Re: [DNA-BOF] Using L2 to provide Instantaneous Movement Detection andNeighborhood Discovery

[Bernard Aboba <aboba@internaut.com>]

> Are you referring/proposing a new message exchange prior to the actual
> Association message ? E.g. Pre-AssociationRequest (to obtain L3
> information ON-DEMAND) ? I guess it is even harder to convince the
> 802.11 WG.

I'm just suggesting that this information has two (distinct) purposes:

a. To help the station make better roaming decisions;
b. To enable the station to optimize DNA.

In discussing the issue it's worth distinguishing which benefit is
desired.  For example, in advertising prefixes in the Beacon/Probe
Response benefit a) is more easily achievable than b).

> Even if the station perform association with a new AP, it can
> potentially associate with another neighboring AP at the next 'seconds'.
> Possible ?

Yes, if the roaming latency (L2 + L3) is sufficiently short.  Otherwise
the station will spend more time roaming than sending packets.

> In my draft, I proposed that mobile stations maintain a table of all its
> neighborhood APs/ARs. For each AP (BSSID), MN can learn the network
> prefix or other L3 information for this AP. Therefore, after L2 handover
> is completed, MN should be able to tell IMMEDIATELY using this table if
> it has moved again. Right ?

Sure -- but there are situations in which a client will not return to the
same AP.  Also, an AP can have many BSSIDs, so the client can "return"
without knowing it using this technique.