1000BASE-T (also known as IEEE 802.3ab) is a standard for Gigabit Ethernet over copper wiring. Each 1000BASE-T network segment can be a maximum length of 100 meters (330 feet), and must use Category 5 cable or better. Autonegotiation is a requirement for using 1000BASE-T according to Section 28D.5 Extensions required for Clause40 (1000BASE-T). At least the clock source has to be negotiated, as one endpoint must be master and the other endpoint must be slave. In a departure from both 10BASE-T and 100BASE-TX, 1000BASE-T uses all four cable pairs for simultaneous transmission in both directions through the use of adaptive equalization and a five-level pulse amplitude modulation (PAM-5) technique. The symbol rate is identical to that of 100BASE-TX (125 megabaud) and the noise immunity of the five-level signaling is also identical to that of the three-level signaling in 100BASE-TX, since 1000BASE-T uses four-dimensional trellis coded modulation (TCM) to achieve a 6 dB coding gain across the four pairs.
1000BASE-T came into wide use in 1999, gradually replacing fast Ethernet for wired local networks simply because it was 10 times as fast. Equipment and cables are very similar to previous Ethernet standards and by 2011 were very common and economical. These were the biggest factors that ensured this standard's wide acceptance. 1000BASE-T is a shorthand designation by the Institute of Electrical and Electronics Engineers (IEEE). The 1,000 refers to the transmission speed of 1,000 Mbps, while "base” refers to baseband signaling, which means that only Ethernet signals are being carried on this medium. The “T” refers to the twisted pair cables this technology uses. 1000BASE-T can be used in data centers for fast server switching or in desktop PCs for broadband applications. The biggest advantage of 1000BASE-T is that it can use existing copper cabling, negating the need to rewire the system with newer optical fiber cables.
The 1000BASE designation is an IEEE shorthand identifier. The "1000" in the media type designation refers to the transmission speed of 1000 Mbps. The "BASE" refers to baseband signalling, which means that only Ethernet signals are carried on the medium. (Through repeaters, media segments of different physical types can be sometimes be used in the same system.) 1000BASE-T can be used in data centers for server switching, for uplinks from desktop computer switches, or directly to the desktop for broadband applications. A big advantage of 1000BASE-T is that existing copper cabling can be used instead of having to rewire with optical fiber. The designation for "1000BASE-T" is also sometimes seen as "1000BASE T."
|Transceiver package||Ethernet standard|