|
|
|
|
 Glossary |
|
Wireless Glossary
Access point:
Any point where access to a network can be found, such as a wireless
transceiver that connects to a fixed network.
Asymmetrical: Describes a two-flow of data where the data
rate in one direction differs from the other. For instance, with
Asymmetrical DSL (ADSL), the downstream data rate from the Internet
is much faster than that going back upstream to the Internet.
Asynchronous: Literally, not synchronized. Usually refers
to communications where a data stream is not tied to a specific
clock speed. Modems transfer data asynchronously.
Authentication: Security mechanism that prevents access to
critical data and makes it impossible to falsify the origin of a
message.
Baseband: Low bandwidth.
Broadband: High bandwidth.
CardBus: A 32-bit interface that describes how PC Cards communicate
with a computer.
CDMA: Code Division Multiple Access (CDMA) is a standard
that separates voice signals using spread spectrum technology.
Cellular phone: A mobile telephone that works using radio
frequencies arranged in cells, such as is used in GSM phones.
Circuit switching: Describes a circuit that is held open
as long as the parties are communicating. This is how a standard
voice telephone call works. Circuit switching ensures consistent
throughput, but is very bandwidth inefficient in managing silences
between and within words and sentences.
Cordless headset: A headset, which includes a microphone,
that connects without wires.
Cordless phone: A telephone that connects without wires to
a base station
DECT: The signalling system that describes how digital cordless
phones work.
Device address: The unique address of a Bluetooth device.
Device discovery: Before a link can be established, a Bluetooth
device needs to discover other Bluetooth devices that are active
within its range.
Device name: The name that a Bluetooth device presents itself
with when supplying identity information to another device.
Direct sequence: A method of wireless transmission that can
provide higher data rates and greater robustness than frequency
hopping in radionoisy environments. The trade-off is higher cost
and fewer users for a given area.
DSP: Digital signal processor - a chip specifically designed
and optimized for processing signals such as voice and video.
Encryption: Security mechanism that prevents eavesdropping
and maintains link privacy.
EPOC: EPOC is a 32-bit operating environment used in Psion's
Series 5 palmtop computers. It is comprised of a suite of applications,
customized user interfaces, connectivity options and a range of
development tools.
FireWire: Apple's name for IEEE 1394.
Frequency hopping: Describes a system of communication based
on radio waves whose frequencies change (or hop) over time. For
example, the frequencies used by Bluetooth hop 1600 times a second.
The advantage is that it is less susceptible to interference, and
confers some security on the signal.
GPRS: General Packet Radio Service - a technology that packetizes
data on top of GSM transmissions to increase data rates by sharing
bandwidth, allowing users to get data rates of up to 115 Kbps.
GSM: Global System for Mobile Communications is the standard
cellular phone technology used inAustralia, Europe and most of Africa
and Asia.
IEEE 1394: A high speed serial link, currently working at
400 Mbps.
IEEE 802.11: A standard that describes a wireless networking
standard, currently working at 1 Mbps. This standard is the basis
for most modern wireless networking systems.
iLink: Sony's name for IEEE 1394.
IrDA: The InfraRed Data Association is the industry body
whose name has become synonymous with the infrared based communication
standard that it developed. IrDA has become the standard in the
computer industry, but not in consumer areas such as remote controls.
ISDN: Integrated Services Digital Network is a system invented
in the 1970s that passes data down a standard phone line digitally.
Most common is the Basic Rate ISDN, which offers two 64 Kbps channels
plus a 16 Kbps control channel.
ISM band: Industrial, Scientific and Medical Band is a set
of radio frequencies centered around 2.4 GHz. These frequencies
are available for use by wireless technologies such as Bluetooth.
Java: A technology invented by Sun Microsystems that allows
programs to be run on almost any type of computer that includes
a Virtual Java Machine (JVM). Java is almost completely platform
independent. Such programs are generally small and can be quickly
downloaded across a typical Internet connection for execution within
a browser.
Linux: A version of Unix rewritten by Linus Torwalds.
MAC layer: The Media Access Control layer of networking -
in other words, the circuitry (often a network interface card) that
manages access to the physical layer of the network (such as the
cable or fiber). MAC can also refer to a wireless link.
MAN: Metropolitan Area Network is a network that spans several
buildings spread out over an area larger than a town.
Master: The device that initiates a connection and, during
this connection, controls all traffic in a piconet.
Notebook: A portable PC, that includes a display, runs a
full copy of a standard operating system. It can run standard applications.
It often cannot accept adapter cards.
Open technology: A flexible term often used to describe a
computing technology, such as software, whose source code is either
open to all to modify as they see fit, or which has been developed
by a committee composed of members of the computing industry.
Packet switching: Describes a data signal that has been chopped
into discrete pieces or packets. Like parcels, these packets can
be sent individually to their various destinations by the switching
fabric. The advantage is that one message or series of messages
do not take over a communication channel which allows much greater
bandwidth efficiency. See circuit switching.
Palm: A palm-sized PDA running PalmOS. The Palm was invented
by Palm Computing which was subsequently acquired by 3Com.
PAN: Personal Area Network ensures that all the electronic
devices on and around an individual can communicate. A PAN is the
type of network set up by Bluetooth.
Parallel port: Sends data in a parallel stream, typically
to a printer.
Park mode: Economical, low-power “sub-mode” of
standby. In park mode, a slave does not participate in the piconet
but remains synchronized to it. Park mode is used to increase the
number of slaves connected to a master.
PBX: Private Branch Exchange is a type of switchboard found
in many businesses.
PC Card: Describes the types of cards that can be plugged
into the slots found in computers to add functionality such as networking,
a modem or Bluetooth.
PDA: Personal Digital Assistant is a small, usually palm-sized
electronic organizer that includes a calendar, schedule, to-do list,
contacts database and memo pad.
Piconet: An ad hoc network that can be initiated by Bluetooth
devices as they encounter other Bluetooth devices to allow all of
them to inter-communicate. [A wireless network formed by two or
more Bluetooth devices.]
PIN: Personal Identification Number.
PPP: Point-to-Point Protocol is a way of setting up a two-ended
link using the Internet Protocol (IP). Most often encountered when
dialling an ISP but can also be used by Bluetooth to set up an IP
link.
Profile: Application that a Bluetooth device facilitates.
For one device to communicate with another, the two devices must
have a shared profile. For instance, to transfer files from one
computer to another, both computers must feature the file transfer
profile.
Protocol: A kind of language that two or more devices have
in common which allows them to inter-communicate. An example is
the Internet Protocol (IP) which all devices connected to the Internet
must use in order to exchange information.
PSTN: Public Switch Telephone Network.
Quality of Service: When used in the context of data communications,
QoS refers a guarantee of a a certain level of service for a particular
type of traffic, most often voice or video. These types of traffic
are very sensitive to delayed or lost information.
Scatternet: A group of piconets with overlapping coverage
areas. Connections exist between them.
Serial port: Sends data in a serial stream, typically to
a modem.
SIG: Special Interest Group is group that comes together
with a common aim or purpose, such as the Bluetooth SIG.
Slave: A device in a piconet controlled by another device
(the master).
Smart phone: A GSM terminal with enhanced display capabilities
and new
functions to enable users to access e-mail, faxes and company intranets
easily and quickly. Smart phones have larger displays, often a QWERTY
or touch-sensitive keypad, and specialized built-in software linked
to specific services and applications, combining the functions of
phone and PDA.
Spread spectrum: Is the term used to describe the modulation
technique for 802.11 and Bluetooth. The spread spectrum technique
is used to increase the robustness of the wireless network. Spread
spectrum comes at a cost though, speed is traded for reliability.
Symbian: A joint venture between Psion, Ericsson, Nokia and
Motorola to promote the EPOC operating system for wireless information
devices.
Synchronous: A data stream tied to a particular clock speed.
An example is leased lines.
TCP: Transport Control Protocol refers to the layer below
IP that allows devices on the Internet to communicate and pass messages
along.
TDMA: Time Division Multiple Access (TDMA) is a standard
used for GSM mobile phones and wireless networks. .
UMTS: Universal Mobile Telecommunications System is a third
generation cellular mobile standard operating in the 2 GHz band.
It enables networks to offer packet-based global roaming with voice,
data and multimedia services. UMTS promises data rates up to 2 Mbps.
USB: Universal Serial Bus is the PC industry's attempt to
standardize PC hardware around a single, space-efficient port that
could eventually replace serial, parallel and other types of ports
used on PCs.
WAN: Wide Area Network is a network that can span the globe.
The Internet is a form of WAN, although it actually consists of
multiple networks interworking.
WAP: Wireless Access Protocol, invented by Nokia, is a standardized
way of allowing small devices such as cellular phones and PDAs to
present data from the Internet to the user in a meaningful way,
mainly by stripping off the graphics and reformatting the text.
It is optimized for use on the narrow band radio channels used by
GSM and GPRS. When combined with Bluetooth, WAP is a cornerstone
technology that can permit Web surfing from anywhere.
Wireless LAN: A Local Area Network whose physical layer (the
cabling) has been replaced by radio waves.
xDSL: Digital Subscriber Loop is a technology designed to
provide high speed access to the Internet over existing phone lines
without requiring a phone call or interrupting phone calls. Always
on, the most common form is Asymmetric DSL (ADSL) which provides
a high-speed link (up to 2 Mbps) to the user's computer with slower
transfer upstream.
|
|
|
 |
Home
ENTERPRISE
INDUSTRY
SMALL BUSINESS
HOME USERS
