10BaseT
The most common cabling method for Ethernet. 10BaseT conforms to IEEE standard 802.3. It was
developed to enable data communications over unshielded twisted pair (telephone) wiring at speeds of up
to 10 megabits per second up to distances of approximately 330 feet on a network segment. (See
Ethernet).
3G
The term refers to digital, packet-switched technology and is used to describe the third-generation of
mobile telephony which brings video and broadband Internet access to mobile phones. The first generation
was represented by analog cellular phones and the second generation by digital cellular networks.
802.11
A group of wireless networking standards, also known as Wi-Fi, set by the Institute of Electrical and
Electronics Engineers (IEEE). (See IEEE).
802.11a
An IEEE standard for a wireless network that operates at 5 GHz with rates up to 54Mbps.
802.11b
An IEEE standard for a wireless network that operates at 2.4 GHz with rates up to 11Mbps.
802.11d
An IEEE specification that allows for configuration changes at the Media Access Control layer (MAC layer)
level to comply with the rules of the country in which the network is to be used. (See MAC).
802.11e
An IEEE standard that adds Quality of Service (QoS) features and multimedia support to the existing
802.11b, 802.11g, and 802.11a wireless networks. (See QoS, WMM).
802.11g
An IEEE standard for a wireless network that operates at 2.4 GHz Wi-Fi with rates up to 54Mbps.
802.11h
802.11h supports Dynamic Frequency Selection(DFS) and Transmit Power Control(TPC) requirements to
ensure coexistence between Wi-Fi and other types of radio frequency devices in the 5 GHz band.
802.11i
An IEEE standard specifying security mechanisms for 802.11 networks. 802.11i makes use of the
Advanced Encryption Standard (AES) block cipher. The standard also includes improvements in key
management, user authentication through 802.1X and data integrity of headers. (See 802.1X, AES,
WPA2).
802.11j
An IEEE specification for wireless networks that incorporates Japanese regulatory requirements
concerning wireless transmitter output power, operational modes, channel arrangements and spurious
emission levels.
802.11n
A taskgroup of the IEEE 802.11 committee whose goal is to define a standard for high throughput speeds
of at least 100Mbps on wireless networks. The standard is expected to be ratified by 2007. Some
proposals being fielded by the taskgroup include designs for up to 540 Mbps. Multiple-Input-Multiple-
Output (MIMO) technology, using multiple receivers and multiple transmitters in both the client and access
point to achieve improved performance is expected to form the basis of the final specification. (See Mbps,
MIMO).
802.1X
A standard for port-based authentication, first used in wired networks, that was adapted for use in
enterprise WLANs to address security flaws in WEP, the original security specification for 802.11 networks.
802.1X provides a framework for authenticating users and controlling their access to a protected network
and dynamic encryption keys to protect data privacy. (See EAP, WEP, WPA, WPA2).
802.3
The standard defining wired Ethernet networks. (See Ethernet).
Ad-Hoc mode
An old term used to describe a device-to-device network. (See device-to-device network, peer-to-peer
network).
AES
Advanced Encryption Standard. The preferred standard for the encryption of commercial and government
data using a symmetric block data encryption technique. It is used in the implementation of WPA2. (See
802.11i, WPA2).
AP
Access point. A device that connects wireless devices to another network, that being a wireless LAN,
Internet Modem or others.
Applet
A small application or utility program, usually written In the Java programming language that is designed to
do a very specific and limited task. Applets are most commonly used in hand-held mobile devices.
Application software
A computer program that is designed to do a general operational task such as word processing or payroll.
Internet browsers and graphic design programs are also considered applications. Application software runs
on top of the operating system.
Association
Describes the establishment and maintenance of the wireless link between devices. (If security is enabled,
the devices cannot do anything but exchange security credentials with this link). (See authentication).
Authentication
The process that occurs after association to verify the identity of the wireless device or end user and allow
access to the network. (See association, 802.1X, WPA, WPA2).
Backbone
The central part of a large network that links two or more sub-networks. The backbone is the primary data
transmission path on large networks such as those of enterprises and service providers. A backbone can
be wireless or wired.
Bandwidth
The maximum transmission capacity of a communications channel at any point in time. Bandwidth, usually
measured in bits per second (bps), determines the speed at which information can be sent across a
network. If you compare the communications channel to a pipe, bandwidth represents the pipe width and
determines how much data can flow through the pipe at any one time. The greater the bandwidth, the
faster data can flow. (See bps).
Bluetooth wireless technology
A technology designed for short-range, wireless communications among computing devices and mobile
products, including PCs and laptop computers, personal digital assistants, printers, and mobile phones.
Designed as a cable-replacement, Bluetooth enables short-range transmission of voice and data in the 2.4
GHz frequency spectrum within a range of about 30 feet. (See WPAN).
bps
Bits per second. A measure of data transmission speed across a network or communications channel; bps
is the number of bits that can be sent or received per second. It measures the speed at which data is
communicated and should not be—but often is—confused with bytes per second (Bps, in this reference the
B is capitalized while in bps lower case is used). While "bits" is a measure of transmission speed, "bytes" is
a measure of storage capacity. (See bandwidth, Mbps).
Bridge
A wireless device that connects multiple networks together. (See router).
Broadband
A comparatively fast Internet connection possessing sufficient bandwidth to accommodate multiple voice,
data and video channels simultaneously. Cable, DSL and satellite are all considered to be broadband
channels; they provide much greater speed than dial-up Internet access over telephone wires. (See cable
modem, DSL). Broadband modem
A device that connects a local computer or network to a high-speed Internet service, such as DSL or Cable
Internet. (See cable modem, DSL).
BSSID
Basic Service Set Identifier. A unique address that identifies the access point/router that creates the
wireless network. (See SSID).
Bus adapter
A special adapter card that installs in a PC's PCI or ISA slot and enables the use of PC Card radios in
desktop computers. Some companies offer one-piece PCI or ISA Card radios that install directly into an
open PC or ISA slot.
Cable modem
A device used with broadband Internet service provided by a traditional cable TV service. Cable modems
convert analog data from the cable TV system into a digital format that can be used by a computer. (See
broadband modem).
Channel
One portion of the available radio spectrum that all devices on a wireless network use to communicate.
Changing the channel on the access point/router can help reduce interference.
Client
Any computer connected to a network that requests files and services (files, print capability) from the
server or other devices on the network. The term also refers to end users. (See AP).
Client devices
Wi-Fi client devices include PC Cards that slide into laptop computers, mini-PCI modules embedded in
laptop computers and mobile computing devices, as well as USB radios and PCI/ISA bus Wi-Fi radios.
Client devices usually communicate with hub devices like access points and gateways. (See AP, client).
Collision avoidance
A means of proactively detecting whether a node on an Ethernet network can transmit a signal without risk
that it will collide with other traffic on the network. (See CSMA/CA, CSMA/CD).
Crossover cable
A twisted-pair cable used to network two computers without use of a hub. Instead of traveling in direct
parallel paths between plugs, the signals "crossover," reversing the sending and receiving wire pairs on
each end. Crossover cables may be required to connect a cable or DSL modem to a wireless router or
access point.
CSMA/CA
Carrier Sense Multiple Access/Collision Avoidance. The principal media access control strategy used in
802.11 networks to avoid data collisions. It is a “listen before talk” method of minimizing collisions. The
network node checks to see if the transmission channel is clear before a data packet is sent. (See collision
avoidance, CSMA/CD).
CSMA/CD
Customer Sense Multiple Access/Collision Detection. The principal media access control strategy used to
manage traffic and reduce noise on wired Ethernet networks. It allows a network device to transmit data
after detecting a channel is available. If two devices transmit data simultaneously, the sending device
detects the collision of data packets and retransmits after a random time delay. (See collision avoidance,
CSMA/CA).
DC power module
Modules that convert Alternate Current (AC) power to Direct Current (DC) for the operation of electronic
and computer equipment. Depending on the manufacturer and product, these modules can range from
typical "wall wart" transformers that plug into a wall socket to larger, enterprise-level Power Over Ethernet
systems that inject DC power into the Ethernet cables to provide power to the access points.
Device-to-device network
Two or more devices that connect using wireless network devices without the use of a centralized wireless
access point. Also known as a peer-to-peer network. (See ad hoc mode, Peer-to-peer network).
DHCP
Dynamic Host Configuration Protocol. A protocol for dynamically assigning IP addresses from a predefined
list to nodes on a network. When they log on, network nodes automatically receive an IP address
from a pool of addresses served by a DHCP. The DHCP server provides (or leases) an IP address (to a
client for a specific period of time. The client will automatically request a renewal of the lease when the
lease is about to run out. If a lease renewal is not requested and it expires, the address is returned to the
pool of available IP addresses. Using DHCP to manage IP addresses simplifies client configuration and
efficiently utilizes IP addresses. (See IP address).
Dial-up
A connection to a remote network, or the Internet, using a standard modem and telephone connection, or
Plain Old Telephone Service (POTS). (See POTS).
Diversity antenna
An antenna system that uses multiple antennas to reduce interference and maximize reception and
transmission quality.
DNS
Domain Name Service. An Internet service that translates alphanumeric domain names to assigned IP
addresses and vice versa. The term is typically used to describe the server which makes the translation.
Every website has its own specific IP address on the Internet. DNS typically refers to a database of
Internet names and addresses which translates the alpha-numeric names to the official Internet Protocol
numbers and vice versa. For instance, a DNS server converts a name like mywebsite.com to a series of
numbers like 107.22.55.26. (See IP, IP address).
DSL
Digital Subscriber Line. A dedicated digital circuit between a residence or business and a telephone
company's central office. It allows high-speed data, voice and video transmissions over existing twistedpair
copper Plain Old Telephone Service (POTS) telephone wires. (See broadband, POTS).
Dual-band
A device that is capable of operating in two frequencies. On a wireless network, dual-band devices are
capable of operating in both the 2.4 GHz (802.11b/g) and 5 GHz (802.11a) bands. In cellular phone
technology, dual-band devices typically operate in both the GSM900 and GSM1800 frequencies, allowing
a greater number of roaming options. (See Tri-mode).
EAP
Extensible Authentication Protocol. A protocol that provides an authentication framework for both wireless
and wired Ethernet enterprise networks. It is typically used with a RADIUS server to authenticate users on
large networks. EAP protocol types are used in the 802.1X-based authentication in WPA-Enterprise and
WPA2-Enterprise. (See 802.1X, EAP, LEAP, RADIUS, TLS, WPA-Enterprise, WPA2-Enterprise).
EAP-SIM
Specifies a mechanism for mutual authentication and session key agreement using the GSM-SIM and
used in GSM-based mobile phone networks.
EAP-TLS
Extensible Authentication Protocol Transport Layer Security
EAP-TTLS/MSCHAPv2
EAP-Tunneled TLS/Microsoft Challenge Authentication Handshake Protocol. Securely tunnels clients
authentication within TLS records
Encryption
A mechanism for providing data confidentiality. (See 802.11i, RC4, TKIP, WEP, WPA, WPA2).
Enterprise
Any large corporation, business or organization. The enterprise market can incorporate office buildings,
manufacturing plants, warehouses and research and development facilities, as well as large colleges and
universities.
ESSID
Extended Service Set Identifier. A name used to identify a wireless network. (See SSID, network name).
Ethernet
The most popular international standard technology for wired Local Area Networks (LANs). It provides from
10 Mbps transmission speeds on basic 10BastT Ethernet networks to 100 Mbps transmission speeds on
Fast Ethernet networks, 1000 Mbps on Gigabit Ethernet, and 10,000 Mbps on 10 Gigabit Ethernet. (See
802.3)
FIPS 140-2
The Federal Information Processing Standard that defines the requirements of security technologies used
in the handling and processing of information within government agencies. (See 802.11i, AES, WPA2).
Firewall
A system of software and/or hardware that resides between two networks to prevent access by
unauthorized users. The most common use of a firewall is to provide security between a local network and
the Internet. Firewalls can make a network appear invisible to the Internet and can block unauthorized and
unwanted users from accessing files and systems on the network. Hardware and software firewalls monitor
and control the flow of data in and out of computers in both wired and wireless enterprise, business and
home networks. They can be set to intercept, analyze and stop a wide range of Internet intruders and
hackers. (See Intrusion detection).
FireWire
A high-speed serial bus system defined by the IEEE 1394 standard for input/output technology that
connects multimedia and storage peripherals to a PC. FireWire is similar to USB (Universal Serial Bus)
and can provide a bandwidth of about 400 Mbps. FireWire was the original brand name for Apple
Computer’s implementation of the specification. Today many Windows systems have FireWire capabilities,
as well. Other names for products that perform the same function include 1394 (Linux) and iLink (Sony).
Firmware
Software routines that are embedded as read-only memory (ROM) in a computer chip or hardware device
to prevent modification of the routines. Unlike random access memory (RAM), read-only memory stays
intact in the absence of electrical power. Startup routines and low-level input/output instructions are stored
in firmware.
Gateway
In the wireless world, a gateway is an access point with additional software capabilities such as providing
NAT and DHCP. Gateways may also provide VPN support, roaming, firewalls, various levels of security,
etc.
GPRS
General Packet Radio Service. A radio technology used in GSM networks that transmits digital data
packets, much like Internet protocols do, for both voice and data without the need of a dedicated circuit for
always-on access to data. This allows for more efficient communication and faster data rates. (See 3G,
GSM).
GPS
Global Positioning System. A system that uses satellites, receivers and software to allow users to
determine their precise geographic position. (See War driving).
GSM
Groupe Speciale Mobile, or Global System for Mobile Communications. A 2G digital standard for cellular
phone communications adopted by many countries around the world. Its frequency bands range from 900-
1800MHz. (See 3G, GPRS).
Hotspot
A location where users can access the Internet using Wi-Fi laptops and other Wi-Fi enabled devices.
Access may be provided free or for a fee. Hotspots are often found at coffee shops, hotels, airport lounges,
train stations, convention centers, gas stations, truck stops and other public meeting areas. Corporations
and campuses often offer it to visitors and guests. Hotspot service is sometimes available aboard planes,
trains and boats. (See Wi-Fi ZONE™).
Hub
A multi-port device used to connect client devices to a wired Ethernet network. Hubs can have numerous
ports and can transmit data at speeds ranging from 10 to 1000 Mbps per second to all the connected ports.
A small wired hub may only connect 4 computers; a large hub can connect 48 or more. (See Router).
HZ
Hertz, not the car rental company. The international unit for measuring frequency equivalent to the older
unit of cycles per second. One megahertz (MHz) is one million hertz. One gigahertz (GHz) is one billion
hertz. The standard US electrical power frequency is 60 Hz; 802.11a devices operate in the 5 GHz band;
802.11b and g devices operate in the 2.4 GHz band.
I/O
Input/Output. The term used to describe any operation that transfers data to or from a computer. (See
MIMO).
IEEE
Institute of Electrical and Electronics Engineers. A global technical professional society and standardssetting
organization serving the public interest and its members in electrical, electronics, computer,
information and other technologies.
IEEE 802.11
The family of specifications developed by the Institute of Electrical and Electronics Engineers (IEEE)
802.11 committee which establishes standards for wireless Ethernet networks. 802.11 standards define
the over-the-air interface between wireless clients and a base station, or access point that is physically
connected to the wired network. (See 802.11, IEEE).
iLink
Sony Corp’s name for the high-speed serial bus system defined by the IEEE 1394 standard for input/output
technology that connects multimedia and storage peripherals to a PC. (See FireWire).
Infrastructure mode
An old term used to describe a wireless network consisting of devices connected to a network using a
centralized wireless access point. One of two types of wireless network modes; the other is a device-todevice
network (also known as peer-to-peer or ad hoc mode). (See ad hoc mode, device-to-device
network, peer-to-peer network).
Internet appliance
A computing device used primarily for Internet access. It can be Wi-Fi enabled or connected to a wired
network and generally offers customized web browsing, touch-screen navigation, with built-in e-mail
services, entertainment and personal information management applications. Applications cannot be
installed independently.
Intrusion detection
A security service that monitors and analyzes system events to identify security breaches to the network
and provide real-time warnings when an unauthorized intrusion, or break-in, to the network is attempted.
(See Rogue, War chalking, War driving).
IP
Internet Protocol. The basic communications protocol of the Internet. (See IP address, TCP/IP).
IP (Internet Protocol) telephony
Technology that supports voice, data and video transmission via IP-based LANs, WANs, and the Internet.
This includes VoIP (Voice over IP).
IP address
Internet Protocol address. IP Version 4, the most widely used Internet protocol, provides 32-bit number that
identifies the sender or receiver of information sent across the Internet. An IP address has two parts: The
identifier of the particular network on the Internet and the identifier of the particular device (which can be a
server or a workstation) within that network. The newer IP, Version 6, provides a 128-bit addressing
scheme to support a much greater number of IP addresses. (See DHCP, DNS, IP).
IP telephony
A general term referring to technologies that use IP packet-switched connections to exchange voice, data,
video, and other forms of information traditionally carried over public telephone networks. (See IP, VoIP).
IPX-SPX
IPX, short for Internetwork Packet Exchange, a networking protocol used by the Novell NetWare operating
systems. Like UDP/IP, IPX is a datagram protocol used for connectionless communications. Higher-level
protocols, such as SPX and NCP, are used for additional error recovery services. Sequenced Packet
Exchange, SPX, a transport layer protocol (layer 4 of the OSI Model) used in Novell Netware networks.
The SPX layer sits on top of the IPX layer (layer 3) and provides connection-oriented services between two
nodes on the network. SPX is used primarily by client/server applications. Whereas the IPX protocol is
similar to IP, SPX is similar to TCP. Together, therefore, IPX-SPX provides connection services similar to
TCP/IP.
ISA
A type of internal computer bus that allows the addition of card-based components like modems and
network adapters. ISA has been replaced by PCI and is not very common anymore.
ISDN
Integrated Digital Services Network—A service offered by most telephone carriers that provides highspeed
digital service for voice and data over ordinary telephone lines. ISDN uses standard POTS copper
wiring to deliver voice, data or video. (See broadband, POTS).
ISO Network Model
A model developed by the International Standards Organization (ISO) that defines seven levels, or layers,
in a network. By standardizing these layers and the interfaces that connect them, different portions of a
given protocol can be modified or changed as technologies advance or systems requirements are altered.
The seven layers are, beginning at the lowest layer: Physical, Data link, Network, Transport, Session,
Presentation, Application. The IEEE 802.11 Standard encompasses the physical layer (PHY) and the lower
portion of the data link layer which is often referred to as the Media Access Control (MAC) sub-layer. (See
PHY).
ISS
A special software application that allows all PCs on a network access to the Internet simultaneously
through a single connection and Internet Service Provider (ISP) account.
LAN
A system of connecting PCs and other devices within the same physical proximity for sharing resources
such as an Internet connections, printers, files and drives. When Wi-Fi is used to connect the devices, the
system is known as a wireless LAN or WLAN. (See WAN, WLAN, WMAN, WPAN).
LEAP
Lightweight Extensible Authentication Protocol—A proprietary Cisco protocol used for 802.1X
authentication on wireless LANs (WLANs). (See 802.1X, EAP).
MAC address
Media Access Control address. A unique hardware number that identifies each device on a network. A
device can be a computer, printer, etc. (See IP address).
MAN
Metropolitan Area Network. A data network, typically operated by a municipality or communications carrier
that provides high-speed service within a geographical area such as a college campus, town or city. A
MAN is larger than a Local Area Network (LAN) but smaller than a Wide Area Network (WAN). (See
WiMAX).
Mapping
Assigning a PC to a shared drive or printer port on a network.
Mbps
Megabits per second. A measurement of data speed that is roughly equivalent to a million bits per second.
(See bps).
Mesh network
A communications network with least two pathways to each node, forming a net-like organization. When
each node is connected to every other node, the network is said to be fully meshed. When only some of
the nodes are linked, switching is required to make all the connections and the network is said to be
partially meshed, or partially connected.
MIC
Message Integrity Check. A technology that is employed to prevent an attacker from capturing data
packets, altering them and resending them. The MIC provides a strong mathematical function in which the
receiver and the transmitter each compute and then compare the MIC. If it does not match, the data is
assumed to have been tampered with and the packet is dropped. (See Packet, TKIP, WPA, WPA2).
MIMO
Multiple-Input-Multiple-Output. An advanced signal processing technology that uses multiple receivers and
multiple transmitters in both the client and access point to achieve data throughput speeds of 100Mbps.
(See 802.11n).
Mobile professional
Often called “road warrior.” Any employee or professional person who travels frequently and requires the
ability to regularly access his or her corporate networks, via the Internet, to post and retrieve files and data
and to send and receive e-mail from remote locations. (See hotspot, roaming).
NAT
Network Address Translation. A network capability that enables multiple of computers to dynamically share
a single incoming IP address from a dial-up, cable or DSL connection. NAT takes a single incoming public
IP address and translates it to a new private IP address for each client on the network. (See DHCP, IPaddress).
Network name
A name used to identify a wireless network. (See ESSID, SSID)
NIC
Network Interface Card. A wireless or wired PC adapter card that allows the client computer to utilize
network resources. Most office wired NICs operate at 100 Mbps. Wireless NICs operate at data rates
defined by 802.11 standards. (See PC card).
Packet
A unit of information transmitted from one device to another on a network. A packet typically contains a
header with addressing information, data, and a checksum to insure data integrity. (See MIC).
Pass phrase
A series of characters used to create a key which is used by Wi-Fi Protected Access (WPA). (See PSK,
WPA).
PC Card
A removable, credit-card-sized memory or I/O device that fits into an expansion slot on a notebook
computer or a personal digital assistant (PDA). PC Cards are used primarily in notebook computers and
PDAs. PC Card peripherals include Wi-Fi network cards, memory cards, modems, wired NICs, and hard
drives. (See NIC, PCI).
PCI
Peripheral Component Interconnect. A high-performance I/O (input/output) computer bus that allows
expansion slots to be spaced closely for high-speed operation. (See NIC, PC Card).
PCMCIA
Expansion cards now referred to as "PC Cards" were originally called "PCMCIA Cards" because they met
the standards created by the Personal Computer Memory Card International Association.
PDA
Personal Digital Assistant. Smaller than laptop computers but with many of the same computing and
communication capabilities, PDAs range greatly in size, complexity and functionality. PDAs can provide
wireless connectivity via embedded Wi-Fi Card radios, slide-in PC Card radios, or Compact Flash Wi-Fi
radios. (See PC Card).
PEAP
PEAP—Protected Extensible Authentication Protocol. A protocol proposed by Microsoft, Cisco and RSA
Security for 802.1X authentication on wireless LANs (WLANs). (See EAP, LEAP).
PEAPv0/EAP-MSCHAPv2
Protected Extensible Authentication Protocol, a protocol developed jointly by Microsoft, RSA Security and
Cisco for transmitting authentication data, including passwords, over 802.11 wireless networks. PEAP
authenticates wireless LAN clients using only server-side digital certificates by creating an encrypted
SSL/TLS tunnel between the client and the authentication
PEAPv1/EAP-GTC
Protected Extensible Authentication Protocol, a protocol developed jointly by Microsoft, RSA Security and
Cisco for transmitting authentication data, including passwords, over 802.11 wireless networks. PEAP
authenticates wireless LAN clients using only server-side digital certificates by creating an encrypted
SSL/TLS tunnel between the client and the authentication
Peer-to-peer network
A wireless or wired computer network that has no server or central hub or router. All the networked PCs
are equally able to act as a network server or client, and each client computer can talk to all the other
wireless computers without having to go through an access point or hub. However, since there is no
central base station to monitor traffic or provide Internet access, the various signals can collide with each
other, reducing overall performance. (See Ad hoc mode, Device-to-device network).
PHY
The physical, or lowest, layer of the OSI Network Model. In a wireless network, the PHY defines
parameters such as data rates, modulation method, signaling parameters, transmitter/receiver
synchronization, etc. Within an actual radio implementation, the PHY corresponds to the radio front end
and baseband signal processing sections. (See ISO Network Model).
Plug-and-play
Features that provide for automatic configuration of add-ons and peripheral devices such as wireless PC
Cards, printers, scanners and multimedia devices. (See PC Card).
POTS
Plain Old Telephone Service. The traditional analog telephone service provided by most common carriers.
(See broadband, dial-up, DSL, ISDN).
Print server
A network device, often a computer, that connects to at least one printer, allowing it to be shared among
computers on a network.
Proxy server
A technique used in larger companies and organizations to improve network operations and security. The
proxy server receives requests intended for another server to prevent direct communication between two
or more networks. The proxy server forwards allowable data requests to remote servers and/or responds
to data requests directly from stored remote server data.
PSK
A mechanism in Wi-Fi Protected Access (WPA)—Personal that allows the use of manually entered keys or
passwords to initiate WPA security. The PSK is entered on the access point or home wireless gateway and
each PC that is on the Wi-Fi network. After entering the password, Wi-Fi Protected Access automatically
takes over. It keeps out eavesdroppers and other unauthorized users by requiring all devices to have the
matching password. The password also initiates the encryption process which, in WPA is Temporal Key
Integrity Protocol (TKIP) and in WPA2 is Advanced Encryption Standard (WPA2). (See TKIP, WPAPersonal,
WPA2-Personal).
QoS
Quality of Service. Required to support wireless multimedia applications and advanced traffic
management. QoS enables Wi-Fi access points to prioritize traffic and optimize the way shared network
resources are allocated among different applications. Without QoS, all applications running on different
devices have equal opportunity to transmit data frames. That works well for data traffic from applications
such as web browsers, file transfers, or e-mail but it is inadequate for multimedia applications. Voice over
Internet Protocol (VoIP), video streaming, and interactive gaming are highly sensitive to latency increases
and throughput reductions and require QoS. QoS extensions for 802.11 networks will be addressed in the
upcoming IEEE 802.11e standard. (See 802.11e, WMM).
RADIUS
Remote Access Dial-Up User Service. A standard technology used by many major corporations to protect
access to wireless networks. RADIUS is a user name and password scheme that enables only approved
users to access the network; it does not affect or encrypt data. The first time a user wants access to the
network, secure files or net locations, he or she must input his or her name and password and submit it
over the network to the RADIUS server. The server then verifies that the individual has an account and, if
so, ensures that the person uses the correct password before she or he can get on the network. RADIUS
can be set up to provide different access levels or classes of access. For example, one level can provide
blanket access to the Internet; another can provide access to the Internet as well as to e-mail
communications; yet another account class can provide access to the Net, email and the secure businessfile server. Like other sophisticated security technologies, RADIUS comes in a variety of types and levels.
(See EAP, WPA, WPA2).
Range
The distance covered by a wireless network or radio device. Depending on the environment and the type
of antenna used, Wi-Fi signals can have a range of up to a mile.
RC4
An encryption cipher designed RSA Data Security. It allows key lengths up to 1024 bits and is a
component in many encryption schemes, including SSL, WEP, and TKIP. (See SSL, WEP, TKIP).
Repeater
A wireless repeater is a device that extends the coverage of an existing access point by relaying its signal.
A wireless repeater does not do intelligent routing performed by wireless bridges and routers.
Residential gateway
A wireless device that allows multiple devices accessing a home network, including PCs and peripherals to
access the Internet and communicate with one another. (See gateway).
RFID
Radio Frequency Identification. An electronic identification technology that uses radio frequency signals to
read identifying data contained in tags on equipment and merchandise. An alternative to bar codes.
RJ-45
Standard connectors used in Ethernet networks. They appear similar to standard RJ-11 telephone
connectors. However, RJ-45 connectors can have up to eight wires, whereas telephone connectors have
only four.
Roaming
The ability to move seamlessly from one area of Wi-Fi or cellular phone coverage to another with no loss in
connectivity. Roaming also refers to the ability of road warriors to wirelessly connect to the Internet from
different hotspots without confronting the array of schemes used by different providers to authorize use
and track billing. Roaming agreements among providers allow mobile professionals to a single
authentication and authorization scheme to have all charges resolved to a single bill. (See hotspot, mobile
professional).
Rogue
file server. Like other sophisticated security technologies, RADIUS comes in a variety of types and levels.
(See EAP, WPA, WPA2).
Range
The distance covered by a wireless network or radio device. Depending on the environment and the type
of antenna used, Wi-Fi signals can have a range of up to a mile.
RC4
An encryption cipher designed RSA Data Security. It allows key lengths up to 1024 bits and is a
component in many encryption schemes, including SSL, WEP, and TKIP. (See SSL, WEP, TKIP).
Repeater
A wireless repeater is a device that extends the coverage of an existing access point by relaying its signal.
A wireless repeater does not do intelligent routing performed by wireless bridges and routers.
Residential gateway
A wireless device that allows multiple devices accessing a home network, including PCs and peripherals to
access the Internet and communicate with one another. (See gateway).
RFID
Radio Frequency Identification. An electronic identification technology that uses radio frequency signals to
read identifying data contained in tags on equipment and merchandise. An alternative to bar codes.
RJ-45
Standard connectors used in Ethernet networks. They appear similar to standard RJ-11 telephone
connectors. However, RJ-45 connectors can have up to eight wires, whereas telephone connectors have
only four.
Roaming
The ability to move seamlessly from one area of Wi-Fi or cellular phone coverage to another with no loss in
connectivity. Roaming also refers to the ability of road warriors to wirelessly connect to the Internet from
different hotspots without confronting the array of schemes used by different providers to authorize use
and track billing. Roaming agreements among providers allow mobile professionals to a single
authentication and authorization scheme to have all charges resolved to a single bill. (See hotspot, mobile
professional).
Rogue
An unauthorized access point installed on a company’s WLAN, typically by a user. Rogue access points
present security risks. They rarely conform to the organization’s security policies and, typically, no security
at all is enabled on them. Rogues present open, insecure interfaces to the company’s network. (See
intrusion detection).
Router
A wireless router is device that accepts connections from wireless devices to a network and includes a
network firewall for security, and provides local network addresses. (See hub).
Satellite broadband
Wireless high-speed Internet service provided by satellites. Some satellite broadband connections are twoway—
up and down. Others are one-way, with the satellite providing a high-speed downlink and then using
a dial-up telephone connection or other land-based system for the uplink to the Internet. (See broadband,
dial-up).
Security supplicant
Client software that coordinates authentication and session key creation.
Server
A computer that provides resources or services to other computers and devices on a network. Types of
servers can include print servers, Internet servers, mail servers, and DHCP servers. A server can also be
combined with a hub or router. (See DHCP, hub, router).
Site survey
A comprehensive facility study performed by network managers to insure that planned service levels will
be met when a new wireless LAN, or additional WLAN segments to an existing network, are deployed. Site
survey’s are usually performed by a radio frequency engineer and used by systems integrators to identify
the optimum placements of access points to insure that planned levels of service are met. Site surveys are
sometimes conducted following the deployment to insure that the WLAN is achieving the necessary level
of coverage. Site surveys can also be used to detect rogue access points. (See intrusion detection, rogue).
Sniffer
A software program that monitors network traffic. Sniffers can capture data being transmitted on a network
and are sometimes used illegitimately to hack a network.
SOHO
The term describes an office or business with ten or fewer computers and/or employees.
SSID
A unique 32-character network name, or identifier, that differentiates one wireless LAN from another. All
access points and clients attempting to connect to a specific WLAN must use the same SSID. The SSID
can be any alphanumeric entry up to a maximum of 32 characters. (See ESSID, network name).
SSL
SSL—Secured Sockets Layer. A protocol used to secure Internet communications. SSL is commonly used
to encrypt transactions on online retail and banking. SSL encrypts the exchange of information between a
user’s browser and Web server so only the intended parties can read it. When an SSL session begins, the
server sends its public key to the browser. The browser then sends a randomly generated secret key back
to the server in order to have a secret key exchange for that session. (See RC4).
Subnetwork, or subnet
An IP address range that is part of a larger address range. Subnets are used to subdivide a network
address of a larger network into smaller networks. Subnets connect to other networks through a router.
Each individual wireless LAN will typically use the same subnet for all of its clients. (See IP address,
router).
Switch
A type of hub that controls device usage to prevent data collisions and insures optimal network
performance. A switch acts as a network traffic cop: Rather than transmitting all the packets it receives to
all ports, as a hub does, a switch transmits packets to only the receiving port. (See hub).
TCP
Transmission Control Protocol. The Transport level protocol used with the Internet Protocol (IP) to route
data across the Internet. (See IP, TCP/IP).
TCP/IP
The underlying technology of Internet communications. While IP handles the actual delivery of data, TCP
tracks the data packets to efficiently route a message through the Internet. Every computer in a TCP/IP
network has its own IP address that is either dynamically assigned at startup (See DHCP) or permanently
assigned as a static address. All TCP/IP messages contain the address of the destination network, as well
as the address of the destination station. This enables TCP/IP messages to be transmitted to multiple
networks (subnets) within an organization or worldwide. For example, when a user downloads a web page,
TCP divides the page file on the web server into packets, numbers the packets, and forwards them
individually to the user’s IP address. The packets may be routed along different paths before reaching the
user’s address. At the destination, TCP reassembles the individual packets, waiting until they have all
arrived to present them as a single file. (See IP, IP address, packet, TCP).
Throughput
Usually measured in bps, Kbps, Mbps or Gbps, throughput is the amount of data that can be sent from one
location to another in a specific amount of time. (See bps, Mbps).
TKIP
Temporal Key Integrity Protocol. The wireless security encryption mechanism in Wi-Fi Protected Access.
TKIP uses a key hierarchy and key management methodology that removes the predictability that intruders
relied upon to exploit the WEP key. It increases the size of the key from 40 to 128 bits and replaces WEP’s
single static key with keys that are dynamically generated and distributed by an authentication server,
providing some 500 trillion possible keys that can be used on a given data packet. It also includes a
Message Integrity Check (MIC), designed to prevent an attacker from capturing data packets, altering them
and resending them. By greatly expanding the size of keys, the number of keys in use, and by creating an
integrity checking mechanism, TKIP magnifies the complexity and difficulty involved in decoding data on a
Wi-Fi network. TKIP greatly increases the strength and complexity of wireless encryption, making it far
more difficult—if not impossible—for a would-be intruder to break into a Wi-Fi network. (See AES, WPA,
WPA2).
TLS
Transport Layer Security. A newer version of the SSL protocol, It supports more cryptographic algorithms
than SSL. TLS is designed to authenticate and encrypt data communications, preventing eavesdropping,
message forgery and interference. (See EAP, SSL).
Tri-mode
In the Wi-Fi context, tri-mode refers to devices which are 802.11b, a, and g-compatible. In the mobile
context, tri-mode describes a cellular phone that is capable of using analog, digital and GSM frequencies.
(See dual band).
USB
A high-speed bidirectional serial connection between a PC used to transfer data between the computer
and peripherals such as digital cameras and memory cards. The USB 2.0 specification, announced in
2000, provides a data rate of up to 480 Mbps, 40 times faster than the original specification which provided
only 12 Mbps.
UWB
Ultra Wideband. A relatively new term that is used to describe a technology known since the early 1960s
as "carrier-free", "baseband" or "impulse". UWB transmits and receives extremely short bursts of radiosignals, typically a few trillionths of a second to a few billionths of a second (nanoseconds) in duration.
These bursts produce waveforms that are extremely broadband.
Voice over Wi-Fi
VoIP services delivered over wireless networks. Sometimes referred to as wireless voice over IP. (See IP
telephony, VoIP).
VoIP
Voice over Internet Protocol. A technology for transmitting ordinary telephone calls over the Internet using
packet-based networks instead of standard public switched telephone networks or Plain Old Telephone
Service (POTS). (See IP telephony, Voice over Wi-Fi).
VPN
Virtual Private Network. A network layer encryption scheme that allows remote clients to securely connect
to their corporate networks using the Internet. Most major corporations today use VPN to protect their
remote-access workers and their connections. It works by creating a secure virtual "tunnel" from the enduser's
computer through the end-user's access point or gateway, through the Internet, all the way to the
corporation's servers and systems. It also works for wireless networks and can effectively protect
transmissions from Wi-Fi equipped computers to corporate servers and systems.
WAN
Wide Area Network (WLAN). A data communications network that spans large local, regional, national or
international areas and is usually provided by a public carrier (such as a telephone company or service
provider).The term is used to distinguish between phone-based data networks and Wi-Fi networks. Phone
networks are considered WANs and Wi-Fi networks are considered Wireless Local Area Networks. (See
LAN, WMAN, WPAN).
WAP
Wireless Applications Protocol. A protocol designed to deliver applications to mobile devices, including cell
phones, pagers, two-way radios, smartphones and communicators.
War chalking
The practice of indicating the presence of both secured and unsecured wireless networks by using chalk to
mark nearby buildings or sidewalks.
War driving
The practice of driving around with a GPS, laptop equipped with WNIC and an antenna (usually built intothe WNIC) to document the location of secured and unsecured WLANs. The locations of the WLANs
derived from the GPS readings, and their corresponding SSIDs, are published in databases that live on the
Internet. War driving derives its name from the movie, War Games, in which hackers gained access to
traditional networks by randomly dialing telephone numbers until a modem answered. (See GPS).
WEP
The original security standard used in wireless networks to encrypt the wireless network traffic. (See
WPA).
Wi-Fi CERTIFIED™
The certification standard designating IEEE 802.11-based wireless local area network (WLAN) products
that have passed interoperability testing requirements developed and governed by the Wi-Fi Alliance. (See
Wi-Fi Interoperability Certificate).
Wi-Fi Interoperability Certificate
A statement that a product has passed interoperability testing and will work with other Wi-Fi CERTIFIED
products. (See Wi-Fi CERTIFIED).
Wi-Fi ZONE™
A certification program of the Wi-Fi Alliance that allows users to easily identify public hotspot locations that
have Wi-Fi connectivity available. The program allows customers from anywhere in the world to look for a
single Wi-Fi ZONE brand. The Wi-Fi ZONE logo assures users that they will be able to get a fast, reliable
Internet connection in a coffee shop, hotel, airport, convention center or other public venue. (See hotspot).
Wi-Fi®
Short for wireless fidelity. A term developed by the Wi-Fi Alliance to describe wireless local area network
(WLAN) products that are based on the Institute of Electrical and Electronics Engineers’ (IEEE) 802.11
standards. (See Wi-Fi CERTIFIED™).
WiMAX
Worldwide Interoperability for Microwave Access. Refers to the 802.16 standard being developed by the
IEEE to provide a wireless coverage of up to 31 miles. It operates in the 2 to 11 GHz bands and enables
connectivity without a direct line-of-sight to a base station although line-of-site is probably required to
achieve connectivity at the distance of 31 miles.. It provides shared data rates up to 70 Mbps, which,
according to WiMAX proponents, is enough bandwidth to simultaneously support more than 60 businesses
and hundreds of homes. (See WMAN).
Wireless network
Devices connected to a network using a centralized wireless access point. (See WLAN).
WLAN
Wireless Local Area Network. A type of local-area network in which data is sent and received via highfrequency
radio waves rather than cables or wires. (See LAN, wireless network).
WMAN
Wireless Metropolitan Area Network—A wireless data network that is comparable to a cell phone network
in that users throughout a metropolitan area can freely access the Internet. WiMAX technology provides
the basis of WMAN networks. (See WiMAX).
WMM™
Wi-Fi Multimedia. A group of features for wireless networks that improve the user experience for audio,
video and voice applications. WMM is based on a subset of the IEEE 802.11e WLAN QoS draft standard.
WMM adds prioritized capabilities to Wi-Fi networks and optimizes their performance when multiple
concurring applications, each with different latency and throughput requirements, compete for network
resources. By using WMM, end-user satisfaction is maintained in a wider variety of environments and
traffic conditions. WMM makes it possible for home network users and enterprise network managers to
decide which data streams are most important and assign them a higher traffic priority. (See 802.11e,
QoS).
WPA-Enterprise
Wi-Fi Protected Access–Enterprise. A wireless security method that provides strong data protection for
multiple users and large managed networks. It uses the 802.1X authentication framework with TKIP
encryption and prevents unauthorized network access by verifying network users through an authentication
server. (See 802.1X, TKIP, WPA).
WPA-Personal
Wi-Fi Protected Access–Personal. A wireless security method that provides strong data protection and
prevents unauthorized network access for small networks. It uses TKIP encryption and protects against
unauthorized network access through the use of a pre-shared key (PSK). (See WPA, PSK).
WPA™
Wi-Fi Protected Access. An improved security standard for wireless networks that provides strong data
protection and network access control. WPA was developed by the Wi-Fi Alliance and addresses all known
WEP vulnerabilities. It provides strong data protection by using encryption, as well as strong access
controls and 802.1X-based user authentication which was largely missing in WEP. WPA is designed to
secure all versions of 802.11 devices, including 802.11b, 802.11a, and 802.11g, dual-band and tri-mode.
WPA can be enabled in two versions, WPA-Personal and WPA-Enterprise. WPA-Personal protects against
unauthorized network access by utilizing a set-up pass phrase, or pre-shared key. WPA-Enterprise verifies
network users through an authentication server. In either mode, WPA utilizes 128-bit encryption keys and
dynamic session keys to ensure the wireless network's privacy and security. (See PSK, WEP, WPA2).
WPA2-Enterprise
Wi-Fi Protected Access 2 – Enterprise. The follow on wireless security method to WPA that provides
stronger data protection for multiple users and large managed networks. It prevents unauthorized network
access by verifying network users through an authentication server. (See WPA2).
WPA2-Personal
Wi-Fi Protected Access 2 – Personal. The follow on wireless security method to WPA that provides
stronger data protection and prevents unauthorized network access for small networks. (See WPA2, PSK).
WPA2™
Wi-Fi Protected Access 2. The follow on security method to WPA for wireless networks that provides
stronger data protection and network access control. It provides enterprise and consumer Wi-Fi users with
a high level of assurance that only authorized users can access their wireless networks. Based on the
ratified IEEE 802.11i standard, WPA2 provides government grade security by implementing the National
Institute of Standards and Technology (NIST) FIPS 140-2 compliant AES encryption algorithm and 802.1Xbased
authentication. There are two versions of WPA2: WPA2-Personal, and WPA2-Enterprise. WPA2-
Personal protects unauthorized network access by utilizing a set-up password. WPA2-Enterprise verifies
network users through a server. WPA2 is backward compatible with WPA. Like WPA, WPA2 uses the
802.1X/EAP framework as part of the infrastructure that ensures centralized mutual authentication and
dynamic key management and offers a pre-shared key for use in home and small office environments. Like
WPA, WPA2 is designed to secure all versions of 802.11 devices, including 802.11b, 802.11a, and
802.11g, multi-band and multi-mode. (See WPA2-Enterprise, WPA2-Personal).
WPAN
Wireless Personal Area Network. A network that wirelessly connects personal devices centered within a
radius of about 30 feet such as an individual’s workspace or room environment in a home. WPAN
technologies include Bluetooth and others defined by the IEEE 802.15 standard. Devices specifications
include low data rates (250 kbps, 40 kbps, and 20 kbps), and multi-month to multi-year battery life and
include such things as joy sticks and interactive toys. WPAN devices operate in unlicensed international
frequency bands and can communicate directly with one another, a concept called “plugging in”. (See
Bluetooth wireless technology).




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