Triple-Play Service Deployment

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Glossary
AAL5 ATM Adaptation Layer 5
Absorption In an optical fiber, loss of optical power resulting from conversion of power into heat.
AC-3 Audio compression standard adopted by ATSC and owned by Dolby.
Actual Down Rate Bearer channel rate downstream
Actual Up Rate Bearer channel rate upstream
ADC Analog to Digital Converter
ADSL Asymmetric Digital Subscriber Line. A digital subscriber line (DSL) technology in
which the transmission of data from server to client is much faster than the
transmission from the client to the server The difference between ADSL1 and
ADSL2/2+ is the standard that defines them:
ADSL1: ITU G.992.2
ADSL2: ITU G.992.3 and .4
ADSL2+: ITU G.992.5
ADSL2
(ITU G.992.3 and G.992.4) Adds new features and functionality targeted at improving performance and
interoperability, and adds support for new applications, services, and deployment
scenarios. Among the changes are improvements in data rate and reach
performance, rate adaptation, diagnostics, and stand-by mode.
ADSL2+ (ITU 9.992.5) Reached consent at the ITU in January 2003, joining the ADSL2 standards as G.992.5.
The ADSL2+ recommendation doubles the downstream bandwidth, thereby
increasing the downstream data rate on telephone lines to a maximum down
stream rate of 24 Mbps and with the use of a special Amendment 1 configuration, to
29 Mbps at the DSLAM.
ADSLAM Advanced Digital Subscriber Line Access Multiplexer. Concentrates and multiplexes
signals at the telephone service provider location to the broader wide area network.
APD Avalanche Photodiode. Photodiode which operates in the avalanche mode,
providing internal gain that is advantageous in reception.
ASCII American Standard Code for Information Interchange. Defines a conversion from
letters, numbers, and symbols (128) to a digital form of ones and zeros for use by
computers and data communications.
ASI Asynchronous Serial Interface. A standard DVB interface for a transport stream. See
also DVB Asynchronous Serial Interface
ATM Asynchronous Transfer Mode. A network standard that specifies fixed length cells to
transmit voice, video, and data information. ATM is scalable in that it can operate at
different transmission speeds such as 51, 100, 155, 622 Mb/s and beyond.
ATSC Advanced Television Systems Committee. The digital broadcasting standard
developed in the US and used in several countries worldwide. Digital broadcasting
standard developed in North America