Re: [ns] multicast support for wireless nodes

[Harsh Shah <harshsha@usc.edu>]

Hi,

Thanks for your replies. Actually, I cannot use two different types of
multicast protocols for the same topology. I have to setup
wired-cum-wireless topology and I have to use same kind of multicast
protocol (either DM or SM) on all the nodes. As Lloyd said it might
require several modifications in NS and I am trying to look for that. I
have thought of doing some application level hack rather than modifying
mobile node to support multicast. I am looking to implement virtual node
between Base station and it's upstream router. I will enable multicast on
only wired nodes including virtual node. My mulitcast protocol will run
only on those wired nodes. I am using application level agent to send
unicast packets from virtual node to downstream mobile nodes(including
base station) when the virtual node receive mcast packets. Similarly
the application level agent will reside on mobile nodes(receiver and
BS) which will send joins to the upstream application level agents
until the virtual node. Does anyone of you can think what sort of hassles
can be there in such solution. Is it possible to have hack like this? I am
not much acquainted with ns internals and haven't gone through its code
yet. 

Thanks
harsh.


On Thu, 19 Apr 2001, Parveen Patel wrote:

> I get it. are you by any chance implying that i meant to say to use the same
> multicast protocol for both wired and wireless. that was not my intention. i
> meant that the folks at isi have implemented ODMRP, a multicast protocol for
> ad hoc networks, on ns. So we can use that for multipcast in the wireless
> domain. you would still have to use traditional protocols in the wired
> domain and a combination of both in mixed scenarios. in fact, as part of our
> class project we are implementing ODMRP and are almost done with it modulo
> perfect validation.
> 
> -parveen.
> 
> > On Wed, 18 Apr 2001, Parveen Kumar Patel wrote:
> >
> > > I don't entirely agree with this. I know of at least one multicast
> > > implementation that has been there for a while and would be made public
> in
> > > a few days. and I personally (although i may be wrong) don't think its
> > > that big a task, because you don't need all that wired multicast
> > > code to implement wireless multicast.
> >
> > Harsh was asking about multicast support for wireless nodes.
> >
> > Enabling global multicast functionality by extending support for
> > what's already there to include use on wireless nodes is not _quite_
> > the same thing as getting a single instance of an ad-hoc-specific
> > flooding protocol working for the wireless C++ code...
> >
> > imo.
> >
> > L.
> >
> > > Contact the authors of
> > >
> > > "Flooding for reliable multicast in multi-hop ad hoc networks"
> > >
> > > @isi. They have implemented multicast and have promised to make the code
> > > public.
> > >
> > > hth,
> > > -parveen.
> > >
> > >  On Wed, 18 Apr 2001, Lloyd Wood wrote:
> > >
> > > > On Tue, 17 Apr 2001, Harsh Shah wrote:
> > > >
> > > > > I am trying to implement multicast support for wireless nodes in
> > > > > ns-2. Has anyone already done this? Anyone have any idea which files
> are
> > > > > needed to be changed in order to implement this support.
> > > >
> > > > Pretty much everything.
> > > >
> > > > The multicast routing code is in Tcl, the wireless stuff in in C++,
> > > > and they're entirely separate (different authors, origins - the
> > > > works). You could try implementing Tcl callbacks in the wireless code
> > > > as a first step to getting Tcl routing functionality working over
> > > > wireless... but better men than me have thought twice about beginning
> > > > such a large effort.
> > > >
> > > > L.
> >
> > <L.Wood@surrey.ac.uk>PGP<http://www.ee.surrey.ac.uk/Personal/L.Wood/>
> >
> >
> >
> 

-harsh.
==================================================
HARSH J. SHAH (GRADUATE STUDENT-MS COMPUTER ENGG.>
UNIV. OF SOUTHERN CALIFORNIA
HOME ADDRESS: 2669 D, MENLO AVE.
LA, CA-90007,USA. PH: 323-766-1399
URL: www-scf.usc.edu/~harshsha
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