Method and system for a low-overhead mobility management protocol in the internet protocol layer

A method for mobile Internet communication system which includes a plurality of networks each having a Network Address Translation router (NAT) and a unique global address, at least one Host associated with the NAT, and at least one Mobile Node (MN), each Host having a service area in which it can communicate data to the MNs, each MN having a home Host and a home network which defines a default local address which is paired with the global address of the HN's NAT to define a default binding of the MN, the method comprising:

• providing an associated Mobile-Home Database (MHD) for the NAT of each network which identifies:
• each MN, which has the network as its home network, with:
• a local address of a current association of the MN with a Host within the network, or
• a binding defined by a local address of an association of the MN with a Host within a different network and the global address of the different network's NAT;
• and
• each visiting MN, which is a MN currently associated with a Host within the network, but has a different home network, with a local address of the current Host association of the MN;
• when a MN moves from a location where the MN communicates data via a first associated Host within a first network having a first NAT to a location within the service area of a second Host within the first network to communicate data via the second Host, communicating to the MHB of the first NAT a local address reflecting the MN's association with the second Host;
• when a MN moves from a location where the MN communicates data via the first associated Host within the first network to a location within the access range of a third Host within a different second network having a second NAT, to communicate data via the third Host, communicating to the MHB of the second NAT a local address reflecting the MN's association with the third Host and, where the second network is not the MN's home network, by also communicating to the MHB of the MN's home network's NAT a binding including a new local address reflecting the MN's association with the third Host and the global address of the second NAT;
• and
• communicating a data communication from a corresponding node (CN) to a selected MN by:
• establishing a binding with a NAT based on the MN's default binding or the binding reflected in the MHB of the MN's home network's NAT, and
• directing the communication to the local address identified in the MHB of the NAT with which the binding is established for the MN.

A Network Address Translation router (NAT) for a network system which includes a plurality of networks, each having a NAT with a unique global address, at least one Host associated with the NAT and at least one Mobile Node (MN), each Host having a service area in which it can communicate data to the MNs, each MN having a home Host and home network which defines a default local address which is paired with the global address of the home network's NAT to define a default binding of the MN, the NAT comprising:

• a Mobile-Home Database (MHD) which identifies:
• each MN, which has as its home Host, a Host associated with the NAT, with:
• a local address of a current association of the MN with a Host associated with the NAT, or
• a binding defined by a local address of an association of the MN with a Host not associated with the NAT and the global address of the NAT associated with that Host;
• and
• each MN, which is currently associated with a Host associated with the NAT, but has a home Host which is not associated with the NAT, with a local address of the current Host association;
• such that a data communication from a corresponding node (CN) to a selected MN which has as its home Host, a Host associated with the NAT, is communicated to the selected MN by:
• establishing a binding based on the MN's default binding or the binding reflected in the MHB of the NAT, and
• if the binding is established is established with the NAT, directing the communication to the local address identified in the MHB.