Wireless Glossary – F

The difference between strength of the received signal and the strength that the receiver requires for maintaining a reliable link. A higher fade margin is characteristic of a more reliable link. Standard operating margin.

Frame Check Sequence

Frequency Division Duplexing means that the transmitter and receiver operate at different carrier frequencies. The term is frequently used in ham radio operation, where an operator is attempting to contact a repeater station. The station must be able to send and receive a transmission at the same time, and does so by slightly altering the frequency at which it sends and receives. This mode of operation is referred to as duplex mode or offset mode.

Fiber-optic network with dual, counter-rotating ring topology and (Fiber Distributed Data Interface) 100 Mbit/s bandwidth. Fiber multiplexing Transmission method in which each transmission channel is assigned a fiber.

Frequency Division Multiplexing is a technique by which the total bandwidth available in a communication medium is divided into a series of non-overlapping frequency sub-bands, each of which is used to carry a separate signal. This allows a single transmission medium such as a cable or optical fiber to be shared by many signals.

Frequency Division Multiple Access is a channel access method used in multiple-access protocols as a channelization protocol. FDMA gives users an individual allocation of one or several frequency bands, or channels. FDMA, like other Multiple Access systems, coordinates access between multiple users.

The composite metric composed of the advertised distance to a destination plus the composite metric to reach that advertising router from the local router.

Software key file whose file name includes the ESN of the target module. When installed on the module, this file activates the module to have the feature enabled or disabled in a separate operator action.

Independent United States government agency, created, directed, and empowered by Congressional statute.

The FCC was established by the Communications Act of 1934 as the successor to the Federal Radio Commission and is charged with regulating all non-Federal Government use of the radio spectrum (including radio and television broadcasting), and all interstate telecommunications (wire, satellite and cable) as well as all international communications that originate or terminate in the United States. The FCC took over wire communication regulation from the Interstate Commerce Commission. The FCC’s jurisdiction covers the 50 states, the District of Columbia, and U.S. possessions.

The crosstalk measured at the far end of the cable from where the transmission was sent.

Fast Fourier Transform is an efficient algorithm to compute the discrete Fourier transform (DFT) and its inverse.

A cable that uses light to send data transmissions, rather than electrical signals. These optical light signals traverse a fiberglass core. This technology is also known as fiber optics or optical cabling. Fiber is not vulnerable to electromagnetic interference.

Fibers arranged parallel to each other and equally spaced, bonded in a flat configuration by a coating. Several fiber ribbons can be placed on each other to form a stack.

File identifier, The 2-byte name of a file or a directory on the UICC.

A program or device that breaks up data and signals by utilizing a defined set of criteria.

A firewall protects a computer network from unauthorized access. Network firewalls may be hardware devices, software programs, or a combination of the two.

Fiber in the local line network. A distinction is made according to where (Fiber in the Loop) the fiber terminates, as follows: FTTB – Fiber to the building, FTTC – Fiber to the curb, FTTH – Fiber to the home, FTTP – Fiber to the pedestal

A word used to illustrate a failing interface which is constantly going up and down.

Flash Orthogonal Frequency Division Multiplexing.

When the primary route fails, this route with a higher administrative distance, then enters the routing table.

A process that supplies buffer controls which work to prevent packet flooding to the destination host. These buffers store bursts of data for processing when the transmission ends.

Fixed Mobile Convergence is a change in telecommunications that removes differences between fixed and mobile networks.

Forward Error Correction is a coding scheme used to improve the performance of digital signal transmission. It utilizes a mechanism for correcting bits that may otherwise be received incorrectly.

The time (15 seconds) to transition from listening to learning and learning to forwarding.

An STP port condition in which the interface transmits and receives data.

Array of logic, relational data, and wiring data that is factory programmed and can be reprogrammed.

A method of frame transmission that checks the first 64 bytes for frame fragments (resulting from collisions) before forwarding the frame.

The Data Link Layer (OSI model) formats this packet for transmission to the Physical layer.

A popular packet-switched connection type that sets up site-to-site connections through a service provider network. These connects can reach speeds of up to T3 and uses DLCI numbers as its Layer 2 addressing.

Transmission of a beacon in only frames where the receiver expects a beacon (rather than in every frame). This avoids interference from transmissions that are not intended for the receiver.

Fixed Reference Channel is a group of parameters used to describe a configuration for packet-based performance evaluation of 3GPP systems in which the adaptation of modulation and coding rate is in principle possible.

A phenomenon related to line of sight whereby an object that does not obstruct the visual line of sight obstructs the line of transmission for radio frequencies.

Of an antenna, the gain in a specified direction, i.e., azimuth, usually that of maximum gain, compared to the gain in a direction 180° from the specified azimuth. dB

A variation of frequency modulation to transmit data, in which two or more frequencies are used.

An Application Layer protocol that enables a user to transfer files and provides access to directories and files.

Cabling in which optical fibers extend to the desk.

Bidirectional transmissions of data which produce higher throughput because CSMA/CD is disabled. Connections to other devices can be full duplex.

All routers in this expensive, but fully redundant, packet-switched network design are directly connected to all other routers through virtual circuits.

A network topology that is designed so that each device is directly connected to every other network device providing built-in redundancy. If one link fails, the device transmits via another link.

A permanent joint produced by the application of localized heat sufficient to fuse or melt the ends of the optical fiber, forming a continuous single fiber.