Patents
Literature
Hiro is an intelligent assistant for R&D personnel, combined with Patent DNA, to facilitate innovative research.
Hiro

57 results about "International telecommunication" patented technology

The International Telecommunication Union (ITU) is an agency of the United Nations (UN) whose purpose is to coordinate telecommunication operations and services throughout the world. Originally founded in 1865, as the International Telegraph Union, the ITU is the oldest existing international organization.

Broadband MIMO radio frequency transceiving system for next-generation wireless communication network

ActiveCN101944924AAchieving Spectrum Utilization EfficiencyMeet the requirements of digital mobile communication system (4G)Diversity/multi-antenna systemsFrequency spectrumIntermediate frequency
The invention discloses a broadband MIMO radio frequency transceiving system for the next-generation wireless communication network. The system comprises a receiving module, a local oscillation module, a transmitting module, a power supply module and a control module. In the invention, the frequency utilization efficiency of over 10bit/Hz is realized through the adoption of a 100MHZ channel bandwidth and six-transmitting and six-receiving MIMO configuration. Site tests show that the system can support the data transmission rate of over 1Gbit/s and meets the requirements of International Telecommunications Union on the next-generation digital mobile communication system (4G). The system fully combines and takes full advantage of a superheterodyne architecture and a zero intermediate frequency architecture, adopts an asymmetric structure, adopts the zero intermediate frequency architecture in the transmitting module and adopts the superheterodyne architecture in the receiving module. The way reduces the complexity of circuits and the costs of the system while guaranteeing the performances of the system. The local oscillation module of the system adopts an innovative design, so that the cost of the system and the complexity of the circuits are reduced.
Owner:SOUTHEAST UNIV

Optical access passive network supportive of quantum communication

Disclosed is an optical access passive network supportive of quantum communication. The network is supportive of bidirectional data communication of a GPON (gigabit passive optical network) accordant with the ITU (International Telecommunication Union)-T G.984 standard or an EPON (Ethernet passive optical network) accordant with the IEEE802.3 (Institute of Electrical and Electronics Engineers) standard and quantum key distribution (QKD) of uplink direction. An improved optical network unit is adopted in the network to add a QKD emitter and an alternating time-division multiple-address access control module on a basis of an original GPON or EPON, an improved optical line terminal is adopted to add a QKD receiver and a clock extraction module on a basis of the original GPON or EPON, and an improved passive optical splitter is adopted and comprises two 1: N optical splitters and N Bragg gratings (N is the number of the optical network unit). The network integrally greatly avoids inferences, on quantum signals, of high-light signals to enable the QKD to be capable of coexisting with the GPON or EPON. The optical access passive network supportive of quantum communication can thoroughly improve potential security loopholes of common optical access networks and provides a feasible scheme for popularizing the quantum communication technology to a fiber to house (building) FTTx (fiber to the x) access network.
Owner:ZHEJIANG UNIV OF TECH

Method and system for locking transmission wavelengths for lasers in a dense wavelength division multiplexer

The method and system operate to calibrate a transmission laser of the dense wavelength division multiplexer (DWDM) and to lock the laser to a selected transmission wavelength. In one example, the transmission laser is a widely tunable laser (WTL) to be tuned to one of a set of International Telecommunications Union (ITU) transmission grid lines for transmission through an optic fiber. To lock the WTL to an ITU grid line, a portion of the output beam from the WTL is routed through the etalon to split the beam into a set of transmission lines for detection by a detector. Another portion of the beam is routed directly to another detector. A wavelength-locking controller compares signals from the two detectors and adjusts the temperature of the etalon to align the wavelength of one of the transmission lines of the etalon with the wavelength of the output beam, then controls the WTL in a feedback loop to lock the laser to the etalon line. The wavelength-locking controller thereafter monitors the temperature of the etalon and keeps the temperature constant to prevent any wavelength drift in the etalon. In one example, the etalon is a silicon etalon configured to have finesse of about 20 and to provide a free spectral range of about 8 GHz. With these parameters, the system is able to lock the wavelength of the WTL to within a precision of about 0.2 GHz.
Owner:SPECTRASENSORS INC

Detection method and detection system for audio frequency transmission characteristics of building intercom system

The invention relates to a detection method and a detection system for audio frequency transmission characteristics of a building intercom system. The detection method comprises the steps: a sound source portion generates specific voice signals, the specific voice signals taken as input voice signals are input into a detected access, the specific voice signals are transmitted in the detected access, and are output as detected output voice signals; the specific voice signals comprise a P.50 simulation voice signal or a P.501 human voice signal of the international telecommunication union-telecommunication standardization organization (ITU-T); the sound pressure related to the detected output voice signals are detected based on the detected output voice signals, and audio frequency characteristic parameter values are calculated in dependence on the detected sound pressure related to the detected output voice signals in order to determine audio frequency transmission characteristics of the detected access. By improving the measurement of sound sources, backboards and audio frequency distortion, the detection accuracy and the detection result precision of the audio frequency transmission characteristics of the simulation (bus-mode) building intercom system are improved, and the detection result is relatively close to the actual using effect.
Owner:THE THIRD RES INST OF MIN OF PUBLIC SECURITY

Method for performing interference analysis and avoidance on synchronous orbit satellite communication system

ActiveCN107809298AReduce the amount of online dataReduce the impact of communication qualityNetwork topologiesActive radio relay systemsCommunications systemSynchronous orbit
The invention relates to a method for performing interference analysis and avoidance on a synchronous orbit satellite communication system, characterized by including the following steps: 1) designinga recursive orbit for medium-earth and low-earth orbit satellites in a non-synchronous orbit satellite communication system to ensure that tracks of sub-satellite points of each satellite are periodically overlapped and cross over the equator at a plurality of fixed longitude points; 2) determining a range of the synchronous orbit satellite communication system that needs to perform interferenceanalysis according to relevant protection standards of the International Telecommunication Union; 3) performing interference analysis on the synchronous orbit satellite communication system, and setting corresponding interference protection belt zones for synchronous orbit satellites; and 4) enabling an earth station of the non-synchronous orbit satellite communication system to determine whetherthe medium-earth and low-earth orbit satellites need to take avoidance measures according to predicted system parameters and the running states of each medium-earth and low-earth orbit. The method disclosed by the invention can be widely applied in the field of interference analysis and avoidance of the synchronous orbit satellite communication system.
Owner:TSINGHUA UNIV

COTM (communication on the move) satellite communication dual polarization quadruple ridged horn array antenna

ActiveCN103390798AGood transceiver gainExcellent transceiver gainWaveguide hornsAntenna arraysRadarSide lobe
The invention relates to a COTM satellite communication dual polarization quadruple ridged horn array antenna which is characterized in that 192 quadruple ridged horns are arranged at equal intervals in a square regular array; an azimuth plane comprises 32 columns, and a pitch plane comprises 6 rows; metal compensation grid plates are arranged at openings of the 192 quadruple ridged horns; each metal compensation grid plate divides each quadruple ridged horn into four small equal radiation units, so that the space of the 768 small radiation units formed on an array plane is smaller than a wave length, and when constant-amplitude same-phase feeding occurs to the planes, grating lobes cannot appear in a visible space, and the technical index requirements of the International Telecommunication for access wide-angle sidelobe envelope can be met. According to the antenna system, all technical indexes are advanced, the work is stable and reliable, the insertion loss is low, noise is little, and the antenna is provided with an ultrathin low profile and particularly suitable for being taken as a COTM satellite communication antenna of a mini-automobile, and can be widely used in fields such as radars, communication, remote sensing, remote measuring and the like.
Owner:NANJING YOUQIAO ELECTRONICS TECH

V.8bis suppression method and apparatus for modem relay

The invented method involves one or more gateways sniffing the voice channel during the voice mode. If it is determined that V.8bis signals are being initiated, then the gateway breaks these exchanges by suppressing such signaling, thereby avoiding the above-described detrimental effects. Modem relay communications then are allowed to proceed. Briefly, the method and apparatus involve monitoring a call during a voice mode phase for an initiating signal representative of the defined signaling, the monitoring being performed by a local gateway and, if such an initiating signal is detected during the monitoring, then suppressing such detected signaling in such manner that the signaling does not reach the remote gateway. Preferably, the monitoring is for an initiating signal characterized by a dual tone of defined frequency and duration of approximately 1375 Hz and 2002 Hz for a duration of approximately 400 ms or 285 ms, in agreement with the ITU-T Recommendation V.8bis (standard) adopted by the International Telecommunication Union. Monitoring is continued at least until an answer back from an answering station is received by the gateway. When the suppression succeeds and the remote (non-initiating gateway that may be awaiting such an initiating signal halts any further V.8bis transaction attempts, the local gateway initiates a modem relay session of operation with the remote gateway.
Owner:CISCO TECH INC

C+L band multi-wavelength optical fiber laser with one-way feedback

The invention relates to the field of optical fiber lasers, in particular to a C+L band multi-wavelength optical fiber laser with one-way feedback, which comprises an optical fiber annular chamber, a high birefringence optical fiber annular mirror and an one-way feedback mirror, wherein the optical fiber annular chamber comprises a first semiconductor optical amplifier, a second semiconductor optical amplifier, an optical fiber annular chamber coupler, a first optical isolator, a second optical isolator, a first optical fiber polarization controller, a second optical fiber polarization controller and a circulator; the high birefringence optical fiber annular mirror comprises a 3dB coupler, a high birefringence optical fiber and a third optical fiber polarization controller; and the one-way feedback mirror is formed by sequentially connecting a fourth optical fiber polarization controller, an output coupler and a Faraday feedback mirror. The optical fiber laser of the invention can obtain multi-wavelength stable output in the C+L band at room temperature, the wavelength interval meets the WDM ITU (Wavelength Division Multiplex International Telecommunication Union) standard of 100GHz and can be integrally adjusted continuously in the range of 50GHZ, the line width of the output wavelength of the laser is less than 0.1nm, the output power of each channel is uniform, the power difference between every two wavelengths is less than 6dB, and the signal-to-noise ratio is greater than 25dB.
Owner:TIANJIN UNIV

Expansion processing method under international telecommunication union telecommunication standardization sector (ITU-T) G.8032/Y.1344 multi-point fault

ActiveCN102510353AAvoid issues with incorrect transfers between ring nodesImprove reliabilityData switching networksRing networkComputer science
The invention discloses an expansion processing method under international telecommunication union telecommunication standardization sector (ITU-T) G.8032/Y.1344 multi-point fault. The method comprises the following steps of: defining a protocol expansion frame with a specific target address, and forwarding the protocol expansion frame to a port of a central processing unit (CPU) under the condition that a ring port is blocked; sending a protocol frame through a ring network node, sending an expansion frame and setting a forwarding hop initial value; after the ring network node receives the expansion frame, forwarding the expansion frame which is sent by other nodes through another ring port after forwarding hops in the expansion frame gradually increase or decrease, wherein the forwarding hops of the expansion frame do not exceed a forwarding hop threshold value; and processing the expansion frame according to a flow which is defined by a protocol. The method has the advantages that: on the premise that a protocol state machine is not changed and the convergence speed of a ring network is not influenced, the problem that a loop can be blocked after recovery of breaking points in ITU-T G.8032/Y.1344 is thoroughly solved; and the method is applicable to the occasions with a high reliability requirement for data communication in a severe industrial environment.
Owner:BEIJING INHAND NETWORKS TECH

An ultra-narrow-band comb filter

InactiveCN102289038AWith polarization splitting functionWith ultra-narrowband multi-channel filtering functionCoupling light guidesBeam splittingCenter frequency
The invention relates to an ultra-narrow band comb type filter, which belongs to a photoelectronic device and solves the problems that the existing comb type filter does not have the polarization beam splitting function, and the single channel has wide band width. The ultra-narrow band comb type filter consists of a photoisolator, a polarization beam splitter, a first multi-channel filter and a second multi-channel filter, wherein an incident light beam enters the polarization beam splitter through the photoisolator and is divided into a path of S light and a path of P light, the S light and the P light respectively enter the first multi-channel filter and the second multi-channel filter to be filtered, the center frequencies of the first multi-channel filter and the second multi-channel filter are staggered and conform to the international telecommunication union regulations, the output channel intervals are respectively 50GHz, 100GHz or 200GHz, and the output of the first multi-channel filter and the output of the second multi-channel filter are the output of the ultra-narrow band comb type filter. The ultra-narrow band comb type filter simultaneously has the polarization beam splitting function of the polarization beam splitter and the ultra-narrow band multi-channel filtering function of the multi-channel filters, adopted optical devices are few, the structure is simple, the output signal line width is narrow, the output channel intervals can select 50GHz, 100GHz or 200GHz, the center frequency conforms to the international telecommunication union regulations, and the ultra-narrow band comb type filter is suitable for being used in dense wave multiplexer systems with different requirements.
Owner:HUAZHONG UNIV OF SCI & TECH
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products