Dr. Howard Johnson discusses the innovative design of Broadcom’s T4 chip, showcasing its ability to transmit data through four pairs of old, rusty barbed wire with impressive results. The use of digital adaptive equalization at high speeds on poor quality cables revolutionized the industry, with the Broadcom T4 design proving its capability to work effectively without the need for upgrades. The demonstration at Interop in 1998 emphasized the importance of key transmission line properties – impedance, delay, high-frequency loss, and crosstalk – in determining performance. Ultimately, the success of the T4 chip on barbed wire highlights the significance of these properties in digital transmission structures.
https://www.sigcon.com/Pubs/edn/SoGoodBarbedWire.htm