Attenuation Crosstalk Ratio

Also known as headroom, attenuation crosstalk ratio (ACR) is the difference between attenuation and crosstalk at a given frequency along a cable. Measured in decibels, ACR is a calculation used in networking transmission to assure that a signal transmitted across a twisted-pair cable is stronger at the receiving end than any interference signals imposed on that same pair by crosstalk from adjacent pairs.