What is the difference between Rate , throughput and capacity ? Their unit are all bps/s,but it seems that there are something different between them,can anyone tell me?

My research is optimizing something in energy harvest and SWIPT,and in the internet,it said the throughput and capacity have some difference,but i did't understand it.


Capacity: capacity is the tight upper bound on the rate at which information can be reliably transmitted over a communication channel.

throughput: throughput is the rate of production or the rate at which something is processed.

rate formula : $time \times log_2(1+SINR)$

Because the unit of them are different,so i think maybe they should be the same,just apply to different place,but i am not sure about this! When i maximize the rate,do i also maximize the throughput and capacity ?

  • $\begingroup$ What research have you done so far? These concepts are defined in multiple places; can you be more precise in what about those definitions is confusing? $\endgroup$
    – MBaz
    Commented Jun 3, 2019 at 2:07
  • $\begingroup$ @MBaz I have edited the question $\endgroup$
    – XM551
    Commented Jun 3, 2019 at 2:25

1 Answer 1


Rate: the actual rate you transmit data at.

Throughput: the percentage of signal data that is actually delivered correctly to the receiver in the overall data (signal data + coding + overhead ... etc).

Capacity: maximum rate that a channel allows for a given SNR such that the received signals can be reliably decoded at the receiver.

  • $\begingroup$ What is the difference between rate and throughput,i am still a little bit confused $\endgroup$
    – XM551
    Commented Jun 3, 2019 at 3:14
  • $\begingroup$ Say you have $N$ data bits (e.g.: the content of an email) and $K$ overhead bits for error detection and other processes that are used to help deliver the data intact (in packets there are headers that are used by the receiver for synchronization for example, channel estimation, ...). Then the throughput in my understanding is $N/(N+K)$, which is basically the percentage of useful data transmitted relative to the total data transmitted. Data rate is how many bits you transmit per second. $\endgroup$
    – BlackMath
    Commented Jun 3, 2019 at 4:19
  • $\begingroup$ oh!i know ,the is the rate is the actual rate we transmit things,this thing is all data,including signal data,coding,etc.but the throughput is the actual rate we transmit the "signal data" $\endgroup$
    – XM551
    Commented Jun 3, 2019 at 4:39
  • $\begingroup$ To me throughput is a percentage not rate, but I guess you can derive an effective rate from the throughput percentage by multiplying the actual rate by the throughput percentage. I haven't worked on throughput before, so, I advice you to take this with some caution. I made an edit on the throughput in my answer, as throughput is usually related to the amount of data that is delivered successfully, not just delivered. $\endgroup$
    – BlackMath
    Commented Jun 3, 2019 at 5:11
  • 1
    $\begingroup$ i think throughput is a rate, bits per second. see the wikipedia article on it. but i think it's the rate of net data (less overhead) where baud rate includes the overhead. $\endgroup$ Commented Jun 3, 2019 at 6:28

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