One of the changes that modern digital communication systems have brought to radio engineering is the need for end-to-end performance measurements. The measure of that performance is usually the bit error rate (BER), which quantifies the reliability of the entire radio system from "bits in" to "bits out", including the electronics, antennas and signal path in between. In order to ensure that the bit error rate can be measured easily and quickly, you need a bit error rate tester. A bit error rate tester (BERT), also known as a bit error ratio tester or a bit error rate test solution (BERTs) is an electronic test equipment used to test the quality of signal transmission of single components or complete systems.
As illustrated below, a bit error rate tester consists of five main components:
