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802.x - a set of specifications for LANs for
IEEE. 802.3 - an IEEE specification for SCMA/CD based
Ethernet networks. 802.5 - an IEEE specification for token ring
networks 802.11 - an IEEE specification for 1 and 2
Mbps wireless LANs 802.11HR - an IEEE specification for 11 mpbs
high rate wireless LANs A ADSL - See Asymmetric Digital Subscriber Line. Algorithm - A specific procedure used to modify
a signal. For example, the key to a digital compression system is the
algorithm that eliminates redundancy. American National Standards Institute (ANSI) -
An official body within the United States delegated with the responsibility
of defining standards. American Standard Code for Information Interchange
(ASCII) - Assigns specific letters, numbers, and control codes to
the 256 different combinations of 0s and 1s in a byte. American Wire Gauge (AWG) - A measurement of
wire diameter - the lower the AWG number, the larger the wire diameter.
Copper phone wiring usually comes in 24 or 26 AWG. Analog - A continuously varying signal or wave.
As with all waves, analog waves are susceptible to interference which
can change the character of the wave. ANSI - See American National Standards Institute ASCII - See American Standard Code for Information
Interchange. Asynchronous - Occuring at different times.
For example, electronic mail is asynchronous communication because it
does not require the sender and receiver to be connected at the same time. Asynchronous Transfer Mode (ATM) - A method
of data transportation whereby fixed length packets are sent over a switched
network. The ability to ensure reliable delivery of packets at a high
rate makes it suitable for carrying voice, video, and data. AWG - See American Wire Gauge B Bandwidth - A measure of capacity of communications
media. Greater bandwidth allows communication of more information in a
given period of time. Bandwidth is generally described either in terms
of analog signals in units of Hertz (Hz), which describes the maximum
number of cycles per second, or in terms of digital signals in units of
bits per second. Basic rate ISDN (BRI-ISDN) - The basic rate
ISDN interface provides two 64 Kb/s chan-nels (called B channels) to carry
voice or data and one 16 Kb/s signaling channel (the D channel) for call
information. Bit - A single unit of data, either a one or
a zero, used in digital data communications. When discussing digital data
a small "b" refers to bits, and a capital "B" refers
to bytes. Bluetooth - a specification for short-range
wireless technology created by a consortium of computer and communication
companies that make up the Bluetooth Special Interest Group. Broadband - An adjective used to describe large-capacity
networks that are able to carry several services at the same time, such
as data, voice, and video. BISDN - See broadband integrated services digital
network. Byte - A compilation of bits, seven bits in
accordance with ASCII standards and eight bits in accordance with EBCDIC
standards. C Carrier - an electromagnetic wave or alternating
current which is modulated to carry signals in radio, telephonic, or telegraphic
transmission. Carrierless Amplitude Phase (CAP) - A type
of quadrature amplitude modulation, used for some types of DSL, that stores
pieces of a modulated message signal in memory and then reassembles the
parts in the modulated wave. Central Office (CO) - A telephone company facility
that handles the switching of telephone calls on the public switched telephone
network (PSTN) for a small regional area. Central Processing Unit (CPU)
- The "brains" of a computer, which uses a stored program to
manipulate information. Circuit -switched network - A type of network
in which a continuous link is established between a source and a receiver.
Circuit switching is used for voice and video to ensure that individual
parts of a signal are received in the correct order by the destination
site. CO - See central office Common Carrier - A business, including telephone
and railroads, which is required by lawto provide service to any paying
customer on a first-come, first-serve basis. Competitive Local Exchange Carrier (CLEC) -
An American term for a telephone company that was created after the Telecommunications
Act of 1996 made it legal for companies to compete with the ILECs. Contrast
with ILEC. CLEC - See competitive
local exchange carrier. Compression - The process of reducing the amount
of information necessary to transmit a specific audio, video, or data
signal. core network - The combination of telephone switching offices
and transmission plant connecting switching offices together. In the U.S.
local exchange network, core networks are linked by several competing
Interexchange networks; in the rest of the world the core network extends
to national boundaries. CPE - See customer premises equipment. CPU - See central processing unit. Crosstalk - Interference from an adjacent channel. Customer Premises Equipment (CPE) - Any piece
of equipment in a communication system that resides within the home or
office. Examples include modems, television set-top boxes, telephones
and televisions. D Dedicated Connection - A communication link
that operates constantly. Dial-up Connection - A data communication link
that is established when the communication equipment dials a phone number
and negotiates a connection with the equipment on the other end of the
link. Digital Signal - A signal that takes on only
two values, off or on, typically represented by "0" or "1."
Digital signals require less power but (typically) more bandwidth than
analog, and copies of digital signals can be made exactly like the original. Digital Subscriber Line (DSL) - A data communications
technology that transmits information over the copper wires that make
up the local loop of the public switched telephone network (See local
loop).) Itbypasses the circuit-switched lines that make up that network
and yields much faster data transmission rates than analog modem technologies Digital Subscriber
Line Access Multiplexer (DSLAM) - A device
found in telephone company central offices that takes a number of DSL
subscriber lines and concentrates these onto a single ATM line. Direct Broadcast
Satellite (DBS) - A broadcast technology
that uses satellites orbiting the Earth to broadcast television or data
signals to an 18" dish antenna. Discrete Multi-Tone
Modulation (DMT) - A method of transmitting
data on copper phone wires that divides the available frequency range
into 256 sub-channels or tones, and which is used for some types of DSL. Discrete Wavelet
Multi-Tone (DWMT) - A variation of DMT modulation
that improves performance by using wavelets rather than tones to provide
additional isolation of sub-channels. DMT - See discrete multi-tone modulation. DNS - Domain name system (DNS) - The protocol
used for assigning text addresses (such as www.2wire.com) for specific
computers and computer accounts on the Internet. DSLAM - See Digital Subscriber Lline Access
Multiplexer. DWMT - See Discrete Wavelet Multitone. E Echo Cancellation - The elimination of reflected
signals ("echoes") in a two-way transmission created by some
types of telephone equipment, used in data transmission to improve the
bandwidth of the line. F Fiber-To-The-Cabinet (FTTCab) - network architecture
where an optical fiber connects the telephone switch to a street-side
cabinet where the signal is converted to feed the subscriber over a twisted
copper pair. Fiber-Tto-The-Curb (FTTC) - The deployment
of fiber optic cable from a central office to a platform serving numerous
homes. The home is linked to this platform with coaxial cable or twisted
pair (copper wire). Each fiber carries signals for more than one residence,
lowering the cost of installing the network versus fiber to the home. Fiber-To-The-Home (FTTH) - The deployment of
fiber optic cable from a central office to an individual home. This is
the most expensive broadband network design, with every home needing a
separate fiber optic cable to link it with the central office. Frame Relay - A high-speed packet switching
protocol used in wide area networks (WANs), often to connect local area
networks (LANs) to each other, with a maximum bandwidth of 44.725 megabits
per second. Frequency - The number of oscillations in an
alternating current that occur within one second, measured in Hertz (Hz). Frequency Division Multiplexing (FDM) - The
transmission of multiple signals simultaneously over a single transmission
path by dividing the available bandwidth into multiple channels that each
cover a different range of frequencies. FTTC - See Fiber-To-The-Curb. FTTH - See Fiber-To-The-Home. Full-Motion Video - The projection of 20 or
more frames (or still images) per second to give the eye the perception
of movement. Broadcast video in the United States uses 30 frames per second,
and most film technologies use 24 frames per second. G G.lite [pronounced "G-dot-light"] -
A kind of asymmetric DSL technology, based on DMT modulation, that offers
up to 1.5 megabits per second downstream bandwidth, 384 Kilobits per second
upstream, does not usually require a splitter and is easier to install
than other types of DSL. "G.lite" is a nickname for the standard
officially known as G.992.2. (See International Telecommunications Union.) G.992.1 - See G.dmt. G992.2 - See G.lite. General Switched Telephone Network (GSTN) -
See public switched telephone network. Gigabyte - 1,000,000,000 bytes, or 1,000 megabytes
(see Byte). Graphical User Interface (GUI) - A computer
operating system that is based upon icons and visual relationships rather
than text. Windows and the Macintosh computer use GUIs because they are
more user friendly. GSTN - See General Switched Telephone Network. GUI - See Graphical
User Interface. H Hertz - See frequency. High bitrate Digital Subscriber Line (HDSL)
- A symmetric DSL technology that provides a maximum bandwidth of 1.5
megabits per second in each direction over two phone lines, or 2 Megabits
per second over three phone lines. High bitrate Digital
Subscriber Line II (HDSL II) - A descendant
of HDSL which offers the same performance over a single phone line. High-Definition
Ttelevision (HDTV) - Any television system
that provides a significant improvement in picture quality over existing
television systems. Most HDTV systems offer more than 1,000 scan lines,
in a wider aspect ratio, with superior color and sound fidelity. Home Networking - connecting the different
electronic devices in a household by way of a Local Area Network (LAN) HTML - See HyperText Markup Language. HTTP - See Hypertext Transfer Protocol. Hybrid Fiber/Coax
(HFC) - A type of network that includes
coaxial cables to distribute signals to a group of individual locations
(typically 500 or more), and a fiber optic backbone to connect these groups. Hypertext
- Documents or other information with embedded links that enable a reader
to access tangential information at specific points in the text. HyperText Markup
Language (HTML) - The computer language
used to create hypertext documents, allowing connections from one document
or Internet page to numer-ous others. HTML is the primary language used
to create pages on the World Wide Web. Hypertext Transfer
Protocol (HTTP) - The first part of an address (URL) of a site on
the Internet, signifying a document written in Hypertext Markup Language
(HTML). Hz - See frequency. I IEEE - See Institute of Electrical and Electronics
Engineers. ILEC - See incumbent local exchange carrier. Inter-Exchange Carrier (IXC) - A long-distance
telephone carrier. International Organization of Standardization (ISO)
- Develops, coordinates, and prom-ulgates international standards that
facilitate world trade. International Telecommunication Union (ITU)
- A United Nations organization that coordinates use of the electromagnetic
spectrum and creation of technical standards for telecommunication and
radio communication equipment. International Telecommunication Union/Telecommunication
Standardization Sector (ITU-T) - The branch of the ITU that is responsible
for telecommunication standardization. Internet Engineering Task Force (IETF) - The
standards organization that standardizes most Internet communication protocols,
including Internet protocol (IP) and hypertext transfer protocol (HTTP). IETF - See Internet Engineering Task Force. Internet Protocol (IP) - The standard signaling
method used for all communication over the Internet Internet service provider (ISP) - An organization
offering and providing Internet access to the public using computer servers
connected directly to the Internet. Intranet - A network serving a single organization
or site that is modeled after the Internet, allowing users access to almost
any information available on the network. Unlike the Internet, intranets
are typically limited to one organization or one site, with little or
no access to outside users. IP - See Internet Protocol ISDN - See Integrated Services Digital Network. ISO - See International Organization of Standardization. ISP - See Internet Service Provider. ITU - See International Telecommunication Union. ITU-T - See International Telecommunication
Union/Telecommunication Standardization Sector. IXC - See Inter-exchange Carrier. J JPEG - See Joint Photographic Experts Group. K Kilobyte - One thousand bytes (see byte). L Last Mile - See local loop. Local Access Transport Area (LATA) - The geographical
areas defining local telephone ser-vice. Any call within a LATA is handled
by the local telephone company, but calls between LATAs must be handled
by long-distance companies, even if the same local telephone company provides
service in both LATAs. LATA - See Local Access Transport Area. Local Area Network (LAN) - A network connecting
a number of computers to each other or to a central server so that the
computers can share programs and files. LAN - See Local Area Network. Local Exchange Carrier (LEC) - A local telephone
company. LECs provide telephone service for phone calls originating and
terminating within a single LATA. Local Loop - The copper lines between a customer's
premises and a telephone company's central office (See central office). Megabit - One million bits. Megabyte - 1,000,000 bytes, or 1,000 kilobytes
(see Byte). Microcell - a bounded physical space in which
a number of wireless devices can communicate. Millions of Instructions Per Second (MIPS)
- This is a common measure of the speed of a computer processor. Modem (MOdulator-DEModulator) - A device that
converts digital data into analog signals and vice-versa for transmission
over a telephone line. Moving Pictures Experts Group (MPEG) - A committee
formed by the ISO to set stan-dards for digital compression of full-motion
video. Also stands for the digital compression standard created by this
committee. MPEG-1 - An international standard for the
digital compression of VHS-quality, full-motion video. MPEG-2 - An international standard for the
digital compression of broadcast-quality, full-motion video. Multicast - The transmission of information
over the Internet to two or more users at the same time. Multiplexing - Transmitting multiple signals
over a single communications line or computer channel. The two common
multiplexing techniques are frequency division multiplexing, which separates
signals by modulating the data onto different carrier frequencies, and
time division multiplexing, which separates signals by interleaving bits
one after the other. N Narrowband - A designation of bandwidth less
than 56 kilobits per second. Narrowband ISDN - same as ISDN. Network Access Provider (NAP) - Another name
for a provider of networked telephone and associated services, usually
in the U.S. Network Service Provider (NSP) - A high-level
Internet provider that offers high-speed backbone services. Network Termination Equipment (NTE) - The equipment
at the ends of the communication path. N-ISDN - See Narrowband ISDN. NSP - See Network Service Provider. NTE - See Network Termination Equipment. O ONU - See Optical Network Unit. Optical Network Unit (ONU) - A form of access
node that converts optical signals transmitted via fiber to electrical
signals that can be transmitted via coaxial cable or twisted pair copper
wiring to individual subscribers. (See hybrid fiber/coax.) Packet-Switched Network - A network that allows
a message to be broken into small "packets" of data that are
sent separately by a source to the destination. The packets may travel
different paths and arrive at different times, with the destination sites
reassembling them into the original message. Packet switching is used
in most computer networks because it allows a very large amount of information
to be transmitted through a limited bandwidth. P Peripheral - An external device that increases
the capabilities of a communication system. Point Of Presence (POP) - The physical point
of connection between a data network and a telephone network. PON - See Passive Optical Network. POP - See Point Of Presence. Postal, Telegraph and Telephone (PTT) - The
generic European name usually used to refer to state-owned telephone companies. POTS - See Plain Old Telephone Service. POTS splitter - A device that uses filters
to separate voice from data signals when they are to be carried on the
same phone line, required for several types of DSL service. PRI-ISDN - See primary-rate ISDN. PTT - See Postal, Telegraph and Telephone.
public switched telephone network (PSTN) - The worldwide communications
network that carries phone calls and data. R RADSL - See Rate-adaptive Asymmetric Digital
Subscriber Line. Rate-Adaptive Digital Subscriber Line (RADSL)
- A variation of DSL that uses carrierless amplitude phase modulation,
divides the available frequencies into discrete sub-channels and also
maximizes performance by adjusting the transmission to the quality of
the phone line while in use. RBOC - See Regional Bell Operating Company. Regional Bell Operating Company (RBOC) - One
of the seven local telephone companies formed upon the divestiture of
AT&T in 1984. The seven are: NYNEX, Bell Atlantic, BellSouth, Southwestern
Bell, U S WEST, Ameritech, and Pacific Telesis. Roaming - movement of a wireless note between
two microcells. Router - The central switching device in a
packet-switched computer network that directs and controls the flow of
data through the network. S Small Computer System Interface (SCSI) [pronounced
"scuzzy"] - A type of interface between computers and peripherals
that allows faster communication than most other interface standards,
often used to connect PCs to external disk drives. Symmetric Digital Subscriber Line (SDSL) -
A DSL technology that provides a maximum bandwidth of 1.5 megabits per
second using one phone line, with a downstream transmission rate that
equals the upstream transmission rate, and that allows use of POTS service
on the same phone line. SDSL also refers to Single-Line Digital Subscriber
Line. Contrast with Asymmetric Digital Subscriber Line. T T-1 - A dedicated digital communication link
provided by a telephone company that offers 1.544 megabits per second
of bandwidth, commonly used for carrying traffic to and from private business
networks and Internet service providers. T-3 - A dedicated digital communication link
provided by a telephone company that offers 44.75 megabits per second
of bandwidth, commonly used for carrying traffic to and from private business
networks and Internet service providers. TCP/IP - See Transmission Control Protocol/Internet
Protocol. Terabyte - 1,000,000,000,000 bytes, or 1,000
gigabytes (see Byte). Transmission Control Protocol/Internet Protocol
(TCP/IP) - A method of packet-switched data transmission used on the
Internet. The protocol specifies the manner in which a signal is divided
into parts, as well as the manner in which "address" information
is added to each packet to ensure that it reaches its destination and
can be reassembled into the original message. Twisted Pair - The set of two copper wires
used to connect a telephone customer with a switching office, loosely
wrapped around each other to minimize interference from other twisted
pairs in the same bundle. Synonymous with 2-wire line. U Uniform Resource Locator (URL) - A text-based
address used to identify specific resources on the Internet, such as web
pages. URLs are arranged in a hierarchical form that specifies the name
of the server on which a resource is located (such as www.2wire.com) and
the name of the file on that server (www.2wire.com/index.html). Universal ADSL Working Group (UAWG) - An organization
composed of leading personal computer industry, networking and telecommunications
companies with the goal of creating an interoperable, consumer-friendly
ADSL standard titled the G.992.2 standard, and commonly referred to as
the G.lite standard. Universal Serial Bus (USB) - A computer interface
with a maximum bandwidth of 1.5 Megabytes per second used for connecting
computer peripherals such as printers, keyboards and scanners. URL - See Uniform Resource Locator. USB - See Universal Serial Bus. USP - See universal service provider. V VDSL - See very high bitrate digital subscriber
line. very high bitrate digital subscriber line (VDSL) - An asymmetric
DSL that delivers from 13 to 52 megabits per second downstream bandwidth
and 1.5 to 2.3 megabits per second upstream. Videoconference - Interactive, audiovisual
communication among three or more people at two or more sites. Virtual Reality Markup Language (VRML) - A
computer language that provides a three-dimensional environment for traditional
Internet browsers, resulting in a simple form of virtual reality available
over the Internet. VOD - See Video On Demand. VRML - See Virtual Reality Markup Language. W WAN - See Wide Area Network. Wide Area Network (WAN) - A network that interconnects geographically-distributed computers or LANs. Wireless Node - a user computer with a wireless network interface card. Top of Page X xDSL - See DSL.
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