ORBIT-USER: Setting up Topologies

[Reza Lotun]

Hi,

Thanks for the replies. I suppose, for a concrete topology I'd like to
have 5-hop configuration consisting of 4 AP nodes, each with 1 node
connected to each ap. i'd like to make it so that some AP-node pairs
are completely out of range of each other, and some nodes should
interfere in a hidden-sender and exposed terminal situations.

I suppose the question is, can topogies be set up so that nodes are
not only out of range, but in interference range (i.e. can't decode
transmissions from other nodes, but those transmissions still
interfere with it's own transmissions)?

Thanks!
Reza

On 8/24/07, Sanjit Kaul <sanjitkaul at gmail.com> wrote:
> Hi Reza,
>
> We do have an algorithm to map topologies on to the ORBIT grid, using noise
> injection. The algorithm has not been released to public yet.
>
> I request you to send out the details of the topology you are interested in.
> Currently we treat any topology (infrastructure/ ad-hoc) as a bunch of up or
> down links (connected / dis-connected).
>
> Given the topology I could tell you how feasible it is to map on the grid
> and the caveats.
>
> Lets not go by the word arbitrary, please :).
>
> Regards,
> Sanjit
>
>
> On 8/24/07, Ivan Seskar <Seskar at winlab.rutgers.edu> wrote:
> > Hi Reza,
> >
> > I will let others respond to your particular topology question, but just
> > want to comment on the possibility of triggering carrier sense with
> > noise injection: it is certainly possible to increase noise level to a
> > point of triggering energy detection threshold (mode 1) in the cards
> > (especially for the nodes that are in the vicinity of injection
> > antennas).
> >
> > Regards,
> >
> > Ivan.
> >
> > PS; In addition to noise levels, you should also take into consideration
> > transmit power and CS threshold as knobs that can be used for topology
> > creation.
> >
> > -----Original Message-----
> > From: owner-orbit-user at winlab.rutgers.edu
> > [mailto:owner-orbit-user at winlab.rutgers.edu] On Behalf Of
> Reza Lotun
> > Sent: Friday, August 24, 2007 5:16 PM
> > To: orbit-user at winlab.rutgers.edu
> > Subject: ORBIT-USER: Setting up Topologies
> >
> > Hello,
> >
> > I'd like to pose a general question to the list. Has anyone attempted
> > (and successfully) deployed arbitrary topologies on the grid.
> >
> > A clarification. According to the orbit wiki, the Orbit approach to
> > creating arbitrary (multi-hop) topologies is to use noise injection:
> > http://www.orbit-lab.org/wiki/HowTo/UseNoise
> > As far as I can see, the idea is to inject constant background white
> > gaussian noise to raise the noise level, so that only more powerful
> > signals can be discerned.
> >
> > I'm interested in simulating a real wireless network deployed in a large
> > space operating in convential infrastructure mode - this means that some
> > nodes will naturally be out of range of one another. Is there ever a
> > danger when injecting noise that the nodes will naturally back-off since
> > they sense transmission? Is anyone using orbit to test non-mesh-like
> > 802.11 topologies, that is, the tree topology of
> > client->access_point common to infrastructure networks?
> >
> > Thanks!
> > Reza
> >
> >
>
>