hi guys To change transmission power i did as following but no change: 1- add a field in hdr_cmn like "double txpwr" to save desired transmission power for every packet. 2- add this code in "sendDown" function in wireless-phy.cc to transmit packet as desired Pt_: Pt_ = hdr_cmn::access(p)->txpower(); /* * Stamp the packet with the interface arguments */ p->txinfo_.stamp((MobileNode*)node(), ant_->copy(), Pt_, lambda_); // Send the packet channel_->recv(p, this); } is there something that i missed? thanks