Hi all,
Thank you Mathieu.
* *
2009/4/9 Mathieu Lacage <mathieu.lac...@sophia.inria.fr>
> On Mon, 2009-04-06 at 19:34 +0200, ichrak amdouni wrote:
> > Hi all,
> >
> > I need to fix the transmission range for access points and mobile
> stations
> > in an infrastructure wifi network.
> > I mean, how to manage to let communication restricted to a given
> distance?
> > I know that in the ns3.3 version, this parameter is not explicitly set,
> but
> > affected by others like the TxPower and the channel loss model, but
> > actually, I experimented multiple matching between those parameters but I
> > have always stange results (a sta can affiliate with an APdistant of
> > thousands of meters!!).
>
> I doubt that is the case with the default values of all parameters.
> Maybe you changed some parameters ?
>
Yes, it is the case, the mac association succeed between an access point
and one mobile station distant of 3000m, connectivity is however not
maintained. Note that my nodes simulates vehicles running at 50km/h.
>
> > Having distinct results from those of the wifi-phy-test.cc example, I
> wonder
> > if this issue has a relation with other layers other than the Physical
> one?
>
> No, it's all a PHY layer thing.
>
> > I find the hypothesis very stange but I really reproduced the same
> scenario
> > as in wifi-phy-test.cc.
>
> What kind of scenario ? Could you be more explicit about what you, what
> you get, and what you expect from wifi-phy-test ?
I am expecting to have nodes that can't "see" each other beyond the
theoretical coverage area.
For example I used the following setting:
*channel.AddPropagationLoss("ns3::LogDistancePropagationLossModel","Exponent",
DoubleValue(1.70));
channel.SetPropagationDelay ("ns3::ConstantSpeedPropagationDelayModel");
Ptr<YansWifiChannel> chan = channel.Create ();
** wifiPhy.SetChannel (chan);*
* wifiPhy.SetErrorRateModel ("ns3::ErrorRateModel");
wifiPhy.Set ("TxPowerStart",DoubleValue(5));
wifiPhy.Set ("TxPowerEnd",DoubleValue(5));
wifiPhy.Set ("TxPowerLevels",UintegerValue (1));
wifiPhy.Set ("TxGain",DoubleValue (2));
wifiPhy.Set ("RxGain",DoubleValue (2));
*This make connection impossible beyond 250m, but the problem now is that
packet transfert failure is important due to the condition:*
(m_random.GetValue () < snrPer.per** ) *at the physical layer when sending
probe responses.*
*
>
>
> > May I missing something?
> >
> > - Did someone experiment this issue especially in high mobiliy network?
> or
> > have an idea to deal with it differently?
> > - Is the transmission range explicitly set in ns 3.4? If yes, which
> files
> > were modified?
>
> No, ns-3.4 has no support for this. A patch to add a range-based PHY
> model would be welcome.
>
> Mathieu
>
>
> Best Regards.
Ichrak.
