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A link budget is an accounting of all of the power gains and losses that a communication signal experiences in a telecommunication system; from a transmitter, through a communication medium such as radio waves, cable, waveguide, or optical fiber, to the receiver.
At a SNR of 0 dB (Signal power = Noise power) the Capacity in bits/s is equal to the bandwidth in hertz. If the SNR is 20 dB, and the bandwidth available is 4 kHz, which is appropriate for telephone communications, then C = 4000 log 2 (1 + 100) = 4000 log 2 (101) = 26.63 kbit/s. Note that the value of S/N = 100 is equivalent to the SNR of 20 dB.
In communication systems, in calculations of the Shannon–Hartley channel capacity, bandwidth refers to the 3 dB-bandwidth. In calculations of the maximum symbol rate , the Nyquist sampling rate , and maximum bit rate according to the Hartley's law , the bandwidth refers to the frequency range within which the gain is non-zero.
The speed of light imposes a minimum propagation time on all electromagnetic signals. It is not possible to reduce the latency below = / where s is the distance and c m is the speed of light in the medium (roughly 200,000 km/s for most fiber or electrical media, depending on their velocity factor).
People are often concerned about measuring the maximum data throughput in bits per second of a communications link or network access. A typical method of performing a measurement is to transfer a 'large' file from one system to another system and measure the time required to complete the transfer or copy of the file.
Network calculus is "a set of mathematical results which give insights into man-made systems such as concurrent programs, digital circuits and communication networks." [1] Network calculus gives a theoretical framework for analysing performance guarantees in computer networks.
Carson's bandwidth rule is often applied to transmitters, antennas, optical sources, receivers, photodetectors, and other communications system components. Any frequency modulated signal will have an infinite number of sidebands and hence an infinite bandwidth but, in practice, all significant sideband energy (98% or more) is concentrated ...
In wireless communications, channel state information (CSI) is the known channel properties of a communication link.This information describes how a signal propagates from the transmitter to the receiver and represents the combined effect of, for example, scattering, fading, and power decay with distance.