关于ns2的aodv的疑问，想不通，求解

2013-05-29 03:24:59 434 阅读 AI 写同款 · GEO 优化AI 选题数据监测一键分发 ›

基于NS2的Ad Hoc网络AODV路由协议性能评估的仿真 NS2(Network SimulationVersion 2)是一款功能强大的网络模拟仿真，它是用C++和OTCL两种语言完成的。C++语言编写协议执行模块，OTCL语言编写模拟任务。NS2主要针对有线局域网、无线局域网、Ad Hoc网络、卫星通信网、路由选择协议、组播路由协议等进行网络模拟仿真。阅读详情

最近学习ns2，进行网络仿真，昨天突然发现一个问题，怎么都想不通；不知道是不是我awk文件写不对还是怎么了？分析方法不对？求解
aodv是最小跳数协议
求解throughput，通信速率
采用aodv仿真3个点的实验的时候

三点的结果
start_time: 2.051540,end_time: 100.097301
cbr s:4089,r:4072,r/s Ratio:0.995843,F:4088
time=98.045760,through_put=43192.892658
后来添加2个点发现

5点的结果（理论上添加两个点是没有任何作用的）仍然选择最小跳数链路
start_time: 2.042403,end_time: 100.093324
cbr s:4093,r:4076,r/s Ratio:0.995847,F:4084
time=98.050921,through_put=43233.046143
后来又添加了一个点

发现再次上升了，不明白原因
6个点的结果
start_time: 2.057622,end_time: 100.068675
cbr s:4092,r:4075,r/s Ratio:0.995846,F:4085
time=98.011052,through_put=43240.021435
awk分析文件

BEGIN{

	sendline = 0;

	recvline = 0;

	fowardline = 0;

	package_t =0;

	init=0;

	time_start=0;

}

{

	if($7=="tcp" && $1=="s" && $4 == "AGT" && $8>=1000){

			sendline++;			

	}

	if(($1=="f") && $8>=1000){

			fowardline++;			

	}

	if($8>=1000 && $1=="r" && $4 == "AGT") { 

		if(init ==0){

			time_start=$2;

			init=1;

		}			

		recvline++;

		time_end[recvline]=$2;

	}

}

END{

	printf("start_time: %6f,end_time: %6f\n",time_start,time_end[recvline]);	

	printf("cbr s:%d,r:%d,r/s Ratio:%4f,F:%d\n",sendline,recvline,recvline/sendline,fowardline);

	time=time_end[recvline]-time_start;

	package_t=recvline*1040;

	through_put=package_t/time;

	printf("time=%4f,through_put=%4f\n",time,through_put)

}

3点tcl文件代码，后面类似添加节点

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(nn)	3

set val(rp)	AODV

set val(x)	800

set val(y)	600



puts "\n"

puts "Simulation of a simple wireless have two nodes\n"

puts "Starting simulation...\n"



set ns_ [new Simulator]



$ns_ color 1 Blue  

$ns_ color 2 Red

set tracefd [open node_3_f.tr w]

$ns_ trace-all $tracefd

set namtracefd [open node_3_f.nam w]

$ns_ namtrace-all-wireless $namtracefd $val(x) $val(y)



set topo [new Topography]

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



create-god $val(nn)



$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) \

		-channelType $val(chan) \

		-topoInstance $topo \

		-agentTrace ON \

		-routerTrace ON \

		-macTrace OFF \

		-movementTrace OFF \



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

       	set node_($i) [$ns_ node] 

	$node_($i) random-motion 0

}



$node_(0) set X_ 300

$node_(0) set Y_ 300

$node_(0) set Z_ 0

$node_(1) set X_ 462

$node_(1) set Y_ 417

$node_(1) set Z_ 0

$node_(2) set X_ 623

$node_(2) set Y_ 300

$node_(2) set Z_ 0



#$ns_ at 10.0 "$node_(0) setdest 800.0 200.0 0.0"

#$ns_ at 10.0 "$node_(1) setdest 200.0 200.0 0.0"

#$ns_ at 10.0 "$node_(2) setdest 200.0 200.0 0.0"



set tcp [new Agent/TCP]

$tcp set class_ 2

set sink [new Agent/TCPSink]

$ns_ attach-agent $node_(0) $tcp

$ns_ attach-agent $node_(2) $sink

$ns_ connect $tcp $sink

$tcp set fid_ 1

set ftp [new Application/FTP]

$ftp attach-agent $tcp

$ns_ at 2.0 "$ftp start"



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

	$ns_ initial_node_pos $node_($i) 20

}



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

	$ns_ at 100 "$node_($i) reset" 

}



proc stop {} {

	global ns_ tracefd namtracefd

	$ns_ flush-trace

	close $tracefd

	close $namtracefd

	exec nam node_3_f.nam &

	exit 0

}

$ns_ at 100.1 "stop"

$ns_ at 100.2 "puts \"NS EXITING...\";$ns_ halt"



puts "Starting Simulation...."



$ns_ run