Transmission Medium
Twisted pair (UTP, STP)
- analog signal amplifiers required every 5 to 6 km
- digital signal repeaters required every 2 to 3 km
- interference reduced by sheating
- UTP: ordinary telephone wire, cheapest media for LANs, subject to interference
- STP: less prone to interference, more expensive, harder to work with
EIA-568-A standard recognizes
- category 3 UTP capable of 16MHz
- category 4 UTP capable of 20 MHz
- category 5 UTP capable of 100MHz