Dear Andreas,
Thank you very much for your reply.
My topology is symmetric. Any node can carrier sense the packet
transmitted by any other node. The carrier sense range is 550 meters, while
my x-scale length is 470 meters. Am I correct? I do not think that asymmetry
cause the problem.
Shengyan
On Thu, May 6, 2010 at 6:02 AM, Andreas Kassler <[email protected]>wrote:
> Hi,
> Not strange. This is the node asymmetry problem. See papers by Ed
> Knightleys
> group at Rice university. Similar problem exist in the parking lot
> scenario,
> where all flows go towards node 0.
>
> Andreas Kassler
>
> -----Original Message-----
> From: [email protected] [mailto:[email protected]] On Behalf
> Of Shengyan Hong
> Sent: Donnerstag, 6. Mai 2010 14:44
> To: [email protected]
> Subject: [ns] a question on 802.11 simulation on NS-2
>
>
> Dear all,
> I just did an easier experiment. Topology is a linear line of
> nodes, 5-4-3-2-1-0. The horizontal distance between two neighbor nodes is
> 85
> meters. Stream A comes from 5 to 4, stream B comes from 3 to 2 and stream C
> comes from 1 to 0. The packet size is 512 bytes, and every 0.01 sec, one
> packet is sent from the agent. The MAC protocol is 802.11 and the routing
> algorithm is AODV.
> Out of 36995 packets in stream C, all reach 0. Out of 36998 packets in
> stream B, 15127 packets reach 2. Out of 36985 packets in stream A, 9309
> packets reach 4.
> It is strange that C transmits all its packets, while B and A
> drop many packets. Why? Attach the scripts and trace file. Thank you very
> much.
>
> Shengyan
>
>
