used widely in microwave, BT etc... also

5 Ghz : expensive than 2.4 Ghz but less interference, can have max of 23 non-overlapping channels, but with shorter range

If bandwidth of channel is increased, no. of channels which can be used in a band gets reduced, i.e For 2.4 GHz band if 20MHz is the bandwidth of 1 channel, 3 non-overlapping channels can co-exist, but when we increase bandwidth of channel to 40 MHz only 2 non-overlapping channels co-exist.

Channels and Bands have to be properly checked when installing AP's, to ensure required performance is achieved.

Also signal strength (dB) is important to decide when to allow Roaming (-65 dB was good, for our project) https://www.metageek.com/training/resources/wifi-signal-strength-basics.html

Check : https://github.com/sharmasadhna/mylearnings/wiki/Improved-Wifi-Roaming-Behavior and https://github.com/sharmasadhna/mylearnings/wiki/wpa_supplicant