Exemplary of embodiments of the disclosure include a method which includes determining, by a first device, whether the first device has a current time and transmitting a request for the current time to a second device if the first device does not have the current time. The second device is in a local network. The method further includes receiving, by the first device, the current time from the second device, authenticating a certificate based on the current time received from the second device, and establishing a network connection to the local network based on the authenticated certificate.

A network element includes circuitry configured to receive information related to clock distribution from Precision Time Protocol (PTP) messages from an upstream network element, determine a delta between a network clock from the information and a Primary Reference Time Clock (PRTC), and transmit the delta in PTP messages to downstream network elements. The circuitry can be further configured to receive a configuration of a clock class of a clock at the network element, and transmit the clock class in the PTP messages with the delta. The clock class can be one of A, B, C, and D from G.8273.2 or G.8273.4.

Disclosed herein is a method, a computer program product, and a carrier for indicating one-way latency in a data network (N) between a first node (A) and a second node (B), wherein the data network (N) lacks continuous clock synchronization, comprising: a pre-synchronization step. A measuring step, a post-synchronisation step, an interpolation step, and generating a latency profile. The present invention also relates to a computer program product incorporating the method, a carrier comprising the computer program product, and a method for indicating server functionality based on the first aspect.

A method, performed by a network entity, of performing time sensitive communication (TSC) includes: establishing a first protocol data unit (PDU) session with a first user equipment (UE) and a second PDU session for a second UE; receiving, from the first UE, an announce message obtained from a first time sensitive network (TSN) node; configuring, based on the announce message, a port state of the network entity; and transmitting, to the second UE or a second TSN node, the announce message.

The time synchronization of a network is protected against unauthorized changes to the grandmaster clock of a base time domain by monitoring the physical communication interfaces of a network device for arrival of messages relating to time synchronization. If the messages relating to time synchronization apply to the initially set-up and synchronized base time domain, a check is performed to determine whether the messages relating to time synchronization announce a new grandmaster clock having better clock parameters than those of the present grandmaster clock. If so, a virtual base time domain is started by the network device. If the verification reveals that the proposed new grandmaster clock is trustworthy or valid, the network device discontinues the virtual time domain, updates its stored information concerning the grandmaster clock and, from this time onward, sends messages relating to time synchronization that are based on the new clock parameters to the network.

The communication master repeats transmission of first information indicating a counter value of a synchronization counter of the communication master to the one or more communication slaves through a network. Each of the one or more communication slaves updates the counter value of the synchronization counter of each of the one or more communication slaves based on the received first information upon receiving the first information from the communication master. The communication master manages a total number of pieces of the first information transmitted for each of the one or more communication slaves, and estimates synchronization accuracy with respect to the communication master for each communication slave based on a number of transmissions of the first information for each communication slave.

An information control method and a communications device are provided. The method includes: obtaining first information; and executing at least one of the following operations: determining a first delay according to the first information; determining a second delay according to the first information; determining delay requirement information according to the first information; sending the delay requirement information to a network element in a communications network; sending bridge delay information to a third-party network or a third-party application; executing a first operation when it is determined that a first condition is met; and executing a second operation when it is determined that a second condition is met, where the first information includes at least one of the following: first time information, second time information, clock information of a first clock, and clock information of a second clock.

One embodiment of the present invention sets forth a technique for performing time synchronization within a network. The technique includes receiving, from a first node in the network and at a first receive time, a first periodic beacon that includes a first network time associated with the first node. The technique also includes determining a second receive time at which a second periodic beacon from the first node is to be received based on the first network time and the first receive time. The technique further includes calculating a first listening window for the second periodic beacon based on the second receive time, a first jitter uncertainty, and a first drift uncertainty, and listening for the second periodic beacon during the first listening window.

A communication apparatus sets a first obtaining method for obtaining IP addresses of a first network interface and an external server with which the communication apparatus communicates via the first network interface, and a second obtaining method for obtaining IP addresses of a second network interface and an external server with which the communication apparatus communicates via the second network interface. If the first obtaining method is manual obtaining, if the second obtaining method is automatic obtaining, and if setting of a default gateway has been set with respect to the first network interface, the communication apparatus controls communications by using at least the IP address of the second network interface obtained by the automatic obtaining without using the IP address of the external server obtained by the automatic obtaining via the second network interface.

The disclosure relates to method and system for correcting a clock skew in a slave device using a precision time protocol (PTP). The method includes determining an uplink delay and a downlink delay, based on at least two packet transactions in the PTP protocol and conducted between the slave device and a master device within a pre-defined accumulator time window. The method further includes determining a change in the uplink/downlink delay with respect to a reference uplink/downlink delay. The reference uplink/downlink delay correspond to a first pre-defined accumulator time window at a start of the slave device, or to a last pre-defined accumulator time window during a previous correction of the clock skew. The method further includes correcting the clock skew upon determining the change in the uplink delay to be about same in magnitude as and to be in opposite direction to the change in the downlink delay.