The Importance of SNR in Cable Testing

As Internet connection speeds have increased, so has the need to ensure that equipment is suited to these higher data speeds. This especially applies to Ethernet cable because this is where most problems occur; as speed increases, the more susceptible the signal becomes to noise issues. For example, Cat 3 cable is designed for 10 Mbps and operates using low demand Manchester encoding whereas a Cat 5 100 Mbps line is designed to operate using 3 logic levels and Gigabit Ethernet cable requires the need to have superior Signal to Noise tolerances to tolerate additional logic levels.

In order to achieve these high speeds, the Signal-To-Noise Ratio (SNR) becomes important because a noisy cable affects signal quality, causes errors, and unreliable connections which leads to a downgraded service.