Re: [ns] proper values for 11Mbps wireless simulation

[Joe Macker <macker@itd.nrl.navy.mil>]

At 10:12 AM 6/28/2001 +0200, Felix Ko wrote:
>Hi!
>
> > What I have done is only to change bandwidth_ of Phy/WirelessPhy to 11e+6.
>
>Are you sure that the "bandwidth_"-parameter of "Phy/WirelessPhy" really
>effects the time/speed of your packet-transmissions?
>
>In my opinion, it's only used to calculate the energy consumed during
>the transmission.
>
>If you want to toggle the transmission speed, you should
>use the "bandwidth_" parameter of "Mac/802_11"...

Just a cautionary note to those that may try this.

If one does do this, to say simulate lower data rate "802.11-like" links, 
it would be wise to also reevaluate the other MAC timer settings at the 
lower layer (e.g., RTS/CTS, ack response,etc).  Many of these settings are 
customized for the specific transmission rates and max delay assumptions 
and anomalous behavior could result at other tweaked link rates.  In other 
words, one should check if the additional MAC layer framing and protocol 
timers under the hood are scaled when transmission speed or max delay 
(could also relate to transmit power and range) is modified in an ad hoc 
manner.


>Bye
>
>Felix