Subject: RE: [manet] capturing node motion

From: [email-masked]
Date: Thu, 8 Apr 2004 14:04:02 +0200

Just think about a "mobile" node standing near a highway, with other mobile
nodes attached to cars passing by (in both directions !) ...
What could deduce the standing node from the "frequent changes" it may
detect ?

FP

-----Message d'origine-----
De : samir.chihi [mailto:[email-masked]]
Envoyé : jeudi 8 avril 2004 01:40
À : [email-masked]
Objet : [manet] capturing node motion

Hello all,

Can a node with frequent changes of its neighborhood, detect that it is in
motion?

Best regards

Smir
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Faites un voeu et puis Voila ! www.voila.fr 

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From: Rex Buddenberg <[email-masked]>
Date: 08 Apr 2004 10:55:29 -0700

'Motion' is a slippery term and like a lot of others, it helps if we use
the ISO model as a sorter:

At layer 1, motion might be detectable by doppler shift.  But note that
this physical motion might not result in topology changes.  A ship
moving across the ocean under a comms satellite footprint would clearly
be in motion, but the (GEO) satellite shines on a third of the earth's
surface so the ship may have to move several thousand miles before a
topology shift is triggered.

At layer 3, 'motion' connotes a topology change.  And that topology
change could be triggered by several events other than layer 1 physical
motion.  In circuit-switch cellphone, congestion within one cell may
find relief in pushing some customers off to a neighboring (less busy)
cell that also has physical connectivity with a subset of the congested
phones.  

Some of the MANET issues are layer 7 ones as well where a host finds
itself plugged into a different place in a network, but wants to retain
it's end system identity (so traffic can find it and be delivered).  So
one legitimate definition of mobility is end system mobility as divorced
from network topology.  (This is where Charlie Perkins started out with
his Mobile IP work).  

Help?

-- 
b