[Ns-developers] Numerical values of the attributes inYansWifiPhy::GetTypeId

[Hagen Paul Pfeifer]

On Tue, 24 Feb 2009 12:05:57 +0100, Ruben Merz
<ruben at net.t-labs.tu-berlin.de> wrote:

> I would like to know from where do the numerical values set for the
> 802.11a PHY in YansWifiPhy::GetTypeId come from?
> 
> Was any particular hardware modeled?

Not really, there are some 802.11a restrictions on the one side
and some physical boundaries that maps the physical reality. At least
it is a simulator and the modeled PHY layer is not that complex, at it
is in reality. Not sure if every value is perfect but we can step
through these values:

TxPowerEnd: 16.0206 dBm
RxPowerEnd: 16.0206 dBm

16.0206 dBm are 40mW. 40mW are ETSI standard for 802.11. 50mW
is also possible for some countries. So it looks fine for
802.11a - for 802.11g you can raise this up to 20 dBm (for europe).

EnergyDetectionThreshold: -140dBm
CcaMode1Threshold: -140.0 dBm

Should the sensitive enough to get catch enough information.
Think about asymmetric links, et cetera. This value is used for
SINR calculation.

RxNoise: 7dB

An additional gain to smooth the reception. The term noise
is a little bit misleading here. RxLost may be a better name -
it points misleading that it models channel lost characteristics.

TxGain: 1 dB
RxGain: 1 dB

TxGain/RxGain models a non-isotrope antenna. This value is too
small to have any far-reaching influences.


Best regards, Hagen