What are the three defined implementations of Fast Ethernet?

What will be an ideal response?

Fast Ethernet, which is defined under the IEEE 802.3u standard, has three defined implementations:
• 100Base-TX-Uses two pairs of either Category 5 unshielded twisted-pair (UTP) or shielded twisted-pair (STP); one pair is used for transmit (TX), and the other is used for receive (RX). The maximum segment length is 100 meters; two Class II repeaters and a five-meter patch cable can be used to create a maximum distance of 205 meters between stations for each collision domain.
• 100Base-T4-Uses four pairs of either Category 3, 4, or 5 UTP cable; one pair is used for TX, one pair for RX, and two pairs are used as bidirectional data pairs. The maximum segment length is 100 meters; as with 100Base-TX, two Class II repeaters and a five-meter patch cable can be used to create a maximum distance of 205 meters between stations for each collision domain. Because all four pairs are used, the T4 specification does not support full-duplexing, which is discussed in the next section.
• 100Base-FX-Uses multimode fiber-optic (MMF) cable with one TX and one RX strand per link. The maximum segment length is 412 meters.