Patent classifications
H04J3/0673
Method of remotely monitoring the timing performance of a PTP slave
In some embodiments, a method is performed after locking a first clock of a computing device to synchronize with a second clock associated with a first device where a difference between the first clock and the second clock is determined during the locking. The method measures a path delay to a second device based on sending messages including first timestamps of the first clock to the second device and receiving messages including second timestamps of a third clock from the second device. A third message is sent to the second device that includes a third timestamp of the first clock that has been locked to the second clock, wherein the third message includes the path delay, and wherein the third timestamp and the path delay allow the second device to analyze a lock quality of the first clock to the second clock based on a time of the third clock.
Time stamp replication within a wireless network based on transmission prediction
Time stamp replication within wireless networks is described. In an embodiment, a wireless station receives an input time stamp and uses this input time stamp to generate an output time stamp. The wireless station transmits the output time stamp to wireless stations in one of a number of groups which make up the wireless network. The output time stamp is generated to compensate for delays between receiving the input time stamp and transmitting the output time stamp such that output time stamp which is transmitted at a time T corresponds to the value that the input time stamp would have had if it had been received at time T (and not at a time earlier than T). This may, therefore, reduce or eliminate independent time stamp errors and jitter caused by multiple disparate systems and processes.
Method of remotely monitoring the timing performance of a PTP slave
In some embodiments, a method is performed after locking a first clock of a computing device to synchronize with a second clock associated with a first device where a difference between the first clock and the second clock is determined during the locking. The method measures a path delay to a second device based on sending messages including first timestamps of the first clock to the second device and receiving messages including second timestamps of a third clock from the second device. A third message is sent to the second device that includes a third timestamp of the first clock that has been locked to the second clock, wherein the third message includes the path delay, and wherein the third timestamp and the path delay allow the second device to analyze a lock quality of the first clock to the second clock based on a time of the third clock.
ROBUST DISTRIBUTION OF IP TIMING SIGNALS
Embodiments disclosed herein provide techniques to selectively distribute Precision Time Protocol (PTP) data in a network. The network can include multiple different network devices (e.g., switches) connected to form a network architecture (e.g., a spine/leaf architecture). Rather than distributing the PTP data (e.g., PTP timestamps) through all the network devices in order to synchronize local clocks to a global, master clock, the embodiments herein describe an out-of-band distribution network which selectively distributes the PTP data to select network devices in the network.
Robust distribution of ip timing signals
Embodiments disclosed herein provide techniques to selectively distribute Precision Time Protocol (PTP) data in a network. The network can include multiple different network devices (e.g., switches) connected to form a network architecture (e.g., a spine/leaf architecture). Rather than distributing the PTP data (e.g., PTP timestamps) through all the network devices in order to synchronize local clocks to a global, master clock, the embodiments herein describe an out-of-band distribution network which selectively distributes the PTP data to select network devices in the network.
Lip synchronization of audio and video signals for broadcast transmission
A multi-device lip synchronization method and a device. A secondary device receives an RTCP packet sent by a primary device. The secondary device corrects an STC of the secondary device based on a PCR in the RTCP packet, a program dock frequency of the primary device, a program dock frequency of the secondary device, and an RTCP delay. Then, the secondary device receives RTPs published by the primary device, splice the RTPs into a complete audio data frame, and store the audio data frame into a PCM buffer of the secondary device. The secondary device outputs the audio data frame in the PCM buffer.
Method for Synchronizing Networks
A method for synchronizing networks is disclosed. A first wired communication system having a first time base is set up in a first network. A second wired communication system having a second time base is set up in a second network. The first network and the second network are connected to a wireless communication system via a first translation unit and a second translation unit, respectively. The first translation unit and the second translation unit are synchronized to one another according to a third time base of the wireless communication system independently of the first time base and the second time base. A third synchronization message is transmitted from the first translation unit to the second translation unit. A transmission time for the third synchronization message in the third time base is determined and is used to synchronize the second time base to the first time base.
COMMUNICATION SYSTEM AND SLAVE DEVICE
A grand master device (GM) (10) and a slave device (S1) (20) are connected via a general-purpose hub (HUB) (30) whose relay delay is not constant. The grand master device (GM) (10), at a timing for transmitting a Sync frame for time synchronization, acquires current time as transmission time of the Sync frame, acquires a count value of a master counter as a transmission count value, stores the transmission time and the transmission count value in the Sync frame, and transmits the Sync frame. The slave device (S1) (20) receives the Sync frame, acquires reception time of the Sync frame and a reception count value which is a count value of a slave counter at the reception time, and corrects time of the slave device (S1) (20), using the transmission time, the transmission count value, the reception time and the reception count value.
TIME STAMPING METHOD, TIME STAMPING APPARATUS AND PROGRAM
A time providing method includes: by a computer, upon receiving data from a device, estimating a generation time of the data using a reception time of the data and a first delay time of the device previously estimated; providing information indicating the generation time to the data; and transmitting the data provided with the information indicating the generation time to a destination of the data.
Communication system, communication device and communication method
A communication system according to one aspect of the present disclosure is a communication system in which a plurality of communication devices are connected to a network. The plurality of communication devices include a time master including a master clock that manages time of the communication system and a plurality of time slaves each of which includes a slave clock time-synchronized with the master clock. Each of the plurality of time slaves includes a synchronization unit that performs time synchronization with another communication device connected adjacent to a master side on the network and a communication unit that notifies the time master of time synchronization information indicating time synchronization accuracy of the own device obtained by the synchronization unit.