An improved method of maintaining data throughput during handoff in a wireless
communication link operating with the Mobile IP protocol is described. A first
base station initially servicing a mobile subscriber unit is associated with a
first Mobile IP foreign agent that is registered with the Mobile IP home agent
as a first mobility binding between the subscriber unit and the home agent. When
the subscriber unit issues a request to be handed off from the first base station
to a second base station, a second foreign agent associated with the second base
station is registered with the home agent as a simultaneous binding with the first
mobility binding between the subscriber unit and the home agent. This permits both
foreign agents to simultaneously receive a sequence of data packets from the home
agent. Before handoff is executed, the data packet sequence routed to the second
foreign agent is stored at the second base station. After handoff is complete,
such stored packets are forwarded to the subscriber unit starting with a predetermined
numbered packet in the stored sequence, and the first foreign agent is de-registered
with the home agent.