Topic
Precision Time Protocol
About: Precision Time Protocol is a research topic. Over the lifetime, 604 publications have been published within this topic receiving 6006 citations. The topic is also known as: PTP & IEEE 1588.
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21 Jul 2016
TL;DR: In this paper, the authors proposed a time synchronization system for monitoring earthquakes by using seismic waves and imaging a subsurface geological structure to synchronize the clocks of networks in which seismic wave receivers and seismic source generators are arranged far apart.
Abstract: The present invention relates to a time synchronization system for acquiring seismic data and a time synchronization method for acquiring seismic data and, more specifically, to a time synchronization system and a time synchronization method, which enable an exploration apparatus for monitoring earthquakes by using seismic waves and imaging a subsurface geological structure to synchronize the clocks of networks in which seismic wave receivers and seismic source generators are arranged far apart. The time synchronization system for acquiring the seismic data, according to the present invention, comprises: a central seismic recorder, which has a precision time protocol, for receiving external time data, transmitting a reference pulse in a cycle of one time per second and implementing time synchronization, thereby providing the synchronized time; and seismographs wired or wirelessly connected to the central seismic recorder, synchronizing the time of detected earthquake observation data with the synchronization time provided from the central seismic recorder, and transmitting the time-synchronized earthquake observation data to the central seismic recorder.
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13 Nov 2020
TL;DR: In this paper, the authors present a method, a device and a system for synchronizing communication equipment, under the scene that a synchronous Ethernet (SyncE) is not introduced, time deviation from slave equipment (Slave) to master equipment (Master) is calculated through a timestamp of a precision time protocol (PTP), then frequency deviation is calculated according to the time deviation, and the clock frequency of the slave equipment is corrected through the frequency deviation.
Abstract: The embodiment of the invention discloses a method, a device and a system for synchronizing communication equipment. According to the method, under the scene that a synchronous Ethernet (SyncE) is notintroduced, time deviation from slave equipment (Slave) to master equipment (Master) is calculated through a timestamp of a precision time protocol (PTP), then frequency deviation is calculated according to the time deviation, and the clock frequency of the slave equipment is corrected through the frequency deviation. Then, a new timestamp is calculated by using the corrected clock frequency; andthe new timestamp is used to calculate a new frequency deviation and the new frequency deviation is used to correct the clock frequency of the slave device, so that the time deviation (Offset) is infinitely close to zero through repeated iteration, higher-precision time synchronization is obtained, and the clock precision of the system is greatly improved.
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16 May 2020TL;DR: This work proposes a new clock synchronization architecture that is indifferent to delays and eases the integration to traditional protocols, implements a delay attack--resistant precision time protocol, and validate the results on a hardware-supported testbed.
Abstract: We propose a new clock synchronization architecture for systems under time transfer attacks. Facilitated by a feedforward control with feedback trim--based clock adjustment, coupled with packet filtering and frequency shaping techniques, our proposed architecture bounds the clock errors in the presence of a powerful network attacker capable of attacking packets between a master and a client. A key advantage is consistent measurements, timely coordination, and synchronized actuation in distributed systems. In contrast, current time synchronization architectures behave poorly under attacks due to assumptions that the network is benign and delays are symmetric. The usage of feedback controllers aggravates poor performance. We provide an architecture that is indifferent to delays and eases the integration to traditional protocols. We implement a delay attack--resistant precision time protocol and validate the results on a hardware-supported testbed.
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26 Jul 2016
TL;DR: In this article, a system for synchronizing time for seismic data acquisition is described, where a central earthquake recorder receives external time data, transmits a reference pulse once every second, and has a precision time protocol for realizing time synchronization to provide synchronization time.
Abstract: The present invention relates to a system and a method for synchronizing time for seismic data acquisition, and more specifically, to a system and a method for synchronizing time which allow a probe device for monitoring an earthquake and imaging a subsurface geological structure by using a seismic wave to synchronize time of a network where a seismic wave receiver and an earthquake source generation device are widely arranged. According to the present invention, the system for synchronizing time for seismic data acquisition comprises: a central earthquake recorder which receives external time data, transmits a reference pulse once every second, and has a precision time protocol for realizing time synchronization to provide synchronization time; and a seismometer which is connected to the central earthquake recorder in a wired or a wireless manner, and synchronizes detected earthquake observation data with the synchronization time provided from the central earthquake recorder to transmit the time-synchronized earthquake observation data to the central earthquake recorder.
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28 Aug 2013
TL;DR: The findings clearly illustrate the potential strengths of a probing method based on one-way-delay measurements, under the condition that the required timing accuracy is achieved and delay characteristics is available for the involved network path.
Abstract: This paper presents a measurement study of two different methods for active probing of cross traffic on access links. The categories used in the study are packet pair probing and one-way-delay probing. The first approach uses measured increase in packet spacing as indicator of cross traffic presence, while the latter uses increase in one-way-delay for probe packets as indicator. These methods have been chosen because they are fundamentally different in terms of requirements, benefits and challenges. The main novelty of this paper is the presentation and discussion of measurement results from an access network using an adaptive video service as cross-traffic. The findings clearly illustrate the potential strengths of a probing method based on one-way-delay measurements, under the condition that the required timing accuracy is achieved and delay characteristics is available for the involved network path. The benefit of using Precision Time Protocol instead of Network Time Protocol is illustrated, even in networks of limited size.