Re: Re: [Tinyos-help] collision simulation in tossim

[venkatesh s]

In tossim, every node in the network can here all the rest of the nodes, if they are in the same radio range.  If that is the case, then hidden node problem, doesn't come into picture at all.  The problem might be that all the nodes use a global clock (syncronization) and it may so happen that the random backoff times for two nodes seem to be same, which may result into packet transmissions.  Again its a Collisionr.  I have faced this problem, and i was trying to debug.  Since the simulation was bit level, it was little difficult in finding out this problem. 

As a option you can try the packet level simulation.  Since its a memory copy operation for the whole packet, I dont think so you get CRC errors.  I have tried it, and have got no loss.  But syncronization remains to be..!!!

Date: Thu, 26 Oct 2006 12:27:26 +0200
From: Pela <[EMAIL PROTECTED]>
Subject: Re: Re: [Tinyos-help] collision simulation in tossim
To: [EMAIL PROTECTED]
Cc: tinyos-help@millennium.berkeley.edu
Message-ID: <[EMAIL PROTECTED]>
Content-Type: text/plain; charset=ISO-8859-15

Using the "simple" model means that all the nodes will receive packets
and the bit error rate is set to zero. However, collisions can still
occur as well as the hidden terminal problem, for this reason crc errors
are possible. As far as I know, collisions cannot be disabled in tossim.

--
Marco

--
--
with Cheers,
_,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:
                 VeNkAtEsH
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