Handoff

hi,

I would like to know how hand off is done between two foreign agents.

Say that my computer is in a foreign network(f*). There is another adjacent foreign network(f2). How is hand off done between f* and f2. What in practice happens to all the packets that were already send from the home station when my computers hands off from f* to f2? Are they retransmitted or does f* forward it to f2?

In the case of mobile phones,I have never felt any lag when moving from one base station to another base station(both in the same home network). how is this possible?

thanks.
Data.