[e2e] Simulator for wireless network

Eric W Anderson Eric.Anderson at Colorado.EDU
Mon Apr 16 16:07:17 PDT 2007

At the risk of flogging a dead horse, here are a few observations.
Right now, my group is working on studying the physical- and MAC-layer
impact of using steerable antennas in 802.11-ish networks.   We've
used ns2 and Opnet a fair bit, and right now we're measuring actual
deployments.  With that said here are my thoughts:

(1) RF propagation is extremely sensitive to the details of a physical
environment.  If you do your research using the "40 laptops" approach,
it's important to consider an appropriate range of physical
environments.  If you use a simulator, you need to consider what sort of
physical world you're specifying -- or implicitly assuming.

(2) Both Opnet and ns2 make significant simplifying assumptions about
the RF environment and the sender and receiver hardware.  Whether
these assumptions are OK or not depends very much on what you're

(3) Opnet's main strengths -- to me -- are its extensive library of
equipment models and its built-in statistics gathering.  Both are
handiest if you're a network administrator and want to quickly evaluate
a proposed deployment of stock systems and protocols.  If you're
interested in re-designing things significantly, they're probably less
useful.  In my experience, the built-in statistics tracking proved
inappropriate for the fine granularity data I needed to gather.

(4) Parts of Opnet are modifiable models which come with the source
code, and other parts are opaque and immutable.  The parts I most wanted
to change or instrument were often in the latter category.

In the end, we've settled on actually implementing things as our
preferred approach.  I'll probably use ns2 in the future when an actual
deployment is impractical.  I probably won't be using Opnet again.

That's my two cents' worth,

Thus spake Durga Prasad Pandey (dpsmiles at MIT.EDU):

> What would be considered the best network simulator(s) for wireless  
> networks, particularly for TCP experiments?
> Durga

Eric W. Anderson                                   University of Colorado
eric.anderson at colorado.edu                      Dept. of Computer Science
phone: +1-720-984-8864                             Systems Lab - ECCS 112

                         PGP key fingerprints:
       personal: 1BD4 CFCE 8B59 8D6E EA3E  EBD5 4DC9 3E61 656C 462B
       academic: D3C5 D6FF EDED 9F1F C36D  53A3 74B7 53A6 3C74 5F12
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 189 bytes
Desc: Digital signature
Url : http://mailman.postel.org/pipermail/end2end-interest/attachments/20070416/fd198998/attachment.bin

More information about the end2end-interest mailing list