A network-provided service feature in which a user pays a higher flat rate to obtain wider geographical coverage without paying per-call charges for calls within the wider area.

See EBCDIC.

In T-carrier, a synchronization frame that delineates 24 DS1 frames
Note: ESF requires less frequent synchronization than the T-carrier D-4 superframe format. This frees overhead bits for on-line, real-time testing, and monitoring of circuit parameters. ESF also facilitates nonchannelized operation and clear-channel operation.

Television in which (a) improvements are made to the standard National Television System Committee (NTSC) television system, (b) the improvements are receiver-compatible with the standard NTSC television system, and (c) the improvements modify the standard NTSC television system emission standards.
Note 1: EDTV improvements may include (a) a wider aspect ratio, (b) a higher picture definition than NTSC definition, and… (Read More →)

A property of a system, format, or standard that allows changes in performance or format within a common framework, while retaining partial or complete compatibility among systems that belong to the common framework. [FCC ACATS]

See XML.

In telephony, a user end device, separate from a subscriber telephone, which device produces an audible signal indicating that there is an incoming call from a switchboard or exchange. [From Weik '89]

The first bit of each octet of the address field of a packet. The first octet is identified by the extension bit set to 0, and the second octet is identified by the extension bit set to
1. [T1.312-1991]

A facility that provides access to communications for a user or group of users isolated from a central communications node.

A terminal that is added to an existing terminal and that uses the same circuit and address, i.e., port and number, as the terminal to which it is added.