As higher speed network equipment is introduced, cabling systems that support that capacity are introduced and deployed.
The typical sequence of events has been:
In simple terms, there are three ways of transmitting higher bit rates over cabling, one is to improve the cabling performance, the second is to improve the technology in the electronics, and thirdly and more commonly is a requirement for a mixture of both cabling and networking improvements.
Multi-level encoding/modulation schemes are routinely used in modern systems, with the trade-off being complex and expensive electronics using existing cabling systems vs. simpler and less expensive electronics using enhanced cabling systems.
The network speed improvements may be realized over existing cabling infrastructures albeit at usually a shorter distance, which allow network manager to leverage existing investment.
You don’t have to pull out your existing cabling system in anticipation of applications appearing tomorrow, but there will be a need to evaluate the infrastructure if network problems occur.
Due to the hierarchical nature of the network and the “funneling” effects of network switching, the “need for speed” clearly grows the further one gets out from the user device.
The natural evolution for the general business network over the next few years will involve a migration to switched 1, 2.5, 5 or 10 Gbps at the user device, switched 10 and 40 Gbps capability first at the server interface and then in the building backbone, and finally switched 10, 40 or 100 Gbps capability in the mainstream enterprise environment.
The infrastructure portion will experience a similar migration over the same time period, with high performance twisted pair cabling and wireless strongly positioned as the horizontal media, laser optimized multimode fiber gradually moving to single-mode fiber in the building backbone, and singlemode fiber in the campus and network core.
Several options exist for extending the capability of optical fiber. For example, standards have yet to use multi-level coding on multimode fiber to increase transmission capacity using less bandwidth, a technique very popular in copper-based LANs. Fiber networks can also take advantage of wavelength division multiplexing (WDM), which provides additional channels over the same fiber by using different colors (wavelengths) of light.
Parallel transmission is another way of increasing link speeds, with multiple fibers used to transmit data. Also, devices such as short wavelength lasers and vertical cavity surface emitting lasers (VCSELs), are capable of providing cost-effective gigabit-rate data links over multimode fiber.
As cabling and networking technology continues to evolve ever higher, these new approaches will continue to be developed and deployed.