Local mobility within a subnet is supported by classifying wireless base
stations, and the routers used to forward packets to those base stations,
within defined domains. Domains are defined to incorporate a subnet having
a plurality of base stations. Base stations are used by mobile devices to
attach to the wired portion of a packet-based network, such as the
Internet, and exchange packets thereover with a correspondent node.
Packets sent from the correspondent node to the mobile device have a
packet destination address corresponding to the mobile device. The mobile
device retains this address for the duration of time it is powered up and
attached to the Internet via any base station within a given domain.
Host-based routing is utilized to update routing table entries
corresponding to the mobile device at routers incorporated within a single
domain. The routing table entries are established and updated via path
setup schemes to convey packets destined for the mobile device along the
proper established path through the domain routers and base stations,
regardless of the domain base station through which the mobile device is
attached. Path setup schemes utilize power up, refresh, and handoff path
setup messages to maintain the proper relationship between router
interfaces and packet addresses for routing table entries.
