A lot of useful information is available at the Gigabit Ethernet Consortium Web site , at http://www.gigabit-ethernet.org/.
Gigabit Ethernet standards include
IEEE Standard 802.3, 1998 Edition. "Carrier Sense Multiple Access with Collision Detection (CSMA/CD) Access Method and Physical Layer Specifications." See Chapters 34, 36, 41, and 42.
IEEE Standard 802.3ab, 1999. "Supplement to Carrier Sense Multiple Access with Collision Detection (CSMA/CD) Access Method and Physical Layer Specifications—Physical Layer Parameters and Specifications for 1000Mbps Operation Over 4-Pair of Category 5 Balanced Copper Cabling, Type 1000BASE-T."