IPv6 mobility features
IPv6 has built-in support for mobile devices. Hosts will be able to move from one network to another and keep their current IPv6 address.
As stated in RFC 3775 that defines the IPv6 mobility feature:
Mobile IPv6 allows a mobile node to move from one link to another without changing the mobile node's "home address". Packets may be routed to the mobile node using this address regardless of the mobile node's current point of attachment to the Internet. The mobile node may also continue to communicate with other nodes (stationary or mobile) after moving to a new link. The movement of a mobile node away from its home link is thus transparent to transport and higher-layer protocols and applications.