TP-LINK TL-WN7200ND User Manual

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TL-WN7200ND 
150Mbps High Power Wireless USB Adapter
 
User Guide
 
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Appendix A:  Glossary 
802.11b  - The 802.11b standard specifies a wireless networking at 11 Mbps using 
direct-sequence spread-spectrum (DSSS) technology and operating in the unlicensed radio 
spectrum at 2.4GHz, and WEP encryption for security. 802.11b networks are also referred to as 
Wi-Fi networks. 
802.11g  - Specification for wireless networking at 54 Mbps using direct-sequence 
spread-spectrum (DSSS) technology, using OFDM modulation and operating in the unlicensed 
radio spectrum at 2.4GHz, and backward compatibility with IEEE 802.11b devices, and WEP 
encryption for security. 
Ad-hoc Network - An ad-hoc network is a group of computers, each with a wireless adapter, 
connected as an independent 802.11 wireless LAN. Ad-hoc wireless computers operate on a 
peer-to-peer basis, communicating directly with each other without the use of an access point. 
Ad-hoc mode is also referred to as an Independent Basic Service Set (IBSS) or as peer-to-peer 
mode, and is useful at a departmental scale or SOHO operation. 
DSSS (Direct-Sequence Spread Spectrum) - DSSS generates a redundant bit pattern for all data 
transmitted. This bit pattern is called a chip (or chipping code). Even if one or more bits in the chip 
are damaged during transmission, statistical techniques embedded in the receiver can recover 
the original data without the need for retransmission. To an unintended receiver, DSSS appears 
as low power wideband noise and is rejected (ignored) by most narrowband receivers. However, 
to an intended receiver (i.e. another wireless LAN endpoint), the DSSS signal is recognized as the 
only valid signal, and interference is inherently rejected (ignored). 
FHSS  (Frequency  Hopping  Spread  Spectrum)  - FHSS continuously changes (hops) the carrier 
frequency of a conventional carrier several times per second according to a pseudo-random set of 
channels. Because a fixed frequency is not used, and only the transmitter and receiver know the 
hop patterns, interception of FHSS is extremely difficult. 
Infrastructure Network - An infrastructure network is a group of computers or other devices, 
each with a wireless adapter, connected as an 802.11 wireless LAN. In infrastructure mode, the 
wireless devices communicate with each other and to a wired network by first going through an 
access point. An infrastructure wireless network connected to a wired network is referred to as a 
Basic Service Set (BSS). A set of two or more BSS in a single network is referred to as an 
Extended Service Set (ESS). Infrastructure mode is useful at a corporation scale, or when it is 
necessary to connect the wired and wireless networks.   
Spread Spectrum - Spread Spectrum technology is a wideband radio frequency technique 
developed by the military for use in reliable, secure, mission-critical communications systems. It is 
designed to trade off bandwidth efficiency for reliability, integrity, and security. In other words, 
more bandwidth is consumed than in the case of narrowband transmission, but the trade off 
produces a signal that is, in effect, louder and thus easier to detect, provided that the receiver 
knows the parameters of the spread-spectrum signal being broadcast. If a receiver is not tuned to 
the right frequency, a spread-spectrum signal looks like background noise. There are two main 
alternatives, Direct Sequence Spread Spectrum (DSSS) and Frequency Hopping Spread