72results about How to "Reduce latency jitter" patented technology

This invention provides one Ethernet exchange buffer and transfer method, which comprises the following steps: receiving data pack from input end; cutting data pack into certain length signal element by cut unit; storing signal element into central memory unit; adopting equal time lag transfer through end and line transfer unit and turning output end by each time lag; adopting run require or transfer of different lines at one output end; after getting transfer, reading signal element from common central buffer unit and the data pack resets the signal element sent to the linkage. This invention also provides one Ethernet exchange buffer and transfer device.

The invention discloses a vehicle-mounted delay tolerant network routing method based on node forwarding capability estimation. The vehicle-mounted delay tolerant network routing method comprises: a step 1: judging whether a destination node exists within the communication range of a source node, and if so, directly sending information to the destination node; otherwise, executing a step 2; step 2: estimating effective connection times Ta of the source node with all neighbor nodes within the communication range thereof; a step 3: selecting neighbor nodes with Ta values exceeding a threshold as candidate relay nodes; a step 4: creating a candidate relay node throughput function, and calculating average forwarding capability values of the candidate relay nodes; a step 5: using the candidate relay node having the maximum average forwarding capability value as a next hop relay node; a step 6: selecting the relay node through the source node, sending the information to the relay node, and using the relay node as a new source node; and a step 7: circularly executing the step 1 to the step 6 until streaming media information is successfully transmitted to the destination node. The vehicle-mounted delay tolerant network routing method disclosed by the invention is high in data packet delivery ratio, low in transmission delay and low in delay jitter.

The invention discloses a service flow shaping method and a service flow shaping device for a cascaded port of an avionics full duplex switched Ethernet (AFDX) switch. The main problems of relatively stronger switching delay jitter of packets and incapability of transmitting high-priority packets on time in the prior art are solved, and a system can be conveniently cascaded. The method comprises the following steps of: (1) extracting packet scheduling information; (2) extracting the information of a time registry; (3) receiving and scheduling the packets; (4) selecting and sequencing the packets; (5) updating time tags; (6) transmitting and scheduling the packets; and (7) updating a time registry. The device comprises an input caching module, a receiving scheduling module, a time registry module, a packet information storage area module, a time tag module, an output queue module, a transmission scheduling module and an output caching module. The method and the device have the advantages that: the determinacy of the delay jitter of the packets can be ensured; the forwarding delay jitter of the packets can be effectively reduced; the high-priority packets can be transmitted on time; and the method and the device are applied to the traffic shaping of the AFDX switch.

The invention discloses a retransmission method and a retransmission system for a radio link control (RLC) layer. The method comprises that: a transmitter transmits RLC data by a hybrid automatic repeat request (HARQ) entity, and a receiver fails to receive the RLC data and informs the transmitter of a data transmission failure of the HARQ entity; and the HARQ entity of the transmitter reports the data transmission failure to an RLC entity of the transmitter, and the RLC entity of the transmitter retransmits the RLC data failed to be transmitted by the HARQ entity of the transmitter. By the method and the system, interaction for the HARQ transmission failure is realized between the HARQ entity and RLC entity of the transmitter, so the message retransmission time of the RLC layer is effectively shortened, time delays of data services in high speed packet access (HSPA), evolved HSPA (HSPA+) and long term evolution (LTE) networks are effectively shortened, the fast message retransmission function of the RLC layer is realized, delay jitter caused by the wireless packet loss is reduced, and simultaneously, service downloading and uploading throughput is improved.

A delay unit 103 adds holding time that has been set by a holding time setting unit 104 to a received data. The holding time is computed based on delay time of received data and the minimum delay time of data received up to a certain point for the purpose of reducing a total delay time. The delay time is estimated in a delay time estimating unit 106 from the difference between a reception time of a packet counted based on an internal clock generator 107 and a time designated by a time stamp in the received packet.

The invention discloses an Ethernet flow control device and method based on microwave transmission. The Ethernet flow control method includes the steps: detecting adaptive coded modulation (ACM) information of wireless links in real time, and generating rate-limiting frames and sending the rate-limiting frames to a data sending end when the Ethernet bandwidth is changed due to changes of ACM; and monitoring changes of a buffering water level in real time while the ACM information is detected, generating flow-control frames and sending the flow-control frames to the data sending end when the buffering water level rises to a highest threshold, and generating flow-control removing frames and sending the flow-control removing frames to the data sending end when the buffering water level falls to a lowest threshold. The Ethernet flow control device comprises an ACM real-time detecting module, a rate-limiting frame generating module, a sending and buffering real-time monitoring module, a flow-control frame generating module and a scheduling module. According to the Ethernet flow control device and method, a sending rate is adaptively adjusted through combination of flow control and exit rate limiting, and time delay of high priority services can be guaranteed.

The invention discloses a reshaping scheduling method in an aviation electronic system network. The method comprises the steps of setting an adjusting period in a system, resetting a vector table of historical information, and carrying out static priority distribution on all virtual links in a network; updating the vector table of the historical information when a data base is arrived; updating a transmitting sequence of all virtual links in a next adjusting period according to the statistic priority and the historical information recorded in the vector table of the historical information, after the adjusting period is completed; transmitting the scheduling times according to the transmitting sequence recorded in the transmitting sequence table when a database reaches at the transmitting time. According to the method provided by the invention, the transmitting sequence of all virtual links in the aviation electronic system can be adjusted by adopting a dynamic and static combined way, so as to reduce the delay variation of ordinary links.

The invention discloses a satellite network snapshot routing optimization method. The method comprises the steps that S1 snapshots are generated according to the satellite network topology; S2 according to the preset optimization expectation, the preset average service duration and the duration of a single snapshot, the final value of the number of superimposed snapshots is determined; and S3 snapshots determined by the final value are superimposed to acquire a target topology; the link weight of the target topology is determined; a route is calculated through the target topology. According to the invention, link stability in an optimization interval can be effectively ensured; transmission stability in the optimization interval is ensured; route switching is reduced; and delay jitter, service interruption and the like caused by route switching is reduced.

The invention discloses a synchronization method for Non-IP data transmission. The synchronization method comprises: receives, by a receiver, stream information and time information of a voice streamin a real-time transport protocol RTP packet from a sender; storing the received information and recording a system frame number SFNi at the current moment by the receiver to obtain a mapping relationship between the time information and the system frame number SFNi; and when a receiver receives a voice packet transmitted in an No-IP mode from a sender, obtaining a system frame number SFNj at thecurrent moment, calculating a relative time difference between SFNi and SFNj, calculating a relative timestamp of the voice packet according to the time information, and recovering a corresponding RTPtimestamp. The invention further provides corresponding equipment. By applying the technical scheme disclosed by the invention, the receiver can recover the absolute time and the relative time of thevoice packet in a multi-stream concurrent scene, and multi-stream synchronization is realized, so that synchronous playing of videos and audios is recovered.

The invention discloses a multi-level subqueue layered dispatching method for messages in the communication network of a transformer substation. The method comprises the steps of 1, receiving the messages by a receiver; 2, analyzing the messages by a data analysis module and a label analysis module to obtain information, such as message contents, labels, destination addresses, VLAN (virtual local area network) values and message types; 3, testing whether the time to live TTL is greater than 0 or not, if the TTL is equal to 0, discarding the messages and finishing the process, and if the TTL is greater than 0, continuing the next step; 4, searching an MAC table according to the destination addresses and the VLAN values of the messages, and sending the messages to the corresponding ports; 5, identifying the message types according to the information of a message label tagged value field, and mapping different messages to a label-based multi-level subqueue for queuing up to be sent; 6, when one message reaches the head end of the queue, adding a new label to the current message by a label packaging module, packaging the current message by a data packaging module, and sending the current message to the next switch by a sender for finishing the forwarding process. The problems of delay variation, transmission delay and the like in message switching is well solved, and the real-time reliability of information transmission of the transformer substation is improved.

Disclosed herein is a terminal device including a photodetector, amplitude detecting circuit, light source, drive circuit, and control circuit. The photodetector receives a first optical signal. The amplitude detecting circuit detects the amplitude of an output from the photodetector. The drive circuit supplies a drive current to the light source so that the light source outputs a second optical signal. The control circuit decreases and increases the drive current according to an increase and decrease in the amplitude detected by the amplitude detecting circuit, respectively. In the case that this terminal device is used with another terminal device to construct a network, the dynamic range of the other terminal device can be reduced. Accordingly, the use of this terminal device can improve the extensibility of the network.

The invention controls the up going link and the down going link respectively. The invention is divided into two portions: the up going link control and the down going link control. Both the up going link control and the down going link control include three parts: data reception transmission, data speed control, and data transmission. The invention possesses following advantages: using software to implement data transmission so as to spare dedicated Ethernet data interchange chip (EDIC), and save cost; under condition of less using CPU to accomplish forwarding data in high speed of reaching highest 50Mbps possibly; implementing limited speed, which is unable to be realized by EDIC, with granularity being as 1Kbps; speed control mode with small granularity guarantees stability of data transmission and lesser wobble of time delay.

The invention discloses a priority scheduling method and system for solid state disks. The method includes the steps of by distributing different requests to queues with different priorities, judging whether or not the processing requests finished by current processing queues meet the demands of preset processing capacity values; if yes, conducting circular process on all queues according to the descending order of the priorities. Under different scenes and conditions, the priority of each queue is adjusted and the priority of a most frequent request is adjusted to rank the highest so that delay vibration of users' frequent requests can be decreased; additionally, each priority is assigned with a preset processing capacity value, and therefore requests in the queues with low priorities cannot be delayed for a long time and remain unprocessed. Therefore, the priority scheduling method and system for the solid state disks can preferentially process frequent requests of users according to the preset queue priorities and the processing capability values, reduce delay vibration of the frequent requests, and the requests or operations with low priorities can not be delayed for a long time and remain unprocessed.

The invention discloses a delay line structure and a delay jitter correction method thereof. The delay line structure comprises N delay units and N selectors. The output end of the N-1th delay unit isconnected to the first input end of the N-1th selector and the input end of the Nth delay unit, the N-1th selector inputs the N-1th selection signal, and the N-1th selector outputs the N1th selectionsignal; the output end of the Nth time delay unit is connected to the first input end of the Nth selector, the output end of the Nth selector is connected to the second input end of the N1th selector, and the Nth selector inputs an Nth selection signal. The time delay units and the selectors are stacked forwards according to the rule until the input ends of the first time delay units are connected with input signals and the output ends of the first selectors are connected with output signals. According to the structure, delay control can be carried out on the clock at the sending end or the receiving end to meet the requirement of receiving timing, and the jitter of the delay of the delay line can be reduced.

The invention provides a fog computing Internet of Things networking method based on time delay perception. According to the time delay characteristics of the periodic service, the enhanced mobile broadband service and the non-periodic key service in the industrial Internet of Things scene, a fog computing access point (Fog Access Point, F-AP) can flexibly adopt semi-static scheduling, preemptivescheduling and dynamic scheduling. According to the invention, the storage, processing and forwarding capabilities of the F-AP are fully utilized, a queue and a time perception scheduling table are created for each service data packet, aperiodic key services requiring ultralow time delay are forwarded preferentially and can be directly forwarded to an edge server for service processing, and meanwhile strict low-time-delay jitter of periodic services can be guaranteed based on scheduling of time perception. The method can be applied to the scene of coexistence of various time delay demand differentiated services in the Internet of Things, and the time delay and jitter performance of the network are improved.

The invention discloses a light-operated semiconductor switch. A shielding ground electrode, a chip semiconductor laser, a laser beam splitting coupler, a large-area semiconductor unit and a shieldinghigh-voltage electrode are sequentially arranged in the light-operated semiconductor switch from top to bottom. An electricity taking module or a boosting module is connected in a gap between the chip semiconductor laser and the laser beam splitting coupler; the side face of the light-operated semiconductor switch is wrapped with an insulating packaging shell, and the insulating packaging shell and the shielding electrode jointly form a light-operated semiconductor switch packaging shell. A power supply and trigger signal interface of the light-operated semiconductor switch extends out of thelight-operated semiconductor switch packaging shell. According to the invention, the light-operated semiconductor switch can be used for various occasions such as a high-power pulse power supply, a compact high-power pulse assembly, small-size high-energy pulse triggering and the like, and has the advantages of high power capacity, high reliability, long service life, small size and the like.