Hi Guys,
I am playing with handover simulation in NS-2 and having some difficulty in
interpreting the results. Two 802.11 APs are placed at a certain distance such
that their footprints are not overlapping. A mobile node is made to move from
the footprint of one AP to the next (passing through the uncovered region).
According to the trace file generated for this simulation, the mobile node does
not handover to the next AP even when it enters its footprint. It is tuned to
passive scanning. I reckon it should initiate a handover as soon as it enters
AP footprint?
I simulated another scenario when the AP footprints are overlapping and in this
case handover works fine. But, the authentication messages are a little
strange. Near the edge of the AP-1 footprint, the mobile node authenticates
with the first AP again. After moving out of AP-1 range it authenticates with
AP-2. This may be because of ping-pong effect? If so, I didn't observe this for
simulation where APs are highly overlapping (inter AP distance is equal to the
range of APs).
Could some one please add some sense to what's going on? I shall be grateful.
Cheers,
Faraz
