Structure Means Application Independence
 

A modern cabling system is a structured system that typically meets the requirements of TIA/EIA-568-B and ISO 11801. These standards are performance-driven and application-independent. They specify levels of performance at both the component and the system level. Any application that specifies these performance requirements will run well on the cabling plant. The standards for Category 5e UTP allow 100 MHz operation over a 90-meter horizontal run. Thus no mention is made of Ethernet, Token Ring, Fast Ethernet, FDDI, ATM or other popular network standards. Why? Because all of these applications contain requirements that are well within the performance specifications established by TIA/EIA-568-B and, more specifically, Category 5e UTP. The standard is generic, created not for specific network systems but for specified levels of performance. That's why AMP rates the performance of its cabling systems to cabling specifications rather than to application specifications.

This is a very important consideration in understanding cabling systems: the system does not have to be tested or certified to a specific application; it need only be performance-tested to the TIA/EIA-568-B or ISO 11801.

Remember, there is a difference between bandwidth (MHz) requirements and transmission rates (Mbps). Some people tend to equate data rates with frequency/bandwidth requirements. Most often they are not the same, and this is especially true for emerging high-speed applications. The method used to encode the information can mean a high data rate at a low bandwidth. TP-PMD (UTP-based FDDI), 100BASE-TX Fast Ethernet and 155-Mbps ATM are examples of applications that have transmission rates exceeding 100 Mbps, but which require a much lower bandwidth (MHz) to operate and are specified to use Category 5 systems. In other instances- notably 1000BASE-T - the signal is divided among pairs and transmitted in a parallel fashion, further reducing bandwidth required.