电信专业英英词典T-1（在线收听）

　　T1 Carrier

　　A T1 carrier is a time-division multiplexed digital transmission facility capable of supporting 24 voice channels, (each encoded as a 64 kbps PCM DS0 signal), producing an aggregate multiplexer output signal at the 1.544 Mbps DS1 rate. Developed in the 1960s, the T1 carrier is designed to operate full duplex over two pairs in unshielded twisted pair (UTP) cable.

　　Tandem Switching System

　　A tandem switching system is a broad functional category describing systems that connect trunks to trunks, and route traffic through a network.

　　Tariff

　　A tariff is a published rate for a specific telecommunications service, equipment, or facility that constitutes a public contract between the user and the telecommunications supplier (i.e., carrier); tariff services and rates are established by and for telecommunications common carriers in a formal process in which carriers submit filings for federal or state government regulatory review, public comments, possible amendment, and approval.

　　TA

　　terminal adapter

　　TCP/IP

　　Transmission control protocol/internet protocol. TCP/IP is the transport layer and Internet layer, respectively, of the Internet suite of protocols. TCP corresponds to layer 4 of the OSI protocol stack: IP performs some of the functions of layer 3. It is a connectionless protocol used primarily to connect dissimilar networks to each other.

　　TCP

　　transmission control protocol

　　TDMA

　　time division multiple access

　　TDM

　　time division multiplexing

　　Telecommunications

　　Telecommunications is any process that enables one or more users to pass to one or more other users information of any nature delivered in any usable form, by wire, radio, visual, or other electrical, electromagnetic, optical means. The word is derived from the Greek tele, "far off," and the Latin communicare "to share."

　　Telecommunications Closet

　　In a premises distribution system, a telecommunications closet is an area for connecting the horizontal and backbone wiring and for containing active or passive PDS equipment.

　　Telecommunications Network

　　A telecommunications network is a system of interconnected facilities designed to carry traffic from a variety of telecommunications services. The network has two different but related aspects. In terms of its physical components, it is a facilities network. In terms of the variety of telecommunications services that it provides, it can support a set of many traffic networks, each representing a particular interconnection of facilities.

　　Telecommunications Service

　　Telecommunications service is a specified set of information transfer capabilities provided to a group of users by a telecommunications system.