180 results about "Network Time Protocol" patented technology

One or more methods and systems of effectively transmitting voice and voice band data from one node to another are presented. In one embodiment, the system comprises an NTP time server generating absolute times to computing devices such as residential voice over internet protocol (VoIP) gateways. The NTP time server generates absolute times in response to NTP time requests made by one or more computing devices such as residential VoIP gateways. In one embodiment, the method comprises determining an adequate rate for requesting absolute times from an NTP server, making periodic requests to the NTP server, obtaining the absolute times from the NTP server, and generating an adjustment parameter for use by a computing device such as a residential VoIP gateway.

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.

The invention discloses large screen splicing method and system, wherein the method comprises the following steps of: A, transmitting the same video stream to a plurality of PC (Personal Computer) decoding terminals connected through a network to ensure the synchronous transmission of data through the modes of UDP (User Datagram Protocol) multicasting transmission and the like; B, carrying out delay regulation on each PC decoding terminal through NTP (Network Time Protocol) clock synchronism and frame timestamp to ensure the image quality of a spliced large screen; and C, cutting and displaying part of the image by using each PC decoding terminal to ensure that the image of the spliced large screen is integral and non-overlapped. The invention realizes the infinite amplification on splicing the large screen through the infinite expansion of the PC terminal, realizes the flexible changes of the splicing size and the resolution ratio of the large screen through the arbitrary combination of the PC decoding terminals and ensures the synchronism of each part of the image of the spliced large screen as well as the uniformity and the continuity of the whole image through video delay regulation.

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.

Techniques for synchronizing the clock of a local telecommunications network connected to a remote clock source through an asynchronous transport network such as an Ethernet metropolitan area transport network. A basic holdover loop for retaining the current reconstructed clock frequency signal receives weighted corrections from an open loop and a network time protocol filter loop. The open loop measures data packet interarrival times on the local network and calculates a first reconstructed clock frequency signal. The network time protocol loop applies network time protocol to generate timestamps over the asynchronous transport network which are used to generate a second reconstructed clock frequency signal. The first and second reconstructed clock frequency signals are combined using dynamically adjusted weight factors and compared with the current reconstructed clock frequency signal to correct the latter which then synchronizes the clock of the local telecommunications network.

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.

A local time of a broadband loop carrier terminal is synchronized to a network time received from a source external to the broadband loop carrier terminal by comparing the local time to the network time to generate an error offset, and adjusting the local time based on the error offset. The network time may be received in response to a Network Time Protocol (NTP) poll transmitted by the broadband loop carrier terminal. In some cases, the poll is transmitted over a communication medium using an asynchronous packet protocol, such as Ethernet or TCP / IP. In one embodiment, the local time is based on the output of a local oscillator (e.g., a voltage controlled oscillator), the frequency of which may be adjusted using control logic which uses a filtered version of the error offset along with a factory calibration and / or temperature compensation to produce a control voltage to control the oscillator frequency.

The present invention provides a method for utilizing a backup timing source in digital communication systems when GPS becomes nonfunctional. When a base station fails to receive an expected signal from a GPS satellite, a GPS failure timer is started. If the base station does not receive a signal from the GPS satellite prior to the expiration of the timer, the wireless communication system switches to a backup timing system, such as NTP (Network Time Protocol).

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.

Disclosed is a system and a method for setting an internal time corresponding to a standard time at a current location in a mobile station of an asynchronous scheme. The mobile station of the asynchronous scheme uses a Simple Network Time Protocol (SNTP), which is an application of a Network Time Protocol (NTP), allowing the mobile station to easily update internal time information using a synchronized time. The SNTP can provide a time value which can be used to accurately reset an internal time of the mobile station of the asynchronous scheme. By using the SNTP, the mobile station of the asynchronous scheme can obtain exact time information as in a CDMA network and update the mobile station's internal time with the time corresponding to an area in which a standard time is changed.

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.

An enhanced interactive television broadcast is disclosed wherein an audio / video broadcast is viewed on a first display system, and an “enhancement” to the broadcast is simultaneously viewed or experienced on a second, separate display system. The “enhancement” is synchronized to the broadcast, and delivered to a user as a code fragments, such as a JavaScript message. URLs are not required. Portions or elements of a web page are reduced to single code fragments, rendered client-side upon receipt. The invention implements Network Time Protocol (NTP) to synchronize the client's application clock to global time. Messages, or JavaScript code fragments, are time-stamped and evaluated based on the client's application clock.

The invention discloses an ARM-based network clock synchronization system and method. The system comprises a GPS (Global Positioning System) satellite time service module, an NTP (Network Time Protocol) server, a hardware time service module and a client module, wherein the GPS satellite time service module is used for acquiring satellite time information in a short time through a satellite; the NTP server is an embedded processor with an operating system, and is used for converting a received time message into a standard format and calibrating local time; the hardware time service module is used for storing time which is recently calibrated by the NTP server; and the client module is used for acquiring server time, and synchronizing local system time. The system and the method are easy to implement. Through adoption of the ARM-based network clock synchronizing system and method, simple, convenient, rapid and accurate time calibration is provided for a distributed clock in a local area network; the phenomena of delay of Internet time in a transmission process and the like are avoided; and the accuracy in time synchronization of all terminal equipment in the local area network is ensured. The system and the method have the characteristics of reasonable design, high reliability, high environment suitability, small size, convenience in use, low power consumption and the like.

The invention discloses a Beidou foundation navigation network ground monitoring station pseudolite and a control method. The Beidou foundation navigation network ground monitoring station pseudolite is used for achieving physical simulation of output signals of a single satellite and comprises an interface module, a control module, a base band module, a radio frequency module and an antenna. The input end of the interface module is connected with a data signal and a clock signal. The output end of the interface module is connected with the control module. One output end of the control module is directly connected with the antenna through the radio frequency module, and the other output end of the control module is connected with the radio frequency module through the base band module. The radio frequency module is connected with the antenna. The Beidou foundation navigation network ground monitoring station pseudolite can simulate pseudolite signals of a Beidou system and achieve physical simulation of the output signals of the single satellite. Pseudolite navigation signal pseudo-random codes are selected from the unused Beidou satellite signal pseudo code space and are not relevant to existing satellite signals. High-precision inter-satellite link time synchronization is achieved through a network time protocol.

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 provides a network time system and method based on Beidou satellite positioning. The method includes through accurate time information provided on the basis of a GPS / BD (global positioning system / Beidou) module and combining an internal RTC (real time clock), calculating and correcting time information (year, mouth, date, hour, minute and second); through a TCP / IP (transmission control protocol / internet protocol) network transmission module, establishing a time transmission link with a client side initiating a request on a network in real time; according to the request sent to a server by the client side and through an NTP (network time protocol), synchronizing time with the network client side sending request signals. The network time system and method is higher in network time accuracy and can meet needs of the fields of power communication, communication charging, distributed-type network calculation and weather forecast better.

The invention discloses a clock synchronizing method for an NTP (Network Time Protocol) network and a PTP (Precision Time Protocol) network, which comprises the following steps: a PTP network side is configured as a master clock, an NTP network side is configured as a slave clock, and a message processing server is arranged between the master and slave clocks; a clock synchronizing message sent from the PTP network side is received by the message processing server, converted into message with an NTP message format, and finally transmitted to the NTP network side; and after response message sent from the NTP network and for the clock synchronizing message, the response message is converted into delay request message with a PTP message format, and the delay request message is transmitted to the PTP network side. The method achieves the clock synchronizing of the NTP network and the PTP network, enables the most conventional NTP network can be communicated with the PTP network, and obtains technical effects including cost conversation and precision improvement.

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.

The embodiment of the invention relates to the field of communication transmission, and particularly discloses a method for acquiring synchronous time, a device and a system thereof. The method comprises the following steps: receiving pseusynchronous time information, processing the pseusynchronous time information and obtaining pseusynchronous time T1; acquiring synchronous time information from a synchronous time source, processing the synchronous time source, obtaining synchronous time T2, calculating a time difference value Delta T of the synchronous time T2 and the pseusynchronous time T1 and storing the difference value Delta T; and when failing to acquire synchronous time information from the synchronous time source, correcting the pseusynchronous time T1 with the stored time difference value Delta T, obtaining corrected time T3 and selecting, and outputting the corrected time T3 as synchronous time of equipment needing to synchronize time. The invention solves the problem that in the prior art, the transmission delays of the two-way transmission channel of the transmission network are different so as to cause low accuracy and the like of the synchronous time obtained by operating the network time protocol.

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.

The present invention provides client-side timing method and equipment through network time protocol. Said method includes configuring client-side time deviation threshold; client-side transmitted network time protocol packet; judging whether said network time protocol packet client-side time and local zone time deviation exceeding said time deviation threshold, according to judgment result to control client-side timing. The present invention realizes client-side timing through simple modifying NTP server processing NTP packet process, effectively reducing client-side maintenance and system development work load, in favor of ensuring client-side safe operation.

The invention discloses a method for automatically deploying Oracle rac environment based on a Linux system. The method comprises the following steps of by utilizing a set of Linux shell scripts, automatically configuring oracle user environment, changing account configuration, configuring a network, building a soft link of compress, changing shell limitation and software package, checking an inner core of an operation system and the like, installing JDK (Java Development Kit), configuring a Hangcheck inner core monitoring module, building ssh mutual communication, configuring an NTP (Network Time Protocol) time server, configuring shared storage and configuring vncserver. The method disclosed by the invention is suitable for constructing Oracle rac cluster software environment under all Linux OS, is good in popularity and generalization performance and provides a direct and easy-to-operate method for constructing the Oracle rac cluster environment under a system based on a self-carried general command; the labor cost is greatly lowered, wrong operation caused in manual construction of the environment is avoided, and the efficiency and reliability of configuration of cluster services are greatly improved.