MEDIA SPECIFICATIONS AND REQUIREMENTS
B-4
UTP consists of four pairs of 24 AWG solid wire for data or voice
communication and is typically used to wire cable runs within the walls of
buildings. In some installations, existing UTP building wiring can be used
for Token Ring cabling. UTP cable must conform to the limits shown in
Table B-4.
Better grades of UTP cable known as supergrade or level 4 are now
available. These improved grades of UTP can often be used to permit
operation at 16 Mbps on longer lobe cables.
Attenuation and Impedance
The attenuation values shown in Table B-4 include the attenuation of the
cables, connectors, patch panels, and reflection losses due to impedance
mismatches in the segment.
Table B-4. UTP Voice Grade and Category 3 Specifications
Frequency Impedance Attenuation
1 MHz 100Ω ±15% <26 dB/km (8 dB/1000 ft.)
4 MHz 100Ω ±15% <56 dB/km (16 dB/1000 ft.)
10 MHz 100Ω ±15% <98 dB/km (30 dB/1000 ft.)
16 MHz 100Ω ±15% <131 dB/km (40 dB/1000 ft.)