a cable. A higher value is desirable as it indicates that less of the transmitted signal is coupled into the victim wire pair. NEXT is measured 30 meters (about 98 feet) from the injector/generator. Higher near-end crosstalk values correspond to higher overall circuit performance. Low NEXT values on a UTP LAN used with older signaling standards (IEEE 802.3 and earlier) are particularly detrimental. Excessive near-end crosstalk can be an indication of improper termination. Power Sum NEXT (PSNEXT) Power Sum NEXT (NEXT) is the sum of NEXT values from 3 wire pairs as they affect the other wire pair. The combined effect of NEXT can be very detrimental to the signal. The Equal-Level Far-End Crosstalk (ELFEXT) The Equal-Level Far-End Crosstalk (ELFEXT) test measures Far-End Crosstalk (FEXT). FEXT is very similar to NEXT, but happens at the receiver side of the connection. Due to attenuation on the line, the signal causing the crosstalk diminishes as it gets further away from the transmitter. Because of this, FEXT is usually less detrimental to a signal than NEXT, but still important nonetheless. Recently the designation was changed from ELFEXT to ACR-F (far end ACR). Power Sum ELFEXT (PSELFEXT) Power Sum ELFEXT (PSELFEXT) is the sum of FEXT values from 3 wire pairs as they affect the other wire pair, minus the insertion loss of the channel. Recently the designation was changed from PSELFEXT to PSACR-F (far end ACR). Attenuation-to-Crosstalk ratio (ACR) Attenuation-to-Crosstalk ratio (ACR) is the difference between the signal attenuation produced NEXT and is measured in decibels (dB). The ACR indicates how much stronger the attenuated signal is than the crosstalk at the destination (receiving) end of a communications circuit. The ACR figure must be at least several decibels for proper performance. If the ACR is not large enough, errors will be frequent. In many cases, even a small improvement in ACR can cause a dramatic reduction in the bit error rate. Sometimes it may be necessary to switch from un-shielded twisted pair (UTP) cable to shielded twisted pair (STP) in order to increase the ACR. Power Sum ACR (PSACR) Power Sum ACR (PSACR) done in the same way as ACR, but using the PSNEXT value in the calculation rather than NEXT. DC Loop Resistance DC Loop Resistance measures the total resistance through one wire pair looped at one end of the connection. This will increase with the length of the cable. DC resistance