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<html><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final//EN"><!--Converted with jLaTeX2HTML 2002 (1.62) JA patch-1.4patched version by: Kenshi Muto, Debian Project.LaTeX2HTML 2002 (1.62),original version by: Nikos Drakos, CBLU, University of Leeds* revised and updated by: Marcus Hennecke, Ross Moore, Herb Swan* with significant contributions from: Jens Lippmann, Marek Rouchal, Martin Wilck and others --><HTML><HEAD><TITLE>18.4 Communication range</TITLE><META NAME="description" CONTENT="18.4 Communication range"><META NAME="keywords" CONTENT="everything"><META NAME="resource-type" CONTENT="document"><META NAME="distribution" CONTENT="global"><META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=iso-8859-1"><META NAME="Generator" CONTENT="jLaTeX2HTML v2002 JA patch-1.4"><META HTTP-EQUIV="Content-Style-Type" CONTENT="text/css"><LINK REL="STYLESHEET" HREF="everything.css" tppabs="http://www.isi.edu/nsnam/ns/doc/everything.css"><LINK REL="next" HREF="node222.html" tppabs="http://www.isi.edu/nsnam/ns/doc/node222.html"><LINK REL="previous" HREF="node218.html" tppabs="http://www.isi.edu/nsnam/ns/doc/node218.html"><LINK REL="up" HREF="node215.html" tppabs="http://www.isi.edu/nsnam/ns/doc/node215.html"><LINK REL="next" HREF="node222.html" tppabs="http://www.isi.edu/nsnam/ns/doc/node222.html"></HEAD><BODY ><!--Navigation Panel--><A NAME="tex2html4660" HREF="node222.html" tppabs="http://www.isi.edu/nsnam/ns/doc/node222.html"><IMG WIDTH="37" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="next" SRC="file:/usr/share/latex2html/icons/next.png"></A> <A NAME="tex2html4654" HREF="node215.html" tppabs="http://www.isi.edu/nsnam/ns/doc/node215.html"><IMG WIDTH="26" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="up" SRC="file:/usr/share/latex2html/icons/up.png"></A> <A NAME="tex2html4648" HREF="node220.html" tppabs="http://www.isi.edu/nsnam/ns/doc/node220.html"><IMG WIDTH="63" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="previous" SRC="file:/usr/share/latex2html/icons/prev.png"></A> <A NAME="tex2html4656" HREF="node1.html" tppabs="http://www.isi.edu/nsnam/ns/doc/node1.html"><IMG WIDTH="65" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="contents" SRC="file:/usr/share/latex2html/icons/contents.png"></A> <A NAME="tex2html4658" HREF="node590.html" tppabs="http://www.isi.edu/nsnam/ns/doc/node590.html"><IMG WIDTH="43" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="index" SRC="file:/usr/share/latex2html/icons/index.png"></A> <BR><B> Next:</B> <A NAME="tex2html4661" HREF="node222.html" tppabs="http://www.isi.edu/nsnam/ns/doc/node222.html">18.5 Commands at a</A><B> Up:</B> <A NAME="tex2html4655" HREF="node215.html" tppabs="http://www.isi.edu/nsnam/ns/doc/node215.html">18. Radio Propagation Models</A><B> Previous:</B> <A NAME="tex2html4649" HREF="node220.html" tppabs="http://www.isi.edu/nsnam/ns/doc/node220.html">18.3.2 Using shadowing model</A>   <B> <A NAME="tex2html4657" HREF="node1.html" tppabs="http://www.isi.edu/nsnam/ns/doc/node1.html">Contents</A></B>   <B> <A NAME="tex2html4659" HREF="node590.html" tppabs="http://www.isi.edu/nsnam/ns/doc/node590.html">Index</A></B> <BR><BR><!--End of Navigation Panel--><H1><A NAME="SECTION031540000000000000000"></A><A NAME="sec:commrange"></A><BR>18.4 Communication range</H1><P>In some applications, a user may want to specify the communication range ofwireless nodes. This can be done by set an appropriate value of the receivingthreshold in the network interface, ,<P><PRE>Phy/WirelessPhy set RXThresh_ \<value\></PRE><P>A separate C program is provided at indep-utils/propagation/threshold.ccto compute the receiving threshold. It can be used for all thepropagation models discussed in this chapter. Assume you have compiled it and getthe excutable named as <TT>threshold</TT>. You can use it to compute the thresholdas follows<P><PRE>threshold -m \<propagation-model\> [other-options] distance</PRE><P>where <TT>propagation-model</TT> is either <TT>FreeSpace</TT>, <TT>TwoRayGround</TT>or <TT>Shadowing</TT>, and the <TT>distance</TT> is the communication range in meter.<P><TT>[other-options]</TT> are used to specify parameters other than theirdefault values. For the shadowing model there is a necessary parameter,<TT>-r receive-rate</TT>, which specifies the rate of correct reception at the<TT>distance</TT>. Because the communication range in the shadowing model is notan ideal circle, an inverse Q-function [<A HREF="node589.html#Rappaport96" tppabs="http://www.isi.edu/nsnam/ns/doc/node589.html#Rappaport96">30</A>] is used to calculate thereceiving threshold. For example, if you want 95% of packets can be correctlyreceived at the distance of 50m, you can compute the threshold by<P><PRE>threshold -m Shadowing -r 0.95 50</PRE><P>Other available values of <TT>[other-options]</TT> are shown below<P><PRE>-pl \<path-loss-exponent\> -std \<shadowing-deviation\> -Pt \<transmit-power\>-fr \<frequency\> -Gt \<transmit-antenna-gain\> -Gr \<receive-antenna-gain\>-L \<system-loss\> -ht \<transmit-antenna-height\> -hr \<receive-antenna-height\>-d0 \<reference-distance\></PRE><P><HR><!--Navigation Panel--><A NAME="tex2html4660" HREF="node222.html" tppabs="http://www.isi.edu/nsnam/ns/doc/node222.html"><IMG WIDTH="37" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="next" SRC="file:/usr/share/latex2html/icons/next.png"></A> <A NAME="tex2html4654" HREF="node215.html" tppabs="http://www.isi.edu/nsnam/ns/doc/node215.html"><IMG WIDTH="26" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="up" SRC="file:/usr/share/latex2html/icons/up.png"></A> <A NAME="tex2html4648" HREF="node220.html" tppabs="http://www.isi.edu/nsnam/ns/doc/node220.html"><IMG WIDTH="63" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="previous" SRC="file:/usr/share/latex2html/icons/prev.png"></A> <A NAME="tex2html4656" HREF="node1.html" tppabs="http://www.isi.edu/nsnam/ns/doc/node1.html"><IMG WIDTH="65" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="contents" SRC="file:/usr/share/latex2html/icons/contents.png"></A> <A NAME="tex2html4658" HREF="node590.html" tppabs="http://www.isi.edu/nsnam/ns/doc/node590.html"><IMG WIDTH="43" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="index" SRC="file:/usr/share/latex2html/icons/index.png"></A> <BR><B> Next:</B> <A NAME="tex2html4661" HREF="node222.html" tppabs="http://www.isi.edu/nsnam/ns/doc/node222.html">18.5 Commands at a</A><B> Up:</B> <A NAME="tex2html4655" HREF="node215.html" tppabs="http://www.isi.edu/nsnam/ns/doc/node215.html">18. Radio Propagation Models</A><B> Previous:</B> <A NAME="tex2html4649" HREF="node220.html" tppabs="http://www.isi.edu/nsnam/ns/doc/node220.html">18.3.2 Using shadowing model</A>   <B> <A NAME="tex2html4657" HREF="node1.html" tppabs="http://www.isi.edu/nsnam/ns/doc/node1.html">Contents</A></B>   <B> <A NAME="tex2html4659" HREF="node590.html" tppabs="http://www.isi.edu/nsnam/ns/doc/node590.html">Index</A></B> <!--End of Navigation Panel--><ADDRESS>2003-09-23</ADDRESS></BODY></HTML>⌨️ 快捷键说明
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