| 释义 |
bandwidth
bandwidththe range of frequencies or the measured amount of information that can be transmitted over a connection; also used as a measure of a person’s ability or lack of it: He’s not good at multitasking; he has low bandwidth.band·width B0056300 (bănd′wĭdth′, -wĭth′)n.1. The numerical difference between the upper and lower frequencies of a band of electromagnetic radiation, especially an assigned range of radio frequencies.2. The amount of data that can be passed along a communications channel in a given period of time.bandwidth (ˈbændˌwɪdθ) n1. (Electronics) the range of frequencies within a given waveband used for a particular transmission2. (Electronics) the range of frequencies over which a receiver or amplifier should not differ by more than a specified amount3. (Telecommunications) the range of frequencies used in a specific telecommunications signalband•width (ˈbændˌwɪdθ, -ˌwɪtθ)
n. 1. the smallest range of electronic frequencies constituting a band, within which a particular signal can be transmitted without distortion. 2. the transmission capacity of an electronic communications device. [1925–30] bandwidthThe difference between the limiting frequencies of a continuous frequency band expressed in hertz (cycles per second). The term bandwidth is also loosely used to refer to the rate at which data can be transmitted over a given communications circuit. In the latter usage, bandwidth is usually expressed in either kilobits per second or megabits per second.Thesaurus| Noun | 1. |  bandwidth - a data transmission rate; the maximum amount of information (bits/second) that can be transmitted along a channelinformation measure - a system of measurement of information based on the probabilities of the events that convey information |
Translationsbandwidth
bandwidth 1. The range of frequencies over which an instrument, such as a radio telescope, is sensitive. A wide bandwidth gives good sensitivity to sources that emit over a wide range of frequencies (e.g. by synchrotron emission), whereas a narrow bandwidth gives good sensitivity to spectral lines. 2. (coherence bandwidth) The range of frequencies over which electromagnetic or other emissions from a source maintain coherence.bandwidth[′band‚width] (communications) The difference between the frequency limits of a band containing the useful frequency components of a signal. A measure of the amount of data that can travel a communications path in a given time, usually expressed as thousands of bits per second (kbps) or millions of bits per second (Mbps). bandwidth (communications)The difference between the highest and lowestfrequencies of a transmission channel (the width of itsallocated band of frequencies).
The term is often used erroneously to mean data rate orcapacity - the amount of data that is, or can be, sentthrough a given communications circuit per second.
bandwidth(1) Computer people may use the term for capability and time. For example, "not enough bandwidth to get the job done" means not enough staff or time to do it. Its true meaning follows.
(2) The transmission capacity of an electronic pathway such as a communications line, computer bus or computer channel. Digital bandwidth is the number of pulses per second measured in bits per second (bps). For example, Ethernet transmits at different speeds, including 10 Mbps, 100 Mbps and 1000 Mbps (see Mbps and baseband).
When transmitting alternating frequencies, as with all wired analog, many wired digital and most wireless communications, the bandwidth is the difference between the highest and lowest frequencies, measured in cycles per second, or Hertz (Hz). For example, 802.11n Wi-Fi transmits in 20 MHz and 40 MHz channels within the 2.4 GHz and 5 GHz bands. The 20 and 40 MHz channel frequencies are the bandwidths, and each channel is divided into subchannels.
From Hertz to Bits - A Complicated Process
When using alternating frequencies for digital transmission, the frequencies are modified (modulated) by the digital input. Using the 802.11n Wi-Fi example, the resulting bit rate can range from 6.5 Mbps to 600 Mbps. This extremely wide range is determined by the signal strength and interference in the environment at any given moment. Any one of more than 30 combinations of channel bandwidth (20, 40 MHz), modulation scheme, error correction rate, channel spacing and number of antennas may be selected, on a packet-by-packet basis. See modulation, video bandwidth, space/time and bandwidth junkie.
 | | Bandwidth in Hertz to Bandwidth in Bits |
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| This quadrature PSK (QPSK) example is one of the simplest modulation schemes. Each set of two input bits modifies the carrier into four phase angles. The amplitude remains constant, unlike QAM modulation, in which the amplitude is varied (see QAM). |
bandwidth
band·width (band'width), In MRI, the range of frequencies or wavelengths received for a given image, inversely related to signal:noise ratio; it must be sufficient or wraparound artifact will occur.bandwidth Informatics
A measure of the amount of data that can be transmitted at once through a communication conduit.
Multimedia
A theoretical limit of product expandability into different media, venues and market segments.
Telemedicine
A measure of transport—speed of throughput—of data between connected computers.
Vox populi
A popular term for a person’s intelligence—e.g., an unintelligent person would be said to have low bandwidth.band·width (band'width) The arithmetic difference between the upper and lower frequencies of a band of electromagnetic radiation. LegalSeespeedBandwidth
BandwidthIn investment banking, a slang term for extra time available to take on more work. For example, an employee has bandwidth if she can be assigned another project and still be able to complete all other assignments in the allotted time.See BW
See Bbandwidth
Words related to bandwidthnoun a data transmission rateRelated Words |
