An Ethernet transceiver in an in-vehicle network, comprising: a media access control, MAC, controller; a physical layer, PHY, device comprising: a transmit buffer configured to buffer first media independent interface, MII, data received from the MAC controller over a first path; a receive buffer configured to buffer second MII data for transmission to the MAC controller over a second path; a transmitter configured to convert the first MII data buffered by the transmit buffer from a first-bit packet stream to a second-bit packet stream, the second-bit packet stream having fewer bits than the first-bit packet stream, to map the second-bit packet stream to a plurality of first bit streams, and to multiplex the plurality of first bit streams into a first single stream to form a transmit signal for transmission over a single-pair, shielded or coaxial cable to a remote Ethernet transceiver in the in-vehicle network; a receiver configured to process a receive signal received over the single-pair, shielded or coaxial cable from the remote Ethernet transceiver in the in-vehicle network to demultiplex the receive signal from a second single stream to a plurality of second bit streams, to map the plurality of second bit streams to a third-bit packet stream, and to convert the third-bit packet stream to a fourth-bit packet stream, the third-bit packet stream having fewer bits than the fourth-bit packet stream, to provide the second MII data to the receive buffer for buffering; and a time-division duplex, TDD, controller configured to control a duration of time the transmitter transmits the transmit signal during a TDD frame over the single-pair, shielded or coaxial cable to the remote Ethernet transceiver. a media access control, MAC, controller; a physical layer, PHY, device comprising: a transmit buffer configured to buffer first media independent interface, MII, data received from the MAC controller over a first path; a receive buffer configured to buffer second MII data for transmission to the MAC controller over a second path; a transmitter configured to convert the first MII data buffered by the transmit buffer from a first-bit packet stream to a second-bit packet stream, the second-bit packet stream having fewer bits than the first-bit packet stream, to map the second-bit packet stream to a plurality of first bit streams, and to multiplex the plurality of first bit streams into a first single stream to form a transmit signal for transmission over a single-pair, shielded or coaxial cable to a remote Ethernet transceiver in the in-vehicle network; a receiver configured to process a receive signal received over the single-pair, shielded or coaxial cable from the remote Ethernet transceiver in the in-vehicle network to demultiplex the receive signal from a second single stream to a plurality of second bit streams, to map the plurality of second bit streams to a third-bit packet stream, and to convert the third-bit packet stream to a fourth-bit packet stream, the third-bit packet stream having fewer bits than the fourth-bit packet stream, to provide the second MII data to the receive buffer for buffering; and a time-division duplex, TDD, controller configured to control a duration of time the transmitter transmits the transmit signal during a TDD frame over the single-pair, shielded or coaxial cable to the remote Ethernet transceiver. a transmit buffer configured to buffer first media independent interface, MII, data received from the MAC controller over a first path; a receive buffer configured to buffer second MII data for transmission to the MAC controller over a second path; a transmitter configured to convert the first MII data buffered by the transmit buffer from a first-bit packet stream to a second-bit packet stream, the second-bit packet stream having fewer bits than the first-bit packet stream, to map the second-bit packet stream to a plurality of first bit streams, and to multiplex the plurality of first bit streams into a first single stream to form a transmit signal for transmission over a single-pair, shielded or coaxial cable to a remote Ethernet transceiver in the in-vehicle network; a receiver configured to process a receive signal received over the single-pair, shielded or coaxial cable from the remote Ethernet transceiver in the in-vehicle network to demultiplex the receive signal from a second single stream to a plurality of second bit streams, to map the plurality of second bit streams to a third-bit packet stream, and to convert the third-bit packet stream to a fourth-bit packet stream, the third-bit packet stream having fewer bits than the fourth-bit packet stream, to provide the second MII data to the receive buffer for buffering; and a time-division duplex, TDD, controller configured to control a duration of time the transmitter transmits the transmit signal during a TDD frame over the single-pair, shielded or coaxial cable to the remote Ethernet transceiver.