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无线网络中吞吐量、丢包率、端到端时延的测量

2013年08月31日 ⁄ 综合 ⁄ 共 10062字 ⁄ 字号 评论关闭

链接:http://blog.chinaunix.net/u3/105477/showart_2087878.html

 

 

关键点:

        学习采样过程的编写,如何获得所需参数,如何利用单独的文件做记录;
        了解吞吐量、丢包率和端到端时延的具体物理含义;
        进一步了解NS2提供的参数接口!
[场景说明]: 8个节点中,4个作为数据流的源节点,其余作为数据流的目的节点;
           每个源节点和对应目的节点间通过UDP方式连接,运行CBR应用;
           CBR应用的参数: 数据包大小--512字节;  传输率----600Kbps;
      假定每个节点在对方(数据包的下一中转路由节点)的通信半径内(每个节点的通信半径:195m);
      网络模拟过程持续时间: 80秒。

#
#
#
#===================================================================
# Define Node Configuration paramaters
#===================================================================
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/PriQueue   ;# 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)             8                          ;# number of mobilenodes
set val(rp)             DSDV                       ;# routing protocol
set val(x)              500                        ;# X dimension of the topography
set val(y)              500                        ;# Y dimension of the topography
Mac/802_11 set RTSThreshold_  3000
Mac/802_11 set basicRate_ 1Mb
Mac/802_11 set dataRate_  2Mb
#=====================================================================
# Initialize trace file desctiptors
#=====================================================================
# *** Throughput Trace ***
set f0 [open out02.tr w]
set f1 [open out12.tr w]
set f2 [open out22.tr w]
set f3 [open out32.tr w]
# *** Packet Loss Trace ***
set f4 [open lost02.tr w]
set f5 [open lost12.tr w]
set f6 [open lost22.tr w]
set f7 [open lost32.tr w]
# *** Packet Delay Trace ***
set f8 [open delay02.tr w]
set f9 [open delay12.tr w]
set f10 [open delay22.tr w]
set f11 [open delay32.tr w]

#以下部分的代码,在 入门实例2 中已有详尽的注释啦!
set ns_ [new Simulator]
set tracefd   [open trace2.tr w]
$ns_ trace-all $tracefd
set namtrace [open sim12.nam w]
$ns_ namtrace-all-wireless $namtrace $val(x) $val(y)

set topo [new Topography]
$topo load_flatgrid 500 500
 
# Create  General Operations Director (GOD) object.
#It is used to store global information about the state of the environment, network, or nodes that an
# omniscent observer would have, but that should not be made known to any participant in the simulation.
 
create-god $val(nn)
# configure nodes
        $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                   

# Create Nodes
        for {set i 0} {$i < $val(nn) } {incr i} {
                set node_($i) [$ns_ node]
                $node_($i) random-motion 0            ;# disable random motion
        }
# Initialize Node Coordinates
$node_(0) set X_ 5.0
$node_(0) set Y_ 5.0
$node_(0) set Z_ 0.0

$node_(1) set X_ 200.0
$node_(1) set Y_ 5.0
$node_(1) set Z_ 0.0

$node_(2) set X_ 5.0
$node_(2) set Y_ 50.0
$node_(2) set Z_ 0.0

$node_(3) set X_ 200.0
$node_(3) set Y_ 50.0
$node_(3) set Z_ 0.0
 
$node_(4) set X_ 5.0
$node_(4) set Y_ 100.0
$node_(4) set Z_ 0.0

$node_(5) set X_ 200.0
$node_(5) set Y_ 100.0
$node_(5) set Z_ 0.0

$node_(6) set X_ 2.0
$node_(6) set Y_ 150.0
$node_(6) set Z_ 0.0

$node_(7) set X_ 200.0
$node_(7) set Y_ 150.0
$node_(7) set Z_ 0.0

# Setup traffic flow between nodes
# TCP connections between node_(0) and node_(1)
# Create Constant four Bit Rate Traffic sources
#============================================================
#以下的这段代码可以写成一个过程,那样就方便多啦!
#先整理, 以后我再回头改吧!
#============================================================
set agent1 [new Agent/UDP]              ;# Create TCP Agent
$agent1 set prio_ 0                     ;# Set Its priority to 0
# Create Loss Monitor Sink in order to be able to trace the number obytes received

set sink [new Agent/LossMonitor]       
$ns_ attach-agent $node_(0) $agent1     ;# Attach Agent to source node
$ns_ attach-agent $node_(1) $sink       ;# Attach Agent to sink node
$ns_ connect $agent1 $sink              ;# Connect the nodes
set app1 [new Application/Traffic/CBR]  ;# Create Constant Bit Rate application
$app1 set packetSize_ 512               ;# Set Packet Size to 512 bytes
$app1 set rate_ 600Kb                   ;# Set CBR rate to 200 Kbits/sec
$app1 attach-agent $agent1              ;# Attach Application to agent

set agent2 [new Agent/UDP]              ;# Create TCP Agent
$agent2 set prio_ 1                     ;# Set Its priority to 1
# Create Loss Monitor Sink in order to be able to trace the number obytes received
set sink2 [new Agent/LossMonitor]        
$ns_ attach-agent $node_(2) $agent2     ;# Attach Agent to source node
$ns_ attach-agent $node_(3) $sink2      ;# Attach Agent to sink node
$ns_ connect $agent2 $sink2             ;# Connect the nodes
set app2 [new Application/Traffic/CBR]  ;# Create Constant Bit Rate application
$app2 set packetSize_ 512               ;# Set Packet Size to 512 bytes
$app2 set rate_ 600Kb                   ;# Set CBR rate to 200 Kbits/sec
$app2 attach-agent $agent2              ;# Attach Application to agent

set agent3 [new Agent/UDP]              ;# Create TCP Agent
$agent3 set prio_ 2                     ;# Set Its priority to 2
# Create Loss Monitor Sink in order to be able to trace the number obytes received
set sink3 [new Agent/LossMonitor]        
$ns_ attach-agent $node_(4) $agent3     ;# Attach Agent to source node
$ns_ attach-agent $node_(5) $sink3      ;# Attach Agent to sink node
$ns_ connect $agent3 $sink3             ;# Connect the nodes
set app3 [new Application/Traffic/CBR]  ;# Create Constant Bit Rate application
$app3 set packetSize_ 512               ;# Set Packet Size to 512 bytes
$app3 set rate_ 600Kb                   ;# Set CBR rate to 200 Kbits/sec
$app3 attach-agent $agent3              ;# Attach Application to agent

set agent4 [new Agent/UDP]              ;# Create TCP Agent
$agent4 set prio_ 3                     ;# Set Its priority to 3
# Create Loss Monitor Sink in order to be able to trace the number obytes received
set sink4 [new Agent/LossMonitor]        
$ns_ attach-agent $node_(6) $agent4     ;# Attach Agent to source node
$ns_ attach-agent $node_(7) $sink4      ;# Attach Agent to sink node
$ns_ connect $agent4 $sink4             ;# Connect the nodes
set app4 [new Application/Traffic/CBR]  ;# Create Constant Bit Rate application
$app4 set packetSize_ 512               ;# Set Packet Size to 512 bytes
$app4 set rate_ 600Kb                   ;# Set CBR rate to 200 Kbits/sec
$app4 attach-agent $agent4              ;# Attach Application to agent

# defines the node size in Network Animator
for {set i 0} {$i < $val(nn)} {incr i} {
    $ns_ initial_node_pos $node_($i) 20
}

# Initialize Flags
set holdtime 0
set holdseq 0

set holdtime1 0
set holdseq1 0

set holdtime2 0
set holdseq2 0

set holdtime3 0
set holdseq3 0

set holdrate1 0
set holdrate2 0
set holdrate3 0
set holdrate4 0

# Function To record Statistcis (Bit Rate, Delay, Drop)
proc record {} {
       
global sink sink2 sink3 sink4 f0 f1 f2 f3 f4 f5 f6 f7 holdtime holdseq
holdtime1 holdseq1 holdtime2 holdseq2 holdtime3 holdseq3 f8 f9 f10 f11
holdrate1 holdrate2 holdrate3 holdrate4
        set ns [Simulator instance]
    set time 0.9 ;#Set Sampling Time to 0.9 Sec
        set bw0 [$sink set bytes_]
        set bw1 [$sink2 set bytes_]
        set bw2 [$sink3 set bytes_]
        set bw3 [$sink4 set bytes_]
        set bw4 [$sink set nlost_]
        set bw5 [$sink2 set nlost_]
        set bw6 [$sink3 set nlost_]
        set bw7 [$sink4 set nlost_]
        set bw8 [$sink set lastPktTime_]
        set bw9 [$sink set npkts_]
        set bw10 [$sink2 set lastPktTime_]
        set bw11 [$sink2 set npkts_]
        set bw12 [$sink3 set lastPktTime_]
        set bw13 [$sink3 set npkts_]
        set bw14 [$sink4 set lastPktTime_]
        set bw15 [$sink4 set npkts_]
       
    set now [$ns now]
        # Record Bit Rate in Trace Files
        puts $f0 "$now [expr (($bw0+$holdrate1)*8)/(2*$time*1000000)]"
        puts $f1 "$now [expr (($bw1+$holdrate2)*8)/(2*$time*1000000)]"
        puts $f2 "$now [expr (($bw2+$holdrate3)*8)/(2*$time*1000000)]"
        puts $f3 "$now [expr (($bw3+$holdrate4)*8)/(2*$time*1000000)]"
       
        # Record Packet Loss Rate in File
        puts $f4 "$now [expr $bw4/$time]"
        puts $f5 "$now [expr $bw5/$time]"
        puts $f6 "$now [expr $bw6/$time]"
        puts $f7 "$now [expr $bw7/$time]"
 
        # Record Packet Delay in File
        if { $bw9 > $holdseq } {
                puts $f8 "$now [expr ($bw8 - $holdtime)/($bw9 - $holdseq)]"
        } else {
                puts $f8 "$now [expr ($bw9 - $holdseq)]"
        }

        if { $bw11 > $holdseq1 } {
                puts $f9 "$now [expr ($bw10 - $holdtime1)/($bw11 - $holdseq1)]"
        } else {
                puts $f9 "$now [expr ($bw11 - $holdseq1)]"
        }

        if { $bw13 > $holdseq2 } {
                puts $f10 "$now [expr ($bw12 - $holdtime2)/($bw13 - $holdseq2)]"
        } else {
                puts $f10 "$now [expr ($bw13 - $holdseq2)]"
        }
 
        if { $bw15 > $holdseq3 } {
                puts $f11 "$now [expr ($bw14 - $holdtime3)/($bw15 - $holdseq3)]"
        } else {
                puts $f11 "$now [expr ($bw15 - $holdseq3)]"
        }

        # Reset Variables
        $sink set bytes_ 0
        $sink2 set bytes_ 0
        $sink3 set bytes_ 0
        $sink4 set bytes_ 0

        $sink set nlost_ 0
        $sink2 set nlost_ 0
        $sink3 set nlost_ 0
        $sink4 set nlost_ 0

        set holdtime $bw8
        set holdseq $bw9
        set  holdrate1 $bw0
        set  holdrate2 $bw1
        set  holdrate3 $bw2
        set  holdrate4 $bw3

    $ns at [expr $now+$time] "record"   ;# 定时采样的设置, 哈哈!
}
# set events for simulating!
$ns_ at 0.0 "record"
$ns_ at 1.4 "$app1 start"            
$ns_ at 10.0 "$app2 start"              
$ns_ at 20.0 "$app3 start"              
$ns_ at 30.0 "$app4 start"             

$ns_ at 80.0 "stop"
# Reset Nodes at time 80 sec
for {set i 0} {$i < $val(nn) } {incr i} {
    $ns_ at 80.0 "$node_($i) reset";
}

# Exit Simulatoion at Time 80.01 sec
$ns_ at 80.01 "puts /"NS EXITING.../" ; $ns_ halt"
proc stop {} {
        global ns_ tracefd f0 f1 f2 f3 f4 f5 f6 f7 f8 f9 f10 f11
        # Close Trace Files
        close $f0 
        close $f1
        close $f2
        close $f3
        close $f4 
        close $f5
        close $f6
        close $f7
        close $f8
        close $f9
        close $f10
        close $f11

        # Plot Recorded Statistics
        exec xgraph out02.tr out12.tr out22.tr out32.tr -geometry 800x400 &
        exec xgraph lost02.tr lost12.tr lost22.tr lost32.tr -geometry 800x400 &
        exec xgraph delay02.tr delay12.tr delay22.tr delay32.tr -geometry 800x400 &
        # Reset Trace File
        $ns_ flush-trace
        close $tracefd
        exit 0
}
puts "Starting Simulation..."
$ns_ run

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