# Rate vs throughput vs capacity

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.

WIKI:

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 ?

• 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? – MBaz Jun 3 at 2:07
• @MBaz I have edited the question – XM551 Jun 3 at 2:25

• 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. – BlackMath Jun 3 at 4:19