Wired Broadband and Related Industry Glossary of Terms with Acronyms As of 13 June 2011 Compiled By: Conrad L. Young, Director, Broadband Technical Strategy



Download 6.44 Mb.
Page64/69
Date conversion08.07.2018
Size6.44 Mb.
1   ...   61   62   63   64   65   66   67   68   69

A three-port optical coupler. [Fib111]

Tee Coupler Diagram courtesy of Fiber Optics info, http://www.fiber-optics.info/fiber_optic_glossary/t


TEI
Terminal Endpoint Identifier

Telco
A local exchange telephone carrier.

Telecommunications


Communicating over a distance through wire, radio, optical or other electromagnetic means.


Telecommunications & Internet Protocol Harmonization Over Network (TIPHON)
A project within the European Telecommunications Standards Institute (ETSI) aimed at enabling systems level interoperability for Voice Over IP technologies. ETSI has historically been focused primarily on H.323-based systems; however, they recently have become interested in MGCP-based technologies, such as PacketCable NCS.

Telecommunications Management Network (TMN)


A management concept that defines the relationship between basic network functional building blocks (operations systems, data communications networks, and network elements) in terms of standard interfaces.

Teledensity


Teledensity refers to the number of telephone lines (including wired residential and business lines) per 100 people, a rough measure of the ubiquity of the public switched telephone network (PSTN) in a country.

Teledesic



The name of the U.S. proposed low earth orbit (LEO) satellite system that would deploy 840 satellites for global telecommunications services. [Sat07]
Telephone Number (TN)
A 10-digit number that specifies the location of a particular telephone and consists of a 3-digit area code, 3-digit central office code, and 4-digit station number.

Teletext


Broadcast service using several otherwise unused scanning lines (vertical blanking intervals) between frames of TV pictures to transmit information from a central database to receiving television sets.

Television


The electronic transmission and presentation of pictures and sounds.

Television Broadcast Band



In North America, the UHF and VHF frequencies extending from 54 to 890 MHz assigned to television broadcast stations. These include VHF channels 2-13 and UHF channels 14-69. [Arr11]. The following is a summary of North America OTA TV broadcast band changes and variations from the 1940s to today. Channel 1 was removed early on as a community television reservation and given to amateur radio and other uses. Channels 70 through 83 were removed from the bandplan in the 1980s to make way for AMPS mobile phone service. These channels were mainly used in the U.S., and mainly for broadcast translators, some of which continued in operation if their frequencies were not used by cellular. Channel 37 is allocated to radio astronomy and may not be used by any station. In the U.S., channels 52 through 69 are being reallocated for other purposes as the transition to digital television broadcasting is completed for low-power TV stations. All full-power analog broadcasts ended in June 2009, and all temporary full-power digital broadcasts moved back down to the lower channels. While most other countries abandoned VHF due to its poor suitability for TV broadcasting and allocation for Digital Audio Broadcasting, the FCC chose to cut high-UHF channels instead, because frequency-use rights could be auctioned for a greater price. Channels 14 through 19 are used for two-way radio in major cities on a non-interference basis, although the transition to digital television (DTV) has caused problems in certain instances when a previously unused channel has begun to be used for DTV broadcasts. The same holds true for wireless microphones and medical telemetry devices in that band. In most regions, new digital television stations are placed on UHF (14 to 51, except 37 and sometimes 14 and 20) or high-VHF channels (7-13), although others are used in some of the more crowded media markets. With virtual channel numbering, many digital televisions group digital channels with their corresponding analog broadcasts. For example, the first digital TV stream of a station that broadcasts analog TV on channel 4 will usually appear as 4-1 or 4.1 on a DTV receiver, even though the digital transmissions may be on channel 38. Several digital subchannels can be multiplexed together, so 4-1 through 4-5 might be used by one station. Subchannel 0 (e.g., 4-0) designates the analog broadcast. In the U.S., all channels from 7-36 and 38-51 are frequently used for digital TV broadcasts. However, VHF 2 to 6 are rarely used by DTV broadcasters due to ongoing problems with impulse noise, and channel 6 being an adjacent channel to the FM broadcast band. Additionally, VHF performance is poor for mobile TV, with ATSC-M/H being the standard finalized and approved in late 2009. The VHF bandplan was modified several times before 1948. The last change was the transfer of channel 1, originally intended as a low-power (less than 1,000 watts) LPTV community channel, to two-way land-mobile radio and the six-meter amateur radio band. [1] Amateur television (ATV) is used on four channels in the 420-450 MHz (70-centimeter) amateur band; UHF TV channel 14 starts at 470 MHz. These ATV channels are popular for repeater output and direct communications and are seen over-the-air with a cable-ready tuner set to channels 57 to 60 (14 being seen on 65). ATV is also used on the other amateur bands above 450 MHz. ATV is also known as HAM TV or Fast Scan TV. [Wik113]
Television Channel

For NTSC, a standard 6 MHz RF channel included in the television broadcast band. For PAL and SECAM variants, a standard 8 MHz RF channel included in the television broadcast band. [Arr11]
Television Households
A household having one or more television sets. Estimates for each county are based on an updating of ARB (American Research Bureau) TV penetration estimates. The number of households that watch television in any locality during prime-time hours determines the top 100 markets for FCC cable rules.

Television Market


A city or complex of closely associated cities served by commercial television broadcast signals from one or more TV stations located within the area. The FCC uses television markets for designating what kind of cable services an operator should provide in terms of signal carriage and non-broadcast channel use.

Television Receiver-Only (TVRO)


A satellite receive system consisting of a satellite antenna, LNA or LNB, satellite receiver and any other necessary electronic equipment and hardware needed to receive and process a satellite transmission of viewing. [Arr11]


Telnet
A TCP/IP protocol which allows terminal-type login access to computers on the Internet for the purpose of entering remote commands. The protocol name is capitalized; when used in the form “telnet,” it refers to the client software that implements the protocol, or the act of using the protocol.


Telstar

The AT&T Corporation has maintained its trademark for the Telstar name and currently operates its domestic satellite system under the Telstar name. [Sat07]
Tensile Strength

The maximum stress that a material subjected to a stretching load can withstand without permanent damage. This is a common way of specifying the strength of optical fibers and cables. [Arr11]
TEP
Test Execution Package

Terahertz (THz)

1012 HZ. [Arr11]
Terminal
Generally, connection point of equipment, power or signal. Any “terminating” piece of equipment such as computer terminal.

Terminal Endpoint Identifier (TEI)
A unique number that the telephone company switching equipment assigns to each ISDN adapter when it is turned on or connected to a telephone line.


Termination

An electrical load connected to a cable, device, or net-work, to terminate the unit in a specific manner. Generally a termination will have the same impedance as the unit to which it is connected. [Arr11]
Terminator
A resistive load for an open coaxial line to eliminate reflections; usually capacitively coupled to avoid shorts in cable-powered systems.

Ternary



A semiconductor compound made of three elements (e.g., GaAlAs). [Fib111]
Terrestrial Interference (TI)

Interference of earth-based microwave communications with reception of satellite broadcasts. [Arr11]
Test Execution Package (TEP)
The actual set of instructions, scripts, results tables, and any other document used to test and report compliance with certain specifications.

TFTP
Trivial File Transfer Protocol (Trivial FTP)

TGS
Ticket Granting Server


Thermal Equalizer

A network of temperature-sensitive components which cause a loss inverse to the loss suffered in the cable caused by changes in temperature; a frequency equalizer con-trolled by pilot channels. [Arr11]
Thermal Noise

Noise resulting from thermally induced random fluctuation in current in the receiver’s load resistance. [Fib111]
Thermoelectric Cooling

A method of cooling in which an electric current is passed through two dissimilar metals joined at two points; heat is liberated at one junction and absorbed at the other junction (the process is the reverse of that in a thermocouple detector). In a thermo-electric refrigerator, the cold (heat-absorbing) junction is thermally coupled to the device to be cooled. [Arr11]
THHN

Thermoplastic high heat nylon. [Arr11]
Three-Axis Stabilization

Type of spacecraft stabilization in which the body maintains a fixed attitude relative to the orbital track and the earth's surface. The reference axes are roll, pinch, and yaw, by nautical analogy. [Sat07]
Third Harmonic

In a complex wave, a signal component whose frequency is three times the fundamental or original frequency. [Arr11]
Thickwire
Half-inch diameter coax cable.

Thinwire
Thin coaxial cable similar to that used for television/video hookups.

Third Harmonic
A third order beat whose three beating carriers all have the same frequency.


Third Order Beat
An unwanted carrier created by three separate carriers beating against each other. These beating carriers may have the same or different frequencies.


Threshold
The minimum level at which a signal of any kind can be detected, either by the human senses or by using any electronic instrument.


Threshold Extension

A technique used by satellite television receivers to improve the signal-to noise ratio of the receiver by approximately 3 dB (50%). When using small receive-only antennas, a specially equipped receiver with a threshold extension feature can make the difference between obtaining a decent picture or no picture at all. [Sat07]
Throughput
The speed at which the data is received. Throughput can be increased by compressing data before it is transmitted, then decompressed when it is received, or by using a more efficient transmission protocol.

Throughput Loss

In a coupler where the splitting ratio between output ports is not equal, the output port containing the greater power. [Fib111]
Thru Loss

See insertion loss.
Thruster

A small axial jet used during routine stationkeeping activities. These are often fueled bydrazine or bi-propellant. In time ion-engines will probably replace such thrusters. [Sat07]
THW

Thermoplastic high temperature wire.

TIA


Transimpedance Amplifier

TIA
Transmission Amplifier

Tick
The 6.25-microsecond time intervals that are the reference for upstream mini-slot definition and upstream transmission times in the DOCSIS protocol.


Ticket Granting Server (TGS)
A sub-system of the Key Distribution Center (KDC) used to grant Kerberos tickets.


TICL

Abbreviation for temperature induced cable loss. Optical loss as a result of extreme temperatures outside a fiber optic cable’s specifications. [Fib111]
Tiered Programming
A group of programs for which the customer is charged a fee. For example, most cable systems offer a satellite programming tier.

Tiering
Supplying cable subscribers with one or more program services beyond the basic offerings at an extra charge. Each additional price increment is called a tier.


Tight-Buffer

A material tightly surrounding a fiber in a cable, holding it rigidly in place. [Fib111]

Tight-Buffer Diagram courtesy of Fiber Optics Info, http://www.fiber-optics.info/fiber_optic_glossary/t


Tilt
Maximum difference in transmission gain of a cable television system over a given bandwidth (typically the entire forward operating frequency range).

Time Division Duplex (TDD)
The method of multiplexing transmit/ receive (uplink/downlink) parts of a communications link together; the exchange of uplink and downlink information takes place on the same frequency, but is distinguished by time-slot characteristics. See also Frequency Division Duplex.

Time Division Multiple Access (TDMA)



A communications technique that uses a common channel (multipoint or broadcast) for communications among multiple users by allocating unique time slots to each user. Used extensively in satellite systems, local area networks, physical security systems, and combat-net radio systems. [Fib111]
Time Division Multiplexing Access (TDMA)
A multiple access physical layer technology that enables a large number of users to access, in sequence, a single channel without interference by allocating unique time slots to each user within each channel. DOCSIS® 1.0, 1.1, and 2.0 use TDMA technology.

Time Division Multiplexer (TDM)

A device that permits the transmission of two or more independent data channels on a single high speed circuit by interleaving the data from each channel on the circuit by time. [Arr11]
Time of Day (ToD)
An internet protocol used by a device to learn the current time from a ToD server.


TIPHON
Telecommunications & Internet Protocol Harmonization Over Network

TL/1 or TL-1
Transaction Language 1

TLS
Transport Layer Security

TLV
Type/Length/Value

TMN
Telecommunications Management Network

TN
Telephone Number

ToD
Time of Day


Token
The character sequence or frame, passed in sequence from node to node, to indicate that the node controlling it has the right to transmit for a given amount of time.

Token Ring


Developed by IBM, this 4 or 16 Mbps network uses a ring topology and a token- passing access method.
Also, a ring-based network scheme in which a token is used to control access to a network. Used by IEEE 802.5 and Fiber Distributed Data Interface (FDDI). [Fib111]

Top 100 Market
Ranking of largest television broadcast areas by size of market; i.e., number of viewers and TV households. Used in FCC rulemaking and in selling of airtime to advertisers.


Topology
The arrangement of the nodes and connecting hardware that comprises the network. Types include ring, bus, star and tree.


ToS or TOS
Type of Service (also DiffServ Code Point, DSCP)


Total Activity Report (TAR)
A quarterly Nielsen report which lists all the television activity during a sweep including broadcast stations, basic cable, pay cable, and superstations. It shows household rating and share delivery by daypart in both the DMA (total market) and cable household universe for all program sources.

Total Internal Reflection



The reflection that occurs when light strikes an interface at an angle of incidence (with respect to the normal) greater than the critical angle. [Fib111]
Traceroute
A command-prompt utility in MS-DOS and UNIX that reports the gateways, or hops, that your data travels through on the Internet to reach its destination.


Traffic Parameter
A parameter for specifying a particular traffic aspect of a connection.


Transaction Capabilities Application Part (TCAP)
TCAP is a protocol within the signaling system number 7 (SS7) suite of protocols that is used to perform database queries across the SS7 network.


Transaction Language 1 (TL/1 or TL-1)
A management interface protocol defined to configure and manage Telco systems. Telco operations systems support (OSS) providers define this language. The TL-1 provides a specific syntax and it varies from one network element to another vendor.


Transceiver
A combination of a transmitter and a receiver having a common frequency control and usually enclosed in a single package. Extensively used in two-way radio communications at all frequencies.


Transducer
A device that converts one form of energy or disturbance into another. Transducers convert AC and DC into sound, radio waves, or other forms.


Transfer Orbit

A highly elliptical orbit which is used as an intermediate stage for placing satellites into geostationary orbit. [Sat07]
Transient Application
A transient application is an application that must be downloaded before it can be run and may be deleted afterward. Transient applications, such as a program enhancement, are typically delivered via the broadcast system or by request if 2- way functionality is present.

Transimpedance
The transfer function of a TIA, the output voltage divided by the input current.


Transistor
A semiconductor device consisting of three or four layers used for switching or amplification at frequencies ranging from direct current to ultra-high.


Transit Delays
The time difference between the instant at which the first bit of a PDU crosses one designated boundary, and the instant at which the last bit of the same PDU crosses a second designated boundary.


Translator
Relay system that picks up distant television signals, converts the signals to another channel to avoid interference, and retransmits them into areas that the original television signal could not reach.


Transmission

Passing information, using electromagnetic energy, from one point to another. [Arr11]
Transmission Amplifier (TIA)
A device used to convert input currents to output voltages.

Transmission Control Protocol (TCP)
A transport-layer Internet protocol which ensures successful end-to-end delivery of data packets without error.

Transmission Control Protocol/Internet Protocol (TCP/IP)
The most common protocol used for communication between computers on a network. Originally developed by the US Department of Defense for a worldwide communications network that eventually developed into the Internet.

Transmission Convergence Sublayer
A sublayer of the physical layer that provides an interface between the data link layer and the physical media dependent (PMD) Sublayer.


Transmission Levels

The signal levels (input and output), expressed in dBmV, that system amplifiers are operating at, or are designed to operate at, in a CATV system. [Arr11]
Transmission Link
The physical unit of a subnetwork that provides the transmission connection between adjacent nodes.


Transmission Loss

The ratio, expressed in decibels, between the level of power at the input to a system, cable, or device, and the level of power at the output. [Arr11]
Transmission Medium
The material on which information signals may be carried; e.g., optical fiber, coaxial cable, and twisted-wire pairs.


Transmission System
The interface and transmission medium through which peer physical layer entities transfer bits.


Transmit Delay
The time difference between the instant at which the first bit of a PDU crosses one designated boundary, and the instant at which the last bit of the same PDU crosses a second designated boundary.


Transmit On/Off Ratio
In multiple-access systems, the ratio between the signal powers sent to line when transmitting and when not transmitting.

Transmitter



In a fiber optic system, the device which converts a modulated electrical signal into an optical signal for transmission through a fiber. A transmitter typically consists of a light source (LED or diode laser) and driving electronics. [Arr11]

Fiber Optic Communications Network Transmitter to Receiver Diagram courtesy of Fiber Optics Info, http://www.fiber-optics.info/fiber_optic_glossary/t


Transponder
The part of a satellite that receives and transmits a signal.

1   ...   61   62   63   64   65   66   67   68   69


The database is protected by copyright ©dentisty.org 2016
send message

    Main page