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2G
Most common type of wireless telephone communication today. It allows
slow data communication, but its primary focus is voice.
2.5G
Bridging standard between 2G and 3G. Digital communication allows e-mail
and simple Web browsing.
3G
3G stands for the third generation of wireless communication technology.
It refers to pending improvements in wireless data and voice communications
through any of a variety of proposed standards. The immediate goal is
to raise transmission speeds to 2Mbit/sec. (Read
more.)
802.11
A group of wireless specifications developed by the IEEE. It details a
wireless interface between devices to manage packet traffic (to avoid
collisions, etc.) Some common specifications and their distinctive attributes
include the following:
- 802.11a -- Operates in the 5-GHz frequency
range (5.125 to 5.85 GHz) with a maximum 54Mbit/sec. signaling rate.
The 5-GHz frequency band isn't as crowded as the 2.4-GHz frequency because
it offers significantly more radio channels than the 802.11b and is
used by fewer applications. It has a shorter range than 802.11g, is
actually newer than 802.11b and isn't compatible with 802.11b.
- 802.11b -- Operates in the 2.4-GHz Industrial,
Scientific and Measurement (ISM) band (2.4 to 2.4835 GHz) and provides
signaling rates of up to 11Mbit/sec. This is a very commonly used frequency.
Microwave ovens, cordless phones, medical and scientific equipment,
as well as Bluetooth devices, all work within the 2.4-GHz ISM band.
- 802.11e -- Ratified by the IEEE in late
September of 2005, the 802.11e quality-of-service specification is designed
to guarantee the quality of voice and video traffic. It will be particularly
important for companies interested in using Wi-Fi phones.
- 802.11g -- Similar to 802.11b, but this
standard supports signaling rates of up to 54Mbit/sec. It also operates
in the heavily used 2.4-GHz ISM band but uses a different radio technology
to boost overall throughput. Compatible with older 802.11b.
- 802.11i -- Also sometimes called Wi-Fi
Protected Access 2 (WPA 2), 802.11i was ratified in June 2004. WPA
2 supports the 128-bit -and-above Advanced Encryption Standard, along
with 802.1x authentication and key management features.
- 802.11k -- Predicted for ratification
in mid-2006, the 802.11k Radio Resource Management standard will provide
measurement information for access points and switches to make wireless
LANs run more efficiently. It may, for example, better distribute traffic
loads across access points or allow dynamic adjustments of transmission
power to minimize interference.
- 802.11n -- The Standard for Enhancements
for Higher Throughput is designed to raise effective WLAN throughput
to more than 100Mbit/sec. Final ratification is expected in late 2006.
- 802.11r -- Expected to be ratified in
mid to late 2006, the 802.11r Fast Roaming standard will address maintaining
connectivity as a user moves from one access point to another. This
is especially important in applications that need low latency and high
quality-of-service standards such as voice-over-WLAN.
- 802.11s -- This standard will deal with
mesh networking. It is predicted to be ratified
in mid-2008.
Access point
A WLAN transceiver or "base station" that can connect a network to one
or many wireless devices. APs can also bridge to one another.
Ad hoc mode
A wireless network framework in which devices can communicate directly
with one another without using an AP or a connection to a regular network.
Contrasts with an infrastructure network, in which all devices communicate
through an AP.
Bluetooth
A low-cost, short-range radio link between laptops, mobile phones, network
access points and other devices. Bluetooth can replace cables and can
be used to create ad hoc networks and provide a standard way to connect
devices anywhere in the world. (Read
more.)
CDMA
Code Division Multiple Access is a digital cellular technology that uses
spread spectrum techniques that, instead of separating users by frequency,
separates them through the use of digital frequency codes across the full
available spectrum. Competes with GSM and TDMA. (Read
more.)
CDPD
Cellular Digital Packet Data technology is used by telecommunications
carriers to transfer data to users via unused analog cellular networks.
If one part of the network -- a specific geographic area or "cell" --
is overused, CDPD can automatically reallocate network resources to handle
extra traffic.
CTIA
The Cellular Telecommunications & Internet Association is the international
organization that aims to represent all elements of wireless communication
-- cellular, personal communications services, enhanced specialized mobile
radio and mobile satellite services -- and serve the interests of service
providers, manufacturers and others.
EDGE
Enhanced Data rates for GSM Evolution -- this 3G technology allows wireless
transmission of data at speeds up to 384K bit/sec. It's based on GSM technology
and allows for high-bandwidth services such as multimedia. It has more
support in North America than in other areas where technologies such as
CDMA2000 and UMTS may be favored.
EVDO
Evolution Data Only/Evolution Data Optimized is an "evolution" of CDMA
networks that is based on the 1xRTT standard, providing faster wireless
data transmission speeds of 400K bit/sec. to 700K bit/sec. with a theoretical
peak of 2.4M bit/sec. Verizon Wireless and Sprint Corp. in the U.S. were
rolling out the service in early 2005, connecting to laptops via a plug-in
card.
FLASH-OFDM
Flash-OFDM is a proprietary cellular broadband technology that network
operators can deploy either for notebook computers of mobile users or
serve as a fixed wireless access system, bridging the "last mile" to connect
computers in homes and small offices. Key features include an all-IP architecture
and fast speeds. The technology is capable of letting users traveling
at 250 kilometers per hour to download data at speeds up to 1.5Mbit/sec.
or upload at speeds up to 500Kbit/sec. Orthogonal Frequency Division Multiplexing
(OFDM) works by splitting radio signals into smaller low-speed signals
that are transmitted in parallel, reducing crosstalk and using bandwidth
efficiently, but decreasing range.
GPS
The Global Positioning System is a "constellation" of 24 satellites that
orbit the Earth at a height of 10,900 miles, making it possible for people
using ground receivers to determine their geographic location within 10
to 100 meters. The satellites use simple mathematical calculations to
broadcast information that is translated as longitude, latitude and altitude
by Earth-based receivers. (Read
more.)
GPRS
General Packet Radio Service technology runs at speeds up to 115Kbit/sec.,
compared with the 9.6Kbit/sec. of older GSM systems. It enables high-speed
wireless Internet and other communications such as e-mail, games and applications.
It supports a wide range of bandwidths and is an efficient use of limited
bandwidth. It's particularly suited for sending and receiving small amounts
of data, such as e-mail and Web browsing, as well as large volumes of
data. (Read
more.)
GSM
Global System for Mobile Communications is a digital cellular system based
on TDMA narrowband technology, which gives users access to time slots
on the same frequency bands. It allows up to eight simultaneous communications
on the same frequency. It competes with CDMA.(Read
more.)
HSDPA
High-Speed Downlink Packet Access is a 3G high-speed data technology that
is an improvement to the WCDMA standard. It boosts speed and reduces latency.
It operates in the 5MHz spectrum and will initially provide real-world
speeds of 400K bit/sec. to 600K bit/sec., with theoretical peak speeds
of 14.4M bit/sec.
Hot spot
A place, such as a hotel, restaurant or airport, that offers Wi-Fi access,
either free or for a fee.
I-Mode
A popular wireless Internet service rolled out in 1999 by NTT DoCoMo Inc.
in Japan. It's based on a simplified form of HTML and delivers packet-based
information -- such as games, e-mail and even business applications --
to handheld devices.
IEEE
Institute of Electrical and Electronics Engineers Inc. is a nonprofit,
technical professional association of more than 360,000 individual members
in approximately 175 countries that is an authority in technical areas
such as computer engineering and telecommunications. It developed the
802.11 specifications.
MAC
Every wireless 802.11 device has its own specific Media Access Control
address hard-coded into it. This unique identifier can be used to provide
security for wireless networks. When a network uses a MAC table, only
the 802.11 radios that have had their MAC addresses added to that network's
MAC table are able to get onto the network.
Mesh networking
Mesh networking features freestanding, non-wired network nodes that communicate
among one another and form self-configuring networks, with only one node
required to hook into a wired LAN. The other nodes are simply plugged
in to an electrical outlet, so cabling is much less of an issue. (Read
more.)
MIMO
Multiple Input Multiple Output refers to using multiple antennas in a
WiFi device to improve performance and throughput. The MIMO technology
takes advantage of a characteristic called multipath, which occurs when
a radio transmission starts out at point A and then reflects off or passes
through surfaces or objects before arriving, via multiple paths, at point
B. MIMO technology uses multiple antennas to collect and organize signals
arriving via these paths. The technology is expected to be used in the
802.11n standard.
RFID
Radio frequency identification uses low-powered radio transmitters to
read data stored in a transponder (tag) at distances ranging from one
inch to 100 feet. RFID tags are used to track assets, manage inventory
and authorize payments, and they increasingly serve as electronic keys
for everything from autos to secure facilities. (Read
more.)
Roaming
Movement of a mobile device from one wireless network location to another
without interruption in service or loss in connectivity.
Smart phone
A wireless phone with text and Internet capabilities. Smart phones can
handle wireless phone calls, hold addresses and take voice mail and can
also access information on the Internet and send and receive e-mail and
fax transmissions. (Read
more.)
Site survey
Done at the location for a new WLAN in an effort to avoid what could be
time-consuming and costly problems down the road. It involves diagramming
the network, checking the building and testing the equipment. (Read
more.)
SMS
Short Message Service allows the transmission of short text messages among
mobile devices such as cell phones, fax machines and BlackBerry devices.
Messages -- up to 160 alphanumeric characters but not containing images
or graphics -- appear as text on the display screen of the receiving device.
It works with GSM networks. (Read
more.)
SSI
A Service Set Identifier is a sequence of characters unique to a specific
network or network segment that's used by the network and all attached
devices to identify themselves and allow devices to connect to the correct
network when more than one independent network is operating in nearby
areas.
Symbian Ltd.
A joint venture among LM Ericsson Telephone Co., Motorola Inc., Nokia
Corp. and Psion PLC to develop new operating systems based on Psion's
EPOC32 platform for small mobile devices for wireless devices such as
phones and handhelds.
TDMA
Time Division Multiple Access divides a radio frequency available to a
network into time slots and then allocates slots to multiple calls. So
one frequency can support multiple, simultaneous data channels, using
bandwidth more efficiently than earlier technologies. Available in 800-MHz
or 1900-MHz frequencies, TDMA is used by the GSM digital cellular system.
UMTS
Universal Mobile Telecommunications System, is a 3G
cellular network technology that uses WCDMA (Wideband Code Division Multiple
Access), which was operating in 25 countries as of mid-2005. The transmission
rates range from a theoretical 384K bit/sec. for phones that are moving
up to 2M bit/sec. for stationary devices.
UWB
Ultrawideband, also called digital pulse, is a wireless technology for
transmitting digital data over a wide swath of the radio frequency spectrum
with very low power. Because of the low power requirement, it can carry
signals through doors and other obstacles that tend to reflect signals
at more limited bandwidths and a higher power. It can carry large amounts
of data and is used for ground-penetrating radar and radio locations systems.
VoIP
Voice over Internet Protocol is a system for delivering digitized voice
communications across IP networks. VoIP technology allows phone calls
to be made between compatible handsets or on computers with appropriate
software. (Read
more.)
WAP
The Wireless Application Protocol is a set of specifications, developed
by the WAP Forum, that lets developers using Wireless Markup Language
build networked applications designed for handheld wireless devices. WAP
was designed to work within the constraints of these devices: a limited
memory and CPU size, small, monochrome screens, low bandwidth and erratic
connections. WAP is a de facto standard, with support from more than 200
vendors. (Read
more.)
WCDMA
Wideband Code Division Multiple Access is a 3G wireless technology derived
from CDMA that transmits digitized data over a wide range of frequencies
to boost speed. It uses wide 5 MHz channels and is associated with UMTS
and GSM, where it boosts speed by substituting TDMA technology for CDMA.
It's used for voice, data and video services and can achieve data rates
up to 2M bit/sec.
WEP
Wired-Equivalent Privacy protocol was specified in the IEEE 802.11 standard
to provide a WLAN with a minimal level of security and privacy comparable
to a typical wired LAN, using data encryption. It's now widely recognized
as flawed because of an insufficient key length and other problems and
can be cracked in a short time with readily available tools.
WPA
Wi-Fi Protected Access is a data encryption specification for 802.11 wireless
networks that replaces the weaker WEP. Created by the WiFi Alliance before
a 802.11i security standard was ratified by the IEEE, it improves on WEP
by using dynamic keys, Extensible Authentication Protocol to secure network
access, and an encryption method called Temporal Key Integrity Protocol
(TKIP) to secure data transmissions.
WPA2
Wi-Fi Protected Access 2 is an enhanced version of WPA. It is the official
802.11i standard that was ratified by the IEEE
in June 2004. It uses Advanced Encryption Standard instead of TKIP (see
above). AES supports 128-bit, 192-bit and 256-bit keys.
Wi-Fi
Wireless fidelity is the generic term for 802.11 technology (see
802.11 above).
WLAN
Wireless local-area networks use radio waves instead of a cable to connect
a user device, such as a laptop computer, to a LAN. They provide Ethernet
connections over the air and operate under the 802.11 family of specifications
developed by the IEEE. (Read
more.)
War driving
Typically refers to driving around with a wireless-enabled laptop and
antenna to find places where it's possible to access exposed wireless
networks. These are usually company networks that extend beyond the physical
infrastructure of the company and are left unprotected.
War chalking
Marking buildings or sidewalks with chalk to show others where it's possible
to access an exposed company wireless network. These access points are
typically found through war driving (see above).
WiMax
Popular name of the 802.16 wireless metropolitan-area network standard
that's currently being developed. WiMax, which will have a range of up
to 31 miles, is primarily aimed at making broadband network access widely
available without the expense of stringing wires (as in cable-access broadband)
or the distance limitations of Digital Subscriber Line. There are two
flavors of WiMax: 802.16-2004 or 802.16d, for fixed implementations, and
802.16e, for mobile service. (Read
more.)
WML
Wireless Markup Language is like the Internet programming language HTML.
It delivers Internet content to small wireless devices, such as browser-equipped
cellular phones and handheld devices, which typically have very small
displays, slow CPUs, limited memory capacity, low bandwidth and restricted
user-input capabilities. (Read
more.)
Wi-Fi Alliance
A nonprofit international association formed in 1999 to certify interoperability
of WLAN products based on the IEEE 802.11 specification. Currently, the
Wi-Fi Alliance has over 200 member companies from around the world, and
over 1,000 products have received Wi-Fi certification since certification
began in March of 2000. The goal of the Wi-Fi Alliance's members is to
enhance the user experience through product interoperability.
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