What if you use a UTP cable?
Structured Cabling is the pathway of choice. Structured Cabling is a 4 pair unshielded twisted pair (UTP) cable in a single sheath. The conductors are solid core copper with a single insulation layer. The conductors are twisted at a high rate of twist. Each pair is twisted at a different twist rate. The Impedance of UTP cable is given as 100 Ohms plus or minus 15 Ohms. The Impedance of UTP cable is measured across the broad spectrum of frequencies that the cable will carry. Different frequencies will have different losses thus we say +/- 15 Ohms to allow for these variations in frequencies and there respective losses. But because the circuit of any given pair in the cable is balanced at 100 Ohms this is our central impedance which will vary with frequency components generated by our transmitters in the equipment, the HUB/Switch or NIC. If you take a multimeter and measure the resistance, a d.c. measurement, in a HUB or NIC it is only a few Ohms, because the circuit is not activated until the NIC is connected then 100 Ohms is presented but when combined with the cables resistance (d.c.), inductance (a.c.) and capacitance (a.c.) we may derive a nominal impedance of 100 Ohms +/- 15 Ohms. Whether the cable is classified as Cat 5, Cat 5e (enhanced) or Cat 6 the impedance is the same, 100 W +/- 15 W where "W" is the symbol for Ohms.

• R = Resistance measured in Ohms
• L = Inductance measured in Henry's
• C = Capacitance measured in Farad's
• Z = Impedance where Z = resistance + inductance + capacitance measured in ohms referenced to a test frequency (NOTE...this is not the mathematical formula but is merely a statement that all effects of RLC are a combined effect that impedes the flow of the ac signal)

• reduce capacitance by making the insulation out of dielectric materials as used in coax cables.
• increase the copper conductor diameter to reduce resistance.
• use termination products to balance the effects of RLC on the frequency components of the data signals.

The information in many networks utilises binary directly onto the copper cable, 1V. Binary has little energy. Binary that is switched rapidly has high frequency (H.F.) components, H.F. sine waves. H.F. Sine waves attenuate badly and cause other problems such as pulse dispersion. Binary also causes other problems by charging the copper pair with voltage which effects the receiver. Binary as a constant string of one’s is like putting a battery on the pair, it charges and holds that charge. This must be eliminated because the receiver makes errors when sensing voltage.

If you have ever tried putting a multimeter on a long pair of wires and then reversing the multimeters leads you'll see the needle flick on the meter, this is an indication of how the cable charges with the voltage impressed by the multimeter. This is a d.c. effect.

What I will now explain in the next few sections are the problems in more detail associated with transmitting data on a cable and then show you how we overcome those problems by encoding the data in special ways to beat the problems and achieve error free transmission.

The purpose of explaining these parameters to you is simply to make you aware of the complexities associated with the complex signals carried over the cabling that you install. My hope is that you may then appreciate why it is so important to install your cabling in the correct manner to give these tiny complex signals the best chance of performing in the circuit without errors. Any deformation in the cable installation impacts on the cable circuits causing problems. Did you know that 80% of data cabling faults are attributed to poorly installed cable?