TWDA Category 6a
The latest standard from the TIA for enhanced performance standards for twisted pair cable systems was defined in February 2008 in ANSI/TIA/EIA-568-B.2-10. Category 6a (or Augmented Category 6) is defined at frequencies up to 500 MHz—twice that of Cat 6.
Category 6a performs at improved specifications, particularly in the area of Alien Cross-talk (AXT) as compared to Cat6 UTP which exhibited high alien noise in high frequencies.
The global cabling standard ISO/IEC 11801 will soon be extended by the addition of amendment 2. This amendment defines new specifications for Cat. 6A components and Class EA permanent links. These new global Cat. 6A / Class EA specifications require a new generation of connecting hardware offering far superior performance compared to the existing products which are based on the American TIA standard.
The most important point is a performance difference between ISO/IEC and EIA/TIA component specifications for the NEXT transmission parameter. At a frequency of 500 MHz, an ISO/IEC Cat. 6A connector performs 3 dB better than a Cat. 6A connector that conforms with the EIA/TIA specification. 3 dB equals 100% increase of near-end crosstalk noise reduction when measured in absolute magnitudes.
TIA comp. Cat. 6A ≠ ISO/IEC Cat. 6 A comp.3
Maximum Length of TWDA cat6/6A cable
The maximum allowed length of a TWDA Cat-6 cable is 100 meters (330 ft) when used for 10/100/1000baseT. This consists of 90 meters (300 ft) of solid "horizontal" cabling between the patch panel and the wall jack, plus 10 meters (33 ft) of stranded patch cable between each jack and the attached device. Since stranded cable has higher attenuation than solid cable, exceeding 10 meters of patch cabling will reduce the permissible length of horizontal cable.
When used for 10GbaseT, Cat-6 cable's maximum length is 55 meters (180 ft) in a favorable alien crosstalk environment, but only 37 meters (121 ft) in a hostile alien crosstalk environment such as when many cables are bundled together. 10GbaseT runs of up to 100 meters (330 ft) are permissible using Cat-6a.
Installation Caveats of TWDA cat6/6A cable
Category 6 and 6a cable must be properly installed and terminated to meet specifications. Incorrect installation practices include kinking the cable or bending it with too tight a radius. Incorrect termination practices include untwisting the wire pairs or stripping the outer jacket back too far.
Shielded Category 6a cable must have the foil grounded at one end to achieve specified alien crosstalk performance.Unshielded Category 6a cable does not have this limitation, but has a larger diameter.TWDA cat6/6A cables are avaible in both solid ones and strand ones.Both are of 23 AWG.
位访客
