[ns] Distributed Coordination Function (DCF) packet are not receiving at AGT level

[Ashraf Bourawy]

hi there,

According to the Interface cards and to be realistic, CSThresh_ and
RXThresh_ should be different !!!! In addition, you can find some notes
regarding this issue in the IEEE 802.11 standard in the physical layer
chapters,,,,,,, Actually, CSthresh_ (carrier sense threshold) should be
smaller in value (i.e, larger in sensing range) than RXThresh_ (receiver
threshold),,,,,
As defined in the ns simulator, CSThresh_ is 1.559e-11 (approximately to -78
dBm) and RXThresh_ is 3.652e-10 (approx. -65 dBm),,,,,,,Those values depend
on the interface card real specifications which you cannot change,
though,,,,,,,,,If you'd like to use another card type, you need to specify
all these parameters as suplied by the card manufacturer,,,,,

hope this will help,,

Best regards,
Ashraf Bourawy.


On 3/24/06, Rudrashetty shetty <rudrashetty05 at yahoo.co.in> wrote:
>
>
> hi !
>     i have attached  my Distributed Coordination Fucntion, tcl file,
> problem over here is in trace file, packet are not  receiving at Agent
> level, showing till at
>   RTR level.
>   i have taken all physical and mac layer parameters and
>   binded in PHY-MIB and MAC_MIB in mac-802.11.h file
>   scenari and traffic as i have specified in it.
>   i think Distributed Interframce service(DIFS) mac802.11.cc will take
> care
>
>   what exactly went wrong, any addtional things to be done in .cc or .h
> file
>
>   waiting for u r reply
>
>
>   # setting the scripts DCF tcl file
> set endtime 1000  ;#duration of the simulation
> set val(chan)   Channel/WirelessChannel
> set val(prop)   Propagation/TwoRayGround
> set val(netif)  Phy/WirelessPhy
> set val(mac)    Mac/802_11
> set val(ifq)    Queue/DropTail/PriQueue
> set val(ll)     LL
> set val(ant)    Antenna/OmniAntenna
> set val(ifqlen) 50
> set val(seed)   1.0
> set val(nn)     50
> set val(cp)    "/root/ns-allinone-2.26/ns-2.26/tcl/cbr-50-10-1"
> set val(sc)   "/root/ns-allinone-2.26/ns-2.26/tcl/scen-670-670-100-20-10"
> set val(x)     670
> set val(y)     670
> set val(tr)   "dcf.tr"
> set val(adhocRouting)    DSDV
>   # unity gain, omni-diractinal antennas
> # set up the antennas to be centered in the nodes and 1.5 meters above it
> puts "setting up the Antennas configuration "
> Antenna/OmniAntenna set X_ 0
> Antenna/OmniAntenna set Y_ 0
> Antenna/OmniAntenna set Z_ 0
> Antenna/OmniAntenna Gt_ 1.0
> Antenna/OmniAntenna Gr_ 1.0
>
> ##########physical layer
> Phy/WirelessPhy set CPThresh_ 10.0
> Phy/WirelessPhy set per_ 0.0   ;#check it
> Phy/WirelessPhy set CSThresh_ 2.5e-10
> Phy/WirelessPhy set RxThresh_ 2.5e-10
> Phy/WirelessPhy set Rb_ 2*1e6
> Phy/WirelessPhy set Pt_ 0.2818
> Phy/WirelessPhy set freq_ 914e+6
> Phy/WirelessPhy set L_ 1.0
> puts "Physical channel set ....... "
>
> Mac/802_11 set bandwidth  36Mb
>   Mac/802_11 set RTSThreshold_ 3000
> Mac/802_11 set ShortRetryLimit_ 7
> #MAC_MIB set RTSThreshold_ 3000
> #MAC_MIB set ShortRetryLimit_ 7
> Mac/802_11 set LongRetryLimit_ 4
> Mac/802_11 set MinimumBandwidth_ 6mb
>
> # simple wireless scenario
>
> Mac/802_11 set SlotTime_ 0.000020
> Mac/802_11 set SIFS_ 0.000016
> Mac/802_11 set PreambleLength_  144
> Mac/802_11 set PLCPHeaderLength_ 48
> Mac/802_11 set PLCPDataRate 1.0e6
> Mac/802_11 set dataRate_ 2M
>
>
> # option for the MAC parameter
> Mac/802_11  set  CWmin_  31
> Mac/802_11  set  CWMax_  1023
>
>
> ### primary simulation objects
> set ns_ [new Simulator]
> # $ns_ use-newtrace   ;# displaying the new wireless format.
>           set tracefd [open dcf1.tr w]
> $ns_ trace-all $tracefd
>
> #set tracefd [open $outfile_.tr w]
> #$ns_ trace-all $tracefd
>   # set tracefd [open dcf.tr w]
> #        $ns_ trace-all $tracefd
>
> #        set nf [open dcf.nam w]
> # $ns_ namtrace-all $nf
>         set topo [new Topography]
>       $topo load_flatgrid $val(x) $val(y)
>   ###### create God objects
> #### create-god $nn #from main-AEDCF-EDCF.tcl
> set god_ [create-god $val(nn)]
>   ###### createing channel
> #set chan_1_ [new $val(chan)]
>
> #configureing a nodes to attach to the channel
>   $ns_ node-config -adhocRouting $val(adhocRouting) \
> -llType $val(ll) \
>         -macType $val(mac) \
> -ifqType $val(ifq) \
>         -ifqLen $val(ifqlen) \
> -antType $val(ant) \
> -propType $val(prop) \
> -phyType $val(netif) \
> -channelType $val(chan) \
> -topoInstance $topo \
> -agentTrace ON \
> -routerTrace ON \
> -macTrace ON \
> -movementTrace OFF
> #       -channel $chan_1_
>   # Create nodes with IFQ send tracing enabled.
>         for { set i 0} {$i <$val(nn)} { incr i} {
> set node_($i) [$ns_ node]
> #        $node_($i) add-ifq-send-trace
> #from main_AEDCF_EDCF_TCL
>    $node_($i) random-motion 0
>            }
>   puts "Loading Connection patterns ....."
> source $val(cp)
>   puts "Loading Scenario Files ....."
> source $val(sc)
>
> #simulation END Conditions
>     for {set i 0} {$i< $val(nn)} {incr i} {
> $ns_ at $endtime "$node_($i) reset";
>             }
>    $ns_ at $endtime "do_stop"
>    set delta 0.01
> set endtime [expr $endtime + $delta]
> $ns_ at $endtime "$ns_ halt"
>    proc do_stop {} {
> global ns_ tracefd nf
> $ns_ flush-trace
> close $tracefd
> close $nf
> }
> # proc do_halt {} {
> # global ns
> # puts "NS Exiting ..."
> # $ns_ halt
>    #start up the simulation
> puts "Starting Simulation .."
> $ns_ run
>
>
>   thanking u
>   with regards
>   Rudrashetty.H
>
>
>
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