公开(公告)号：US11018789B2

公开(公告)日：2021-05-25

申请号：US16036178

申请日：2018-07-16

Applicant: Khalifa University of Science and Technology ,  British Telecommunications plc ,  Emirates Telecommunications Corporation

Inventor： James Aweya

IPC: H04J3/06

Abstract: This invention relates to end-to-end transparent clocks and methods of estimating skew in end-to-end transparent clocks. Embodiments of the invention relate to techniques for estimating clock skew between a free-running clock in a transparent clock and a master clock, in particular by using the timing information embedded in timing messages passing through the transparent clock. Further embodiments of the invention set out uses of these estimates to modify the residence times computed by the transparent clock and a synchronization network including such transparent clocks.

公开(公告)号：US10979164B2

公开(公告)日：2021-04-13

申请号：US16036186

申请日：2018-07-16

Applicant: Khalifa University of Science and Technology ,  British Telecommunications plc ,  Emirates Telecommunications Corporation

Inventor： James Aweya

IPC: H04J3/06

Abstract: This invention relates to peer-to-peer transparent clocks and methods of estimating skew in peer-to-peer transparent clocks. Embodiments of the invention relate to techniques for estimating clock skew between a free-running clock in a transparent clock and a master clock, in particular by using the timing information embedded in timing messages passing through the transparent clock. Further embodiments of the invention set out uses of these estimates to modify the residence times computed by the transparent clock and a synchronization network including such transparent clocks.

公开(公告)号：US10608764B2

公开(公告)日：2020-03-31

申请号：US15358229

申请日：2016-11-22

Applicant: Khalifa University of Science, Technology, and Research ,  British Telecommunications plc ,  Emirates Telecommunications Corporation

Inventor： Zdenek Chaloupka ,  Ivan Boyd

IPC: H04J3/06

Abstract: This invention relates to methods and devices for timing synchronization. The invention has particular application where timing is being carried out over packet networks using, for example, the IEEE 1588 Precision Time Protocol (PTP). Embodiments of the invention make use of estimated forward and reverse path delay asymmetries directly in the estimation algorithm (for example a Kalman filter). This can allow the variation in the timestamps which have been compensated for the delay asymmetry to be significantly reduced, which can reduce the complexity of the phase offset estimation algorithm.

公开(公告)号：US10284414B2

公开(公告)日：2019-05-07

申请号：US15179288

申请日：2016-06-10

Applicant: Khalifa University of Science, Technology and Research ,  British Telecommunications PLC ,  Emirates Telecommunications Corporation

Inventor： Zdenek Chaloupka ,  Ivan Boyd

IPC: H04L27/38 ,  H04L29/06 ,  H04J3/06

Abstract: This invention relates to methods and systems for estimating skew based on, for example, the IEEE 1588 Precision Time Protocol (PTP). These methods and systems can allow the clock skew between a master clock (server) and slave clock (client) exchanging PTP messages over a packet network to be estimated more rapidly than conventional estimation techniques and thereby improve the convergence of standard estimation algorithms. In one embodiment, the skew estimation is derived from a set of timestamps from a message exchange between the master and slave using a non-linear least square-fitting algorithm. An example of the fitting algorithm is the Levenberg-Marquardt algorithm.

公开(公告)号：US20180278713A1

公开(公告)日：2018-09-27

申请号：US15933995

申请日：2018-03-23

Applicant: Khalifa University of Science, Technology and Research ,  Emirates Telecommunications Corporation ,  British Telecommunications PLC

Inventor： Carla Di Cairano-Gilfedder ,  Siddhartha Shakya ,  Beum Seuk Lee ,  Gilbert OWUSU ,  Kin Poon

IPC: H04L29/08 ,  H04L29/06 ,  H04L12/24 ,  G06F15/18

CPC classification number: H04L67/2842 ,  G06N20/00 ,  H04L41/0823 ,  H04L41/5019 ,  H04L41/509 ,  H04L43/08 ,  H04L65/4069 ,  H04L67/2833

Abstract: A method for designating a class of data content for determining how the content will be handled by a content delivery network (CDN) into one of: a transport designation by which content is transported from an entrance node to one or more edge nodes; a caching designation by which the content is stored at one or more edge nodes; and a hybrid designation by which content is stored at a node in the CDN for subsequent transport to one or more edge nodes in the CDN, the method comprising: determining a set of one or more transport designation options; determining a set of one or more caching designation options; determining a set of one or more hybrid designation options; determining a normalised measure resource requirement for each of the transport, caching and hybrid designation options; and selecting one designation option for the class of content from all of the transport, caching and hybrid designation options by an optimisation function for selecting the designation option based on the determined normalised resource requirement for each option.

公开(公告)号：US20180145781A1

公开(公告)日：2018-05-24

申请号：US15358229

申请日：2016-11-22

Applicant: Khalifa University of Science, Technology, and Research ,  British Telecommunications plc ,  Emirates Telecommunications Corporation

Inventor： Zdenek Chaloupka ,  Ivan Boyd

IPC: H04J3/06

CPC classification number: H04J3/0667 ,  H04J3/0644

Abstract: This invention relates to methods and devices for timing synchronization. The invention has particular application where timing is being carried out over packet networks using, for example, the IEEE 1588 Precision Time Protocol (PTP). Embodiments of the invention make use of estimated forward and reverse path delay asymmetries directly in the estimation algorithm (for example a Kalman filter). This can allow the variation in the timestamps which have been compensated for the delay asymmetry to be significantly reduced, which can reduce the complexity of the phase offset estimation algorithm.

公开(公告)号：US09973292B2

公开(公告)日：2018-05-15

申请号：US15088468

申请日：2016-04-01

Applicant: Khalifa University of Science, Technology and Research ,  British Telecommunications Plc ,  Emirates Telecommunications Corporation

Inventor： James Aweya

IPC: H04J3/06 ,  H04W56/00 ,  H04L7/04

CPC classification number: H04J3/0661 ,  H04L7/04 ,  H04W56/001 ,  H04W56/005

Abstract: This invention relates to methods and systems for estimating offset and skew using linear programming. Embodiments of the invention relate to methods and systems which apply linear programming principles to links with asymmetric transmission rates which are estimated from an exchange of timing messages (for example under IEEE 1588 PTP). Further embodiments provide for the estimation of clock offsets using linear programming techniques when the skew is known or estimated.

公开(公告)号：US20170293597A1

公开(公告)日：2017-10-12

申请号：US15092941

申请日：2016-04-07

Applicant: Khalifa University of Science, Technology and Research ,  British Telecommunications Plc ,  Emirates Telecommunications Corporation

Inventor： Di Wang ,  Ahmad Al-Rubaie

IPC: G06F17/24 ,  G06F17/21 ,  G06F17/27

CPC classification number: G06F17/2775 ,  G06F16/35 ,  G06F17/2705

Abstract: This invention relates to methods and systems for message analysis and classification. It is particularly applicable to analysis and classification of very short messages such as “Tweets”. Embodiments of the invention provide methods for unbiased enriched representation for messages which can be used to transform very short messages into comparatively longer text. These methods can make use of word context information in addition to word information itself. This can provide text with enough information for analysis and classification without changing the information in the original message. Embodiments of the invention also provide a statistical learning mechanism which does not require pre-defined keywords, and can automatically detect inherent frequent words and word patterns. These methods can provide satisfactory classification accuracy even for very short messages.

公开(公告)号：US09673970B1

公开(公告)日：2017-06-06

申请号：US15053402

申请日：2016-02-25

Applicant: Khalifa University of Science, Technology and Research ,  British Telecommunications Plc ,  Emirates Telecommunications Corporation

Inventor： James Aweya ,  Ivan Boyd

IPC: H04L7/00 ,  H04L7/033 ,  H04W36/30 ,  H04L12/26

CPC classification number: H04W36/30 ,  H04B17/318 ,  H04J3/0667 ,  H04L43/08 ,  H04L43/106 ,  H04W36/08 ,  H04W36/36 ,  H04W56/0035 ,  H04W74/04

Abstract: This invention relates to methods and systems for estimating and checking synchronization accuracy, in particular frequency synchronization accuracy. It is particularly applicable to synchronization methods and systems which involve a digital phase-locked loop (DPLL) and embodiments provide methods and systems for estimating and tracking how well the DPLL is frequency synchronized to a source frequency. In one embodiment, frequency synchronization accuracy is used as an additional quality metric for mobile call handover between base stations. Call handover is of major importance within any mobile network; without checking frequency synchronization before handover dropped calls and interrupted communication can result.

公开(公告)号：US09671822B2

公开(公告)日：2017-06-06

申请号：US14566990

申请日：2014-12-11

Applicant: Khalifa University of Science, Technology, and Research ,  British Telecommunications plc ,  Emirates Telecommunications Corporation

Inventor： James Aweya

IPC: G06F1/12 ,  H04L29/06 ,  G06F1/10

CPC classification number: G06F1/12 ,  G06F1/10 ,  H04L69/28

Abstract: This invention relates to methods and devices for time transfer. The invention has particular application in the alignment of slave clocks to a master clock and dealing with packet delay variations. In embodiments of the invention, the slave clock uses the residence times measured by end-to-end transparent clocks to compensate for clock synchronization errors that arise due to variability in message transfer delays. Embodiments provide a simple linear approximation technique and a Kalman filter-based technique for estimating offset and skew of the slave clock.