=============================================================================== _ _ _______ | \/ | / _____/ |_||_|etal / /hop __________/ / /___________/ (314)432-0756 Proudly Presents The MCI Telecommunications Glossary Part I Volume IV (T - W) Typed and edited by Knight Lightning =============================================================================== - T - T-CARRIER A time-division, pulse modulation, voice carrier used on exchange cable to provide short-haul trunks. TAIL END HOP OFF (TEHO) In a private network, a call which is carried over a flat rate facilities (Intermachine Trunks or IMT) to the closest switch node to the destination of the call, and then connected into the public network as a local call. TANDEM A switching arrangement in which the trunk from the calling office is connected to a trunk to the called office through an intermediate point. TANDEM SWITCHING SYSTEM Synonym: Tandem Tie Trunk Network. TANDEM TIE TRUNK NETWORK (TTTN) A serving arrangement which permits sequential connection of tie trunks between PBX/CENTREX locations by utilizing tandem operation. TANDEM TRUNKING Trunks which connects two or more switches together. TARIFF The published rates, regulations, and descriptions governing the provisions of communications service. TELCO Local telephone company. TELECOMMUNICATIONS The transmission of voice and/or data through a medium by means of electrical impulses and includes all aspects of transmitting information. TELEGRAPH A system employing the interruption of, or change in, the polarity of DC current signaling to convey coded information. TELEPHONE A device which converts acoustical (sound) energy into electrical energy for transmission to a distant point. TELETYPEWRITER A machine used to transmit and/or receive communications on printed page and/or tape. TERMINAL (1) The device used at a subscriber's location for purposes of communicating, such as the telephone instrument, teleprinter, computer terminal, etc., (2) The "end point" or extremity" such as Terminal Pole of an open wire line, or Terminal Office representing the final central office in a switching network where the subscriber's call originates or terminates. TERMINAL EQUIPMENT Devices, apparatus, and their associated interfaces used to forward information to a local customer or a distant terminal. TERMINATION (1) An item that is connected to the terminal of a circuit or equipment. (2) An impendance connected to the end of a circuit being tested. TIE-LINE A private line connecting two PBXs. TIME DIVISION MULTIPLEXING (TDM) Equipment which enables the transmitting of a number of signals over a single path by transmitting them sequentially at different instants of time. TOLL CALL Any call to a point outside the local service area. TOLL CENTER (1) A central office where operators (human or mechanical) are present to assist in completing incoming toll calls. (2) A center for the switching of toll calls. TOLL PLANT The facilities that connect toll offices throughout the country. TOUCH-TONE ADAPTOR A device that can be connected to a rotary dial telephone to allow for DTMF signaling. TRAFFIC Calls being sent and received over a communications network. TRAFFIC MEASUREMENT AND RECORDING A computer generated report showing usage SYSTEMS (TMRS) usage information of telephone systems. Usually this includes trunk utilization, outages, queueing time, and the need for additional common equipment. TRAFFIC SERVICE POSITION SYSTEM A toll switchboard position configured (TSPS) as a push button console. TRANSMISSION The electrical transfer of a signal, mesage or other forms of data from one location to another without unacceptable loss of information content due to attenuation, distortion, or noise. TRANSMISSION LEVEL The level of power of a signal normally 1,000 Hz, which should be measured at a particular reference point. TRANSMISSION SPEED Number of pulses or bits transmitted in a given period of time, usually expressed as Bits Per Second (BPS) or Words Per Minute (WPM). TRUNK A single circuit between two points both of which are switching centers and/or individual distribution points. TRUNK GROUP An arrangement of communications channels into an identical group. TRUNK TYPE (TT) Trunks that use the same type of equipment going to to the same terminating location. TRUNK UTILIZATION REPORT (TUR) A computer printout detailing the traffic use of a trunk. TWO-WIRE CIRCUIT 1. A channel for tranamitting data in one direction at a time. 2. A short distance channel using a single send/receive pathway, usually 2 copper wires, connecting a telephone to a switch. TELETYPEWRITER EXCHANGE SERVICE A service whereby a customer's leased (TWX) teletypewriter is connected to a "TWX" switchboard and from there connected over regular toll circuits to teletypewriter of any U.S. customer who subscribes to a similar service. - U - UNIFORM CALL DISTRIBUTOR (UCD) A device located at the telephone office or in a PABX which distributes incoming calls evenly among individuals. UNIFORM SERVICE ORDER CODE (USOC) The information in coded form for billing purposes by the local telephone company pertaining to information on service orders and service equipment records. - V - VALUE-ADDED NETWORK SERVICE (VANS) A data transmission network which routes messages according to available paths, assures that the message will be received as it was sent, provides for user security, high speed transmission, and conferencing among terminals. VIA NET LOSS (VNL) The lowest loss in dB at which a trunk facility can be operated considering limitations of echo, crosstalk, noise, and singing. VOICE CONNECTING ARRANGEMENT An interface arrangement provided by the telephone company to accomodate the connections of non-carrier provided voice terminal equipment to the public switched telephone network. VOICE FREQUENCY (VF) Any of the frequencies in the band 300-3,400 Hz which must be transmitted to reproduce the voice with reasonable fidelity. VOICE GRADE FACILITY (VGF) A circuit designed to DDD network standards which is suitable for voice, low-speed data, facsimile, or telegraph services. - W - WIDE AREA TELECOMMUNICATIONS A special direct distance dialing (toll) SERVICE (WATS) service whereby a subscriber installs a dedicated line arranged for either inward or outward calls (not both) between the customer's premises and a specific gepgraphic area. WIDEBAND A term applied to facilities or circuits where bandwidths are greater than that required for one voice channel. WIRE CENTER The physical structure that house one or more channel office switching systems. ======================================-======================================== This concludes Part I Volume IV of the MCI Telecommunications Glossary. Look for more G-philes on MCI by Knight Lightning coming soon to Metal Shop. This has been a 2600 Club production Thanx to Taran King Call The Works BBS - 1600+ Textfiles! - [914]/238-8195 - 300/1200 - Always Open