Equal loss at all frequencies, such as caused by attenuators.
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.
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.”
Coaxial cable that has a layer of viscous, non-hardening, non-drying material placed between the shield and jacket to provide water proofing and sealing properties. [Arr11]
A sticky substance placed between the aluminum sheath and the jacket of a coaxial cable to maintain a protective seal should the jacket develop any cuts. [Arr11]
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).
The distance from the reflective surface of a parabolic antenna to the point at which incoming satellite signals are focused; the focal point. [Arr11]
The point to which incoming satellite signals are focused from the reflective surface of a parabolic antenna. [Arr11]
An aluminum-based metallic foil which overlies the dielectric insulation of a coaxial cable to provide a shielding effect. [Arr11]
The geographic area towards which a satellite downlink antenna directs its signal. The measure of strength of this footprint is the EIRP. [Arr11]
The direction of radio frequency (RF) signal flow away from the headend toward the end user; equivalent to downstream.
Field Programmable Gate Array; a type of logic integrated circuit (IC) that can be programmed. An FPGA is similar to a programmable logic device (PLD), but whereas PLDs are generally limited to hundreds of gates, FPGAs support up to many thousands of gates. They are especially popular for prototyping complex integrated circuit (IC) designs. Once the design is set, hardwired chips are produced for faster performance. [Web11_FPGA]
A process to eliminate frequency interference between different satellite systems or between terrestrial microwave systems and satellites. In the U.S. this activity relies upon a computerized service utilizing an extensive database to analyze potential microwave interference problems that arise between organizations using the same microwave band. [Sat07]
A technique which maximizes the capacity of a communications satellite through the use of specially isolated beam antennas and/or the use of dual polarities. [Sat07]
The direction of the signal flow away from the headend. See also downstream. [Arr11]
Forward Error Correction (FEC)
FEC enables the receiver to detect and fix errors to packets without the need for the transmitter to retransmit packets.
Also known as Downstream or Forward Channel. Signals are transmitted to a subscriber from the headend.
Field Programmable Gate Array
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.
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.
One complete picture consisting of two fields of interlaced scanning lines.
The rate at which a complete frame is scanned nominally 30 frames per second.
The percentage of frames that did not reach the destination.
The frame rate is the rate at which still images are shown on a screen in order to achieve a full-motion effect. A slow frame rate makes for a flickering, stuttering image. A fast frame rate improves the image quality of a motion sequence. Generally, 15 frames per second is the minimum amount for avoiding motion problems. Any less, and the motion sequence begins to flicker. Standard televisions these days display between 30 (interlacing) and 60 (progressive) images per second. [Glo07]
A frame set consists of one downstream, one upstream and one background frame size.
The size of the frames being generated and sent by the SmartBits Tester (including cyclic redundancy check [CRC]).
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.
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.
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 Multiplexing (FDM)
Frequency division is a method for multiplexing several carriers on a transmission system by assigning a different frequency to each, thus each separate carrier can be recovered by tuning. In optical communications, one also encounters wavelength division multiplex (WDM) which involves the use of several distinct optical sources, each having a distinct center lightwave frequency. [Arr11]
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.
The change of signal gain and phase with frequency.
Frequency Shift Keying (FSK)
A form of frequency modulation commonly used in low-speed modems in which the two states of the signal are transmitted as two separate frequencies. [Arr11]
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.
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.
A ratio, measured in decibels, of the rejection of unwanted off-air signals received at the back of an antenna versus the reception of desired off-air signals received at the front of the antenna. [Arr11]
Full Service Network
File Transfer Protocol
Fiber To The Antenna; commonly used to describe OC-192 SONET 10Gbps connections made between cable operator backhaul networks and cellular system antennas. May also be used to describe fiber optic connections between S-MATV (Satellite, Master Antenna Television) and SATCOM-DBS (Satelitte Communications, Direct Broadcast System) systems.
Fiber To The Building
Fiber To The Business
Fiber To The Curb
Fiber To The Desk
Fiber To The Home
Fiber To The Node
Fiber To The Premise
Fiber To The School
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 cannot hear the other party. See also Half Duplex.
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.
A method of operating a communications circuit so that each end can simultaneously transmit and receive.
Not compressed; a standard video signal of 30 frames per second, 525 horizontal lines per frame, capable of complete action.
Full Width, Half Maximum (FWHM)
The absolute difference between the wavelengths at which the spectral radiant intensity is 50 percent of the maximum power. [Fib111]
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.
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.
A splice accomplished by the application of localized heat sufficient to fuse or melt the ends of two lengths of optical fiber, forming a continuous single fiber. [Arr11]
An instrument which permanently joins two optical fibers by welding their cores together with a brief electric arc. [Arr11]
Nondispersion-Shifted Fiber (ITU-T G.652). The ITU-T G.652 fiber is also known as standard single-mode fiber (SMF) and is the most commonly deployed fiber. This fiber has a simple step-index structure and is optimized for operation in the 1310-nm band. It has a zero-dispersion wavelength at 1310 nm and can also operate in the 1550-nm band, but it is not optimized for this region. The typical chromatic dispersion at 1550 nm is high at 17 ps/nm-km. Dispersion compensation must be employed for high-bit-rate applications. The attenuation parameter for G.652 fiber is typically 0.2 dB/km at 1550 nm, and the PMD parameter is less than 0.1 ps/ km. An example of this type of fiber is Corning SMF-28.
G Type Connector
An unthreaded, push-on version of the 75-Ohm impedance Type F-connector. Type G is a slide-on alternative to the Type F with 15A continuous current rating. Amphenol Type G connectors comply with the Mil-Std 202 specification for vibration, shock, thermal shock, moisture resistance and salt spray. Since the Type G has an impedance of 75 Ω, it is ideal for CATV applications. Type G connectors include Coaxial Cable Receptacles, Bulkhead Mount Jack Receptacles and PCB Mount Jack Receptacles.
Illustration courtesy of Amphenol® RF, http://www.amphenolrf.com/products/typeg
Gallium Aluminum Arsenide; generally used for short wavelength light emitters. [Fib111]
Gallium Arsenide; used in light emitters. [Fib111]
A measure of amplification expressed in dB. Gain of an amplifier is usually specified at the highest frequency of operation, for example, at Channel 13 of all- band equipment.
An adjustable control that changes the gain of an amplifier.
A linear variation in gain from the lowest frequency to the highest frequency.
Gallium Indium Arsenide Phosphide; generally used for long wavelength light emitters. [Fib111]
Gallium Nitride; a wide bandgap III-V compound semiconductor process suitable for low noise, high RF power out, ultra linear amplification from DC to 60 GHz. GaN die enabled power doublers (PDs) within cable operator HFC network optical nodes, trunk/bridger, and line extender (LE) amplifiers offer the capability to replace HFC network line amplifiers using Gallium Arsenide (GaAs) and silicon die based amplifier modules in a two-to-one ratio. In addition GaN amplifier die are more rugged than GaAs die amplifiers in fielded applications with respect to surge and transient voltage conditions. In summary, GaN die based amplifiers employed within HFC networks have the following advantages versus any other available semiconductor process available today:
High RF output amplifiers (to >+60dBmV to 1.2 GHz bandwidth; 1024-QAM carriers)
Wide band gap: GaN-3.4 eV, GaAs-1.4 eV, Si-1.2 eV for ruggedness against electrostatic discharge (ESD), surge, and transient voltage conditions
Higher operational temperatures possible in fielded products without degradation
Higher operating voltages than GaAsFETs or Silicon die based amplifiers (operation from +90Vdc power supplies is possible today as some commercially available GaN amplifier die have a 400Vdc breakdown voltage)
10 times higher power density @ wide bandwidth (up to 4GHz)
2 x better thermal conductivity than GaAs
Higher output level + robustness + thermal stability + lower noise all at the same time!
GaN Die Enabled Amplifier Benefits Summary, courtesy of Vector presentation, “Impact of GaN amplifiers on the performance of future cable plant”, Maciej Muzalewski, 17 Nov 09