FDDI – Fiber Distributed Data Interface
FDDI is a set of
ANSI and
ISO standards for data transmission on
Fiber Optic lines in a local area network (
LAN) that can extend in range up to 200 km (124 miles). FDDI is based on
Token Ring. In addition to being large geographically, an FDDI local area network can support thousands of users. FDDI is frequently used on the
Backbone for a wide area network (
WAN).
Fiber optic (or "optical fiber") refers to the medium and the technology associated with the transmission of information as light impulses along a glass or plastic wire or fiber. Fiber optic wire carries much more information than conventional copper wire such as 10BASE-5, 10BASE-2, 10BASE-T, or 100BASE-T and is far less subject to electromagnetic interference. Most telephone company long-distance lines are now fiber optic.
Transmission on fiber optic wire requires repeating at distance intervals. The glass fiber requires more protection within an outer cable than copper and fiber is more expensive than copper.
FDDI and 10BASE-F use fiber optic cable.
FIPS – Federal Information Processing Standards
FIPS are a set of standards that describe document processing, provide standard algorithms for searching, and provide other information processing standards for use within government agencies.
A firewall is a set of related programs, located at a network
Gateway Server, that protects the resources of a private network from users from other networks. (The term also implies the security policy that is used with the programs.) An enterprise with an
Intranet that allows its workers access to the wider Internet installs a firewall to prevent outsiders from accessing its own private data resources and for controlling what outside resources its own users have access to.
Firmware is software that is inserted into programmable read-only memory (PROM), thus becoming a permanent part of a computing device. Firmware is created and tested like software using processor emulators. When ready, it can be distributed like other software and, using a special user Interface, installed in the programmable read-only memory by the user. Most data collection scanners, readers, printers, network devices and other devices have firmware.
Flash memory (sometimes called "flash
RAM") is a type of constantly-powered
Nonvolatile Memory that can be erased and reprogrammed in units of memory called blocks. It is a variation of electrically erasable programmable read-only memory (
EEPROM).Flash memory is not very useful as RAM because of the overhead involved in writing data to a flash memory device. Flash memory tends to be much less expensive than
SRAM. Flash memory is available in a
PC Card format. The term flash is also used as a verb to describe the act of burning or loading
Firmware onto a data collection computer, scanner, printer, network device.
Electromagnetic waves travel at the speed of light. Frequency is the number of complete cycles or oscillations of the wave per second. The standard unit of frequency is the
Hertz, abbreviated Hz. If a wave completes one cycle per second, then the frequency is 1 Hz; 60 cycles per second equals 60 Hz.
Larger units of frequency include the kilohertz (kHz) representing thousands (1,000's) of cycles per second, the megahertz (MHz) representing millions (1,000,000's) of cycles per second, and the gigahertz (GHz) representing billions (1,000,000,000's) of cycles per second. Occasionally the terahertz (THz) is used; 1 THz = 1,000,000,000,000 cycles per second.
Computer clock speed is generally specified in megahertz and, more recently, in gigahertz. Frequency is important in
Wireless communications, where the frequency of a signal is mathematically related to the
Wavelength.
c = speed of light
ƒ= Frequency | | λ= Wavelength
ƒ= c / λ
λ= c / ƒ |
Frequency Hopping Spread Spectrum is an RF Modulation technology that uses up to 79 1MHzwide channels. Each “channel”is actually a preset sequence of frequencies. Transmissions will run the sequence for a given channel, in other words, it hops from one frequency to another during transmission.
It can stay on a given channel for up to 400ms before hopping.
As a result, this technology is more immune to interference than DSSS.
Intermec’s devices with Open Air radios and Symbol’s Spring and 802.11 radios use Frequency Hopping.
FTP –File Transfer Protocol
A Protocol used to transfer files from one computer to another. FTP is an application protocol which is part of the IP suite.
FUD –Fear Uncertainty and Doubt
FUD is a sales or marketing strategy of disseminating negative (and vague) information on a competitor's product. The term was originated by Gene Amdahl when he left IBM to form his own company. He postulated that IBM sales people created fear, uncertainty and doubt in the minds of potential customers considering Amdahl products.
FUD is used to describe misinformation tactics in the vast range of technology industries. FUD is very common in politics as well.