Patent application number | Description | Published |
20090310625 | METHOD FOR DISTRIBUTING A COMMON TIME REFERENCE WITHIN A DISTRIBUTED ARCHITECTURE - A method of distributing a common time reference within a distributed architecture includes one or more of the following: generating at least one electrical pulse at a central entity; distributing the at least one electrical pulse to a subassembly; receiving the at least one electrical pulse at the subassembly; recording a reception counter value corresponding to a value of a local frequency counter when the at least one electrical pulse is received at the subassembly; querying the central entity to obtain a generation time value corresponding to a time at which the at least one electrical pulse was generated; and determining a global time value using the generation time value, the reception counter value, and a current counter value of the local frequency counter. | 12-17-2009 |
20100109787 | METHOD AND APPARATUS FOR OSCILLATOR STABILITY VERIFICATION - A technique for oscillator stability and accuracy verification involves analysis of parameters from a plurality of phase locked loops (PLLs). During testing, each PLL receives a stable reference clock to identify variations in its clock oscillator. Mathematical calculations on the data extracted from each PLL permit identification of clock oscillators having undesirable timing characteristics. Remedial measures may then be implemented to correct problems with any faulty oscillators. | 05-06-2010 |
20100111113 | NETWORK ELEMENT CLOCKING ACCURACY AND STABILITY MONITORING OVER A PACKET-SWITCHED NETWORK - Various exemplary embodiments include a method and related system and monitoring entity including one or more of the following: generating timing information at a master node in a packet-switched network, the timing information specifying a value of a master clock; communicating the timing information from the master node to a plurality of slave nodes over a first plurality of time-division multiplexing (TDM) pseudowires; running a digital phase-locked loop on each slave node to synchronize each slave node to the master clock, wherein each digital phase-locked loop outputs a frequency at which the respective slave node is operating; sending the frequency outputted by each digital phase-locked loop to a monitoring entity over a second plurality of TDM pseudowires; utilizing the outputted frequencies at the monitoring entity to identify all slave nodes that are experiencing timing problems; and implementing a remedial measure for all slave nodes that are experiencing timing problems. | 05-06-2010 |
20100172453 | High availability clock synchronization and distribution for mobile backhaul networks - Fully redundant clock systems are provided on network nodes coupled by redundant multisegment psuedowires (MSPWs) within an internet-protocol (IP)-based mobile backhaul network. The primary clock system includes a primary master clock on a first node and a primary slave clock on a second node coupled via a primary MSPW, while the secondary clock system includes a secondary master clock on the first node and a secondary slave clock on the second node coupled via a secondary MSPW. The primary and secondary slave clocks synchronize with their respective primary and secondary master clocks via their respective MSPWs. A clock controller maintains the secondary clock system in a hot-stand-by mode, and upon determining that a switch-over is needed, automatically switches from the primary clock system to the secondary clock system. | 07-08-2010 |
20100329125 | TIMING OVER PACKET PERFORMANCE - The invention is directed to a method and apparatus for providing improved packet over timing clock synchronization in a packet switching network using Operations, Administration, and Maintenance (OAM) tools to compensate for asymmetrical characteristics between forward and reverse data paths. | 12-30-2010 |
20100329284 | CENTRALIZED NODE CLOCK AUTO RECONFIGURATION - The invention is directed to a method and system for providing centralized automated synchronization clock reconfiguration in packet switched telecommunications networks having network nodes that do not implement Synchronization Status Messaging (SSM) internally. This is especially useful when integrating TDM networks with packet switching network elements having T1 and E1 interfaces. | 12-30-2010 |
20110142077 | NETWORK SYNC PLANNING AND FAILURE SIMULATIONS - The invention is directed to a method and system for providing synchronization clock performance simulation in a timing-over-packet network having a network management system. The system retrieves information from nodes in a network and determines a timing-over-packet topology in a simulated model of the network, and determines clock stability statistics. The system further accepts simulation inputs such as addition or deletion of nodes in the simulated network, or introduction of failures into in the simulated network. The system provides predicted clock stability performance of an existing network under various simulated conditions without requiring modifications or introduction of failures to the existing network which would be useful for network optimization and network planning. | 06-16-2011 |
20110142078 | NETWORK TIMING TOPOLOGY VIA NETWORK MANAGER - The invention is directed to providing a method and system for monitoring and managing from a network management entity, timing-over-packet synchronization performance in a packet switching network having multiple network nodes. The network management entity determines a physical topology and a synchronization topology of the network and monitors synchronization performance by collecting virtual path information. | 06-16-2011 |
20110142079 | NETWORK IMPAIRMENT METRICS FOR TIMING OVER PACKET - The invention is directed to providing a system and method for monitoring a clock synchronization metric in a timing-over-packet system to provide a metric for service-level agreements (SLA), by providing a measure of the stability of the packet transfer delay relative to a representative statistic such as a median or minimum. | 06-16-2011 |
Patent application number | Description | Published |
20140334311 | SYMMETRICAL LATENCY WITH TDM CIRCUIT EMULATED SERVICE - A method and system are provided for allowing time-alignment of teleprotection measurements of power signals. Teleprotection observations are communicated between teleprotection ends through a packet switched network. At each end of a teleprotection segment, a teleprotection device communicates with the network through a router providing CES and located at the edge of the network. Clocks within the two routers are synchronized using IEEE 1588v2 signals. Using this synchronization, accurate one-way latency of data through the network between the two routers in each direction can be determined. The router at the incoming end of the faster path delays playout of packets by the difference between the two one-way latencies, thereby ensuring time-alignment of observations as they are sent from the routers to the teleprotection devices. | 11-13-2014 |
20140348278 | USING MULTIPLE OSCILLATORS ACROSS A SUB-NETWORK FOR IMPROVED HOLDOVER - A method and system are provided for improving maintenance of timing information when a node enters holdover due to a lost connection between a sub-network and a reference clock. Each node within the sub-network sends information concerning the drift of its local oscillator to a single node, and the single node uses this information to determine timing information for the entire sub-network. The single node may also use knowledge of the characteristics of the local oscillators. In this way, drift from the reference clock can be minimized without incurring significant added hardware costs. | 11-27-2014 |
20150078405 | MONITORING CLOCK ACCURACY IN ASYNCHRONOUS TRAFFIC ENVIRONMENTS - Various exemplary embodiments relate to a method and related network system including one or more of the following: a first network device comprising a first clock; and a second network device comprising a second clock, wherein the first network device and the second network device are configured to employ a frequency distribution scheme to attempt to set the second clock to operate at the same frequency as the first clock; the first network device is configured to generate and transmit a synchronous stream of timing packets to the second network device, wherein the timing packets are periodically transmitted based on the first clock; and the second network device is configured to receive the synchronous stream of timing packets and determine, based on comparing the synchronous stream of timing packets to the second clock, whether the second clock is out of sync with the first clock. | 03-19-2015 |