10Base-T is the part of the 802.3 standard that allows the use of a star-shaped cabling structure for Ethernet. 10Base-T specifies a CSMA/ CD network with 10 Mbit/s on UTP cable with RJ45 connector. The bus is concentrated in a hub in this 802.3 version. All stations are connected to this hub in a star configuration via four- wire cables. Two pairs of wires of the TP cable are used: Receive and Transmit.
The core diameter is between 0.4 mm( AWG 26) and 0.6 mm (AWG 22) with an impedance of 85 to 111 ohms and a coupling impedance of 100 ohms. The propagation speed on the UTP cable is >0.59c. The permissible attenuation must not exceed values of 11.5 dB in the frequency range between 5 MHz and 10 MHz. The near-end crosstalk attenuation is calculated from the formula `lt26-15*log(f/10)` and is 30.5 dB at 5 MHz and 26.0 dB at 10 MHz. 10 Base-T has a bit error rate that is below 1: 100,000,000.
The max. distance between two transceivers( MAU) without repeaters has been set to 100 m, whereby the hub is also a collection of transceivers that are interconnected via the internal bus of the hub. However, this 100 m includes wall outlets and patch panels as well as distances, e.g. between terminal equipment and outlets.
With the 10Base-T1interface, another Ethernet interface has been developed for automotive technology. This interface belongs to Single-Pair Ethernet( SPE) and uses only a single TP cable for data transmission in both directions.