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Re: [ns] Ad hoc emulator based on ethernet
> Have you ever thought that there are many similar character between
>ethernet and MANET. In fact the first IEEE wavelan controlled by ethernet
>chips.
>
> They all share the media and using CSMA.
actually (i think!!) ethernet is CSMA/CD (ie has collision detect built
in)...that's because since frame error rate on wire is so low, an
unsuccsessful reception is more likely be due to collision...
on the other hand in 802.11 (which the cmu extensions seek to
follow) there is no CD built in...and the primary reason is that since
frame error rates are so high for a wireless medium an
"unsuccsessful" reception of a packet could be either due to collisions
and/or due to frame error...so its not easy to assume that all
unsuccsessful transmissions are due to collisions.....
in such a scenraio a transmitter assumes on RTStimeout that a collision
took place and does exponential backoff retry etc...
Nevertheless your emulator sound interesting....send me more
information...
-Vikram
>
> The differents between they are connectivity and communication channel
>performances.
>
> For the transmission range, the connectivity in MANET is incomplete.
>Ad Hoc netwroks have high frame error rate and communication decay. The
>frame error rate is the function of distant between transmitter and
>receiver.
>
> We can insert a small program on top of network interface, and emulate the
>MANET characteristics on ethernet. We call it MPRN NE (Mobile Packet
Radio Network Network Emulator).A center scenarios generator broadcast the
>position packet to all the emulators. Your real MANET routing protocol
>can run on top of emulators. TCPDUMP or other network performance analyse
>software can be used in test.
>
> It's cheaper and more easier to be controlled than ns.
>Millions of people use linux TCP/IP stack,You will not worry about the
>bugs in TCP/IP stacks.
>
> The client part of NE is developed under linux, the scenarios generator and
>center controller is developed under windows for good graphic interface
>and easy implementation.
>
> We took a MANET emulation on computing center. More than one hundred
>computers connected in one network segment worked in true time for 3
>hours in mid night.
>
> NE was developed by Beijing Institute of Technology, MPRN research group.
>It will be provided to all Ad Hoc researcher freely.
>
> If you are interested in this,please email to my, I will give you more
>detail information about our emulation.
>
> Weiguo Liu
>
> PHD Student
>
> Computer Engineering Department
> Beijing Institute of Technology
> China
>
> [email protected]
>
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