A system and apparatus for obtaining clock synchronization of networked devices and related method are provided. Embodiments include a computer-implemented system, including a primary device having a first high accuracy timestamping assist (HATA) unit attached to a first physical layer; a first time stamping unit; a first clock control; a first medium access control layer connected to the first time stamping unit and the first physical layer via a medium independent interface. A secondary device includes a second HATA unit attached to a second physical layer; a second timestamping unit; a second clock control. The first and second HATA units are configured to detect a departure time, an arrival time, or a combination thereof of a first alignment marker over transmitter serializer and receiver deserializer interfaces of a data transmission between the primary device and the secondary device.

A method for operating a first communication node connected to an in-vehicle network is provided. The method comprises generating a header including a count field indicating a wraparound count for a presentation time of contents and a timestamp field indicating the presentation time, generating a payload field including the contents, and transmitting a frame including the header and the payload field to a second communication node connected to the in-vehicle network.

A packet processing method includes receiving a first packet by a first receiving interface of a media conversion module of a first network device, where the first packet includes a first alignment marker (AM), sending a second packet by a first sending interface of the media conversion module, where the second packet includes the first AM, and the second packet is the first packet processed by the media conversion module, and calculating a time interval T.sub.1 between a time at which the media conversion module receives the first packet and a time at which the media conversion module sends the second packet, where the T.sub.1 is used to compensate for a first timestamp at which the first network device receives or sends the third packet.

A method for transmit timestamp autocalibration includes generating a calibration pulse for calibrating a transmit timestamp in a transmitting device. The method further includes applying the calibration pulse to a transmit data pipeline in the transmitting device. The method further includes sampling a transmit timestamp when the calibration pulse reaches a timestamp sample triggering location in the transmit data pipeline upstream from an egress point of the transmitting device. The method further includes measuring a latency between a time that the calibration pulse reaches the timestamp sample triggering location and a time that the calibration pulse reaches a location downstream from the timestamp sample triggering location. The method further includes generating an adjusted timestamp based on the measured latency and inserting the adjusted timestamp into a data packet to be transmitted from the transmitting device.

A system and apparatus for obtaining clock synchronization of networked devices and related method are provided. Embodiments include a computer-implemented system, including a primary device having a first high accuracy timestamping assist (HATA) unit attached to a first physical layer; a first time stamping unit; a first clock control; a first medium access control layer connected to the first time stamping unit and the first physical layer via a medium independent interface. A secondary device includes a second HATA unit attached to a second physical layer; a second timestamping unit; a second clock control. The first and second HATA units are configured to detect a departure time, an arrival time, or a combination thereof of a first alignment marker over transmitter serializer and receiver deserializer interfaces of a data transmission between the primary device and the secondary device.

A system and method for clock-skew-based covert communication in which a message formed of message bits is mapped to corresponding symbols having predetermined clock skew values. For each corresponding symbol, an offset value is calculated and added to each timestamp in a predetermined quantity of outgoing TCP segments to generated altered TCP segments, such that an artificial clock skew is induced as measured by a receiver. A clock skew value is determined from each predetermined quantity of TCP segments and mapped to corresponding symbol. The symbols are then mapped to corresponding message bits, and the message is determined from the bits. In this way a message can be sent from a transmitter to a receiver in a way that is covert during transmission and deciphered at the receiver.

A time synchronization method includes receiving, by a receive-end device, a first timestamp and a first header signal sent by a transmit-end device, where the first timestamp indicates a first moment at which a first channel medium conversion module sends the first header signal, and a second moment at which the receive-end device receives the first header signal. The method further includes sending a second header signal to the transmit-end device, where a third moment at which the receive-end device sends the second header signal. The method further includes receiving a fourth timestamp sent by the transmit-end device, where the fourth timestamp indicates a fourth moment at which the transmit-end device receives the second header signal. The method further includes synchronizing time with the transmit-end device based on the first moment, the second moment, the third moment, and the fourth moment.

Techniques for clock synchronization over a wireless connection are provided. A first wireless node determines an offset between a first clock used by the first wireless node for a wired connection between the first wireless node and at least one upstream node and a second clock used by the first wireless node for a wireless connection between the first wireless node and a second wireless node on the downstream. The first wireless node transmits an indication of the determined offset to the second wireless node for use by the second wireless node to calibrate a third clock corresponding to the first clock to synchronize the third clock with the first clock, wherein the third clock is used by the second wireless node for a second wired connection with at least one downstream node.

Methods and systems for providing a virtual HDBaseT link. In one embodiment, a first switch transmits packets over an Ethernet network that includes one or more hops. The payload of each of the packets includes an HDBaseT T-packet belonging to an HDBaseT session. A first processor sets, for each packet from among a plurality of the packets, a timestamp value in the packet to correspond to the time at which the packet is transmitted by the first switch. A second switch receives the packets over the Ethernet network. A second processor calculates a clock correction value based on the timestamps in the plurality of packets, and utilizes the clock correction value to perform at least one of the following: (i) control transmission, by the second switch, of data in T-packets in the payloads of the packets, and (ii) recover a source clock of native media delivered over the Ethernet network.

Methods and systems for enabling recovery of lost packets transmitted over a communication network. In one embodiment, a device includes a processor and a transmitter. The processor is configured to calculate a row parity packet (RPP) and a diagonal parity packet (DPP) for n packets. Each of the RPP, the DPP, and the n packets comprises n segments. The processor utilizes each packet, from among the n packets, to update parity values in the RPP and the DPP in such a way that each segment in the packet is used to update one segment in the RPP and at most one segment in DPP. The transmitter transmits the n packets, the RPP, and the DPP over the communication network. Receiving a subset of n members of a set comprising: the RPP, the DPP, and the n packets, enables recovery of two lost packets.