Category 5 standards.
The basic
standard
Category 5
establishes the minimum performance requirements for generic
telecommunications cabling systems.
The Category 5
specification defines acceptable performance levels and cable
characteristics at speeds up tp 100 MHz. But in the period of time since
Category 5 was introduces, information transmission and cabling
technologies are advancing well beyond the Category 5 performance
limits.
The future
New technologies
such as Gigabit Ethernet (1000 Mbps) and 155-Mbps ATM (Asynchronous
Transfer Mode) are pushing the limits of Category 5 cable. While there
is no established standard above Category 5, new levels are emerging.
Category 5+ (Enhanced
Category 5 or Level 6) cables offers better performance. But it must
also meet tougher specifications, such as an attenuation-to-crosstalk
ratio (ACR) of 10 db at 155 MHz and 4-pair power-sum NEXT (near-end-crosstalk)
testing.
Category 5++ (Level 7) increases performance even
more with the capability to support Gigabit Ethernet at 100 meters. Its
bandwidth must be at least twice that of Category 5. Accordingly, test
requirements increase. Category 5++ should meet an ACR level of 10 dB at
200 MHz and an even higher power-sum NEXT level. |