A communication system and a communication method for one-way transmission are provided. The communication method includes: receiving, by a precision time protocol switch, a first synchronization message from a grandmaster clock; generating, by the precision time protocol switch, a second synchronization message according to the first synchronization message; transmitting, by the precision time protocol switch, the second synchronization message to a transmitting server and a programmable logic device; generating, by the transmitting server, a timestamp according to the second synchronization message; transmitting, by the transmitting server, at least one data packet and the timestamp to the precision time protocol switch; forwarding, by the precision time protocol switch, the at least one data packet and the timestamp to the programmable logic device; and determining, by the programmable logic device, whether to output the at least one data packet according to the timestamp and the second synchronization message.

The time signal verification and distribution device disclosed herein verifies and distributes a time signal to consuming devices. The device determines a time quality status of a first and second time signal, calculates a difference between a first and a second time signal, and compares the difference to a predetermined threshold. Based on the time quality status and the comparison, the time signal verification and distribution device distributes a time signal to a plurality of time signal consuming devices. Exceeding the predetermined threshold may indicate a spoofing attack or other problem with the time signals.

Novel tools and techniques are provided for implementing network timing functionality. In some embodiments, a grand master clock(s) might receive a first timing signal from a global positioning system (“GPS”) source via a GPS antenna(s), and might send a second timing signal (which might be based at least in part on the first timing signal) to a slave clock(s), in some cases, via one or more network elements or the like. A computing system might calculate various transmission times for the second timing signal to be transmitted between the grand master clock(s) and the slave clock(s), and might calculate any time delay differences in the transmission times, might generate a third timing signal based at least in part on the calculated time delay differences (if any), and might send the third timing signal to one or more network elements, thereby providing Accurate Synchronization as a Service (“ASaaS”) functionality.

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.

Systems and methods to enable 5G system support for conveying time synchronization are provided. In some embodiments, a method performed by a wireless device for conveying external time domain information is provided. The method includes receiving a message in a first time domain used by the wireless device, the message comprising external time domain information; determining information about a second time domain based on the external time domain information; and conveying information about the second time domain to another node. In some embodiments, timing information is included into a GPRS Tunneling Protocol (GTP) payload, and the wireless device can get timing information directly from the data payload. This minimizes the RAN and/or gNB impact and adds the potential for multiple time domain support.

One embodiment includes a system. The system includes a receiver configured to extract a timestamp from a header of each packet of a data stream received from a network and to de-packetize the data stream to provide a stream of data blocks. The timestamp can correspond to generation of each data block associated with each respective packet of the data stream according to a global timebase. The system also includes a delay controller configured to measure a delay associated with each packet of the data stream based on the timestamp relative to the global timebase and to control converting the data stream to a corresponding analog output signal for transmission based on the measured delay.

A method of facilitating clock synchronization over redundant networks may include, when a SYNC message and a DELAY_REQ message of a PTP clock synchronization cycle are carried by different redundant networks, adjusting a timestamp associated with one of the messages to emulate carriage of the SYNC message and the DELAY_REQ message by the same redundant network. In a method of facilitating PTP clock synchronization, an indicator of an operational status of each of a pair of redundant networks for carrying messages from a slave clock to a master clock may be embedded in a PTP message destined for the slave clock. An indicator of which one of the pair of redundant networks is valid for PTP clock synchronization may be obtained from a PTP message destined for the master clock. PTP messages to the master clock may be selectively relayed based on whether the PTP messages have been received from the valid one of the redundant networks.

The invention generally relates to the field of vehicular communications. In particular, the invention relates to method, system and apparatus for establishing and maintaining vehicular communications, such as wireless vehicular communications in a vehicular ad hoc network (VANET).

In a satellite-based communication network comprised of a central hub and plurality of remote terminals configured to transmit data to and receive data from the central hub in accordance with EN 301 790 (DVB-RCS), and where one or more of these remote terminals may be configured to include an additional receiver module configured to receive MF-TDMA transmission of other remote terminals, a mesh receiver and methods for coupling the mesh receiver with the host remote terminal. In addition, described herein are methods for synchronizing the mesh receiver on the network's timing and frequency and for utilizing the available link power for achieving efficient connectivity.

A system for time synchronization of a network element including a GNSS receiver operative to receive at least one signal from at least one but less than four GNSS satellites, a locator operative to supply a location of a network element including the GNSS receiver to the GNSS receiver and a time synchronization calculator operative to time synchronize the network element with the GNSS satellites based on the at least one signal and the location.