A home network is the network that a subscriber has a contract with for their wireless service. For example, someone with an AT&T contract would say AT&T is their home network. A home network can typically be changed through the Mobile Number Portability (MNP) process which is available in most countries and allows a subscriber to take their phone number to a new network. For example, an AT&T subscriber could port their number from AT&T to Verizon at which point Verizon would become their home network.