There are 49 names in this directory beginning with the letter F.
FACCH: Fast Associated Control Channel
Fast Associated Control Channel (FACCH) is the channel derived by preempting information in a traffic channel. It is used to send handoff and similar messages.
Fading is the variation in signal strength from its normal value. Fading is normally negative and can be either fast or slow. It is normally characterized by the distribution of fades, Gaussian, Rician, or Rayleigh.
FASS: Fast Access Station Switching
Fast Access Station Switching (FASS), a concept in the WiMAX network, is a method by which an MS can change its access station from frame to frame depending on the station selection mechanism. The access station can be an RS, BS, or MMRBS. The MS refers to transmitting/receiving data to/from one of the active stations (the anchor station) during any given frame.
Fast fading is the short term component associated with multipath propagation. It is influenced by the speed of the mobile terminal and the transmission bandwidth of the signal.
Fast Handoff is a way that access points can let authenticated users roam among different access points without losing authentication. Fast handoff also makes voice-over-IP possible. Fast handoff will be made possible with the 802.11f specification.
Fast Packet Switching
Fast Packet Switching is a packet-orientated, digital technology that transmits all data in a single packet format whether the information is video, voice or data. Fast packet switching uses short, fixed length packets (cells) and, via hardware switching, is capable of speeds between 100,000 and 1,000,000 packets/second.
FAW: Frame Alignment Word
Frame Alignment Word (FAW) is a unique digital word used by codecs to allow them to resynchronize to the framing structure in the event of errors.
FBSS: Fast Base Station Switching
Fast Base Station Switching (FBSS), defined in the IEEE 802.16-2005 (mobile WiMAX) network, is a method to allow switching between any type of access stations (like RS, BS, or MMR-BS). Switching can occur between the same type or different types of access stations.
FCC: Federal Communications Commission
Federal Communications Commission (FCC) is the regulatory body governing communications technologies in the US. established by the Communications Act of 1934, as amended, and regulates interstate communications (wire, radio, telephone, telegraph and telecommunications) originating in the United States.
FCCH: Frequency Correction Channel
Frequency Correction Channel(FCCH) is the logical channel in GSM systems used to transmit a frequency correction data burst of all “zeros”. The resulting frequency shift seen by the mobile is then used for frequency correction.
FCH: Frame Control Header
Frame Control Header (FCH) is a field in the IEEE802.16-2004 WIMAX protocol. The FCH specifies the burst profile and the length of one or more DL bursts that immediately follow the FCH.
FDCCH: Forward Digital Control CHannel
Forward Digital Control Channel (FDDCH), defined in the IS-136, provides cellular standards for TDMA-based networks. FDCCH includes all downstream signalling and control information from cell site to user equipment. FDCCH works together with RDCCH (Reverse Digital Control CHannel) which is for the upstream signaling and controling information. FDCCH can be divided into a few logic channels such as BCCH, SCF and SPACH.
FDD: Frequency Division Duplex
Frequency Division Duplex (FDD), used in cellular communication systems such as GSM, is a radio technology using a paired spectrum.
FDM: Frequency Division Multiplex
Frequency Division Multiplexing (FDM) is a technique by which the carrier bandwidth is divided into sub-channels of different frequency widths — each carrying a signal at the same time in parallel. Each channel is 30 kHz. All the signals may be amplified, conducted, translated in frequency and routed toward a destination as a single signal, resulting in economies which are the motivation for multiplexing. Receivers at the receiving end separates the multiplexed signals by means of frequency passing or rejecting filters, and demodulates the results individually, each in the manner appropriate for the modulation scheme used for that band or group.
FDMA: Frequency Division Multiple Access
Frequency Division Multiple Access (FDMA) is a method of allowing multiple users to share the radio frequency spectrum by assigning each active user an individual frequency channel. In this practice, users are dynamically allocated a group of frequencies so that the apparent availability is greater than the number of channels.
Feature Group D
Feature Group D is a local exchange carrier network service that, among other things, lets public-safety dispatch offices receive a 10-digit data stream, including the full call-back number, alongside wireless 911 calls. Offered as a way by which wireless carriers can meet FCC enhanced 911 rules and dispatch offices can overcome their current bandwidth limits.
FEC: Forward Error Correction
Forward Error Correction (FEC) is a method of increasing the reliability of data communication. In one-way communication channels, a receiver does not have the option to request a re-transmission if an error was detected. Forward Error Correction is a method of sending redundant information with the data in order to allow the receiver to reconstruct the data if there was an error in transmission.
FER: Frame Erasure/Error Rate
Frame Erasure/Error Rate is a measure of the number of frames of data that contained errors and could not be processed. FER is usually expressed as a percentage or exponent.
FFT: Fast Fourier Transform
Fast Fourier Transform (FFT) is an efficient algorithm to compute the discrete Fourier transform (DFT) and its inverse. FFTs are of great importance to a wide variety of applications, from digital signal processing to solving partial differential equations to algorithms for quickly multiplying large integers.
FGD: Feature Group D
Feature Group D (FGD) is a local exchange carrier network service that, among other things, lets public-safety dispatch offices receive a 10-digit data stream, including the full call-back number, alongside wireless 911 calls. FGD is offered as a way by which wireless carriers can meet FCC-enhanced 911 rules and dispatch offices can overcome their current bandwidth limits. This access group is associated with equal access arrangements which allow the end user to have the same dialing plan (1 plus the telephone number) to reach any predetermined long distance phone companies of their choice.
FH-CDMA: Frequency Hopping – Code divisi
Frequency hopping – code division multiple access (FH-CDMA) is one of two basic modulation techniques used in spread spectrum signal transmission for CDMA-based wireless systems. It is the repeated switching of frequencies during radio transmission, often to minimize the effectiveness of the unauthorized interception or jamming of telecommunications.
FH: Frequency Hopping
Frequency Hopping (FH) is a periodic changing of frequency or frequency set associated with transmission. It is a sequence of modulated pulses having a pseudorandom selection of carrier frequencies.
FHMA: Frequency hopping multiple access
Frequency hopping multiple access (FHMA) is a digital technology used in Geotek Communications Inc.'s specialized mobile radio network.
FHSS: Frequency Hopped Spread Spectrum
Frequency Hopped Spread Spectrum (FHSS) is a spread-spectrum method of transmitting signals by rapidly switching a carrier among many frequency channels, using a pseudorandom sequence known to both transmitter and receiver. It is used in WLAN 802.11 physical layer.
FIRFinite Impulse Response
Finite Impulse Response (FIR) is a technique used to characterize electrical circuits and networks in the time domain.
Fixed WiMax refers to the fixed wireless broadband services as defined by the IEEE 802.16d (also known as IEEE 802.16-2004). IEEE 802.16d product profile utilizes the OFDM 256-FFT (Fast Fourier Transform) system profile. The Fixed WiMAX 802.16-2004 standard supports both time division duplex (TDD) and frequency division duplex (FDD) services — the latter of which delivers full duplex transmission on the same signal if desired. The mobility features of WiMax are defined in IEEE 802.16e (or 802.16-2005).
Fixed wireless refers to the over-the-air transmission of information to and from systems and end-user equipment that are stationary, rather than mobile. Operators of fixed wireless networks potentially can offer broadband services without having to lay expensive cable systems or deal with the complexities of mobility management.
Flat fading is a type of fading in a communications channel that attenuates or fades all frequencies in the channel in the same amount.
FLEX is the Motorola's flexible high-speed paging coding scheme that gives carriers more capacity on their networks and faster transmission time. FLEX also refers to the FLEX family of protocols: FLEX, InFLEXion and ReFLEX.
FM: Frequency Modulation
Frequency Modulation (FM) is a form of angle modulation in which the instantaneous frequency of a sine-wave carrier is caused to depart from the carrier frequency by an amount proportional to the instantaneous value of the modulating wave. In FM, signals of different frequencies represent different data values.
Reductions in signal strength or quality is due to signal absorption by trees or foliage obstructions in the signal's line-of-sight path. For example, 800 MHz systems are seldom deployed in forested areas. Pine needles-nearly the same length as 800 MHz antennas can negatively affect signal reception in that band.
FOMA: Freedom of Mobile Multimedia Acces
Freedom of Mobile Multimedia Access (FOMA) is the brand name for the 3G services being offered by Japanese mobile phone operator NTT DoCoMo. FOMA was the world's first W-CDMA 3G service when launched in 2001. FOMA is compatible with standard UMTS, both via the radio link as well as via USIM card exchange, and hence provides several alternative options for global roaming: either with or without change of handset.
Footprint in wireless communications refers to geographical areas in which an entity is licensed to broadcast its signal.
In radio communications, a forward link is the link from a fixed location (e.g., a base station) to a mobile user. If the link includes a communications relay satellite, the forward link will consist of both an uplink (base station to satellite) and a downlink (satellite to mobile user).
Frequency is the measurement of the number of times that a repeated event occurs per unit time. To calculate the frequency of an event, the number of occurrences of the event within a fixed time interval are counted, and then divided by the length of the time interval.
Frequency diversity is the simultaneous use of multiple frequencies to transmit information. This is a technique used to overcome the effects of multipath fading since the wavelength for different frequencies result in different and uncorrelated fading characteristics.
Frequency reuse is a technique of reusing frequencies and channels within a communications system to improve capacity and spectral efficiency. Frequency reuse is one of the fundamental concepts on which commercial wireless systems are based that involves the partitioning of an RF radiating area (cell) into segments of a cell. One segment of the cell uses a frequency that is far enough away from the frequency in the bordering segment that it does not provide interference problems. Frequency re-use in mobile cellular systems means that each cell has a frequency that is far enough away from the frequency in the bordering cell that it does not provide interference problems. The same frequency is used at least two cells apart from each other. This practice enables cellular providers to have many times more customers for a given site license.
Frequency selective fading
Frequency selective fading is a type of signal fading occurring over a small group of frequencies caused by a strong multipath component at those frequencies.
Fresnel Zone is an elliptical area on either side of the straight line of sight that must also be clear for a long-range wireless network to work.
Fringe Area is the outermost range of a cellular system where cellular signals may be weaker.
FRS: Family Radio Service
Family Radio Service is a very low power, short range two-way radio service in the 460 MHz band.
FRS: Fixed Relay Station
Fixed Relay Station (FRS) refers to a relay station that is permanently installed at a fixed location.
FSKFrequency Shift Keying
Frequency Shift Keying (FSK) is a form of modulation using multiple carrier frequencies to carry the digital information. The most common one is the two-frequency FSK system using the two frequencies to carry the binary ones and zeros.
FSSS: Fast Serving Station Switching
Fast Serving Station Switching (FSSS) refers to the serving station switching with which a Moble Station (MS) can change its serving station from frame to frame depending on the serving station selection mechanism. A serving station can be an RS, BS, or MMR-BS. Fast BS switching (FBSS) was defined in 802.16e, and the terminology is modified to allow switching between any types of serving stations (RS, BS, or MMR-BS). Switching can be either between a same type of serving stations or between different types of serving stations.
Full rate refers to voice codecs in a communications system. Most frame formats are designed to accommodate full and half-rate channels, with the intention of implementing half-rate coding as the technology permits to double the capacity of the system. The full-rate codec uses all of the time-slots available.
Full user mobility
Full user mobility is a wireless classification under which users can access data while in motion, for example, in a car.
FUSC: Fully Used SubChannel
Fully Used SubChannel (FUSC), also known as Fully Used SubCarrier, is a method used in the WiMAX network that uses all the subchannels and employs full-channel diversity by distributing the allocated subcarriers to subchannels using a permutation mechanism. This mechanism is designed to minimize the probability of hits (probably of using the same physical subcarriers in adjacent cells and sectors) between adjacent sectors/cells by reusing subcarriers while frequency diversity minimizes the performance degradation due to fast fading characteristics of mobile environments.