Electrical Requirements of Differential Signals

The electrical requirements consider the complete the complete elecreical

interical interconnection system,connectors and cable

Nominal Differential Impedance :100 ±10

Cable Intra-Pair differential skew : <10psec/m

Max.Mulitpair Crosstalk 1)<8% @0to3.125GHz

Insertion Loss Sdd21 :<3.2dB @0to3.125GHz

Return Loss Sdd11 :>6dB @0to3.125GHz

请各位大虾帮帮忙解释一下，尽可能详尽！谢谢！如果可以请帮忙解释原理！