Network throughput: Difference between revisions

Revision as of 14:16, 22 October 2023

Revision as of 22:35, 6 November 2023

Line 1:

{{Short description|Rate at which data is processed in communication networks}}

{{redirectRedirect-distinguish|Throughput|Throughput (disk drive)|Throughput (business)}}

{{Multiple issues|

{{Tone|date=October 2017}}

Line 6:

}}

'''Network throughput''' (or just '''throughput''', when in context) refers to the rate of message delivery over a [[communication channel]], such as [[Ethernet]] or [[packet radio]], in a [[communication network]]. The data that these messages contain may be delivered over physical or logical links, or through [[network nodes]]. Throughput is usually measured in [[bits per second]] (bit/s or bps), and sometimes in [[data packets]] per second (p/s or pps) or data packets per [[Timetime-division multiplexing|time slot]].

The '''system throughput''' or '''aggregate throughput''' is the sum of the data rates that are delivered to all terminals in a network.<ref>[[Guowang Miao]], Jens Zander, K-W Sung, and Ben Slimane, Fundamentals of Mobile Data Networks, Cambridge University Press, {{ISBN|1107143217}}, 2016.</ref> Throughput is essentially synonymous to [[digital bandwidth consumption]]; it can be determined numerically by applying the [[queueing theory]], where the load in packets per time unit is denoted as the arrival rate ({{mvar|λ}}), and the drop in packets per unit time is denoted as the departure rate ({{mvar|μ}}).

Line 56:

The maximum achievable throughput (the channel capacity) is affected by the bandwidth in hertz and [[signal-to-noise ratio]] of the analog physical medium.

Despite the conceptual simplicity of digital information, all electrical signals traveling over wires are analog. The analog limitations of wires or wireless systems inevitably provide an upper bound on the amount of information that can be sent. The dominant equation here is the [[Shannon-HartleyShannon–Hartley theorem]], and analog limitations of this type can be understood as factors that affect either the analog bandwidth of a signal or as factors that affect the signal-to-noise ratio. The bandwidth of wired systems can be in fact surprisingly narrow, with the bandwidth of Ethernet wire limited to approximately 1&nbsp;GHz, and PCB traces limited by a similar amount.

Digital systems refer to the 'knee frequency',<ref>Johnson, 1993, 2-5</ref> the amount of time for the digital voltage to rise from 10% of a nominal digital '0' to a nominal digital '1' or vice versa. The knee frequency is related to the required bandwidth of a channel, and can be related to the [[3 db bandwidth]] of a system by the equation:<ref>Johnson, 1993, 9</ref> <math>\ F_{3dB} \approx K/T_r </math>