学步园

为了自己的MANET研究，最近一直做网络仿真。第一步就想做一个DSR路由协议的模拟。遗憾的是，例子中的代码实在是太简单了，根本没有实现多跳功能。网上找了不少版本，均有相应的问题，有的run起来数据通信太小，根本看不到多跳，有的压根就无法看到数据通信。

 

综合了一下网上的版本，修改了其中的错误，把NS2安装目录下的wireless-mitf.tcl做一下修正，分享一个可以看到多跳的基于DSR路由的模拟脚本。相信对于刚入门想做这个的人会有帮助。

 

脚本名字为multi-hop.tcl，生成的动画文件为multi_hop.nam。

#Copyright (c) 1997 Regents of the University of California.
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
# 1. Redistributions of source code must retain the above copyright
#    notice, this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright
#    notice, this list of conditions and the following disclaimer in the
#    documentation and/or other materials provided with the distribution.
# 3. All advertising materials mentioning features or use of this software
#    must display the following acknowledgement:
#      This product includes software developed by the Computer Systems
#      Engineering Group at Lawrence Berkeley Laboratory.
# 4. Neither the name of the University nor of the Laboratory may be used
#    to endorse or promote products derived from this software without
#    specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
# ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
# SUCH DAMAGE.
#
# $Header: /cvsroot/nsnam/ns-2/tcl/ex/wireless-mitf.tcl,v 1.2 2000/08/30 00:10:45 haoboy Exp $
#
# Simple demo script for the new APIs to support multi-interface for 
# wireless node.
#
# Define options
# Please note: 
# 1. you can still specify "channelType" in node-config right now:
# set val(chan)           Channel/WirelessChannel
# $ns_ node-config ...
#   -channelType $val(chan)
#                  ...
# But we recommend you to use node-config in the way shown in this script
# for your future simulations. 
# 
# 2. Because the ad-hoc routing agents do not support multiple interfaces
#    currently, this script can't generate anything interesting if you config
#    the interfaces of node 1 and 2 on different channels
#   
#     --Xuan Chen, USC/ISI, July 21, 2000
#
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

# 如果用DSR，则需要用CMUPriQueue队列，否则用Queue/DropTail/PriQueue
set val(ifq)            CMUPriQueue                ;#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)             3                          ;# number of mobilenodes
#set val(rp)             DSDV                       ;# routing protocol
set val(rp)             DSR                       ;# routing protocol
set val(x)   500
set val(y)   500

# Initialize Global Variables
set ns_   [new Simulator]
set tracefd     [open multi_hop.tr w]
$ns_ trace-all $tracefd

set namtrace [open multi_hop.nam w]
$ns_ namtrace-all-wireless $namtrace $val(x) $val(y)

# set up topography object
set topo       [new Topography]

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

# Create God
# 这几句和下面的god set set-dist相关
# 我觉得不要手动设置最短路径也行的。
#set god [create-god $val(nn)]

create-god $val(nn)

# New API to config node: 
# 1. Create channel (or multiple-channels);
# 2. Specify channel in node-config (instead of channelType);
# 3. Create nodes for simulations.

# Create channel #1 and #2
set chan_1_ [new $val(chan)]
set chan_2_ [new $val(chan)]
set chan_3_ [new $val(chan)]
# Create node(0) "attached" to channel #1

# configure node, please note the change below.
$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 ON /
   -routerTrace ON /
   -macTrace ON /
   -movementTrace OFF /
   -channel $chan_1_

set node_(0) [$ns_ node]

# node_(1) can also be created with the same configuration, or with a different
# channel specified.
# Uncomment below two lines will create node_(1) with a different channel.
# $ns_ node-config /
#   -channel $chan_2_ 
set node_(1) [$ns_ node]

set node_(2) [$ns_ node]

$node_(0) random-motion 0
$node_(1) random-motion 0
$node_(2) random-motion 0

#
# Provide initial (X,Y, for now Z=0) co-ordinates for mobilenodes
# 设置节点的初始位置
# 注意设置节点位置的代码必须放到设置节点大小的代码前面
$node_(0) set X_ 0.0
$node_(0) set Y_ 0.0
$node_(0) set Z_ 0.0

$node_(1) set X_ 300.0
$node_(1) set Y_ 255.0
$node_(1) set Z_ 0.0

$node_(2) set X_ 100.0
$node_(2) set Y_ 100.0
$node_(2) set Z_ 0.0

# $god set set-dist 0 2 2
# $god set set-dist 0 1 1
# $god set set-dist 1 2 1

# 注意这点代码必须放到上述设置节点位置的后面
# 不然的话，初始的节点会混到一起，居然有这个bug
for {set i 0} {$i < $val(nn)} {incr i} {
# 设置节点的大小
$ns_ initial_node_pos $node_($i) 30
}

#
# Now produce some simple node movements
# Node_(1) starts to move towards node_(0)
#
$ns_ at 3.0 "$node_(0) setdest 48.0 38.0 5.0"
$ns_ at 3.0 "$node_(1) setdest 220.0 50.0 25.0"
$ns_ at 3.0 "$node_(2) setdest 450.0 400.0 8.0"

# Node_(1) then starts to move away from node_(0)
$ns_ at 20.0 "$node_(2) setdest 490.0 480.0 30.0"

# Setup traffic flow between nodes
# TCP connections between node_(0) and node_(2)

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
set ftp [new Application/FTP]
$ftp attach-agent $tcp
$ns_ at 3.0 "$ftp start"

#
# Tell nodes when the simulation ends
#
for {set i 0} {$i < $val(nn) } {incr i} {
    $ns_ at 30.0 "$node_($i) reset";
}
$ns_ at 30.0 "stop"
$ns_ at 30.01 "puts /"NS EXITING.../" ; $ns_ halt"
proc stop {} {
    global ns_ tracefd
    $ns_ flush-trace
    close $tracefd
}

puts "Starting Simulation..."
$ns_ run

 

说明，上述脚本中，生成了3个无线网络节点，都处于运动状态。最后第三个节点node2跑出了node0和node1的范围。本脚本模拟了网络由一跳到二跳到最终分裂的过程。

但愿对相应需求的和我一样的初学者能少走弯路