Mobility Management in IEEE 802.11 Wireless Networks

Abstract: This thesis proposes a new method to achieve fast handover between access
points for a mobile client.

The focus is on the situation in LKAB’s iron ore mine in Kiruna. In the mine
an 802.11g wireless network is used to remotely control unmanned mobile
loaders. Instead of using the standard implementation of the 802.11 handoff
function the thesis presents a method where the distance from the mobile
client to an access point is used to determine when the client should handoff
to a new access point.

The distance to an access point can be determined by letting the mobile
client inspect the beacon messages that are sent out by all access points at
regular intervals. In simulator tests this method was found to produce both
faster handoff times as well as a more predictable handoff pattern in a
situation that resembles the mine.