In certain aspects, the present disclosure is related to devices, methods, systems and/or computer-readable media for use in an isochronous media network in which media devices connected to a network employ one or more synchronization signal to regulate or facilitate the transmission of media signals through the network. In certain aspects, the present disclosure is also related to devices, methods, systems and/or computer-readable media for use in a larger unified, or substantially unified, isochronous network created from aggregating local isochronous media networks in which media devices connected to a network employ a one or more synchronisation signal distributed from a local master clock to regulate or facilitate the transmission of media signals.

A technique for determining a radio device residence time, RDRT (620), and scheduling the radio device (100) accordingly is described. More specifically, and without limitations, according to a first method aspect, a method for determining the RDRT (620) for a radio device (100) in radio communication with a network node (200) of a telecommunications network is provided, comprising a step of setting, at the radio device (100), a first time stamp (602) of a packet of the radio communication, wherein the first time stamp (602) is indicative of a time (602) of handling (720) the packet at a first layer (506) of a protocol stack at the radio device (100). The method further comprises a step of transmitting the packet to the network node (200) through a second layer (508) of the protocol stack, the second layer (508) being below the first layer (506) in the protocol stack. In a first variant, the packet comprises the first time stamp (602) of the packet for determining the RDRT (620) based on a difference between the first time stamp (602) and a second time stamp (710; 712) of the packet, wherein the packet is configured to initiate setting the second time stamp (710; 712) upon handling (724; 726) the packet at the telecommunications network. In a second variant, the packet comprises the RDRT (620) determined based on a difference between the first time stamp (602) of the packet and a second time stamp of the packet set at the radio device (100), wherein the second time stamp is indicative of a time of handling (722) the packet at the second layer (508) of the radio device (100). In a third variant, the packet comprises the first time stamp (602) of the packet and a second time stamp of the packet set at the radio device (100), wherein the second time stamp is indicative of a time of handling (722) the packet at the second layer (508) of the radio device (100), wherein the packet is configured to initiate determining, at the telecommunications network, the RDRT (620) based on a difference between the first time stamp (602) and the second time stamp.

There is provided a technique of securing clock synchronization between master clock node (MCN) and client clock node (CCN). During a cycle of exchanging PTP messages between MCN and CCN, MCN generates an associated paired message for each PTP message generated thereby and informative of t.sub.1 or t.sub.4 timestamps provided by MCN and sends each paired message to a validation entity (VE) via a secured channel between MCN and VE. When PTP messages traverse transparent clock nodes (TCN) between MCN and CCN, each TCN generates a paired message for each version of PTP message updated thereby and sends each generated paired message to VE via a secured channel between respective TCN and VE. VE uses the received paired messages to provide a validation of the cycle, wherein synchronization-related task(s) (e.g. clock correction by the client clock node, etc.) are provided only subject to successful validation of the cycle by VE.

A system is provided for aligning data stream signals that includes a plurality of end points each having a system clock and a communication circuit. The plurality of end points are configured to generate operation data having a system clock value based on the system clock. The system also includes a first node having a communication circuit configured to be communicatively coupled to the plurality of end points by a bi-directional communication link. The first node receives the operation data from the plurality of end points along the bi-directional communication link. The first node includes a controller circuit configured to determine a clock value and speed offsets between the first node and a first end point. Additionally, the controller circuit is configured to transmit a message sequence to determine the clock value and speed offsets.

A control plane, available to all of the line cards in a system, is used to exchange time stamps to align the Time of Day counters in the master line cards. The master line cards are locked to a system clock distributed over the backplane by a timing card. The timing card is locked to timing of a slave line card that is synchronized with the grand master. Each master line card synchronizes updating its Time of Day counter based on a time stamp exchange and a local clock locked to the system clock and without the use of a 1 pulse per second signal.

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.

Methods, systems, and apparatus for preserving timing domains of different communications types of signals in a telecommunications network are disclosed. In one aspect a network element (NE) includes a receiver configured to receive communications signals of two different communications types. The NE can include a timing analyzer configured to obtain a local reference clock (LRC), detect two different received reference clocks (RRCs) corresponding to the two different communications types, and for each received communications signal, determine a quantized value (QV) based on a difference between the LRC and the RRC. The NE can include a timing generator configured to generate, for the received communications signal, a transmit reference clock (TRC) that is referenced to, but different from, each of the LRC and the QV. The NE can include a transmitter configured to output an output signal based on the received communications signal and the TRC for the received communications signal.

A method and apparatus for synchronizing nodes in a communication network. A such as an EPoC, PON, or EPoC/PON hybrid access network. The network node receives or originates a ToD value and calculates future ToD value for a second node, which the first node includes in a ToD message for sending to the second node. The ToD message preferably includes a correction based on an OFDM ranging delay value and an adjustment based on a total transmit/receive PHY path asymmetry value with respect to the two nodes. A similar future ToD message is preferably sent to each downstream node that the first node is serving.

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 time synchronization method includes, a boundary device of a third-party network side receives a synchronization packet carrying a time synchronization offset and is delivered by a boundary device of an upstream network side on the basis that boundary devices in an entire network are all boundary clock (BC) devices, where the time synchronization offset is a time offset between a time domain of the upstream network and a time domain of the third-party network, and the boundary device of the third-party network side transparently transmits the synchronization packet carrying the time synchronization offset to a boundary device of a downstream network side such that the boundary device of the downstream network side performs time synchronization with the boundary device of the upstream network side according to the time synchronization offset. Thus time synchronization among multiple time domains in a network.