[ns] Problem with MAC 802.11 in NIST model

[Pedro J. Fernández Ruiz]

Hi all!,

I've just found a possible error in MAC 802.11 in NIST model. The handovers
didn't finish correctly, so I found a possible missing step in the handover
process.

When we create the mobile nodes in TCL scripts, in the NIST examples we use
the command:

$node ($i) base-station [AddreParams addr2if [$bstation1 node-addr]];

in order to get the mobile-node will be connected to a initial basestation.

This command call the set_base_stn(addr) { base_stn_ = addr} method definde
in mobilenode.h.

The problem comes when the mobile node want to be attached with another base
station.

This command is never executed again for new basestation, so I've coded this
by myself to execute it after Association negotiation:

            MobileNode *node_ = (MobileNode *)
Node::get_node_by_id(netif_->node()->nodeid());
            if (node_ != NULL)    {
                MobileNode *bs_ = (MobileNode *) Node::get_node_by_id(src);
                if (bs_!= NULL) {
                    node_->set_base_stn(bs_->address());
                }
            }

The problem here is in this line:

MobileNode *bs_ = (MobileNode *) Node::get_node_by_id(src);

get_node_by_id(src) waits for an node ID, not a MAC ID!!!! (they aren't the
same). "src" it the basestation mac id, so the question is: How to get the
basestation node ID??? (this code is in the mobile node mac instance, so no
problem to get mobile node ID from the Mobile node mac id:
netif_->node()->nodeid()))

In order to avoid this problems I assign to the MAC ID the same ID from the
node where it is, so get_node_by_id(src) returns the good one.

Is this a bug??

I hope I have explained my problem in a understandable way. I tried to do
that as crearly as I could.

Best regards and thanks for your help.

Pedro J. Fernández


-- 
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Pedro Javier Fernández Ruiz
Faculty of Computer Science - University of Murcia
Murcia - Spain
Phone: +34 968 364644 (Dibulibu)  -  Mobile: +34 657112324
e-mails:
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