Data Wiring Standards – What is Category 6 all about? What is Category (CAT) 6 Data Cable? The Category 6 (CAT 6) data cable standard is the latest and most rapidly growing standard in the market today, quickly replacing CAT 5/5e. CAT 6 has been under development since late 1997. Originally, the wiring was intended to go from the 100 MHz capability of CAT 5 to 200 MHz, but later that was revised to 250 MHz. CAT 6 provides for other metrics as well, variables that become important at high bandwidth rates. These include crosstalk, or interference between wire pairs, and skew, the difference in timing of signals on the wires. CAT 6 is the latest type of four pair twisted copper cable designed for high speed data transmission. CAT 5 was initially touted as the “last cable you'll ever need”, but then came Gigabit Ethernet, which pushed the technology to its limits and used all four pairs of wires in the cable. As a result, manufacturers started making "enhanced" versions of the cable referred to as CAT 5e. The main difference between CAT 5/5e and CAT 6 is the extension of the bandwidth from 100MHz to 250MHz, or higher bandwidth. In addition, the physical makeup of the cable allows for better signal to noise ratio with minimal loss which translates to faster and more reliable networks for any current application in the market place today. Companies are installing CAT 6 to “future proof” network infrastructures. Applications such as Voice over IP (VoIP), Video Conferencing, and streaming digital videos are here and benefit from the higher bandwidth provided by CAT 6. Is Category 6 Really needed? Bandwidth increase precedes data rate increase, just as highways come before traffic. Doubling the bandwidth is like adding twice the number of lanes on a highway. The trends of the past and the predictions for the future indicate that data rates have been doubling every 18 months. Current applications running at 1 Gb/s are really pushing the limits of Category 5e cabling. As streaming media applications such as video and multi-media become commonplace, the demands for faster data rates will increase and spawn new applications that will benefit from the higher bandwidth offered by Category 6. This is exactly what happened in the early ’90s when the higher bandwidth of Category 5 cabling compared to Category 3 caused most local area network (LAN) applications to choose the better media to allow simpler, cost effective, higher speed LAN applications, such as 100BASE-TX. It is also important to note that cabling infrastructure is generally considered a 10 year investment as opposed to two or three years for electronics. Work has already started on 10G BASE-T, and Category 5e cabling is not being considered. With additional throughput requirements right around the corner, it makes sense to plan ahead. What about Migrating to Category 6 Making a decision to migrate an existing network up to Category 6 (CAT 6) is a big choice. As you are determining what cable type to install the decision usually comes down to performance versus cost. However there is one other item to determine which is; “The Life Cycle of the Product”. Category 6 is the best choice for future proofing your network. Most networks today are structured with Category 5e technology, but migrating to CAT 6 provides several benefits. The general difference between CAT 5e and CAT 6 is in the transmission performance and extension of the available bandwidth from 100 MHz for CAT 5e to 250 MHz for CAT 6. Migrating to CAT 6 provides better insertion loss, near end crosstalk (NEXT) return loss and equal level far end crosstalk (ELFEXT). These improvements give a higher signal-to-noise ratio, allowing higher reliability for current applications and higher data rates for future applications. The additional performance parameters provide a sort of "forgiveness factor" for things that happen within a cabling infrastructure over its lifetime assuring that bandwidth remains available for applications. The bandwidth referred to above is the bandwidth to achieve a positive signal to noise ratio between insertion loss and power sum near end crosstalk (PSACR is greater than 0). CAT 6 cabling performance is specified to 250 MHz, or 25 percent beyond the 0 dB PSACR frequency of 200 MHz. Why choose Category 6 in the First Place? Current applications are pushing the bandwidth requirements of CAT 5e to its limits and the cost differential of CAT 6 over CAT 5e can be as little as 35% depending, on plenum versus non-plenum cable requirements. Since the actual cost is typically only about 5% of the overall IT installation cost anyway, and the lifespan is likely to be at least 10-15 years, it only makes sense to consider Cat 6. Also, the cost to subsequently replace the cabling infrastructure can be as high as 2 to 4 time’s the original cost. | 
