Hello, Since I want set transmission range to 10m and interference range to 30m, I use the indep-utils/.../"threshold" utility to calculate transmission and interference range. Firstly I use: threshold -m TwoRayGround -Pt 0.1 -fr 2.4e+9 10 Receiving threshold RXThresh_ is: 9.89465e-08 threshold -m TwoRayGround -Pt 0.1 -fr 2.4e+9 10 Receiving threshold RXThresh_ is: 1.09941e-08 so here is my setting: Phy/WirelessPhy set bandwidth_ 1MbPhy/WirelessPhy set Pt_ 0.1Phy/WirelessPhy set freq_ 2.4e+9Phy/WirelessPhy set L_ 1.0 # 10mPhy/WirelessPhy set RXThresh_ 9.89465e-8# 30mPhy/WirelessPhy set CSThresh_ 1.09941e-8Phy/WirelessPhy set CPThresh_ 10.0 #RTS/CTS disabledMac/802_11 set RTSThreshold_ 3000 There are only 2 nodes, src and sink. The problem is: when I am using MAC/Simple as following settings, from trace file I see everything works as expected: if node distance <=10m, pkt are received successfully, if distance is between 11m to 30m then pkt is sensed but dropped, if dist >30 then sink node can not hear any pkt at all. set val(chan) Channel/WirelessChannel ;#Channel Type set val(prop) Propagation/TwoRayGround ;# radio-propagation model set val(netif) Phy/WirelessPhy ;# network interface typeset val(mac) Mac/Simpleset val(ifq) Queue/DropTail/PriQueue ;# interface queue typeset val(ll) LL ;# link layer typeset val(ant) Antenna/OmniAntenna ;# antenna model However, when I switch to Mac/802_11 (set val(mac) Mac/802_11) and keep everything else unchanged, sink can receive all pkt when distance <=10m, however, when dist > 10m, sink CAN NOT hear any pkt, no "dropped packet" in trace file, same when dist > 30m. When I switched to 802_11Ext and WirelessPhyExt, now the Receiving threshold RXThresh_ calculated by "threshold" utility is not correct, and again there is no "grey zone" like in Mac/802_11. Since there are only 2 nodes, I expect to observe the "pkt heard but dropped" range of (10,30) as in both MAC/Simple and MAC/802_11 at least, but results are not. I am not sure if the threhold utility can apply to 802_11Ext/WirelessPhyExt or Not. Any one can advise me what could be the problem or I misunderstood the ns2 802_11 implementation? Thanks. _________________________________________________________________ Get more out of the Web. Learn 10 hidden secrets of Windows Live. http://windowslive.com/connect/post/jamiethomson.spaces.live.com-Blog-cns!550F681DAD532637!5295.entry?ocid=TXT_TAGLM_WL_domore_092008
