NS2上如何利用无线网络组播H.264/SVC视频

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本文转载网址：http://140.116.164.80/~smallko/ns2/svc_multicast.htm

[To Read before running this example]

Please refer to How to do H.264 SVC simulations? first. If you use this work, please add the following into your reference.

C. H. Ke, " myEvalSVC: an Integrated Simulation Framework for Evaluation of H.264/SVC Transmission ", KSII Transactions on Internet and Information Systems, vol. 6, no. 1, pp. 378-393, Jan. 2012 (SCI)

[Preparation]

1. To fix two bugs.

a. Go to /ns-allinone-2.29/ns-2.29/myvideo

b. Open myevalsvc.cc

c. Modify the code.

void myEvalSVC::timeout()

{

…………………..

if(x_ > 0){

for(i=0 ; i<x_; i++)

agent_->sendmsg(max_);

}

if(y_!=0)

agent_->sendmsg(y_);

……………………

}

d. Modify the prepare_receivedtrace1.awk

BEGIN{

i=0;

}

{

time=$1

frameno=$2

len=$3

lid=$4

tid=$5

qid=$6

if(frameno>i)

i=frameno;

FrameLen[frameno]+=len;

if(time>FrameRcvTime[frameno]){

FrameRcvTime[frameno]=time;

}

FrameLid[frameno]=lid;

FrameTid[frameno]=tid;

FrameQid[frameno]=qid;

}

END{

for(j=0;j<=i;j++)

if(FrameLen[j]!=0)

printf("%f\t%d\t%d\t%d\t%d\t%d\n", FrameRcvTime[j], FrameLen[j], FrameLid[j],FrameTid[j], FrameQid[j], j);

}

2. To install a multicast routing protocol for wireless networks. In this example, we use PUMA. (I port it into ns-2.29)

a. Modify the packet.h that is under /ns-allineone-2.29/ns-2.29/common

…………………………………..

// HDLC packet

PT_HDLC,

// added by smallko

PT_PUMA,

// insert new packet types here

PT_NTYPE // This MUST be the LAST one

…………………………………..

// XCP

name_[PT_XCP]="xcp";

//added by smallko

name_[PT_PUMA]="PUMA";

name_[PT_NTYPE]= "undefined";

…………………………………..

b. Modify the ns-lib.tcl that is under /ns-allinone-2.29/ns-2.29/tcl/lib

…………………………………..

AODV {

set ragent [$self create-aodv-agent $node]

}

PUMA {

set ragent [$self create-puma-agent $node]

}

TORA {

Simulator set IMEPFlag_ ON

set ragent [$self create-tora-agent $node]

}

…………………………………..

Simulator instproc create-aodv-agent { node } {

Create AODV routing agent

ragent [new Agent/AODV [$node node-addr]]

self at 0.0 "$ragent start" ;# start BEACON/HELLO Messages

ode set ragent_ $ragent

turn $ragent

}

Simulator instproc create-puma-agent { node } {

# Create PUMA routing agent

set ragent [new Agent/PUMA [$node node-addr]]

$self at 0.0 "$ragent start"

$node set ragent_ $ragent

return $ragent

}

…………………………………..

c. Modify the Makefile.in that is under /ns-allinone-2.29/ns-2.29

…………………………………..

xcp/xcpq.o xcp/xcp.o xcp/xcp-end-sys.o \

measure/mtcpsink.o measure/mudp.o measure/mudpsink.o \

myvideo/myevalvid.o myvideo/myevalvid_sink.o myvideo/my_udp.o myvideo/myfifo.o \

myvideo/myevalsvc.o myvideo/myevalsvc_sink.o \

noah/noah.o mac/forwarder.o \

puma/puma.o \

queue/dtrr-queue.o \

…………………………………..

d. Download svc_multicast.rar and decompress it.

e. You will find a puma folder and copy this folder to /ns-allinone-2.29/ns-2.29

f. Recompile.

$cd /ns-allinone-2.29/ns-2.29

$./configure; make clean; make depend; make

g. Test the puma protocol

$cd /ns-allineone-2.29/ns-2.29/puma

$ns puma.tcl

If there is no error, it means that you have successfully install puma.

[Simulation]

In this simple example, there are two nodes. One node sends the H.264/SVC video to the other node using multicast. Very simple.

When you decompress svc_multicast.rar, you will see ns_svc_multicast. Copy this folder to cygwin environment. (to C:\cygwin\home\smallko )

#===================================

# Simulation parameters setup

#===================================

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) 5000 ;# max packet in ifq

set val(nn) 2 ;# number of mobilenodes

set val(rp) PUMA ;# routing protocol

set val(x) 500 ;# X dimension of topography

set val(y) 500 ;# Y dimension of topography

set val(stop) 50.0 ;# time of simulation end

#===================================

# Initialization

#===================================

#Create a ns simulator

set ns [new Simulator]

#Setup topography object

set topo [new Topography]

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

set god_ [create-god $val(nn)]

#Open the NS trace file

set tracefile [open out.tr w]

$ns trace-all $tracefile

set tracenam [open out.nam w]

$ns namtrace-all-wireless $tracenam $val(x) $val(y)

set chan [new $val(chan)];#Create wireless channel

#===================================

# Mobile node parameter setup

#===================================

$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) \

-channel $chan \

-topoInstance $topo \

-agentTrace ON \

-routerTrace ON \

-macTrace ON \

-movementTrace OFF

#===================================

# Nodes Definition

#===================================

#Create 2 nodes

set n0 [$ns node]

$n0 set X_ 100

$n0 set Y_ 100

$n0 set Z_ 0.0

$ns initial_node_pos $n0 20

set n1 [$ns node]

$n1 set X_ 120

$n1 set Y_ 100

$n1 set Z_ 0.0

$ns initial_node_pos $n1 20

#===================================================

set max_fragmented_size 1500

set packetSize $max_fragmented_size

set src_udp1 [new Agent/my_UDP]

#set the multicast address and port number

$src_udp1 set dst_addr_ 0xE000000

$src_udp1 set dst_port_ 100

$src_udp1 set_filename sd

$src_udp1 set packetSize_ $packetSize

$ns attach-agent $n0 $src_udp1

set dst1_f0 [new Agent/myEvalSVC_Sink]

#Set the receiver port number

$n1 attach $dst1_f0 100

$dst1_f0 set_filename rd_n1_f0

set original_file_name ns2send

set trace_file_name video1.dat

set original_file_id [open $original_file_name r]

set trace_file_id [open $trace_file_name w]

set pre_time 0

while {[eof $original_file_id] == 0} {

gets $original_file_id current_line

scan $current_line "%f%d%d%d%d%d" t_ size_ lid_ tid_ qid_ fno_

set time [expr int(($t_ - $pre_time)*1000000.0)]

if { $tid_ == 0 } {

set prio_p 1

}

if { $tid_ == 1 } {

set prio_p 1

}

if { $tid_ == 2 } {

set prio_p 1

}

puts $trace_file_id "$time $size_ $lid_ $tid_ $qid_ $fno_ $prio_p$max_fragmented_size"

set pre_time $t_

}

close $original_file_id

close $trace_file_id

set trace_file [new Tracefile]

$trace_file filename $trace_file_name

set video1 [new Application/Traffic/myEvalSVC]

$video1 attach-agent $src_udp1

$video1 attach-tracefile $trace_file

Node instproc join { group } {

$self instvar ragent_

set group [expr $group]

$ragent_ join $group

}

Node instproc leave { group } {

$self instvar ragent_

set group [expr $group] ;

$ragent_ leave $group

}

#===================================

# Termination

#===================================

#Define a 'finish' procedure

proc finish {} {

global ns tracefile tracenam

$ns flush-trace

close $tracefile

close $tracenam

exit 0

}

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

$ns at $val(stop) "\$n$i reset"

}

$ns at 1.0 "$video1 start"

$ns at $val(stop) "$video1 stop"

$ns at 0.010000000000000 "$n1 join 0xE000000"

$ns at $val(stop) "$n1 leave 0xE000000"

$ns at $val(stop) "finish"

$ns at $val(stop) "puts \"done\" ; $ns halt"

$ns run

Click the cygwin icon on the desktop

$cd ns_svc_multicast

$ns test_svc_multicast.tcl

$awk –f prepare_receivedtrace1.awk rd_n1_f0 > ns2received

$./prepare_receivedtrace2.exe ns2send ns2received temporal_originaltrace-frameno.txt > received.txt

When you decompress svc_multicast.rar, you will see post_processing. Copy this folder to cygwin_new environment. (to C:\cygwin_new\home\smallko )

Please also copy the received.txt to the post_processing folder (C:\cygwin_new\home\smallko\ post_processing)

Click the cygwin_new icon on the desktop

$nalufilter temporal_originaltrace-frameno.txt received.txt 15000 30 > filteredtrace.txt

$BitStreamExtractorStatic.exe temporal.264 temporal-filter.264 –et filteredtrace.txt

$H264AVCDecoderLibTestStatic.exe temporal-filter.264 temporal-filter.yuv

$framefilter filteredtrace.txt 152064 300 temporal-filter.yuv temporal-conceal.yuv

$PSNRStatic.exe 352 288 foreman_cif temporal-conceal.yuv

From the simulation result, you can see that the PSNR is not good as you expect. This is because that multicast sender does not need any acknowledgement from the receiver. Consequently, when the collision occurs, sender does not know that the collision happens and then to retransmit.

In this example, n0 sends to n1. n1 forwards the received packets. Therefore, the packets sent by n0 and n1 may get collided.

So interested readers can think how to improve the protocol to make the performance better.