Poll stations from AP transparently
victor.aleo at estudiant.upc.es
Tue Oct 22 06:38:31 EDT 2002
I already know, from multiple emails with this list and especially with
Jouni, that is not possible to know from the AP side if a station
(client) can reach other APs in the same ESS. The reason to get this
knowledge is very simple: if an AP knows that a STA can reach other APs
it will be potentially possible to reject this station "safely". Thus,
with the security that the station will be able to reassociate with at
least another AP.
However, I still think that this can be implemented without the aid of
any special software in the station side (transparent to the clients).
Thus, only the AP will be "modified". The key question is how? It is
clear to me that there are not specific methods to perform this task
(mainly because the standard specified mobile based handoff but not
network based). But I think there are "indirect" methods to find out the
1) If the AP can poll, by means of beacon frames for instance, the
stations. In this case, the APs in the same ESS send beacon frames to a
specified STA. If the STA answer to this beacon frames, it means that
can be associated to more than one AP. Therefore, if it is rejected by
its current AP it will not have problems to reassociate with another.
My questions are: is this feasible with Prism2? Have you thought about
other mechanisms to find out this information?
Sorry to write such a long email, but I think this is a key issue to
implement load balancing algorithms in WLAN networks and I am working in
Thanks a lot for your comments or suggestions,
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