Cat 6 cabling continues to gain ground against Cat 5e. However, major deployments of Cat 5e cabling products are still going on. The continuing popularity of Cat 5e may be attributed to its capacity to deliver the gigabit speed. It is also a very reasonable solution, something that's a major criterion in most projects.

The most popular horizontal cabling systems today are Cat 5e and Cat 6. Both these systems are capable of carrying data in the gigabit speed range. Fiber (two-core) is also seen in a few applications in the form of fiber-to-the-home (FTTH).

As for the advent of 10G-over-copper, one needs to only look at history to understand that copper, at the same speed has always been cheaper to deploy than fiber.

Fiber's biggest advantage is no-interference. Fiber is completely future proof. It remains unaffected by EMI and RFI effects. Two core tight-jacketed cables are normally used for these applications. Mostly multimode 62.5u fiber goes in multi-storied buildings as a vertical backbone and 50u laser graded or single-mode fiber goes as a horizontal backbone in the big campus-wide projects.