This xDSL Glossary is ©1996 Todd
Ogasawara
Reproduction of the glossary is not
permitted without prior permission from the copyright holder.
Select the first letter of the word from the list above to
jump to appropriate section of the glossary. If the term you are
looking for starts with a digit or symbol, choose the '#' link.
- aardvark
- Animal commonly referred to as an "ant-eater."
-
- ADSL
- Asymetric Digital Subscriber Line. 1.5 to 9Mbps downstream.
16 to 640Kbps upstream.
-
- ATM
- Asynchronous Transfer Mode.
- apple
- A popular fruit.
-
- bit
- A contraction for BInary digiT. A bit has only two
states: Off or on (0 or 1).
-
- byte
- A data length unit consisting of 8 bits with a value
range from 0 to 255 (28-1).
- Cable Modem
- This device is not really a modem in the
modulator-demodulator sense. It is a device that uses
Cable TV fiber/coax transport facilities to deliver
Ethernet-like data network services.
-
- CAP
- Carrierless Amplitude Phase. One of two methods used to
provide ADSL. See also DMT.
-
- CPE
- Customer Premise Equipment.
-
- DirecPC
- A satellite based service from Hughes Network Systems
that delivers an extremely asymetric bandwidth service.
The downstream data from the
satellite to the user's satellite dish is 400Kbps. The upstream data is sent using a POTS based analog modem limited to
33.6Kbps (V.34 Annex 12).
-
- DMT
- Discrete MultiTone. One of two methods used to provide
ADSL. See also CAP.
-
- downstream
- Data moving from the head-end source to the customer. See
also upstream.
-
- DSLAM
- Digital Subscriber Line Access Multiplexer.
-
- DWMT
- Discrete Wavelet MultiTone. A cable modem modulation
scheme. See also QPSK.
- (empty)
- FDM
- Frequency Division Multiplexing
-
- (empty)
-
- HDSL
- High-data-rate Digital Subscriber Line. 1.544Mbps using two twisted pair lines. 2.048Mbps using three twisted pair lines.
-
- HFC
- Hybrid Fiber Coaxial.
-
- IEEE
- Institute for Electronic and Electrical Engineers.
-
- IETF
- Internet Engineering Task Force.
-
- IPng
- Internet Protocol next generation.
-
- ISDN-BRI
- Integrated Services Digital Network-Basic Rate Interface.
-
- ITU
- International Telecommunications Union.
- (empty)
- (empty)
- LAN
- Local Area Network. See also WAN.
-
- LMDS
- Local Multipoint Distribution Service. A broadband
wireless technology that provides two-way digital
broadcasting using ground based tranceivers instead of
satellites.
-
- Local Loop
- The
-
- Mbps
- Megabits per second. This is the usual unit of measure
for network speed. Note that it is measuring the
throughput of millions of bits
and not bytes per second.
-
- MPEG
- Motion Pictures Expert Group.
-
- NIC
- Network Interface Card.
- (empty)
-
- POP
- Point Of Presence.
-
- POTS
- Plain Old Telephone Service.
-
- PSTN
- Public Switched Telephone Network
-
-
- QAM
- Quadrature Amplitude Modulation.
-
- QPSK
- Quadrature Phone Shift-Keying
-
- RADSL
- Rate Adaptive Digital Subscriber Line. 600Kbps to 7Mbps
(or 32Kbps to 8Mbps) downstream. 128Kbps to 1Mbps (or
64Kbps to 1Mbps) upstream. RADSL permits simultaneous
voice and data communications with little impact on data
throughput.
-
- RBOC
- Regional Bell Operating Company. Any of the independent
regional telephone companies (Baby Bells) that were
formed after the breakup of AT&T in 1984. Ameritech,
Bell Atlantic/Nynex (now merged), Bellsouth, SBC/Pacific
Telesis (now merged), US West.
-
- RG
- Residential Gateway. An intelligent crossconnect device
that provides termination for all access networks to the
home as well as termination for all home networks
(telephones, televisions, alarms, etc.).
-
- SDSL
- Single-line Digitial Subscriber Line. 1.544 or 2.048Mbps
on a single line pair.
- T1E1.4
- The ANSI committee in charge of ADSL
standards.
-
- 10Base-T
- A type of ethernet that uses unshielded twisted pair
cable.
- upstream
- Data moving from the subscriber to the head-end. See also
downstream.
-
-
- VDSL
- Very-high-data-rate Digital Subscriber Line. 13 to 52Mbps
downstream. 1.5 to 2.3Mbps upstream.
- WAN
- Wide Area Network. See also LAN.
- (empty)
- (empty)
- (empty)
- (empty)
- (empty)
Revised: March 17, 1997.
Copyright © 1996 by Todd Ogasawara
All trademarks or product names mentioned herein are the property
of their respective owners.