"HDMI 1.4 introduces a feature called HEC (HDMI Ethernet Channel) among other features.[50][51][80] Like ARC, the HEC feature use two pins from the connector: a previously unused pin and the hot plug detect pin.[80][83]
HDMI Ethernet Channel technology consolidates video, audio, and data streams into a single HDMI cable, and the HEC feature enables IP-based applications over HDMI and provides a bidirectional Ethernet communication at 100 Mbit/s.[51] The physical layer of the Ethernet implementation uses attenuated 100BASE-TX type signals on a single twisted pair for both transmit and recei…