公开(公告)号：US20180351676A1

公开(公告)日：2018-12-06

申请号：US15612525

申请日：2017-06-02

Applicant: Apple Inc.

Inventor： Ashley I. Butterworth ,  Matthew X. Mora

IPC: H04J3/06 ,  H04W56/00

CPC classification number: H04J3/0635 ,  H04J3/0638 ,  H04J3/0661 ,  H04J3/0682 ,  H04W56/001 ,  H04W56/0015

Abstract: Systems and methods are provided for validating time between a local clock included in the slave node of a network with a master clock included in the master node of the network. The master node determines a propagation delay between the master node and the slave node, sends a synchronization message to the slave node at a first time, determines an expected receipt time of the synchronization message at the slave node based on the first time, the determined propagation delay between the master node and the slave node, and a rate ratio of the master clock to the local clock, and sends a follow up message to the slave node, the follow up message including the first time and the expected receipt time.

公开(公告)号：US20170359137A1

公开(公告)日：2017-12-14

申请号：US15275315

申请日：2016-09-23

Applicant: Apple Inc.

Inventor： Ashley I. Butterworth ,  Daniel C. Klingler ,  Simon E. C. Goldrei

IPC: H04J3/06 ,  H04L7/00

CPC classification number: H04J3/0661 ,  H04J3/0664 ,  H04J3/0673 ,  H04L69/08 ,  H04L69/28

Abstract: In a time synchronization process, chain of quality information is provided between interconnected nodes, the chain of quality information relating to information regarding accuracy of a clock, a type of timestamping used by a node, a type of link over which a timestamp is provided, and a clock drift parameter indicating the drift characteristics of the clock. Based on the chain of quality information, parameters are determined for a filter that is applied to a sequence of timestamps in order to remove noise from the timestamps, thereby improving accuracy of the time synchronization process.

公开(公告)号：US20170289231A1

公开(公告)日：2017-10-05

申请号：US15436401

申请日：2017-02-17

Applicant: Apple Inc.

Inventor： Richard M. Powell ,  Ashley I. Butterworth ,  Anthony J. Guetta ,  Daniel C. Klingler ,  Jeffrey C. Moore ,  Alexander C. Powers

IPC: H04L29/06 ,  H04N21/2343 ,  H04N21/43 ,  H04N21/643 ,  H04N21/242

CPC classification number: H04N21/234381 ,  H04L65/601 ,  H04N21/242 ,  H04N21/4302 ,  H04N21/4305 ,  H04N21/4307 ,  H04N21/43615 ,  H04N21/439 ,  H04N21/440281 ,  H04N21/643

Abstract: Methods and systems provide control of media synchronization using time stamp pairs. In an embodiment, a first device may request a time stamp from a second device. The first device may determine any de-synchronization between the first and second devices based on the requested time stamp and characteristics of the request. The first device may define a rate scalar based on the determined de-synchronization. A sample rate conversion may be performed for the first device based on the rate scalar such that the outputs of the first device and the second device are synchronized.