Patents by Inventor Stefano Ruffini

Stefano Ruffini 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).

  • Publication number: 20150207714
    Abstract: Communication between a Radio Equipment Control (REC) and a Radio Equipment (RE) in a wireless network uses a Common Public Radio Interface connection. When the Radio Equipment Control and the Radio Equipment are located remote from each other, and are connected by an asymmetric transport network, such as an Optical Transport Network, path delay data is transmitted in the Common Public Radio Interface data frames. This allows the CPRI end nodes to correct for path delay asymmetry using the path delay data.
    Type: Application
    Filed: September 24, 2012
    Publication date: July 23, 2015
    Inventors: Stefano Ruffini, Bjorn Pohlman
  • Publication number: 20150139663
    Abstract: A method distributes clock synchronization information within an optical communications network having a plurality of network elements. The method receives an ingress clock synchronization message at a first said network element. The ingress clock synchronization message includes a clock synchronisation message identifier and a correction field. The clock synchronisation message identifier is inserted into an optical channel frame overhead and the ingress clock synchronisation message is inserted into an optical channel frame payload. The optical channel frame overhead and the optical channel frame payload are transmitted across the first network element, across the network to a second said network element, and across the second network element. A transit time of the clock synchronisation message identifier is determined across each of the network elements.
    Type: Application
    Filed: August 17, 2012
    Publication date: May 21, 2015
    Applicant: TELEFONAKTIEBOLAGET L M ERICSSON (PUBL)
    Inventors: Sergio Lanzone, Stefano Ruffini, Orazio Toscano
  • Publication number: 20150104167
    Abstract: A method of determining properties of an optical communications path between a first optical network node (A) and a second optical network node (B) determines, at the second optical network node (B), a time difference between respective first and second optical test signals received on different wavelengths (?1, ?2) from the first optical network node. The method also determines, at the second optical network node (B), a real-time chromatic dispersion parameter for each of the wavelengths using a respective coherent receiver at the second optical network node. The method can be used to determine length of the path between the nodes (A, B). The method can be used to determine propagation delay between the nodes (A, B), or asymmetry in propagation delay between the nodes (A, B). Where separate paths are used for forward and reverse transmission directions, measurements can be made of each path.
    Type: Application
    Filed: June 19, 2012
    Publication date: April 16, 2015
    Applicant: Telefonaktiebolaget L M Ericsson (publ)
    Inventors: Giulio Bottari, Stefano Ruffini
  • Patent number: 8929405
    Abstract: There is provided a method of optimizing timing packet transport in a network node, the method comprising using a locally available stable frequency reference at the network node to provide a pre-determined network node transit time for timing packets in at least one direction into or out of the network node. There is also provided a network node comprising a locally available stable frequency reference and circuitry adapted to apply a pre-determined network node transit time, L, to all timing packets transiting the network node in at least one direction into or out of a network node dependent on the locally available stable frequency reference.
    Type: Grant
    Filed: October 29, 2009
    Date of Patent: January 6, 2015
    Assignee: Telefonaktiebolaget L M Ericsson (Publ)
    Inventors: Stefano Ruffini, Raoul Fiorone, Orazio Toscano
  • Patent number: 8842994
    Abstract: A method and system of distributing clock synchronization information within an optical communications network including a plurality of network elements, in which a first network element receives an ingress clock synchronization message, the ingress clock synchronization message including a clock synchronization message identifier and a correction field. The first network element inserts the clock synchronization message identifier into an optical channel frame overhead and inserts the ingress clock synchronization message into an optical channel frame payload. The first network element transmits the optical channel frame overhead and the optical channel frame payload to a second network element, and determines a transit time of the clock synchronization message identifier across each of the network elements. The second network element updates the correction field of the ingress clock synchronization message with said transit times to form an egress clock synchronization message.
    Type: Grant
    Filed: August 22, 2012
    Date of Patent: September 23, 2014
    Assignee: Telefonaktiebolaget L M Ericsson (publ)
    Inventors: Sergio Lanzone, Orazio Toscano, Stefano Ruffini
  • Publication number: 20140219651
    Abstract: A passive optical network comprises a first node configured to transmit a downlink data signal over a communication channel of an optical link, the communication channel having a first wavelength, and a second node configured to transmit an uplink data signal over the optical link using the communication channel having the first wavelength. The first node and/or the second node is adapted to perform at least one monitoring measurement on the communication channel having the first wavelength, and provide monitoring information, comprising the at least one monitoring measurement, in a monitoring channel. Common public radio interface (CPRI) traffic can therefore be transported over an optical transport network (OTN), by using a frequency reuse technique to provide a symmetrical bi-directional communication link between a first node and a second node, and using a frame structure of the optical transport network to provide a monitoring channel.
    Type: Application
    Filed: December 15, 2011
    Publication date: August 7, 2014
    Applicant: Telefonaktiebolaget L M Ericsson (publ)
    Inventors: Stefano Ruffini, Filippo Ponzini
  • Publication number: 20140079409
    Abstract: A method 10 of providing a path delay asymmetry for time synchronization between a master clock at a first client node and a slave clock at a second client node across a server communications network.
    Type: Application
    Filed: April 27, 2011
    Publication date: March 20, 2014
    Applicant: Telefonaktiebolaget L M Ericsson (Publ)
    Inventors: Stefano Ruffini, Giulio Bottari
  • Publication number: 20130315606
    Abstract: A method and system of distributing clock synchronization information within an optical communications network including a plurality of network elements, in which a first network element receives an ingress clock synchronization message, the ingress clock synchronization message including a clock synchronisation message identifier and a correction field. The first network element inserts the clock synchronisation message identifier into an optical channel frame overhead and inserts the ingress clock synchronisation message into an optical channel frame payload. The first network element transmits the optical channel frame overhead and the optical channel frame payload to a second network element, and determines a transit time of the clock synchronisation message identifier across each of the network elements. The second network element updates the correction field of the ingress clock synchronisation message with said transit times to form an egress clock synchronisation message.
    Type: Application
    Filed: August 22, 2012
    Publication date: November 28, 2013
    Applicant: TELEFONAKTIEBOLAGET L M ERICSSON (PUBL)
    Inventors: SERGIO LANZONE, ORAZIO TOSCANO, STEFANO RUFFINI
  • Publication number: 20130202291
    Abstract: A method for measuring asymmetry in propagation delay of first and second links which connect a first node to a second node of a communication network. The method comprises measuring (101) a round trip delay of the first link. The round trip delay can be measured by transmitting (102) a test signal from the first node to the second node over the first link and receiving a reply to the test signal from the second node over the first link. The method further comprises measuring (105) a round trip delay of the second link. The round trip delay can be measured by transmitting (106) a test signal to the second node over the second link and receiving a reply to the test signal from the second node over the second link. A difference in the propagation delay of the first link with respect to the second link is determined (109) using the measured round trip delays of the first link and the second link.
    Type: Application
    Filed: September 13, 2011
    Publication date: August 8, 2013
    Applicant: TELEFONAKTIEBOLAGET LM ERICSON (publ)
    Inventors: Fabio Cavaliere, Giulio Bottari, Luca Giorgi, Stefano Ruffini
  • Publication number: 20130145041
    Abstract: The invention relates to networking in general and in particular to an improved packet timing transport mechanism. The present invention provides a method of optimizing timing packet transport in a network comprising a first network node connected to a second network node. The method comprises forwarding a timing packet received at the first network node to the second network node, and transmitting the timing packet from the second network node a pre-determined duration K after receiving the timing packet at the first network node.
    Type: Application
    Filed: August 31, 2010
    Publication date: June 6, 2013
    Applicant: TELEFONAKTIEBOLAGET L M ERICSSON (PUBL)
    Inventors: Stefano Ruffini, Per-Erik Eriksson
  • Publication number: 20130039220
    Abstract: Configuring a node (410) of a synchronization network involves identifying (10) possible alternative time synchronization trails arranged to carry time synchronization information for time synchronization at the node, and possible alternative frequency trails, arranged to carry frequency synchronization information for frequency synchronization at the node. Using information about the sources (20), a comparison of the trails (30) is biased to increase a likelihood of choosing time synchronization and frequency trails which share the same source, over a likelihood of choosing trails with different sources. This can help avoid divergence and consequent bit errors arising from phase errors, resulting from trails having different sources. It can encompass for example changing both to a new common source, or changing one or both trails while still using the old common source.
    Type: Application
    Filed: January 18, 2010
    Publication date: February 14, 2013
    Inventors: Stefano Ruffini, Raoul Fiorone, Sergio Lanzone, Orazio Toscano
  • Publication number: 20130010813
    Abstract: There is provided a method of optimizing timing packet transport in a network node, the method comprising using a locally available stable frequency reference at the network node to provide a pre-determined network node transit time for timing packets in at least one direction into or out of the network node. There is also provided a network node comprising a locally available stable frequency reference and circuitry adapted to apply a pre-determined network node transit time, L, to all timing packets transiting the network node in at least one direction into or out of a network node dependent on the locally available stable frequency reference.
    Type: Application
    Filed: October 29, 2009
    Publication date: January 10, 2013
    Inventors: Stefano Ruffini, Raoul Fiorone, Orazio Toscano
  • Publication number: 20120287948
    Abstract: Configuring a node (410, A-I, L-O) of a synchronization network, involves determining information about synchronization sources of a plurality of synchronization trails for passing synchronization information from the synchronization source (A, L, O, PRC) to the node to provide a synchronization reference. After determining automatically (210, 230, 330, 335, 340) synchronization transmission characteristics of trails (EF, FG, GH, HM, MN, OF, FI, IH) which use packet-based communication, the trails are compared automatically (240, 370), using their source information and their synchronization transmission characteristics, for selecting which of these trails to use for providing the synchronization reference for the node (N).
    Type: Application
    Filed: January 18, 2010
    Publication date: November 15, 2012
    Inventors: Stefano Ruffini, Giulio Bottari, Manuel Nardelli
  • Publication number: 20120027146
    Abstract: The invention relates in general to clock recovery in a communications network, and in particular to clock recovery in a packet based communications network. Methods and apparatus are disclosed for determining a client timing signal 64, 70 for at least one client device 18, 20, 22, 54, 56, 92, 94, 96 at a master device 24, 58, 98. The client timing signal is compared 126 with a reference timing signal 76 of the master device. A timing difference value 36 is then determined 128 between the client timing signal and the reference timing signal. At least one packet indicative of the timing difference value is transmitted 130 from the master device 24, 58, 98 for receipt by the at least one client device for adjusting the client timing signal at the at least one client device.
    Type: Application
    Filed: February 24, 2009
    Publication date: February 2, 2012
    Applicant: TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
    Inventors: Robert Hodge, Stefano Ruffini
  • Publication number: 20100020829
    Abstract: A method and mechanism for adaptive clock recovery of a service clock of a constant bit rate (CBR) service transmitted as a stream of packets over a packet network from a sending end node to a receiving end node via at least one intermediate node. The intermediate node associates the data packets relating to the CBR service with updated timestamps generated by a second reference timing signal available in the intermediate node. When recovering the service clock in the receiving end node, an adaptive clock recovery mechanism uses the updated timestamps to derive an estimated service clock, thereby reducing the effect of network-caused packet delay variation on clock recovery.
    Type: Application
    Filed: October 27, 2006
    Publication date: January 28, 2010
    Applicant: TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
    Inventor: Stefano Ruffini
  • Patent number: 6711411
    Abstract: Operation of a synchronization network that includes a number of nodes and reference clock distribution logic includes, at each of the nodes, storing a table that represents a most recent status of the synchronization network. Reference clocks are then distributed to each node in the synchronization network. If a change in synchronization status occurs at a node in the synchronization network, this change is detected. The table at the node is updated to represent an updated status of the synchronization network. Then, a synchronization network management protocol is used to distribute the updated status to other nodes in the synchronization network. Other nodes may change their status in response to receipt of the updated information, and information about these additional updates are distributed throughout the synchronization network in a similar manner, thereby facilitating control of the synchronization network.
    Type: Grant
    Filed: November 7, 2000
    Date of Patent: March 23, 2004
    Assignee: Telefonaktiebolaget LM Ericsson (publ)
    Inventor: Stefano Ruffini
  • Patent number: 6636987
    Abstract: The present invention relates to a method and device for determining a synchronization fault in a synchronization network, where values of a clock control parameter associated with the synchronization control in a node are compared with a predicted mask value for said clock control parameter, and a synchronization fault is determined if one or more of the measured values lies outside of the predicted mask.
    Type: Grant
    Filed: August 25, 2000
    Date of Patent: October 21, 2003
    Assignee: Telefonaktiebolaget LM Ericsson (publ)
    Inventor: Stefano Ruffini
  • Patent number: 6532274
    Abstract: The present invention relates to a method and to an arrangement for synchronising at least one local oscillator (21) with a central time-generating unit (11). The local oscillator (21) serves a so-called element (2) included in a network (A), and the time-generating unit (11) is included in a so-called main unit (1) also included in the network (A). The frequency of the local oscillator (21) can be controlled by periodic and automatic calibration. The physical requirements within a part of the network (A) that includes the main unit (1) and all elements (2, 3, 4) concerned, said part being referred to here as a limited network (B), are so well defined that the transmission time of a time stamp from the main unit (1) to an element (2) will be known with a given degree of certainty. The inter-arrival time of the time stamps is used to calibrate the local oscillator (11) together with the known transmission time.
    Type: Grant
    Filed: January 11, 2000
    Date of Patent: March 11, 2003
    Assignee: Telefonaktiebolaget LM Ericsson (publ)
    Inventor: Stefano Ruffini