179 results about "Network Time Protocol" patented technology

A networked system is provided for transporting digital media packets, such as audio and video. The network includes network devices interconnected to send and receive packets. Each network device can receive and transmit media signals from media devices. A master clock generates a system time signal that the network devices use, together with a network time protocol to generate a local clock signal synchronised to the system time signal for both rate and offset. The local clock signal governs both the rate and offset of the received or transmitted media signals. The system, which can be implemented using conventional network equipment enables media signals to be transported to meet quality and timing requirements for high quality audio and video reproduction.

Embodiments of the present invention set forth a method and system for reducing uncertainty in receive and transmit timestamps created by an NTP server. The uncertainty in the receive timestamps is removed by recording the time-of-arrival in the hardware clock of the NTP server before the incoming packets may be delayed by traversing the various layers of software in a timestamping system. The uncertainty in the transmit timestamps is removed by giving the outgoing packets a timestamp in the future using an estimate of the transmission latency calculated by the latency estimator filter. Subsequently, the actual time-of-departure is used to re-calculate and update the estimate of the transmission latency. In this fashion, superior control of the timestamping function may be implemented in existing NTP servers in a manner that retains interworking compatibility with the current NTP standards.

A Hard Real Time Control Center (HRTCC), comprised of hardware, software and firmware, with time synchronisation and time delay compensation methodologies that allows Application Hardware and/or User Input Devices to be networked together on any communications network as if there were negligible network delays in the system, is disclosed. This will allow Application Hardware and/or User Input Devices (connected to an HRTCC at one location (node) on the network) to control or operate Application Hardware and/or User Input Devices connected to another HRTCC at a remote location without the detrimental effects of network time delays. The time synchronisation of the various HRTCCs on the network can be enabled using hardware (e.g. a global positioning system (GPS)) or any other software method (e.g. Network Time Protocol). Using time stamps from the time synchronisation, the time delay of the signals (data) transferred over the network can be determined. The main embodiment of the time delay compensation methodology is an estimator/predictor algorithm. The estimator generates signal information that allows the predictor, using the time delay, to project the signal information characteristics into the future by an amount equal to the time delay. If this predicted signal is used rather than the delayed signal, there will be no readily apparent time delay in the system thereby significantly improving the stability and performance of the associated application. Any software architecture can be used such as servant-client, token ring or peer to peer.

An Internet Protocol (IP)-based mobile TV system and a method for synchronizing the rendering of a streaming service are provided. In the IP-based mobile TV system, a plurality of mobile terminals receives a streaming service from network equipment, along with both a sequence of Network Time Protocol (NTP) time stamps corresponding to the streaming service and a synchronization clock. Each mobile terminal recovers an NTP reference clock for rendering the received streaming service according to both the synchronization clock and a synchronization time difference value, and then renders the received streaming service according to both the recovered NTP reference clock and the received NTP time stamps. Accordingly, the plurality of mobile terminals in the IP-based mobile TV system is able to render the received streaming service synchronously.

Method and apparatus for receiving an estimate of time in a satellite signal receiver receives an estimate of time from a server and compensates for error of a clock in the satellite signal receiver using the estimate of time. The output of the compensated clock is used when computing a position of the satellite signal receiver. The estimate of time is received using a network time protocol (NTP), a simple network time protocol (SNTP), or by one-way broadcast from the server.

The invention relates to a method and a system for synchronously inserting network time. The method comprises the following steps: S1, a client generating an NTP (Network Time Protocol) timestamp query information packet and sending the NTP timestamp query information packet to an optimal time server, wherein the optimal time server is a time server selected by the client according to an optimal time server algorithm; S2, the client receiving an NTP timestamp answer information packet generated by the optimal time server according to the NTP timestamp query information packet; S3, repeating S1 and S2, and executing S4 when the repeated times is N, wherein N is more than or equal to 5 and less than or equal to 10, the repeated time interval is t, and t is more than or equal to 10s and less than or equal to 30s; S4, the client calculating a time difference data mean by adopting an information packet filter algorithm; S5, the client calibrating the client time according to the time difference data mean; and S6,the client displaying the calibrated client time. By adopting the method and the system, the calibrating precision is high, the system is small, the scheme is easy to realize, and the hardware cost is relatively low.

The invention relates to one time simultaneous method and system for multi-point visual point, which comprises the following steps: a, using network time agreement to process all device simultaneous operations; b, separately starting one collection program on collectors for each camera; c, visual collection program monitors control order from servo; d, the servo detects local network maximum reverse time; e, the servo adds current system time and the maximum reverse time as pre-set collection time sent to each collection program; f, collection program compares the current system time and pre-set collection time, if it supers then starting visual data collection.

A method for synchronizing a time architecture of a mobile network that includes a plurality of network components, each having a time subsystem clock that is updated using a network time protocol (NTP) program. The method includes operating the components in a hierarchical fashion and booting up all the network components such that execution of a NTP sub-program for making small incremental changes to the each component time subsystem clock is delayed. Additionally, the method includes iteratively executing a NTP sub-program for making large changes to each component time system clock until each component time sub-system clock establishes an initial synchronization with a parent component time sub-system clock. Furthermore, the method includes iteratively executing the NTP sub-program for making small incremental changes once initial synchronization is established such that each component time sub-system clock maintains synchronization with the parent component time sub-system clock.

A distributed network monitoring system includes a central monitoring device configured to fetch network traffic information from one or more remote monitoring devices in response to receiving a notification from the remote monitoring devices that the network traffic information is available, the remote monitoring devices being communicatively coupled to the central monitoring device. The network traffic information is associated with a timestamp which indicates a time period at which the network traffic information was collected by the remote monitoring devices. The central monitoring device further synchronizes the network traffic information from the remote monitoring devices by comparing the timestamp of the network traffic information with a system timestamp provided by a system clock or network time protocol (NTP) server. The network traffic information is identified as unavailable if the timestamp cannot be located when compared to the system timestamp. In addition, the central monitoring device starts a timeout wait period for the remote monitoring device with the unavailable network traffic information and further ceases collecting the network traffic information if the timeout wait period expires. The synchronized network traffic information is further consolidated to provide information regarding the overall performance of a network system.

A real time remote leak detection system includes leak detection sensor nodes configured to be operated according to a plurality of sensor management modes. The plurality of the leak detection sensor nodes being installed on a underground pipe and at least one network node configured to cause an NTP (Network Time Protocol) node to synchronize timing of the leak detection sensor nodes when a time of the NTP node is set through a timing source such as a Global Positioning System and the leak detection sensor nodes enter a specific sensor management mode. The system may transmit leak sound data collected in real time in a sensor node wirelessly installed in a pipe to a control center to check whether a leak of the pipe occurs and identify leak location as well.

The invention relates to a time synchronization method of a femto base station route (BSR). The method comprises the following steps: extracting line clock information in a core network; comparing the core network line clock information with internal clock information and external clock information and determining the clock information with a highest synchronization quality grade; carrying out time synchronization of the femto BSR according to the clock information with the highest synchronization quality grade. A time synchronization system of the femto BSR comprises: an apparatus used to extract the line clock information in the core network, the apparatus used to comparing the core network line clock information with the internal clock information and the external clock information and determine the clock information with the highest synchronization quality grade and the apparatus used to carry out the time synchronization of the femto BSR according to the clock information with the highest synchronization quality grade. By using the method and the system of the invention, the clock synchronization between a femto BSR clock and a network time protocol (NTP) server can be stable and accurate.

Disclosed is a method for determining the location of a terminal in an AGPS system in a wireless LAN using AGPS data provided from a PDE (position determination entity) and time information provided from a NTP (network time protocol) server.

The invention discloses a method, a system and a device for time synchronization in a mobile communication system. The method comprises the steps of: sending system broadcast information which contains system time information by a base station, wherein the system time information is used for being provided to a terminal which receives the system broadcast information and correcting the local time of the terminal according to the system time information, and the local time of the terminal keeps synchronization with the system time after being corrected. In the invention, the system time can be obtained and the time is synchronized by the terminal of any access system without the conditions that the terminal has a GPS function and the interaction flow of the terminal and an NTP (Network Time Protocol) server is increased or changed, the terminal reliably and easily obtains the system time and realizes time synchronization with the system time without the problem that the terminal cannot obtain the system time and cannot achieve the time synchronization with the NTP system due to the crash of the NTP system.