r146 - community/trunk/en-US

[sradvan at fedoraproject.org]

Author: sradvan
Date: 2010-07-01 04:13:41 +0000 (Thu, 01 Jul 2010)
New Revision: 146

Modified:
   community/trunk/en-US/Communication.xml
Log:


Modified: community/trunk/en-US/Communication.xml
===================================================================
--- community/trunk/en-US/Communication.xml	2010-07-01 01:38:18 UTC (rev 145)
+++ community/trunk/en-US/Communication.xml	2010-07-01 04:13:41 UTC (rev 146)
@@ -4,23 +4,30 @@
 
 <chapter id="chap-Wireless_Guide-Communication">
         <title>Wireless Communication</title>
-        <para>
-	stuff	
-        </para>
 <section id="sect-Wireless_Guide-Hardware-Data_Rates_and_Throughput">
 <title>Data Rates and Throughput</title>
 			<para>
-				Several metrics and measurements are used to define elements of wireless LANs. Some of these include terms to define data rate, throughput, signal to noise ratio, antenna gain, signal loss and encryption strength. One commonly misunderstood set of measurements is <emphasis>data rate</emphasis> and <emphasis>throughput</emphasis>. To use the IEEE 802.11g standard as an example, it is often referred to and marketed as having a 54Mbps (megabits/s) connection speed. This is however only a theoretical maximum speed under perfect conditions defined in the standard. Unfortunately, the real world is not a perfect environment, and in some cases can be outright hostile to facilitating wireless communication.
+				Several metrics and measurements are used to define elements of a WLAN, such as data rate, throughput, signal to noise ratio (SNR), antenna gain, signal loss and encryption strength. One commonly misunderstood concept is the relationship between <emphasis>data rate</emphasis> and <emphasis>throughput</emphasis>.
 			</para>
 			<para>
-				Continuing to use the IEEE 802.11g standard to define these terms, the standard is actually capable of negotiating its connection with other devices at several different <emphasis>data rates</emphasis>. This ability to change data rates is known as <command>Dynamic Rate Switching</command>, and a properly functioning card will negotiate the best possible speed depending on the distance from the Access Point, the amount and type of other devices that are connecting, and overall environmental conditions. 
+				To use the IEEE 802.11g standard as an example, which is often referred to and marketed as having a 54Mbps (megabits/s) connection speed, this is only a theoretical maximum speed under perfect conditions defined in the standard. Unfortunately, the real world is not a perfect environment, and in some cases can be outright hostile to facilitating wireless communication.
 			</para>
-			<para>The IEEE 802.11g standard can operate under the following data rates: 6, 9, 12, 18, 24, 36, 48 and 54 Mbps, and can use 802.11b speeds if in a mixed-mode environment. This series of speeds, and the current connected rate is usually intepreted in a graphical form in your operating system as a graph or bar or other text, representing signal strength (this is known as the <command>Received Signal Strength Indicator</command>). So, while the standard defines 54Mbps as the maximum speed, the data rate is actually negotiating one of the above speeds based on environmental conditions. This data rate is related to, but different from the <emphasis>actual amount</emphasis> of network data coming through the connection at any given time. This actual data transfer speed is known as <emphasis>throughput</emphasis>.
+			<para>
+				The full 54Mbps throughput as defined in the standard never be achieved in the real world. Your actual throughput of network data is typically 15% to 40% of this marketed level. <emphasis>Data rate</emphasis> is the negotiated, variable, maximum possible link to other devices, and <emphasis>throughput</emphasis> is the real-world, measured amount of actual data flow.
 			</para>
+</section>
+<section id="sect-Wireless_Guide-Hardware-Dynamic_Rate_Switching">
+<title>Dynamic Rate Switching</title>
 			<para>
-				As mentioned, the full 54Mbps throughput as defined in the standard can never be achieved in the real world. Your actual throughput of network data is typically 15-40% of this maximum level. <emphasis>Data rate</emphasis> is the negotiated, variable, maximum possible link to other devices, and <emphasis>throughput</emphasis> is the real-world speed of actual data flow.
+				Continuing to use the IEEE 802.11g standard to define these terms, a wireless client is capable of negotiating its connection with other devices at several different <emphasis>data rates</emphasis>. This ability to change data rates is known as <command>Dynamic Rate Switching</command>, and a properly functioning client will be able to negotiate the best possible, theoretical speed depending on the distance from the Access Point, the amount and type of other devices that are connecting, and overall environmental conditions.  The IEEE 802.11g standard can operate under the following data rates: 6, 9, 12, 18, 24, 36, 48 and 54 Mbps, and can use 802.11b data rates if in a mixed-mode environment. 
 			</para>
 </section>
+<section id="sect-Wireless_Guide-Hardware-Received_Signal_Strength_Indicator">
+<title>Received Signal Strength Indicator</title>
+			<para>
+This series of speeds used in Dynamic Rate Switching, and the current connected rate is usually intepreted in some sort of graphical form in your operating system as a graph or bar or other explanatory text. This is known as the <command>Received Signal Strength Indicator</command> (RSSI).
+			</para>
+</section>
 <section id="sect-Wireless_Guide-Hardware-Connection_Modes">
 <title>Connection Modes</title>
 			<para>