A communications architecture for enabling IP-based mobile communications includes a Local Service Function (LSF) component configured to serve as an IP-based serving area network for a set of x-Access Networks, and a Network Service Function (NSF) component configured to serve as an IP-based home network by managing a MN's subscription and associated profile so that the MN is authorized to use the resources of the LSF. An x-Access Network (xAN) is interconnected to the LSF and NSF for providing heterogeneous Layer 2 access for MNs irrespective of access technology.