公开(公告)号：US12052332B2

公开(公告)日：2024-07-30

申请号：US17162098

申请日：2021-01-29

Applicant: Cisco Technology, Inc.

Inventor： Mohammed Hawari ,  Andre Surcouf

IPC: H04L69/28 ,  H03M13/09 ,  H04J3/06 ,  H04L49/90

CPC classification number: H04L69/28 ,  H03M13/09 ,  H04J3/0644 ,  H04J3/065 ,  H04L49/9078

Abstract: Establishing an expected transmit time at which a network interface controller (NIC) is expected to transmit a next packet. Enqueuing, with the NIC and before the expected transmit time, a packet P1 to be transmitted at the expected transmit time. Upon enqueuing P1, incrementing the expected transmit time by an expected transmit duration of P1. Transmitting at the NIC's line rate and timestamping enqueued P1 with its actual transmit time. Adjusting the expected transmit time by a difference between P1's actual transmit and P1's expected transmit time. Requesting, before completion of transmitting P1, to transmit a P2 at time t(P2). Enqueuing, in sequence, zero or more P0, such that the current expected transmit time plus the duration of the transmission of the P0s at the line rate equals t(P2). Transmitting at the line rate each enqueued P0. Upon enqueuing each P0, incrementing, for each P0, the expected transmit time by the expected transmit duration of the P0. Enqueuing P2 for transmission directly following enqueuing the final P0. Transmitting, by the NIC, enqueued P2 at t(P2).

公开(公告)号：US20240154713A1

公开(公告)日：2024-05-09

申请号：US17769525

申请日：2020-10-09

Applicant: ZTE CORPORATION

Inventor： Yuanbin ZHANG ,  Youbao WANG

IPC: H04J3/06 ,  H04J3/16

CPC classification number: H04J3/065 ,  H04J3/1652

Abstract: The present application provides a synchronization method, a synchronization apparatus, a device, and a storage medium. The synchronization method includes: determining an interface event timestamp point of synchronization event information, and encapsulating the synchronization event information; and inserting the encapsulated synchronization event information into a synchronization information channel of a first preset frame or a second preset frame for performing transmission.

公开(公告)号：US11799577B2

公开(公告)日：2023-10-24

申请号：US17891215

申请日：2022-08-19

Applicant: Google LLC

Inventor： Yuliang Li ,  Gautam Kumar ,  Nandita Dukkipati ,  Hassan Wassel ,  Prashant Chandra ,  Amin Vahdat

IPC: H04J3/06 ,  H04L7/00 ,  H04L12/44

CPC classification number: H04J3/0641 ,  H04J3/065 ,  H04L7/0016 ,  H04L12/44

Abstract: A system is provided for synchronizing clocks. The system includes a plurality of devices in a network, each device having a local clock. The system is configured to synchronize the local clocks according to a primary spanning tree, where the primary spanning tree has a plurality of nodes connected through a plurality of primary links, each node of the plurality of nodes representing a respective device of the plurality of devices. The system is also configured to compute a backup spanning tree before a failure is detected in the primary spanning tree, wherein the backup spanning tree includes one or more backup links that are different from the primary links. As such, upon detection of a failure in the primary spanning tree, the system reconfigures the plurality of devices such that clock synchronization is performed according to the backup spanning tree.

公开(公告)号：US20230188237A1

公开(公告)日：2023-06-15

申请号：US17986704

申请日：2022-11-14

Applicant: Skyworks Solutions, Inc.

Inventor： Vivek Sarda

IPC: H04J3/06

CPC classification number: H04J3/065 ,  H04J3/0617 ,  H04J3/0605

Abstract: A baseline difference is determined between a slave line card time stamp corresponding to a slave line card frame sync signal and a master line card time stamp corresponding to a master line card frame sync signal. The slave line card generates subsequent slave line card time stamps for subsequent slave line card frame sync signals and the master line card generates subsequent master line card time stamps for subsequent master line card frame sync signals. Current differences are determined between subsequent slave line card time stamps and the subsequent master line card time stamps and the current differences are compared to the baseline difference. When a mismatch difference occurs (current difference differs from the baseline difference), the mismatch difference causes a phase-locked loop in the master line card to be adjusted or an offset to be provided to the master line card time of day counter.

公开(公告)号：US20190140963A1

公开(公告)日：2019-05-09

申请号：US16231506

申请日：2018-12-22

Applicant: Tellabs Opertations, Inc.

Inventor： Anthony L. Sasak ,  Christopher V. O'Brien

IPC: H04L12/841 ,  H04L12/863 ,  H04J3/14 ,  H04J3/06

CPC classification number: H04L47/283 ,  H04J3/0632 ,  H04J3/065 ,  H04J3/14 ,  H04L41/064 ,  H04L43/106 ,  H04L47/621 ,  H04L47/6245

Abstract: A network device such as a router or switch, in one embodiment, includes a timing analyzer which is capable of providing timing analysis over one or more network circuits. The timing analyzer, in one aspect, receives a data packet traveling across a circuit emulation service (“CES”) circuit such as T1 or E1 circuit. Upon obtaining an arrival timestamp associated with the data packet, the arrival timestamp is stored in a timestamp buffer in accordance with a first-in first-out (“FIFO”) storage sequence. After identifying the oldest arrival timestamp in the timestamp buffer, an offset is generated based on the result of comparison between the arrival timestamp and the oldest timestamp. The timing analyzer can also be configured to generate timing reports on-demand based on generated offset(s).

公开(公告)号：US09948419B2

公开(公告)日：2018-04-17

申请号：US15309509

申请日：2014-05-08

Applicant: Telefonaktiebolaget LM Ericsson (publ)

Inventor： Stefano Ruffini ,  Fabio Cavaliere ,  Stefano Stracca

IPC: H04B10/00 ,  H04J3/06 ,  H04B7/26 ,  H04B10/2575 ,  H04B1/7073 ,  H04B7/212 ,  H04L12/26

CPC classification number: H04J3/0658 ,  H04B1/7073 ,  H04B7/2125 ,  H04B7/2678 ,  H04B10/073 ,  H04B10/25753 ,  H04B10/25758 ,  H04B2215/065 ,  H04J3/0644 ,  H04J3/0647 ,  H04J3/065 ,  H04J3/0667 ,  H04J3/0676 ,  H04L43/0858 ,  H04L43/0864 ,  H04L43/106

Abstract: A method and apparatus for determining propagation delay of a first path and or of a second path which connect a first transceiver unit associated with a first clock to a second transceiver unit associated with a second clock in a communications network. The apparatus comprises a control unit configured to cause the first transceiver unit to transmit a first signal to the second transceiver unit over the first path and to receive a reply to the first signal from the second transceiver unit over the second path, and to transmit a second signal to the second transceiver unit over the second path and to receive a reply to the second signal from the second transceiver unit over the first path. The apparatus further comprises a receiving unit configured to receive a first time reference representing the time of transmission of the first signal from the first transceiver unit, a second time reference representing the time of receipt of the first signal at the second transceiver unit, a third time reference representing the time of transmission of the reply to the second signal from the second transceiver unit and a fourth time reference representing the time of receipt of the reply to the second signal at the first transceiver unit. The apparatus further comprises a determining unit configured to determine a propagation delay of the first path and or of the second path using the first time reference, the second time reference, the third time reference and the fourth time reference.

公开(公告)号：US09893826B2

公开(公告)日：2018-02-13

申请号：US14607659

申请日：2015-01-28

Applicant: Alcatel-Lucent USA Inc.

Inventor： Diana L. Lorenz ,  Kenneth Y. Ho ,  Greg Martin ,  Mark G. Bradac ,  Robert A. Novotny ,  Wayne R. Wilcox

IPC: H04J3/06 ,  H04L12/40

CPC classification number: H04J3/065 ,  H04J3/0632 ,  H04J3/0661 ,  H04J3/0697 ,  H04L12/40 ,  H04L12/40045

Abstract: Network elements within a network are configured to retain clock traceability over an asynchronous interface. The network elements can generate and process multi-frames that include two different types of traffic, each synchronized to a different respective clock source. Each of the multi-frames is synchronized to the clock source of one of the traffic types and further includes a timestamp to enable the original clock signal of the other traffic type to be reconstructed at the receiving network element.

公开(公告)号：US09686051B2

公开(公告)日：2017-06-20

申请号：US14141692

申请日：2013-12-27

Applicant: LORD CORPORATION

Inventor： Stephen J. DiStasi ,  Jacob H. Galbreath ,  Steven W. Arms

IPC: H04J3/00 ,  H04L1/18 ,  H04J3/06 ,  H04W72/04 ,  H04W84/18

CPC classification number: H04L1/189 ,  H04J3/065 ,  H04J3/0655 ,  H04L1/1874 ,  H04L1/1877 ,  H04W72/0446 ,  H04W84/18

Abstract: Systems, methods, and computer readable media for providing lossless transmission of sensor data in a wireless network are provided. In some aspects, a method for transmitting data in a wireless sensor network includes collecting data at a sensor node, attaching a timestamp to the data, buffering the data and the timestamp to a memory device and retransmitting the collected data where the sensor node fails to receive an acknowledgement message from the base station after the data transmission. In some aspects, a system can include a plurality of wireless sensor nodes having synchronized clocks and a base station. Collected sensor data can be associated with a timestamp via the clock prior to transmitting the data to the base station. The data can be buffered at a memory device and retransmitted therefrom to provide lossless data transmission.

公开(公告)号：US09609610B2

公开(公告)日：2017-03-28

申请号：US14613264

申请日：2015-02-03

Applicant: Aviat U.S., Inc.

Inventor： Philip Secker ,  Peter Croy

IPC: H04L7/00 ,  H04W56/00 ,  H03L7/18 ,  H03L7/08 ,  H04J3/06

CPC classification number: H04W56/0015 ,  H03L7/08 ,  H03L7/18 ,  H03L2207/50 ,  H04J3/0602 ,  H04J3/0617 ,  H04J3/0638 ,  H04J3/0641 ,  H04J3/0647 ,  H04J3/065 ,  H04J3/0658 ,  H04J3/0679 ,  H04J3/0688

Abstract: In some embodiments, a system comprises a clock, a root node, a radio channel network, and first and second child nodes. The clock may be configured to generate a clock signal. The root node may be configured to generate a first frame including a first payload and a first overhead and generate a second frame including a second payload and a second overhead. The first and second overheads may comprise a synchronization value based on the clock signal. The radio channel network may be in communication with the root node for transmitting the first and second frames. Each first and second child nodes may be configured to perform clock recovery including frequency synchronization using the synchronization value and a respective phase-lock loop.

公开(公告)号：US09473261B1

公开(公告)日：2016-10-18

申请号：US14284110

申请日：2014-05-21

Applicant: MICROSEMI STORAGE SOLUTIONS (U.S.), INC.

Inventor： Richard Tsz Shiu Tse ,  Calvin Francis Hass ,  Winston Ki-Cheong Mok

IPC: H04B7/212 ,  H04J3/16 ,  H04B10/077 ,  H04J3/14 ,  H04Q11/00

CPC classification number: H04J3/1658 ,  H04J3/0623 ,  H04J3/065 ,  H04J2203/0051 ,  H04J2203/0085 ,  H04Q11/00 ,  H04Q11/0066 ,  H04Q2011/0083

Abstract: A method of enabling transport of symmetric latency-sensitive constant-bit-rate (CBR) client data streams over an optical transport network (OTN) is provided. The method performs, utilizing an OTN wrapping device, an OTN wrapping operation on a received first constant-bit-rate (CBR) client data stream to form a first framed OTN data stream. The method determines a static wrapping delay induced on the first CBR client data stream by the OTN wrapping operation, performs, utilizing the OTN wrapping device, an OTN unwrapping operation on a received second framed OTN data stream to extract a second CBR client data stream from the second framed OTN data stream, determines a static unwrapping delay induced on the second framed OTN data stream by the OTN unwrapping operation, and equalizes the static wrapping and unwrapping delays by adjusting, at the OTN wrapping device, at least one of the static wrapping and unwrapping delays.

Abstract translation: 提供了一种通过光传输网络（OTN）传输对称等待时间敏感常数比特率（CBR）客户端数据流的方法。 该方法利用OTN包装装置对所接收的第一恒定比特率（CBR）客户端数据流进行OTN包装操作，以形成第一帧OTN数据流。 该方法通过OTN包装操作确定在第一CBR客户端数据流上引起的静态环绕延迟，利用OTN包装装置执行OTN解包操作，对接收到的第二帧OTN数据流进行OTN解包操作，从第 第二成帧OTN数据流通过OTN解包操作确定在第二成帧OTN数据流上引起的静态解包延迟，并且通过在OTN包装装置处调整至少一个静态包装来均衡静态包装和展开延迟 并解开延迟。