1000BASE-T Ethernet signalling, also known as Gigabit Ethernet, is a type of standard for fast data transmission. It uses a technology known as Fast Ethernet, which allows for data rates of up to 1000 Mbps, or 1 Gbps. This is achieved by utilising all four pairs of Category 5 unshielded twisted pair cables. In 1000BASE-T Ethernet, each pair of cables is used for both transmission and reception of data, which is a departure from previous Ethernet standards. This is accomplished through a method called "bi-directional signalling" or "4D-PAM5 encoding", which allows for simultaneous transmission and reception of data signals. The 1000BASE-T Ethernet standard is widely used in local area networks (LANs) because it provides a high-speed, reliable, and cost-effective solution for data transmission. It is compatible with existing network infrastructure, making it a popular choice for businesses and organisations looking to upgrade their networks. It is important to consider that while 1000BASE-T Ethernet can technically support distances up to 100 metres, the actual distance may be less depending on the quality of the cables and the presence of any interference.