公开(公告)号：US09444566B1

公开(公告)日：2016-09-13

申请号：US14200619

申请日：2014-03-07

申请人： Integrated Device Technology, Inc.

发明人： Frederic Mustiere ,  Felix Duong ,  Alain Trottier ,  Russell Smiley ,  Peng Xiao

IPC分类号： H04J3/06

CPC分类号： H04J3/0667 ,  H04L43/087 ,  H04L43/106

摘要： Methods of performing time-of-day synchronization in a packet processing network include accumulating timestamps transmitted in packets between master and slave devices, which are synchronized to respective master and slave clocks and separated from each other by the packet processing network. Operations are also performed to determine whether first timestamps accumulated in a first direction across the packet network demonstrate that a first packet delay variation (PDV) sequence observed from the first timestamps is stationary. A phase offset between the master and slave clocks is then adjusted using a time-of-day (ToD) estimation algorithm. This adjusting can include evaluating a location-dependent statistic of the first PDV sequence.

摘要翻译： 在分组处理网络中执行时间同步的方法包括累积在主设备和从设备之间以分组发送的时间戳，其与相应的主时钟和从时钟同步并且由分组处理网络彼此分离。 还执行操作以确定跨分组网络在第一方向上累积的第一时间戳是否显示从第一时间戳观察到的第一分组延迟变化（PDV）序列是静止的。 然后使用时间（ToD）估计算法调整主时钟和从时钟之间的相位偏移。 该调整可以包括评估第一PDV序列的位置相关统计量。

公开(公告)号：US10374786B1

公开(公告)日：2019-08-06

申请号：US14992486

申请日：2016-01-11

申请人： Integrated Device Technology, Inc.

发明人： Frederic Mustiere ,  Russell Smiley ,  Felix Duong ,  Alain Trottier

IPC分类号： H04J3/06 ,  G06F1/10 ,  H04L12/801 ,  H04L7/04 ,  H04L7/00

摘要： Methods of estimating frequency skew in a packet network include determining a representation of a packet delay variation (PDV) sequence from an initial estimate of frequency skew between master and slave devices in the packet network and timestamps transmitted therebetween. An operation is performed to extract a statistical mode from an empirical probability distribution function (PDF) of the representation of the PDV sequence, where the statistical mode corresponds to a value at which the PDF has its maximum value. The, an updated estimate of the frequency skew is generated by determining a slope between timestamps at indices associated with a plurality of points in the representation of the PDV sequence that are within a range of the statistical mode.

公开(公告)号：US09236967B1

公开(公告)日：2016-01-12

申请号：US13799086

申请日：2013-03-13

申请人： Integrated Device Technology, Inc.

发明人： Frederic Mustiere ,  Russell Smiley ,  Felix Duong ,  Alain Trottier ,  Durrey Farooqui ,  Peng Xiao

IPC分类号： H04J3/06

CPC分类号： H04J3/0661 ,  H04J3/0667

摘要： Methods of packet-based synchronization in non-stationary network environments can include accumulating timestamps transmitted in packets between master and slave devices that are separated from each other by a packet network. Operations are also performed to determine whether first timestamps accumulated in a first direction across the packet network demonstrate that a first packet delay variation (PDV) sequence observed from the first timestamps is stationary. Thereafter, estimates of at least one of frequency skew and phase offset between the master and slave clocks are acquired using a first algorithm, from the first timestamps accumulated in the first direction. These operations of determining further include determining whether second timestamps accumulated in a second direction demonstrate that a second packet delay variation (PDV) sequence observed from the second timestamps is stationary.

摘要翻译： 在非固定网络环境中基于分组的同步的方法可以包括在通过分组网络彼此分离的主设备和从设备之间的分组中累积传输的时间戳。 还执行操作以确定跨分组网络在第一方向上累积的第一时间戳是否显示从第一时间戳观察到的第一分组延迟变化（PDV）序列是静止的。 此后，从第一方向累积的第一时间戳，使用第一算法获取主时钟与从时钟之间的频率偏移和相位偏移中的至少一个的估计。 进一步确定的这些操作还包括确定在第二方向上累积的第二时间戳是否表明从第二时间戳观察到的第二分组延迟变化（PDV）序列是静止的。