Telecommunication Copper Cables - PENGG KABEL GmbH

Basic Formulas of Telecommunication Technique
Units
Term Symbol Letter symbol Unit
angular frequency ω s -1 1/second
attenuation (equivalent) a, α dB (Np) dezibel (neper)
attenuation coefficient α dB/km (Np/km) dezibel (neper)/km
capacitance load per unit length C’ F/km farad/km
capacitance unbalance k, / k 1 / k 2,3 /k 9-12 / e 1,2 pF pikofarad
conductivity κ Sm/mm² siemensmeter/mm²
conductance G mS/km millisiemens/km
conductance per unit length G’ S/km siemens/km
conductor cross section q mm² millimeter²
conductor resistance R Ω/km ohm/km
current, strength of current I A ampere
dissipation factor tan δ - -
frequency f Hz hertz
group delay τ g s/km second/km
inductivity L mH/km millihenry/km
inductivity load per unit length L’ H/km henry/km
insulation resistance R is MΩkm megaohmkilometer
image phase change coefficient β rad/km rad/km
impedance (amount) Z Ω ohm
impedance (complex) Z L Ω ohm
impedance (imaginary part) Z i Ω ohm
impedance (real part) Z r Ω ohm
line length l km kilometer
level p dB (Np) dezibel (neper)
magnetic unbalance m nH nanohenry
mutual capacitance C nF/km nanofarad/km
mutual inductance M mH/km millihenry/km
near end cross talk attenuation (equivalent) a n , α n dB (Np) dezibel (neper)
phase delay τ p s/km second/km
power P W watt
reduction factor r k - -
reflection coefficient r - -
relative permittivity ε r - -
resistance load per unit length R’ Ω/km ohm/km
specific resistance s Ωmm²/m ohm mm²/m
temperature t °C degree celsius
velocity of propagation v ü bit/s bit/second
voltage U V volt
wave length λ m meter
Basic formulas for homogeneous, symmetrical cables
Conductor resistance
Complex characteristic impedance
(Ω)
-
Rt resistance at t °C in Ohm
R20 resistance at 20°C in Ohm
t temperature in °C
k 0.00393 for Cu or 0.00403 for Al
Angular frequency Dissipation factor
50 Telecommunication Copper Cables • 09/2012 • © by PENGG KABEL GmbH • Subject to technical alterations