User Guide

Wireless 300 Mbps PCI-Express Wi-Fi Adapter Wireless 300 Mbps PCI-Express Wi-Fi Adapter
User Manaul User ManaulRNX-N250PCEv2 RNX-N250PCEv2
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Appendix B: Glossary
• 802.11b - The 802.11b standard species a wireless product networking at 11 Mbps using
direct-sequence spread-spectrum (DSSS) technology and operating in the unlicensed radio
spectrum at 2.4 GHz and WEP encryption for security. 802.11b networks are also referred to
as Wi-Fi networks.
• 802.11g - Specication for wireless networking at 54 Mbps using direct-sequence spread-
spectrum (DSSS) technology, using OFDM modulation and operating in the unlicensed radio
spectrum at 2.4 GHz. Backward compatible with IEEE 802.11b devices and WEP encryption
for security.
• 802.11n - Builds upon previous 802.11 standards by adding MIMO (multiple-input multiple-
output). MIMO uses multiple transmitter and receiver antennas to allow for increased data
throughput via spatial multiplexing and increased range by exploiting the spatial diversity,
perhaps through coding schemes like Alamouti coding. The Enhanced Wireless Consortium
(EWC) was formed to help accelerate the IEEE 802.11n development process and promote a
technology specication for interoperability of next-generation wireless local area networking
(WLAN) products.
• 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 of 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 xed frequency is not used, and only the
transmitter and receiver know the hop patterns, interception of FHSS, is extremely difcult.
• 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 rst 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.
• SSID (Service Set Identication) - A thirty-two character (maximum) alphanumeric key
identifying a wireless local area network. For the wireless devices in a network to
communicate with each other, all devices must be congured with the same SSID.
This is typically the conguration parameter for a wireless PC card. It corresponds
to the ESSID in the wireless Access Point and to the wireless network name. See also
Wireless Network Name and ESSID.
• WEP (Wired Equivalent Privacy) - A data privacy mechanism based on a 64 or 128-bit or
152-bit shared key algorithm, as described in the IEEE 802.11 standard. To gain access to a
WEP network, you must know the key. The key is a string of characters that you create. When
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using WEP, you must determine the level of encryption. The type of encryption determines the
key length. 128-bit encryption requires a longer key than 64-bit encryption. Keys are dened
by entering in a string in HEX (hexadecimal - using characters 0-9, A-F) or ASCII (American
Standard Code for Information Interchange - alphanumeric characters) format. ASCII
format is provided so you can enter a string that is easier to remember.
The ASCII string is converted to HEX for use over the network. Four keys can be dened so
that you can change keys easily.
• Wi-Fi - A trade name for the 802.11b wireless networking standard, given by the Wireless
Ethernet Compatibility Alliance (WECA; see http://www.wi-.net), an industry standards group
promoting interoperability among 802.11b devices.
• WLAN (Wireless Local Area Network) - A group of computers and associated devices
communicating with each other wirelessly, which network serving users are limited in a local
area.
• WPA (Wi-Fi Protected Access) - A wireless security protocol using TKIP (Temporal Key
Integrity Protocol) encryption, which can be used in conjunction with a RADIUS server.