IP Mobility management

Traffic for mobile terminals have to be prepared in order to guarantee the communication in a non-fixed networks, basically radiointerfaces.
For radio the management is done using paging messages and Location Updates.
In fixed networks Database Update and Interrogation.
The handover can be classified according with the degree of connectivity (Hard or soft), with the execution (network controlled, mobile assisted,..) or by the "exchanging" area (intra-cell or inter-cell).
The location areas are determined by the Network operator. It can be a couple of clusters in order to reduce the location update messages when the mobile changes of area.

Cellular Networks
There are two hierarchy levels to register a user in the network
HLR: Register with all the users of the network
VLR: more volatile memory in each MSC with the users connected in a specific area.

IP Networks
Depending if the displacement is done between two subnets or networks domains we can distinguish micro and macro mobility.
IP don't provide alone a mobility server, so we have to use MovilityIP that is like a "patch". In IPv6 this fact is included in the standard.