On Thu, 2009-04-09 at 15:59 +0200, ichrak amdouni wrote:
>
> 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.
As I said, I don't believe that the default parameter values allow any
kind of packet reception at 3000m.
Here is what I get with ns-3-dev from today:
[mlac...@diese ns-3-dev]$ ./build/debug/src/devices/wifi/wifi-phy-test
Psr --PacketSize=40 --TxMode=wifia-6mbs --Distance=3000
0
or:
[mlac...@diese ns-3-dev]$ ./build/debug/src/devices/wifi/wifi-phy-test
SizeVsRange --TargetPsr=0.0001 --TxMode=wifia-6mbs
10 199.125
50 189.214
90 182.218
130 177.554
170 174.639
210 171.918
250 172.307
290 170.947
330 169.586
370 168.226
...
To summmarize, the default parameter setup and values ensure that the
probability of successful reception of packets 10bytes-long by the PHY
with mode 6mbs is close to zero after 200m. If you don't get this, then,
either you have a very broken version of ns-3 or you have changed some
default parameter, but I have no idea which. Or, I could be wrong, but I
don't have enough information to reproduce the behavior you are
describing.
>
> > 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:
what is the 'theoretical' coverage area ?
>
>
> 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.
I am not sure what you are trying to achieve. Theoretically, all you
need to do to adjust the transmission range is to change the tx power.
Mathieu
