Ethernet over twisted pair

Standard twisted-pair cable usable for most common types of Ethernet
8P8C plug

Ethernet over twisted-pair technologies use twisted-pair cables for the physical layer of an Ethernet computer network. They are a subset of all Ethernet physical layers.

Early Ethernet used various grades of coaxial cable, but in 1984, StarLAN showed the potential of simple unshielded twisted pair. This led to the development of 10BASE-T and its successors 100BASE-TX, 1000BASE-T, 10GBASE-T and 40GBASE-T, supporting speeds of 10 and 100 megabit per second, then 1, 10 and 40 gigabit per second respectively.[a]

Two new variants of 10 megabit per second Ethernet over a single twisted pair, known as 10BASE-T1S and 10BASE-T1L, were standardized in IEEE Std 802.3cg-2019.[2] 10BASE-T1S has its origins in the automotive industry and may be useful in other short-distance applications where substantial electrical noise is present.[3] 10BASE-T1L is a long-distance Ethernet, supporting connections up to 1 km in length. Both of these standards are finding applications implementing the Internet of things. 10BASE-T1S is a direct competitor of CAN XL in the automotive space and includes a PHY-Level Collision Avoidance scheme (PLCA).[4]

The earlier standards use 8P8C modular connectors,[b] and supported cable standards range from Category 3 to Category 8. These cables typically have four pairs of wires for each connection, although early Ethernet used only two of the pairs. Unlike the earlier -T standards, the -T1 interfaces were designed to operate over a single pair of conductors and introduce the use of two new connectors referred to as IEC 63171-1[5] and IEC 63171-6.[6]

  1. ^ Charles E. Spurgeon (2000). Ethernet: the definitive guide. OReilly Media. ISBN 978-1-56592-660-8.
  2. ^ "PhysicalLayers Specifications and Management Parameters for 10 Mb/s Operation and Associated Power Delivery over a Single Balanced Pair of Conductors". IEEE 802.3. Archived from the original on March 18, 2020.
  3. ^ Fionn Hurley, Why 10BASE-T1S Is the Missing Ethernet Link for Automotive Communications, Analog Devices
  4. ^ Cena, Gianluca; Scanzio, Stefano; Valenzano, Adriano (2023-04-26). Composite CAN XL-Ethernet Networks for Next-Gen Automotive and Automation Systems (PDF). 2023 IEEE 19th International Conference on Factory Communication Systems (WFCS). IEEE. doi:10.1109/wfcs57264.2023.10144116.
  5. ^ Cite error: The named reference IEC 63171-1 was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference IEC 63171-6 was invoked but never defined (see the help page).


Cite error: There are <ref group=lower-alpha> tags or {{efn}} templates on this page, but the references will not show without a {{reflist|group=lower-alpha}} template or {{notelist}} template (see the help page).