[Tinyos-help] TOSSIM Issue

Brett Parsons brettmac.parsons at nf.sympatico.ca
Sun Sep 18 16:10:45 PDT 2005


  Hi All,

I'm having an issue with running my simulation in TOSSIM (TinyOS version 
1.1.14) and I'm really hoping someone can help me out. 

I'm doing a very simple experiment with the network topology shown below 
(in the picture):

Topology


Node 0 is my "Base Station" and node 5 is a data source that is supposed 
to send me back sensor readings.  I have created a TOSSIM topology file 
to represent this topology.  The idea is that Node 0 broadcasts out an 
interest message which is then re-broadcasted until it reaches node 5.  
At this point, node 5 begins sending data back to any neighbours that 
requested it (2 and 4). 

Here's the problem:  Data flows on the 0-1-2-5 route perfectly.  
However, when node 4 receives the data and attempts to unicast it to 
node 3, node 3 never hears the message.  I have turned on the AM debug 
messages and it seems that 4 does indeed send a message, but there is 
nothing in the logs to indicate that node 3 hears it. 

The strange part is, if I run the simulation approx. 10 times, node 3 
might receive the message 1 out of the 10 times (very small success 
rate).  Every other simulation run, the message never gets received.  
Does the order the links appear in my .nss file make any difference?

I'm really hoping someone can offer some insight into a solution because 
I've tried everything I can think of to fix this problem.  I am 
including my actual .nss topology file below for reference (maybe I'm 
missing something obvious).  I'd really appreciate people's help with 
this matter !

Thanks,

Brett P

Topology File
--------------
0:1:0.00
1:0:0.00
1:2:0.00
2:1:0.00
2:3:0.00
3:2:0.00
3:6:0.00
6:3:0.00
0:4:0.00
4:0:0.00
5:4:0.00
4:5:0.00
5:6:0.00
6:5:0.00


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