The Cable Center

This glossary of cable and telecommunications terms is intended to enhance your understanding of this dynamic industry. We are able to present this information with the generous help of CableLabs - consult their website for the most up-to-date information about cable technology.

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F-Connector
The final piece of hardware (familiar to subscribers) on a drop cable. It is cylindrical with a center pin sticking out, that plugs into the set-top box, cable ready TV or VCR.

F-Link
F-Links are Signaling System Number 7 (SS7) links that directly connect two SS7 end points, such as two signal switching points (SSPs). ‘F’ stands for “Facility Associated.”

Facsimile
The electronic transmission of pictures, charts, graphs, etc., from one place to another by radio, telegraphy or telephone. With special facsimile equipment, a home television receiver may be able to deliver mail and newspapers by cable.

Factory Alignment
Refers to the bench test alignment conditions with the slope and gain controls (where applicable) are turned to maximum and no pad or equalizer is installed. These specs can be used to verify operation during a bench test.

Fading
The reduction in signal intensity of one or several of the components of a radio signal, typically caused by the reflective or refractive effects of multi-path.

Favorites
The Internet Explorer equivalent of a bookmark, it is a Web site location which has been saved to an organized list for quick access at a later time.

Federal Communications Commission (FCC)
The agency that regulates communications services, including cable television, at the federal level. Or a US Federal agency responsible for establishing policies to govern interstate and international communications.

Feeder Cable
Coaxial cables that run along streets within the served area and connects between the individual taps which serve the customer drops.

Feeder Line
Cable distribution lines that connect the main trunk line or cable to the smaller drop cable.

Fiber Distributed Data Interface (FDDI)
A network based on the use of optical fiber to transmit data at a rate of 100Mbps. Or a fiber-based LAN standard.

Fiber Node
A point of interface between a fiber trunk and the coaxial distribution.

Fiber Optics
(1) Very thin and pliable tubes of glass or plastic used to carry wide bands of frequencies. (2) Transmission medium that uses glass or plastic fibers vs. other, copper-based wires to transmit data or voice signals. Fiber-optic cable offers much greater capacity and transmission speeds than traditional mediums.

Field
One half of a complete picture (or frame) interval, containing all of the odd or even scanning lines of the picture.

Field Frequency
The rate at which a complete field is scanned, nominally 60 times a second.

File & Print Sharing
A network component which allows a user to share files or printers on their computer with others on the network.

File Transfer Protocol (FTP)
A method used to exchange files between computers on a network or the Internet using the TCP/IP protocol. It can also be the verb used to describe that transfer (“I need to FTP a file to them”).

Filter
A circuit that selects the frequency of desired channels. Used in trunk and feeder lines for special cable services such a two-way operation.

Flat Loss
Equal loss at all frequencies, such as caused by attenuators.

Flat Outputs
Operation of a cable television system with equal levels of all TV signals at the output of each amplifier.

Flexible Call Offering (FCO)
Defined by Bellcore as a grouping of three common voice telephone features, call transfer, drop, and hold. Also called the Big Three Feature Set by some companies, FCO is a component of the Easy ISDN1 ordering code.

Flow [DOCSIS Flow]
A unidirectional sequence of packets associated with a Service ID and a QoS. Multiple multimedia streams may be carried in a single DOCSIS Flow. Also known as DOCSIS-QoS “service flow”

Flow [IP flow]
A unidirectional sequence of packets identified by OSI Layer 3 and Layer 4 header information. This information includes source/destination IP addresses, source/destination port numbers, protocol ID. Multiple multimedia streams may be carried in a single IP Flow.

FM Cable System
FM radio signals offered by the cable system (the cable must be connected to the subscriber’s FM stereo receiver)

Forward Error Correction (FEC)
FEC enables the receiver to detect and fix errors to packets without the need for the transmitter to retransmit packets.

Forward Channel
The direction of radio frequency (RF) signal flow away from the headend toward the end user; equivalent to downstream.

Forward Traffic
Also known as Downstream or Forward Channel. Signals are transmitted to a subscriber from the headend.

Fractional T-1
A Fractional T-1 is a full-blown, two-pair T-1 data connection that has been fractionalized, or set up so that it offers data throughput only a fraction of standard 1.54Mbps T-1 speeds. Data service companies offer them in a range of speeds (128, 254, 382, 512, and 764Kbps), and they cost less than full T-1. Fractional and full-blown T-1 lines all use the same CSU/DSU line driver equipment. That means that fractional T-1 user can increase or decrease the speed of their data connection to match demand without changing their data communications equipment.

Fragmentation
When broad television audiences break into smaller segments due to multiple viewing choices and niche programming that targets particular demographics. Also applies to packets in a transmission as a part of DOCSIS 1.1.

Frame
One complete picture consisting of two fields of interlaced scanning lines.

Frame Frequency
The rate at which a complete frame is scanned nominally 30 frames per second.

Frame Loss
The percentage of frames that did not reach the destination.

Frame Set
A frame set consists of one downstream, one upstream and one background frame size.

Frame Size
The size of the frames being generated and sent by the SmartBits Tester (including cyclic redundancy check [CRC]).

Franchise
A contract between a cable television company and a municipal government authorizing the company to install cable and offer cable television service within the community.

Franchising Authority
Governmental body responsible for awarding franchise, specifying the terms of a franchise, and regulating its operation. While the franchise authority is usually a local city or county body, some areas are regulated exclusively on the state level.

Frequency
The number of times a complete electromagnetic wave cycle occurs in a fixed unit of time, usually one second. The rate at which a current alternates, measured in Hertz on a telecommunications medium.

Frequency Division Duplex (FDD)
The simultaneous exchange of uplink and downlink information on different frequencies.

Frequency Division Multiple Access (FDMA)
A multiple access technology that separates users by putting each traffic channel on a discrete frequency band.

Frequency Modulation (FM)
A common method of transmitting information over a carrier wave by changing its frequency.

Frequency Response
The change of signal gain and phase with frequency.

Front End
The first radio-frequency amplifier stage on a receiver. This is one of the most critical components of the receiver because the sensitivity of the front end dictates the sensitivity of the entire receiver.

Front Porch
That portion of the composite picture signal which lies between the leading edge of the horizontal blanking pulse, and the leading edge of the corresponding sync pulse.

Full Duplex
Means that communications between two end points can take place at the same time. A standard voice telephone call is a full-duplex call because both parties can talk at the same time and be heard. A short wave radio conversation between two people is not full duplex because the person talking has to press the transmit button to talk, and while he is talking he can not hear the other party. See Half Duplex.

Full-Duplex Transmission
A method of operating a communications circuit so that each end can simultaneously transmit and receive.

Full-Motion Video
Not compressed; a standard video signal of 30 frames per second, 525 horizontal lines per frame, capable of complete action.

Full Network Station
A commercial television broadcast station that generally carries 85 percent of the hours of programming offered by one of the three major national networks during its weekly prime time hours.

Full Service Network (FSN)
Cable networks that are intended to provide broadcast TV, Internet access, VOD, and voice telephony simultaneously.

Fully Integrated System
A cable television system designed to take advantage of the optimum amplifier-cable relationship for highest performance at lowest cost. Such a system is also admirably suited to the fully automated cable television system concept.

Function
A function is a process which conveys or transforms data in a predictable way. It may be affected by hardware, software or a combination of the two.