Hi, As you said, I have just found that, in NS2, the bandwidth can be set by "Phy/WirelessPhy set bandwidth_ 2e6" and it will be constant, even though the transmission power is changed. I am not sure why bandwidth is not related to transmission power. According to my understand, when the transmission power is decreased, the communication range will be decreased. It is logical true. However, decreasing of transmission power should increase SNR. Once SNR increases, the bandwidth or data rate should be decreased somehow. Do you think so? Could you give me an explaination if i am wrong?
Thank you so much for you previous response, Regards Chakkaphing S. On 1/7/06, Daniel Mahrenholz <[EMAIL PROTECTED]> wrote: > > > Hi, > > On Friday 06 January 2006 15:53, Chakkaphong St. wrote: > > How can I map transmission power with the value of bandwidth? I am > working > > about the transmission power in wireless network. I am also using > shadowing > > Simple answer - you cannot. Bandwidth is not related to the transmission > power. Maybe you mean the different receiver sensitivities (RXTresh_) for > the > different modulation schemes? Here are the values from the Cisco AiroNet > 350 > spec: > > BPSK @1Mbps -94dBm > QPSK @2Mbps -91dBm > CCK @5.5Mbps -89dBm > CCK @11Mbps -85dBm > OFDM @6Mbps -85dBm > OFDM @9Mbps -84dBm > OFDM @12Mbps -82dBm > OFDM @18Mbps -80dBm > OFDM @24Mbps -77dBm > OFDM @36Mbps -73dBm > OFDM @48Mbps -69dBm > OFDM @54Mbps -68dBm > > > propagation model > > with transmission power = 0.2818 Watt, which provides 250m communication > > range. The other mapping between > > This is incomplete. The (mean) transmission range in the shadowing model > is > defined by Pt_, RXTresh_, PathLossExp_. The variance of the range is > defined > by std_db_. You do not have a constant communication range. Just as an > example: with PathLossExp_ = 3.6 and std_db_ =4 you get transmission > ranges > between 70 and over 350m! > > Daniel. > -- > Dipl.-Inf. Daniel Mahrenholz, University of Magdeburg, Germany > Homepage: http://ivs.cs.uni-magdeburg.de/~mahrenho > >
