Phau Ntawv Qhia
27
INSTALLATIONCONFIGURATIONOPERATION
FURTHER
INFORMATION
INDEX
Link cable interference protection
While the Category rating (e.g. CAT 5e, CAT 6a, etc.)
determines the electrical performance of a cable, another vital
part of the overall cable specication is its protection from
interference. As cabling distances and data rates increase, so too
does the susceptibility to interference, from both external and
internal sources.
Proximity to other electromagnetic sources are the main
external threat and these can be subdued using overall screening
that surrounds all four of the cable pairs. However, interference
is also possible from neighbouring twisted pairs within the same
cable and this can be just as hazardous to data integrity. Such
crosstalk is countered by shielding each cable pair separately.
Within each Category rating, you can specify different
combinations of external screening and internal shielding to suit
the environment into which the link is being placed. Please see
the section Tips for achieving good quality links for suggested
combinations.
Interference protection codes
Interference protection is now classied in the following manner:
U/UTP
APPENDIX D
Name Overall Screening Pair Shielding
U/UTP
û û
F/UTP
ü
û
U/FTP û
ü
S/FTP
ü
ü
or S/STP
or PiMF
U/UTP
F/UTP
U/FTP
S/FTP
S/STP
PiMF
Pair shielding
Overall screening
Outer sheath
General cable anatomy
where
U = unshielded
F = foil shielding
S = braided shielding
PiMF = Pairs in Metal Foil
Overall
screening
Pair
shielding
Twisted
Pair