70 results about "PTP protocol" patented technology

The invention relates to a method for realizing sub-microsecond synchronization accuracy based on a PTP (Precision Time Protocol), belonging to the technical field of communication; in order to obtain high-accuracy synchronization efficiency and save hardware investment cost, the method comprises the following steps: before a master time sends synchronization messages, synchronizing a clock and a clock source of an Ethernet transceiver; obtaining average path delay of links by a delay request information packet delay measuring mechanism or measuring a waiting delay information packet delay measuring mechanism; and performing asynchronous correction on the links so as to realize sub-microsecond synchronization accuracy. In the method, the DP83640 Ethernet transceiver is adopted, network message time stamp can be exactly obtained, the PTP protocol on an AT91RM9200 platform is realized, and sub-microsecond synchronization accuracy can be realized. Via test, the synchronization accuracy can be up to 100ns; and the whole system is low in cost, excellent in openness and expandability, and easy to implement.

A method is provided for controlling a Mass Storage Class Digital Imaging Device using a SCSI pass through protocol. The protocol is based on industry standard SCSI protocol with modifications and extensions to allow transparent communication over a medium and is referred to as SCSI Pass Through (SPT). This protocol defines a set of commands that are initiated in a computer. The commands also include and extend industry standard Picture Transfer Protocol and are targeted for application and execution in a Mass Storage Class Digital Imaging Device. The invention includes the definition of data buffers in the form of data structures that can be used for passing and receiving information related to the digital imaging device. The protocol is applicable to communication mediums that can be utilized in connecting any digital storage device to a computing device.

The invention relates to the technical field of network information transmission, and relates to an IEEE1588 clock synchronization system and an implementation method therefor. A CPU control module is connected with an Ethernet MAC (media access control) controller module, and is used for controlling the system and achieving PTP protocol and clock synchronization. The Ethernet MAC controller module is used for achieving the transmitting and receiving of PTP messages. A GPS module is connected with a local clock module, and provides a precise time reference for the system. The local clock module is connected with the CPU control module, and is used for providing a local clock reference during the message transmission. A physical layer (PHY) transceiver with a function of timestamp management is connected with the Ethernet MAC controller module through an independent media interface, thereby completing the stamping and obtaining of a timestamp, and enabling the time information to be embedded into the messages, and completing the transmission of a data package with the timestamp according to the IEEE 802.3 standard.

The invention is applied in a synchronous network and provides a method for realizing a boundary clock in an IEEE1588 protocol and a system thereof. The system comprises a data receiving module which is used to receive a data message sent by an upper grade synchronous network, a received data processing module which is used to analyze time information in the data message received by the data receiving module and to recover the synchronous clock of the upper grade synchronous network, a sent data processing module which is used to pack the synchronous clock into a data packet according to a format of a PTP protocol, and a data sending module which is used to send the data packet which is packed by the sent data processing module to a next grade synchronous network, wherein the data receiving module, the received data processing module, the sent data processing module and the data sending module are used to process the message in turn. The system concretely realizes that the synchronous clock which is synchronous with the upper grade synchronous network and the boundary clock which enables the next grade synchronous network to be synchronous with the synchronous clock are obtained.

The invention relates to a method for selecting a master clock based on a PTP (Picture Transfer Protocol) and link quality, a slave clock and a system. The method comprises the following steps of: configuring a link quality selection strategy according to a link quality index, wherein the link quality index comprises link packet loss rate, delay jitter and/or link delay; and selecting a target master clock according to the configured link quality selection strategy. In the method for selecting a master clock based on a PTP (Picture Transfer Protocol) and link quality, the slave clock and the system, a user configures the link quality selection strategy (mainly comprising the indexes of link packet loss rate, the delay jitter and/or the link delay and the like), and the target master clock is selected according to the user configuring link quality selection strategy by combining with the PTP, which not only satisfies the actual selection demands of the user, but also improves multiselectivity and flexibility when the master clock is acquired and solves the problem that the master clock can not be selected when the master clock in the traditional PTN (Packet Transport Network) does not send a notice message.

The invention discloses a method and a device for processing a precise time transfer protocol message. The method is used for processing a PTP message in a looped network consisting of transparent clocks; the method comprises the following steps: operating a multiple spanning tree protocol MSTP in each transparent clock of the network; selecting the state of each port starting a PTP protocol in each transparent clock; according to the state of the port selected through operation of the MSTP protocol and the type of the PTP message to be processed, processing the PTP message; and forwarding the processed PTP message only in the port with a sending state. According to the method and the device, the looping of the PTP message can be prevented.

Provided is a method and apparatus for sharing content assets using a picture transfer protocol (PTP). The method, in which a first device shares a content asset of a second device, includes requesting for a content asset control file by transmitting an object identifier for the content asset to the second device; and receiving the content asset control file from the second device. Furthermore, in a method of providing a content asset included in a second device to a first device, the method includes receiving a request for a content asset control file from the first device; modifying the content asset control file by additionally recording object identifiers for respective object files included in the content asset to the content asset control file; and transmitting the modified content asset control file to the first device.

The invention relates to a wireless network communication technology, and in particular relates to a time synchronization error compensation method for a multi-hop wireless backhaul network based on a PTP protocol. According to the method, based on the PTP protocol, timestamps for transmitting and receiving a PTP synchronous message Sync and a delay request message Delay_Req is counted by using an intermediate node, and local forwarding time of the synchronous message Sync and the delay request message Delay_Req and link delay of transmitting the same between nodes are detected and compensated based on a linear regression technology, and finally wireless link asymmetrical delay correction of the main and slave nodes is achieved, and time synchronization error compensation is completed. According to the method provided by the invention, message overhead is reduced by using additional time information such as header transmission compensation time of a PTP message, message transmitting and reaching time and time modification value without modifying an existing PTP protocol, requirements on real-time and high precision of time synchronization error compensation are met, existing time synchronization precision is improved and strong practicability is provided.

The invention relates to a PTP precise time protocol time service module in electric power time service and a realizing method thereof; the PTP precise time protocol time service module comprises a main control chip, a time stamp PHY chip, a JTAG debug chip, a transformer, a state indicator lamp, a clock, and an indication light; an ARM chip receives the time information of a main control unit through a RS232 interface, and resolves to obtain time second information; the main control unit sends 1PPS, the ARM chip writes the time second information into the time stamp PHY chip, and the local time source is synchronized; the clock respectively provides a running clock for the ARM chip and a RMII communication clock source for the time stamp PHY chip; the JTAG debug chip debugs program operations and sets breakpoints; real time analysis is carried out; a PC machine obtains the ARM chip output debug information; when the ARM runs a PTP protocol operation task, the time stamp PHY chip uses a transformer + RJ45 interface to send a protocol message to the outer side. The technical effect can reach the nanosecond level precision.

A synchronization module for providing synchronization messages to be sent with a time stamp in accordance with the PTP protocol of standard IEEE 1588 is provided. The synchronization module comprises a program module for generating a synchronization message to be sent and for providing the synchronization message with a first time stamp, and a hardware-implemented time stamp module which receives synchronization messages from the program module and forwards them in accordance with the PTP protocol. The time stamp module comprises a real time clock, a message detector for recognizing a synchronization message by its difference in relation to other messages and a message manipulator for overwriting the first time stamp in a synchronization message recognized by the message detector with a second time stamp actually retrieved from the real time clock.

The invention discloses a time synchronization method and device and a PTP system. When the time synchronization method is applied to transparent clock equipment, the method comprises the following steps: monitoring a signal pulse sent by main clock equipment in an out-of-band mode, and extracting the frequency and phase of the signal pulse to be respectively used as a main clock frequency and a main clock phase; inserting the main clock frequency and the main clock phase into a corresponding position of an extension field in an organization vendor information format in a common PTP signal message generated in advance, and then transmitting the modified PTP signal message to a PTP port; and receiving the modified PTP signal message transmitted by the PTP port, extracting the main clock frequency and the main clock phase carried in the modified PTP signal message, and modifying the local clock frequency and/or local clock phase according to the main clock frequency and the main clock phase. Through the adoption of the method disclosed by the embodiment of the invention, a PTP protocol is extended, so that the clock equipment synchronization result in the PTP system is more precise.

The invention discloses a time synchronization device and method based on a precise time protocol. The device comprises a local clock oscillation source, a PTP (Peering to Peering) hardware auxiliary module, a PTP protocol processing module and a time regulation module, wherein the local clock oscillation source is used for generating a local clock signal; the PTP hardware auxiliary module is used for capturing a PTP message input through an Ethernet physical layer chip, and recording a local time stamp of the local clock signal at the moment; the PTP protocol processing module is used for analyzing the PTP message and acquiring a main clock time stamp of a main clock signal; and the time regulation module is used for regulating the local clock signal according to the difference value of the local time stamp and the main clock time stamp so as to synchronize the local clock signal with the main clock signal. According to the device and the method, an IEEE1588 clock message signal is adopted as an input source, and the synchronous time precision between the local clock time and the PTP main clock time is not greater than 10 microseconds, so that the synchronization precision requirements of various application situations and various systems are met.

The invention discloses a synchronous correction method based on an IEEE1588 clock model, and belongs to the technical field of communication. The method comprises the following steps: (1) acquiring the moment point of the IEEE1588 clock model to obtain each timestamp; (2) acquiring the relation between the time of a server and the time of a client through the IEEE1588 clock model, and acquiring the relation among the timestamps in Sync message sending and receiving processes in combination with a PTP (Picture Transfer Protocol); (3) performing difference operation based on the relation among the timestamps; and (4) acquiring the asymmetrical offset of an nth exchange process according to a first-order difference value given in the step (3), moving an average filter through exponential weighting in order that value theta is close to zero, and finishing correction between the server and the client. According to the method, a conventional thought is jumped out, and compensation is performed once again on the basis of the IEEE1588 clock model, so that the problem of end-to-end time non-synchronization is solved, and end-to-end interaction time becomes symmetrical.

The invention provides an automobile sensor time synchronization method based on a PTP protocol as well as a system. Multiple CPU computing units are mutually connected by virtue of a switch, a localarea network is formed, a master clock and multiple slave clocks are defined, the master clock is utilized for periodically sending a message, so as to determine precise message transceiving times ofthe slave clocks and the master clock, thus clock skew and network delay are obtained through calculation, and a local clock of each CPU computing unit is corrected by virtue of the clock skew and thenetwork delay. By combining hardware and software, synchronization of an internal clock of network equipment with a master clock of a main control computer is realized, an application with synchronization build time of 10 microseconds is provided, compared with Ethernet delay time executing an NTP protocol, a timing synchronization index of the whole network is obviously improved, and requirementof automatic driving on clock synchronization can be met.

The invention discloses a base band unit and remote radio unit data service synchronization method, device and system. The method comprises the following steps of: acquiring frame header phase information of data service to be transmitted by a transmitting end and determining a reference moment according to the frame header phase information to obtain receiving end standard time; transmitting a PTP (Picture Transfer Protocol) message to a receiving end and receiving the PTP message transmitted from the receiving end, and adding a difference value of a receiving service frame header and the reference moment in the data service transmitted to the receiving end; adjusting the receiving end standard time according to the time for receiving and transmitting the PTP message by the receiving end and a time stamp carried in the PTP message; and calculating path time delay of data service according to the analyzed difference value of the transmitting service frame header and the reference moment and the difference value of the time for finishing adjustment of the receiving end standard time and the analyzed transmitting service frame header, and compensating according to the path time delay. According to the method, the device and the system, data service of a base band unit and a remote radio unit can be synchronized, and good performance of the system is guaranteed.

The invention discloses a digital relay protection device supporting a three-in-one network. The digital relay protection device comprises a multichannel Ethernet interface module supporting a three-in-one network interface; an Ethernet frame pretreatment IP (intellectual property) core module supporting SV sampling value, GOOSE, a station control layer and PTP (picture transfer protocol) message; a self-adaptive multichannel sampling value data synchronism module; and a data receiving and processing module for completing protection, measurement and control, metering, and joint locking functions of the relay protection device, and realizing the protection and automation functions of a smart substation. The digital relay protection device can be applied to the smart substation, and realizes the transceiving treatment of in-station data based on sampling value grouping or three-in-one network joint transmission, and provides a solution for realizing the function of the relay protection device of the smart substation under a uniform network frame; besides, the digital relay protection device can simplify an interface of the relay protection device and reduce the data processing ability, and improve the running stability and reliability of the relay protection device.

The invention discloses a clock synchronization method and a device of a communication network. The method comprises the steps of: a current clock node receives a notification message and other PTP (Precision Time Protocol) protocol messages sent by an upstream clock node; when judging that the current clock node needs to be synchronized with the upstream clock node, extracting a grandfather clock ID in the notification message; and when judging that the grandfather clock ID in the notification message is different from the own clock ID of the current clock node or judging that the grandfather clock ID in the notification message is different from the clock ID recorded by the current clock node, carrying out time synchronization operation according to time information of the other PTP protocol message and time information of the current clock node. The invention has the advantages that the occurrence of a clock loop is effectively prevented, normal synchronization between the clock nodes in the network is ensured, the own strategy is adjusted when the clock loop occurs on the upstream, the synchronization with a clock source with the loop is avoided, the clock deterioration is prevented, and the synchronization quality is improved.

The invention discloses a method of realizing PTP nanosecond precision based on a hardware time stamp. A PTP protocol stack module, a clock algorithm module, a network interface and a time stamp unit module are mainly included. The PTP protocol stack module has a main function of acquiring a time packet from a remote PTP server for mainly realizing a slave clock function in an IEEE1588-2008v2 protocol, and unicast and multicast modes are supported; the clock algorithm module is used for evaluating time and frequency errors according to the time stamp in the PTP protocol, the evaluated frequency error can be used for correcting frequency offset of the hardware, and the evaluated time error can be used for correcting a time stamp clock; the time stamp unit module is used for accurately measuring the packet in-out time and mainly comprises a packet analyzer, a time stamp clock, multiple temporary queues for storing the time stamp and the like; and a clock and frequency control unit module acquires the time stamp via the time stamp unit module.

The invention provides a method for processing a message and network element equipment. The method comprises the steps of assembling a precise time protocol (PTP) message, and inserting the PTP message into a reserved byte spent by an optical transmission unit (OTU) frame or mixing the PTP message into an Ethernet message to transmit. According to the method, interaction of the PTP protocol message can be achieved between network elements of a wavelength division network, so that the PTP protocol message can be transferred and analyzed among the network elements, so as to transfer the wavelength division network at a precise time.

Provided are a transparent clock passive port election method and device based on the PTP protocol. In the method, by extracting the TLV field of a received announce message, a first port of a network device acquires the clock identification information, forwarding times information and port identification information carried in the TLV field, and then compares the forwarding times information and clock identification information carried in the TLV field to the forwarding times information carried in the TLV field contained in a received announce message from a port by itself, and its own clock identification information, so as to select a port as a passive port. Therefore, by adding the comparison factors, such as clock identification information, forwarding times information and port identification information, in the TLV field of an announce message, a transparent clock is allowed to support the PTP protocol, thus avoiding a protocol storm formed by a PTP message in a complex topology network and a ring network constituted by the transparent clock to improve the stability of the network.

The invention discloses a system of synchronizing clocks of servers based on a PTP protocol, and relates to a server clock synchronization technology. The servers around the world, when being startedup, starts up the local clock by default, loads a PTP module drive after entering an operating system and obtains a PTP signal transmitted from a satellite navigation information receiving end throughaccessing a synchronous Ethernet switch; the servers around the world parse the PTP signal to obtain clock and time information, provides the clock information to system hardware and synchronizes thetime information to the operating system; and the servers realize high-precision clock time synchronization of multiple servers and reduce cross-server time communication delay through integral design of a network PHY chip, an IEEE1588 SMU chip and a network card chip supporting IEEE1588 synchronization. The system of synchronizing clocks of servers based on the PTP protocol can be deployed in each key application field conveniently and improves application transaction reliability greatly; and a method of synchronizing clocks of servers based on the PTP protocol is also provided.

The invention relates to an Ethernet MAC module realization device and an Ethernet MAC module realization method used for IEEE 1588v2 protocol. The Ethernet MAC module realization device comprises aMAC receiving module and a MAC transmitting module. The MAC receiving module is used for receiving of all Ethernet messages, and is realized on an FPGA or an ASIC. The MAC transmitting module is for the transmitting of all Ethernet messages, and is also used to return the transmitting time stamps of the Ethernet messages to a PTP protocol stack. The MAC transmitting module is formed by a softwareprogram and a hardware logic. The software program of the MAC transmitting module is installed on a CPU or DSP platform, and is used for PTP time stamp related auxiliary computation and MAC part control function. The hardware logic of the MAC transmitting module can be realized on the FPGA or the ASIC, and is used for PTP time stamp processing, time stamp related part real-time computation, and MAC layer protocol realization. Exchange between the MAC receiving module and the PTP protocol stack, the exchange between the MAC transmitting module and the PTP protocol stack, and the exchange between the software program and the hardware logic of the MAC transmitting module are reduced, and the mutual exchange is required to wait.

The invention discloses a method for realizing an IEEE1588 master clock. The method comprises the following steps: receiving ethernet messages, and identifying and classifying the ethernet messages; performing receiving timestamp inserting operation on message data needing to be inserted with timestamps; analyzing the messages of the message data after inserting the timestamps, and extracting a first parameter needed for generating reply messages; generating PTP (picture transfer protocol) protocol reply messages according to the first parameter; buffering the generated PTP protocol reply messages, buffering the received message data, and transmitting buffered ethernet messages under transmitting dispatching control; identifying and classifying the buffered ethernet messages to obtain classified message data; when in a two-step mode, generating two-step PTP protocol messages, and transmitting all the ethernet messages to a PHY (Physical Layer Protocol) transmitting interface; when in a one-step mode, transmitting the PTP protocol messages after treating and the ethernet messages which do not need treating to the PHY transmitting interface.

The invention discloses an SDH transmission method of IEC61588. S1: ethernet bit stream including a PTP protocol message is transmitted by a primary PTP master clock through the ethernet. S2: the ethernet bit stream of S1 is converted to E1 HDB3 bit stream by a protocol converter. S3: the E1 HDB3 bit stream of S2 is transmitted by the SDH internet step by step. S4: the E1 HDB3 bit stream of S3 isconverted to the ethernet bit stream by the protocol converter. S5: the PTP protocol message is obtained by a slave clock from the ethernet bit stream of S4, and time of the slave clock is adjusted according to a hardware time stamp of the PTP protocol message. The SDH transmission method of IEC61588 utilizes the SDH transmission to transmit clock signal so that cost is effectively saved, and precision of the PTP networking is high so that nanometer precision is achieved through precise compensation.

The invention provides a method and system for realizing PTP (Picture Transfer Protocol) synchronization through a 1588 protocol. The method comprises the following steps of: using a recursive algorithm to calculate an offset value in real time; and carrying out synchronization according to the offset value. With the adoption of the method and the system provided by the invention, the dependence of synchronization precision on message interaction frequency can be reduced.