Smartphone Wi-Fi Connection?

[justasktom]

When people switch thier cellular connection to a home or public Wi-Fi connection to save on data usage, does the ISP that provides the Wi-Fi service know the cell phone numbers to thier smartphone devices when connected?

What do the ISP's know about the smartphone devices that connect to them via Wi-Fi?

 

[rgd1101]

they don't know the # just another device