36results about How to "Highly reliable communication" patented technology

A system for transmitting data through a string of downhole components. In one aspect, the system includes first and second magnetically conductive, electrically insulating elements at both ends of the component. Each element includes a first U-shaped trough with a bottom, first and second sides and an opening between the two sides. Electrically conducting coils are located in each trough. An electrical conductor connects the coils in each component. In operation, a varying current applied to a first coil in one component generates a varying magnetic field in the first magnetically conductive, electrically insulating element, which varying magnetic field is conducted to and thereby produces a varying magnetic field in the second magnetically conductive, electrically insulating element of a connected component, which magnetic field thereby generates a varying electrical current in the second coil in the connected component.

A system for transmitting data through a string of downhole components. In one aspect, the system includes first and second magnetically conductive, electrically insulating elements at both ends of the component. Each element includes a first U-shaped trough with a bottom, first and second sides and an opening between the two sides. Electrically conducting coils are located in each trough. An electrical conductor connects the coils in each component. In operation, a varying current applied to a first coil in one component generates a varying magnetic field in the first magnetically conductive, electrically insulating element, which varying magnetic field is conducted to and thereby produces a varying magnetic field in the second magnetically conductive, electrically insulating element of a connected component, which magnetic field thereby generates a varying electrical current in the second coil in the connected component.

A hybrid wireless optical and radio frequency (RF) communication link utilizes parallel free-space optical and RF paths for transmitting data and control and status information. The optical link provides the primary path for the data, and the RF link provides a concurrent or backup path for the network data, as well as a reliable and primary path for the control and status information. When atmospheric conditions degrade the optical link to the point at which optical data transmission fails, the hybrid communication link switches to the RF link to maintain availability of data communications. The switch may occur automatically, based on an assessment of the quality of the optical signal communicated through the optical path.

In a transmitter (2001), when generating a transmission frame having no limitation to a window size, a batch-transmission-end flag generating circuit (2004) and a sequence number generating circuit (2005) respectively adds a batch-transmission-end flag and a sequence number to the transmission frame. In a receiver, if an omission of a sequence number is detected as a result of analyzing sequence numbers of frames having received from the transmitter (2001), retransmission request is made when receiving a frame whose batch-transmission-end flag indicates the end. In this way, retransmission is possible in data transmission using UI frames, and the communication efficiency can be improved.

A first frequency synchronization unit (103) corresponds to the frequency synchronization apparatus of the present invention. A higher apparatus that is, for example, a wireless receiver supplies a reception signal to the first frequency synchronization unit (103) via an A / D converter (101) and an orthogonal detector (102). A synchronization symbol that includes a predetermined waveform at least twice is incorporated into the reception signal. A correlation estimator (104) generates a reference signal expressing the same waveform as the synchronization symbol, and successively finds correlation vectors between the reception signal and the reference signal. A first signal error detector (106) finds a frequency error based on an average phase difference of predetermined correlation vectors, and finds an absolute phase error based on transition of absolute phase of predetermined correlation vectors. A first frequency corrector (108) simultaneously gives the reception signal a frequency shift and phase rotation that cancel the errors.

It is possible to increase the communication system transmission capacity flexibly and at low cost in accordance with a communication system traffic amount. A terminal connected to a plurality of networks distributes a plurality of frame segments generated by dividing a single frame to the plurality of networks connected to the local terminal transmits them. Further, the terminal reconstructs the original frame from the plurality of frame segments generated by dividing the single frame. It should be noted that each of the frame segments contains division configuration information indicating how the frame has been divided (the number of divisions and the order of the frame segments) and also contains information required for performing MAC address learning for determining the path to the destination terminal.

Nodes 901 and 902 have the same address. Upon reception of a broadcast packet whose TTL value is not zero from a ringlet 910a, a forwarding circuit 51 of each of the nodes 901 and 902 copies and transits the packet, and an address table 60 of each node learns the address based on the copied broadcast packet. Upon reception of a unicast packet whose destination is an address common to the two nodes from the ringlet 910a, the forwarding circuit 51 of one node 901 copies and transits the packet, while the forwarding circuit 51 of the other node 902 strips the packet, and each address tables learns the address. A filter circuit of the node 902 prohibits the passage of the packet from the ringlet 910a.

The embodiment of the invention discloses a game-theory-based spectrum allocation method, communication equipment and a game-theory-based spectrum allocation system. The method mainly comprises that: a first user in a cognitive radio cell performs probability calculation on spectrum resources by utilizing a Bernoulli test, and judges whether a communication channel in the spectrum resources is occupied by the first user or not; if the communication channel is occupied by the first user, the first user calculates interference values Io generated on all available communication channels by the first user; after receiving the interference values Io, a receiver of a second user in the cognitive radio cell calculates interference values Id of users except the second user for the second user, and calculates a utility function U1 on each channel in the spectrum resources; and the second user extracts a communication channel corresponding to a value of the utility function U1 according to the value of the utility function U1 as the communication channel of the second user. The embodiment of the invention reduces electromagnetic interference among user equipment, and more effectively utilizes the spectrum resources.

Some semiconductor lasers have an initial failure mode that is advanced as the amount of optical power therein, namely, the amount of optical output observed from the outside increases in almost independent of the temperature. The initial failure mode that is advanced as the amount of optical output increases is not sufficiently screened, so that the initial failure rate is somewhat higher than that of the semiconductor laser having the conventional active layer material. It is effective to introduce a test with large optical output at lower temperature than average operating temperature such as room temperature, during the manufacturing process. This helps to eliminate elements having the initial failure mode that is advanced as the amount optical output increases, thereby to extend the expected life of the laser diodes.

among the plurality of IDT electrodes having serially divided type structures, when designating any three continuously and sequentially arranged IDT electrodes as first, second, and third IDT electrodes in the order of arrangement, electrode fingers are arranged so that a first electrode finger pitch P1 at the boundary between the first IDT electrode and the second IDT electrode in the first region and a second electrode finger pitch P2 at the boundary between the second IDT electrode and the third IDT electrode in the first region are equal, the first and second electrode finger pitches P1 and P2 are the smallest among electrode finger pitches of IDT electrodes in the first region, and each of the IDT electrodes has a third electrode finger pitch P3 larger than the first and second electrode finger pitches P1 and P2 in the first region.

In a surface acoustic wave element 10, in which IDT electrodes 31 and 32, a grounding electrode 37, etc. are formed one main surface of a piezoelectric substrate 20, resistors 40 made of a semiconductor are provided to connection electrodes 38 that interconnect the respective electrodes. By forcing the charges generated in the IDT electrodes to move via the resistors 40, it is possible to provide a compact, highly reliable surface acoustic wave apparatus capable of preventing an electrostatic discharge damage in the IDT electrodes.

A serial communication circuit includes a receiving unit configured to serially receive input data including a command and a synchronization identification code that is different from the command and a determining unit configured to receive the synchronization identification code from the receiving unit and when the synchronization identification code coincides with a slave selection value, to instruct a start of response processing based on the command.

A first clock signal of frequency F is used to couple data to an off-chip driver (OCD) using a master / slave flip flop (FF), wherein the master latch is clocked with the first clock signal and the slave latch is clocked with the complement of the first clock signal. A second clock signal of frequency F / 2 is generated from the first clock signal. The second clock signal is shifted a time equal to substantially one-half the cycle of the first clock signal. In one embodiment, the second clock is shifted using a delay line circuit. In another embodiment, the second clock is shifted using a master / slave FF, wherein the master latch is clocked with the complement of the first clock signal and the slave latch is clocked with the first clock signal. The logic state transitions of the data between edges of the propagating clock thereby reducing coupling to the clock transitions and thus reducing edge jitter.

Among the plurality of IDT electrodes having serially divided type structures, when designating any three continuously and sequentially arranged IDT electrodes as first, second, and third IDT electrodes in the order of arrangement, electrode fingers are arranged so that a first electrode finger pitch P1 at the boundary between the first IDT electrode and the second IDT electrode in the first region and a second electrode finger pitch P2 at the boundary between the second IDT electrode and the third IDT electrode in the first region are equal, the first and second electrode finger pitches P1 and P2 are the smallest among electrode finger pitches of IDT electrodes in the first region, and each of the IDT electrodes has a third electrode finger pitch P3 larger than the first and second electrode finger pitches P1 and P2 in the first region.

A highly reliable communication system is provided, for example. A communication system includes a communication terminal device, and a plurality of base stations configured to perform radio communication with the communication terminal device. The plurality of base stations include a master base station and a secondary base station configuring dual connectivity with respect to the communication terminal device. When failure occurs in a secondary cell group (SCG) used for communication between the communication terminal device and the secondary base station, the master base station acquires latest SCG configuration.

Nodes 901 and 902 have the same address. Upon reception of a broadcast packet whose TTL value is not zero from a ringlet 910a, a forwarding circuit 51 of each of the nodes 901 and 902 copies and transits the packet, and an address table 60 of each node learns the address based on the copied broadcast packet. Upon reception of a unicast packet whose destination is an address common to the two nodes from the ringlet 910a, the forwarding circuit 51 of one node 901 copies and transits the packet, while the forwarding circuit 51 of the other node 902 strips the packet, and each address tables learns the address. A filter circuit of the node 902 prohibits the passage of the packet from the ringlet 910a.

A highly reliable display apparatus, a highly reliable communication system, and a highly reliable communication method capable of performing delivery of high capacity information surely are provided. A display apparatus and an input and output terminal respectively include a light-receiving-emitting section capable of displaying moving pictures and receiving light. The input and output terminal sequentially displays each symbol composing a two-dimensional dynamic code on the light-receiving-emitting section. The display apparatus reads each symbol by the light-receiving-emitting section, acquires symbol-transmission-receiving-status information based on the read symbol, determines display conditions based on the symbol-transmission-receiving-status information, and then displays each symbol of the two-dimensional dynamic code based on the display conditions. By displaying in the aspect, in which the light-receiving-emitting section of the input and output terminal, the receiver can surely reads, contents data can be surely transmitted and received between the display apparatus and the input and output terminal.

Provided are a method for accessing a channel in an unlicensed band and a device using same method. The method is configured such that a wireless device transmits data units, receives feedback information about the data units, and adjusts a contention window size used in a determination of whether there is an access to the channel in the unlicensed band on the basis of the feedback information. The wireless device can adjust the contention window size by using feedback information about, from among the data units, data units which at least partially overlap in reference duration.

A communication system includes a first communication device and a second communication device that performs power line communication with the first communication device via an electric power line, wherein the first communication device transmits an initial packet signal added with an error detection code in each zero crossing period including zero crossing timing while changing transmission timing within the zero crossing period. The second communication device specifies optimum communication timing out of a plurality of pieces of transmission timing within the zero crossing periods based on a result of error detection on each initial packet signal, and transmits an ACK signal including timing information on the optimum communication timing. Then, the first communication device transmits a data packet signal in the optimum communication timing within the zero crossing period, which is specified based on the timing information.

A micro-resonator of a single structure which outputs signals of two resonance frequencies of mutually opposite phases and in which different resonance frequencies are adjusted independently is provided. The micro-resonator includes: an oscillation portion 6 sustained with a gap by support portions 8 [8A, 8B] and an input electrode 3 and an output electrode 4 that become lower electrodes facing the oscillation portion 6 across the gap, in which the input electrode 3 and the output electrode 4 are disposed to face each other along a line intersecting the oscillation portion 6, the oscillation portion 6 generates torsional oscillation and flexural oscillation, and output signals of two resonance frequencies close to each other based on different resonance modes have mutually different phases by 180°.

In a transmitter (2001), when generating a transmission frame having no limitation to a window size, a batch-transmission-end flag generating circuit (2004) and a sequence number generating circuit (2005) respectively adds a batch-transmission-end flag and a sequence number to the transmission frame. In a receiver, if an omission of a sequence number is detected as a result of analyzing sequence numbers of frames having received from the transmitter (2001), retransmission request is made when receiving a frame whose batch-transmission-end flag indicates the end. In this way, retransmission is possible in data transmission using UI frames, and the communication efficiency can be improved.

A communication system includes a first communication device and a second communication device that performs power line communication with the first communication device via an electric power line, wherein the first communication device transmits an initial packet signal added with an error detection code in each zero crossing period including zero crossing timing while changing transmission timing within the zero crossing period. The second communication device specifies optimum communication timing out of a plurality of pieces of transmission timing within the zero crossing periods based on a result of error detection on each initial packet signal, and transmits an ACK signal including timing information on the optimum communication timing. Then, the first communication device transmits a data packet signal in the optimum communication timing within the zero crossing period, which is specified based on the timing information.

A communication system includes a first communication device and a second communication device that performs power line communication with the first communication device via an electric power line, wherein the first communication device transmits a plurality of times an initial packet signal added with an error detection code in each of reference timing at regular intervals in the vicinity of zero crossing timing. The second communication device determines whether a reception state is good or poor based on a result of the error detection on each of the received initial packet signals, and when the reception state is poor, the second communication device transmits an ACK signal in timing shifted by micro time from the reference timing after receiving the initial packet signal. Then, the first communication device transmits a data packet signal in timing at the regular interval after the timing of receiving the ACK signal.

An electromagnetic wave propagation device includes multiple planar propagation media each formed by laminating at least one planar conductor and at least one planar dielectric, multiple transceivers for transmitting and receiving information among electronic apparatuses, and a first interface for transmitting and receiving the electromagnetic wave between the transceivers and the planar propagation media. Planar dielectric spacers are provided for isolating the multiple planar propagation media from one another. The planar propagation medium is disposed to have an overlapped part with at least the other of the planar propagation media so that an obverse face of the medium and a reverse face of the other medium are at least partially overlapped with each other. The planar conductor is provided with an electromagnetic wave linking unit at the overlapped part that transmits and receives the electromagnetic wave between the planar propagation media.