Basically, Mobile-IP extends the existing Internet Protocol to allow a portable computer to be moved from one network to another without changing its IP address and without losing existing connections. This is the working field of the IETF mobileip Working Group.
The Mobile IP Working Group of the Internet Engineering task Force (IETF) is the culmination of efforts by many individuals interested in the problem of mobile routing of hosts. The first meetings were in the form of BOF (Birds of a Feather) sessions held in Atlanta (July 1991), Santa Fe (November 1991), and San Diego (March 1992) IETF meetings. In June 1992 a proposed charter for a formal Working Group was submitted by Steve Deering (who had chaired the BOF sessions) to the IETF and at the same time a mailing list was set up for conduct of the group's business. Following a revision of the charter, the Working Group was officially formed in June 30, 1992. The group uses ftp://software.watson.ibm.com/pub/mobile-ip as its archive, where minutes of meetings, proposals, and a mail archive is kept.
The IETF Mobile IP Working Group (mobileip WG) is chartered to develop or adopt architectures and protocols to support mobility within the Internet. In the near-term, protocols for supporting transparent host ``roaming'' among different subnetworks and different media (e.g., LANs, dial-up links, and wireless communication channels) shall be developed and entered into the Internet standards track. The work is expected to consist mainly of new and/or revised protocols at the (inter)network layer, but may also include proposed modifications to higher-layer protocols (e.g., transport or directory). However, it shall be a requirement that the proposed solutions allow mobile hosts to interoperate with existing Internet systems.
In the longer term, the group may address, to the extent not covered by the mobile host solutions, other types of internet mobility, such as mobile subnets (e.g., a local network within a vehicle), or mobile clusters of subnets (e.g., a collection of hosts, routers, and subnets within a large vehicle, like a ship or spacecraft, or a collection of wireless, mobile routers that provide a dynamically changing internet topology).