Patents by Inventor George P. Zampetti
George P. Zampetti has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
-
Patent number: 10231080Abstract: With the increasing usage of mobile devices for communication, the need for wireless base-stations deployed in strategic locations is becoming increasingly important. The increased bandwidths being transmitted between the base-station and the mobile device has mandated that enhanced transmission formats and techniques be deployed, and, in order to operate correctly, these techniques require a tight synchronization in both time/phase, and in frequency, between the various base-stations serving a general area. Due to the need to establish the geographic location of the mobile device with a high degree of accuracy, it is also necessary to establish the location of the serving base-stations with a high degree of accuracy.Type: GrantFiled: April 24, 2017Date of Patent: March 12, 2019Assignee: Microsemi Frequency and Time CorporationInventors: George P. Zampetti, Christopher A. Reid
-
Publication number: 20170230927Abstract: With the increasing usage of mobile devices for communication, the need for wireless base-stations deployed in strategic locations is becoming increasingly important. The increased bandwidths being transmitted between the base-station and the mobile device has mandated that enhanced transmission formats and techniques be deployed, and, in order to operate correctly, these techniques require a tight synchronization in both time/phase, and in frequency, between the various base-stations serving a general area. Due to the need to establish the geographic location of the mobile device with a high degree of accuracy, it is also necessary to establish the location of the serving base-stations with a high degree of accuracy.Type: ApplicationFiled: April 24, 2017Publication date: August 10, 2017Inventors: George P. ZAMPETTI, Christopher A. REID
-
Patent number: 9698926Abstract: The present invention generally relates to methods and apparatus for precision time transfer wherein the inherent packet delay variation and possible asymmetry introduced in networks is avoided or mitigated. In one embodiment, the timing functions of a master device may be placed closer to a slave device using a Remote Time-Stamp Generator, located in the network between the master and the slave, and whose time reference serves as a proxy for the time reference of the master. Time-of-traversal of packets at the remote time-stamp generator may be used as proxies for the time-of-departure and the time-of-arrival of certain messages at the master. Such proxy times may be used to synchronize the slave with the master, particularly if the master and the Remote Time-Stamp Generator are both synchronized with a Global Navigation Satellite System (GNSS) source.Type: GrantFiled: March 14, 2014Date of Patent: July 4, 2017Assignee: MICROSEMI FREQUENCY AND TIME CORPORATIONInventor: George P. Zampetti
-
Patent number: 9635501Abstract: With the increasing usage of mobile devices for communication, the need for wireless base-stations deployed in strategic locations is becoming increasingly important. The increased bandwidths being transmitted between the base-station and the mobile device has mandated that enhanced transmission formats and techniques be deployed, and, in order to operate correctly, these techniques require a tight synchronization in both time/phase, and in frequency, between the various base-stations serving a general area. Due to the need to establish the geographic location of the mobile device with a high degree of accuracy, it is also necessary to establish the location of the serving base-stations with a high degree of accuracy.Type: GrantFiled: December 23, 2014Date of Patent: April 25, 2017Assignee: MICROSEMI FREQUENCY AND TIME CORPORATIONInventors: George P. Zampetti, Christopher A. Reid
-
Patent number: 9628210Abstract: The notion of a “PTP aware” path is one current proposed approach to reduce asymmetry effects. In a fully PTP aware path there is the notion of on-path support mechanisms such as boundary clocks and transparent clocks at every switching or routing node. However, on-path support methods only address time-transfer errors introduced inside network elements and any asymmetry in the transmission medium, such as, for example, the fiber strands for the two directions of transmission, cannot be compensated for by on-path support mechanisms. Furthermore, in a real operational network, which may traverse different operational domains administered by different entities, full on-path support is a difficult challenge. In certain managed network scenarios full on-path support can be contemplated. Nevertheless, the universal asymmetry compensation method described herein mitigates the asymmetry in a network path, without requiring on-path support mechanisms such as transparent clocks and boundary clocks.Type: GrantFiled: February 15, 2016Date of Patent: April 18, 2017Assignee: MICROSEMI FREQUENCY AND TIME CORPORATIONInventor: George P. Zampetti
-
Patent number: 9264132Abstract: The notion of a “PTP aware” path is one current proposed approach to reduce asymmetry effects. In a fully PTP aware path there is the notion of on-path support mechanisms such as boundary clocks and transparent clocks at every switching or routing node. However, on-path support methods only address time-transfer errors introduced inside network elements and any asymmetry in the transmission medium, such as, for example, the fiber strands for the two directions of transmission, cannot be compensated for by on-path support mechanisms. Furthermore, in a real operational network, which may traverse different operational domains administered by different entities, full on-path support is a difficult challenge. In certain managed network scenarios full on-path support can be contemplated. Nevertheless, the universal asymmetry compensation method described herein mitigates the asymmetry in a network path, without requiring on-path support mechanisms such as transparent clocks and boundary clocks.Type: GrantFiled: January 7, 2014Date of Patent: February 16, 2016Assignee: Microsemi Frequency and Time CorporationInventor: George P. Zampetti
-
Publication number: 20150181385Abstract: With the increasing usage of mobile devices for communication, the need for wireless base-stations deployed in strategic locations is becoming increasingly important. The increased bandwidths being transmitted between the base-station and the mobile device has mandated that enhanced transmission formats and techniques be deployed, and, in order to operate correctly, these techniques require a tight synchronization in both time/phase, and in frequency, between the various base-stations serving a general area. Due to the need to establish the geographic location of the mobile device with a high degree of accuracy, it is also necessary to establish the location of the serving base-stations with a high degree of accuracy.Type: ApplicationFiled: December 23, 2014Publication date: June 25, 2015Inventors: George P. ZAMPETTI, Christopher A. REID
-
Publication number: 20140269672Abstract: The present invention generally relates to methods and apparatus for precision time transfer wherein the inherent packet delay variation and possible asymmetry introduced in networks is avoided or mitigated. In one embodiment, the timing functions of a master device may be placed closer to a slave device using a Remote Time-Stamp Generator, located in the network between the master and the slave, and whose time reference serves as a proxy for the time reference of the master. Time-of-traversal of packets at the remote time-stamp generator may be used as proxies for the time-of-departure and the time-of-arrival of certain messages at the master. Such proxy times may be used to synchronize the slave with the master, particularly if the master and the Remote Time-Stamp Generator are both synchronized with a Global Navigation Satellite System (GNSS) source.Type: ApplicationFiled: March 14, 2014Publication date: September 18, 2014Applicant: MICROSEMI FREQUENCY AND TIME CORPORATIONInventor: George P. ZAMPETTI
-
Publication number: 20140192826Abstract: The notion of a “PTP aware” path is one current proposed approach to reduce asymmetry effects. In a fully PTP aware path there is the notion of on-path support mechanisms such as boundary clocks and transparent clocks at every switching or routing node. However, on-path support methods only address time-transfer errors introduced inside network elements and any asymmetry in the transmission medium, such as, for example, the fiber strands for the two directions of transmission, cannot be compensated for by on-path support mechanisms. Furthermore, in a real operational network, which may traverse different operational domains administered by different entities, full on-path support is a difficult challenge. In certain managed network scenarios full on-path support can be contemplated. Nevertheless, the universal asymmetry compensation method described herein mitigates the asymmetry in a network path, without requiring on-path support mechanisms such as transparent clocks and boundary clocks.Type: ApplicationFiled: January 7, 2014Publication date: July 10, 2014Applicant: Microsemi CorporationInventor: George P. ZAMPETTI
-
Patent number: 8644348Abstract: High accuracy timing over packet networks is achieved by generating correction factors from multiple separation intervals and timing information contained in packets in both directions between a master and a slave. The methods are based on evaluating the weighted average of short-term, medium-term, and long-term measurements of local clock offset. Weighted averages are used to develop robust correction terms that are modified with an ?-shaping factor to provide additional immunity to packet network instabilities.Type: GrantFiled: April 20, 2011Date of Patent: February 4, 2014Assignee: Symmetricom, Inc.Inventor: George P. Zampetti
-
Patent number: 8594134Abstract: A clock at a first network element that is connected to a second network element over an optical fiber link is aligned using bursts of timing information exchanged between the two network elements. According to one method, the bursts from the first network element to the second network element and the bursts from the second network element to the first network element are transmitted over the same wavelength channel of the optical fiber link, in which case zero asymmetry in the transit delays can be assumed during the alignment procedure. According to another method, the bursts from the first network element to the second network element and the bursts from the second network element to the first network element are transmitted over different wavelength channels of the optical fiber link, in which case the asymmetry in the transit delays can be quantified and applied during the alignment procedure.Type: GrantFiled: July 13, 2010Date of Patent: November 26, 2013Assignee: Symmetricom, Inc.Inventors: George P. Zampetti, Sanjay Mani
-
Patent number: 8427963Abstract: Routes of a packet network are analyzed according to various transit delay metrics. Preferred packet network routes are selected between source and destination based on these metrics. In packet networks employing boundary clocks and transparent clocks, faulty boundary clocks and faulty transparent clocks are identified using the metrics.Type: GrantFiled: July 2, 2010Date of Patent: April 23, 2013Assignee: Symmetricom, Inc.Inventors: George P. Zampetti, Kishan Shenoi
-
Patent number: 8385212Abstract: A latency floor between two nodes of a packet-switched network is estimated using transit times of a group of packets traversing the two nodes. In particular, a periodically generated histogram of packet transit times is used to estimate the latency floor. In some packet-switched networks, the behavior of some network elements changes drastically when the network is congested. Because latency floor cannot be accurately estimated under such conditions, packet transit times collected during a congested state of the network are discarded.Type: GrantFiled: December 7, 2009Date of Patent: February 26, 2013Assignee: Symmetricom, Inc.Inventors: George P. Zampetti, Kishan Shenoi
-
Publication number: 20120269204Abstract: High accuracy timing over packet networks is achieved by generating correction factors from multiple separation intervals and timing information contained in packets in both directions between a master and a slave. The methods are based on evaluating the weighted average of short-term, medium-term, and long-term measurements of local clock offset. Weighted averages are used to develop robust correction terms that are modified with an ?-shaping factor to provide additional immunity to packet network instabilities.Type: ApplicationFiled: April 20, 2011Publication date: October 25, 2012Inventor: George P. ZAMPETTI
-
Patent number: 8274999Abstract: Packet network performance is assessed using transit delay metrics and compliance masks generated at various evaluation nodes of the network. The evaluation nodes may employ network probes that make precise measurements of transit delays and thereby of transit delay variations. Based on the assessments, a master may be added to the network or relocated within the network, rate of timing packets generated by the master may be adjusted up or down, or oscillators used at the slaves may be upgraded.Type: GrantFiled: July 2, 2010Date of Patent: September 25, 2012Assignee: Symmetricom, Inc.Inventors: Kishan Shenoi, George P. Zampetti, Lee Cosart
-
Publication number: 20110299853Abstract: A clock at a first network element that is connected to a second network element over an optical fiber link is aligned using bursts of timing information exchanged between the two network elements. According to one method, the bursts from the first network element to the second network element and the bursts from the second network element to the first network element are transmitted over the same wavelength channel of the optical fiber link, in which case zero asymmetry in the transit delays can be assumed during the alignment procedure. According to another method, the bursts from the first network element to the second network element and the bursts from the second network element to the first network element are transmitted over different wavelength channels of the optical fiber link, in which case the asymmetry in the transit delays can be quantified and applied during the alignment procedure.Type: ApplicationFiled: July 13, 2010Publication date: December 8, 2011Inventors: George P. ZAMPETTI, Sanjay MANI
-
Patent number: 8064484Abstract: One embodiment of the present invention sets forth a method for autonomously validating the time and frequency data obtained from multiple sources, and generating a suitable estimate of the frequency difference between the client clock and the source. The method includes the steps of protocol data unit validation, offset measurement, minimum offset filtering, and frequency filtering. With these steps, the negative effects of packet delay variation may be mitigated and a frequency estimate is determined for the source in question, together with an associated validity status. Consequently, quality control of the local clock is achieved in packet networks at significantly reduced cost and decreased level of complexity relative to prior art approaches.Type: GrantFiled: January 31, 2007Date of Patent: November 22, 2011Assignee: Symmetricom, Inc.Inventor: George P. Zampetti
-
Publication number: 20110134766Abstract: A latency floor between two nodes of a packet-switched network is estimated using transit times of a group of packets traversing the two nodes. In particular, a periodically generated histogram of packet transit times is used to estimate the latency floor. In some packet-switched networks, the behavior of some network elements changes drastically when the network is congested. Because latency floor cannot be accurately estimated under such conditions, packet transit times collected during a congested state of the network are discarded.Type: ApplicationFiled: December 7, 2009Publication date: June 9, 2011Inventors: George P. Zampetti, Kishan Shenoi
-
Publication number: 20110122775Abstract: Routes of a packet network are analyzed according to various transit delay metrics. Preferred packet network routes are selected between source and destination based on these metrics. In packet networks employing boundary clocks and transparent clocks, faulty boundary clocks and faulty transparent clocks are identified using the metrics.Type: ApplicationFiled: July 2, 2010Publication date: May 26, 2011Inventors: George P. ZAMPETTI, Kishan SHENOI
-
Publication number: 20110122871Abstract: Packet network performance is assessed using transit delay metrics and compliance masks generated at various evaluation nodes of the network. The evaluation nodes may employ network probes that make precise measurements of transit delays and thereby of transit delay variations. Based on the assessments, a master may be added to the network or relocated within the network, rate of timing packets generated by the master may be adjusted up or down, or oscillators used at the slaves may be upgraded.Type: ApplicationFiled: July 2, 2010Publication date: May 26, 2011Inventors: Kishan SHENOI, George P. ZAMPETTI, Lee COSART