ns2中怎样实现路由协议

如果我们要往NS2中添加自己的模块，那么我们至少要实现两个类： 一， 首先要有一个类继承自TclObject类或者其子类，例如这个Mac802_16类的继承关系为：TclObject/NsObject/Mac /Mac802_16.这个类里面实现了C++类里面的变量与Otcl类的变量的绑定。

这只是一段普通常规参数设置的脚本

第一段：用来获取个变量的参数值

第二段：设置物理层参数

第三段：设置mac层的一些参数

如果说是区分不同协议,那只有

if { $opt(0)=="DSR"} {

set opt(ifq) CMUPriQueue

} else {

set opt(ifq) Queue/DropTail/PriQueue# interface queue type

}

这段代码可能是用来区分不同协议，不同协议采用不同的队列管理机制

其实 只需要编写一个.tcl脚本文件

set val(mac)Mac/802_11

然后要配置节点参数时 指定

$ns_ node-config- -macType $val(mac)即可

附上例子一枚：

set val(chan) Channel/WirelessChannel#Channel Type

set val(prop) Propagation/TwoRayGround # radio-propagation model

set val(netif) Phy/WirelessPhy# network interface type

set val(mac)Mac/802_11 # MAC type

set val(ifq)Queue/DropTail # interface queue type

set val(ll) LL # link layer type

set val(ant)Antenna/OmniAntenna# antenna model

set val(ifqlen) 50# max packet in ifq

set val(nn) 10 # number of mobilenodes

set val(rp) DumbAgent # routing protocol

set val(x) 600

set val(y) 600

Mac/802_11 set dataRate_ 11Mb

#Phy/WirelessPhy set CSThresh_ 10.00e-12

#Phy/WirelessPhy set RXThresh_ 10.00e-11

#Phy/WirelessPhy set Pt_ 0.1

#Phy/WirelessPhy set Pt_ 7.214e-3

# Initialize Global Variables

set ns_ [new Simulator]

set tracefd [open infra.tr w]

$ns_ trace-all $tracefd

# set up topography object

set topo [new Topography]

$topo load_flatgrid $val(x) $val(y)

# Create God

create-god $val(nn)

# Create channel

set chan_1_ [new $val(chan)]

$ns_ node-config -adhocRouting $val(rp) \

-llType $val(ll) \

-macType $val(mac) \

-ifqType $val(ifq) \

-ifqLen $val(ifqlen) \

-antType $val(ant) \

-propType $val(prop) \

-phyType $val(netif) \

-topoInstance $topo \

-agentTrace OFF \

-routerTrace OFF \

-macTrace ON \

-movementTrace ON \

-channel $chan_1_

for {set i 0} {$i <[expr $val(nn)]} {incr i} {

set node_($i) [$ns_ node]

$node_($i) random-motion 0 # disable random motion

set mac_($i) [$node_($i) getMac 0]

$mac_($i) set RTSThreshold_ 3000

$node_($i) set X_ $i

$node_($i) set Y_ 0 # Horizontal arrangement of nodes

$node_($i) set Z_ 0.0

}

#Set Node 0 and Node $val(nn) as the APs. Thus the APs are the ends of the horizontal line. Each STA receives different power levels.

set AP_ADDR1 [$mac_(0) id]

$mac_(0) ap $AP_ADDR1

set AP_ADDR2 [$mac_([expr $val(nn) - 1]) id]

$mac_([expr $val(nn) - 1]) ap $AP_ADDR2

#$mac_([expr $val(nn) - 1]) set BeaconInterval_ 0.2

$mac_(1) ScanType ACTIVE

for {set i 3} {$i <[expr $val(nn) - 1]} {incr i} {

$mac_($i) ScanType PASSIVE #Passive

}

$ns_ at 1.0 "$mac_(2) ScanType ACTIVE"

Application/Traffic/CBR set packetSize_ 1023

Application/Traffic/CBR set rate_ 256Kb

for {set i 1} {$i <[expr $val(nn) - 1]} {incr i} {

set udp1($i) [new Agent/UDP]

$ns_ attach-agent $node_($i) $udp1($i)

set cbr1($i) [new Application/Traffic/CBR]

$cbr1($i) attach-agent $udp1($i)

}

set base0 [new Agent/Null]

$ns_ attach-agent $node_(1) $base0

set base1 [new Agent/Null]

$ns_ attach-agent $node_(8) $base1

$ns_ connect $udp1(4) $base0

$ns_ connect $udp1(5) $base1

$ns_ at 2.0 "$cbr1(4) start"

$ns_ at 4.0 "$cbr1(5) start"

$ns_ at 10.0 "$node_(4) setdest 300.0 1.0 30.0"

$ns_ at 20.0 "stop"

$ns_ at 20.0 "puts \"NS EXITING...\" $ns_ halt"

proc stop {} {

global ns_ tracefd

$ns_ flush-trace

close $tracefd

exit 0

}

puts "Starting Simulation..."

$ns_ run

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