95 results about "Quiet period" patented technology

Provided is a detector system for detecting a plurality of items each having at least one RFID tag attached thereto. The detector system may include a presence detector and / or a message detector. The presence detector may include a signal reader which receives modulated carrier frequencies from the RFID tags during a predetermined response time period for comparison to a reference level. The signal reader may be configured as a power integrator or a constellation discriminator. The power integrator sums the power contained in signals transmitted by the RFID tags by integration for comparison to an environmental noise level measurement taken during a quiet period. For the constellation discriminator, bits contained in the modulating message are compared to the bit pattern of a predetermined reference constellation. The detector system may be configured as a 3-state detector which combines the presence detector with a message detector that indicates the identification code of the RFID tags.

Provided is a detector system for detecting a plurality of items each having at least one RFID tag attached thereto. The detector system may include a presence detector and / or a message detector. The presence detector may include a signal reader which receives modulated carrier frequencies from the RFID tags during a predetermined response time period for comparison to a reference level. The signal reader may be configured as a power integrator or a constellation discriminator. The power integrator sums the power contained in signals transmitted by the RFID tags by integration for comparison to an environmental noise level measurement taken during a quiet period. For the constellation discriminator, bits contained in the modulating message are compared to the bit pattern of a predetermined reference constellation. The detector system may be configured as a 3-state detector which combines the presence detector with a message detector that indicates the identification code of the RFID tags.

Simultaneous transmission of voice and data over the voice channel of a wireless communications network, such as a “cell phone” network, is reconfigurable on the fly among multiple operating modes, including a lull detection mode in which data is transferred during a lull or quiet period in the voice content. Additionally, control signaling in the voice channel, rather than over a separate control or “overhead” channel is employed to support SVD. The described system operates transparently over any wireless telecommunications system.

A method and apparatus of coordinating Time Division Multiple Access operation of wireless communication devices is disclosed. The method comprises an access point announcing a Quiet Period to one or more clients of the access point and transmitting as part of Target Beacons and probe responses an indication to the one or more clients that the access point will be absent from the communication channel for a period of time. The method also comprises the one or more clients establishing a connection with the access point after the Quiet Period when the access point is present on the communication channel on the basis of the indication.

A novel media access control (MAC) mechanism utilizing synchronization signaling that enables nodes from different networks having different technologies and protocols to coexistence using the same shared media. The present invention is suitable for use with a wide range of different types of network and technologies and is particularly useful in providing coexistence capabilities to powerline based data communication systems. Specific time slots are assigned for the transmission of a frame occupation signal to indicate to all nodes that the channel is occupied. A synchronization signal is randomly transmitted during a preassigned time slot within the frame to provide accurate timing for the frame occupation signal. During times that a node does not transmit the synchronization signal, it listens to the channel. A timing signal is derived from the synchronization signals received from other nodes during this quiet period wherein the node is in a listening mode. The node then adjusts its internal clock in accordance with the derived timing signal.

One or more techniques are provided for gating the acquisition or selection of image data based upon the respiration of a patient. The technique provides for the acquisition of respiratory motion data from the image system or from one or more sensor-based motion determination systems. Various attributes of respiratory motion may be derived from the respiratory motion data and motion thresholds determined from the attributes. Based upon the respiratory motion of the patient and the determined thresholds, image data may be acquired or selected which corresponds to one or more breath-holds by the patient or low respiratory motion quiet periods within the breath-holds. The technique may be implemented in a fully automated or operator assisted or supervised manner.

A method of radar detection in a channel for radio local area networks operating in a regulatory band. First, a quiet time and quiet period are set, in which the ratio of the quiet time to the quiet period equals 1:4. The channel is quieted for the quiet time periodically at a rate dictated by the quiet period in order to be tested for radar. During each quiet time, a received power is measured to determine whether it exceeds a predetermined threshold. Radar presence is declared when the received power on that channel exceeds the predetermined threshold.

A method of retaining channel use by a secondary system is described. A secondary channel used during periods of normal communication between a secondary transmitter and receiver is split into sub-bands for use during a quiet period containing quiet phases. During the quiet period, while the transmitter communicates with the receiver on one sub-band, the receiver simultaneously senses for incumbent devices on another sub-band, as well as vice-versa. Transmission and sensing do not occur simultaneously on the same sub-band and transmission is limited to only one of the sub-bands. Transmission and sensing are performed by both the transmitter and the receiver on every sub-band over the course of the quiet period. The locations of secondary receivers are determined and employed during scheduling such that devices sufficiently separated from each other transmit during different quiet phases and transmit and sense in sub-bands separated by another sub-band.

A method and apparatus for sychronizing a Quiet Period (QP) in a Cognitive Radio (CR) system includes receiving QP information based on a channel N from at least one neighbor BS. The method further includes determining whether the channel N is an in-band channel. If the channel N is the in-band channel, QP scheduling is performed according to the received QP information based on the channel N.

A method for obtaining high-quality well logging data acquired during a drilling operation includes acquiring well logging data during a pump-off period when a mud pump is turned off; and extracting a subset of data from the acquired well logging data, wherein the subset of data corresponds to a quiet period within the pump-off period, wherein the quiet period is substantially free of interference from turning the mud pump on or off.

Orthogonal frequency division multiplexing (OFDM) is used to divide a single TDMA time slot into multiple non-contending access request opportunities that are reserved for particular subscriber units. An OFDM burst is divided into multiple tonesets where each toneset is allocated for access request by a particular subscriber unit. One application is providing an efficient mechanism for requesting resumption of periodic grants of time slots to support a voice call after a quiet period during which such time slots were temporarily unnecessary. A single access request slot can provide an opportunity for multiple subscriber units to request such a resumption.

The embodiment of the invention discloses a method for sensing multiple channels, including steps that a base station BS divides customer premises equipment CPE into different physical clusters according to the physical position information of the CPE contained in the system; the physical clusters divided by the BS allocate a plurality of working channels supported by physical clusters to the BS, allocate quiet period QP to the working channels, allocate sensing tasks to the CPE; according to QP allocated by the BS, the CPE executes the sensing tasks allocated by the BS, and sends sensing results to the BS. The embodiment of the invention also discloses a cognitive radio system, the BS and the customer premises equipment CPE. The channel resources and sensing tasks can be allocated equitablely according to the physical position information of the CPE in the system by utilizing the method, the system, the BS and the CPE provided by the embodiment of the invention.

A method and apparatus are described including defining a neighbor set for each access point, selecting a first clock in a first access point, the selected clock having a highest accuracy as a grand master clock, advising neighboring access points to synchronize with the selected grand master clock and transmitting a message to schedule a quiet period based on the grand master clock. Also described are a method and apparatus including receiving a beacon message, inspecting clock descriptors in the beacon message, selecting a best master clock responsive to the inspection and transmitting a message to schedule a quiet period based on the selected best master clock.

The invention provides a strain type rockburst early warning method based on acoustic signal waveform change characteristics. The method includes the following steps: acoustic signals in a strain type rockburst destruction process are collected and transmitted to an acoustic signal processing system, the acoustic signal processing system performs denoising processing first, and then draws and analyzes an acoustic signal oscillogram, main forewarning information of occurrence of rockburst is that after small-amplitude fluctuation of the amplitude of the acoustic signals for a relatively long time, high-amplitude acoustic signals suddenly appear for a short period of time, and soon afterwards, a ''relative quiet period'' of continuous low-amplitude acoustic signals appear; a curve of a time fractal dimension value changing with time is drawn, another piece of forewarning information of occurrence of rockburst is that after continuously increasing to a relatively large value, the value of the time fractal dimensions D<t> continuously declines in a period of time and approaches a historical minimum value; and finally, an alarm is given in the form of sending out high-decibel sound or changing screen graphics. The strain type rockburst early warning method based on acoustic signal waveform change characteristics belongs to a non-contact monitoring means, and has the advantages that the installation operation is safe and the signals are reliable and stable.

A method for collision avoidance in a multi-reader environment comprising a plurality of Radio Frequency Identification (RFID) interrogators, the method comprises each of the plurality of interrogators entering a quiet state during which none of the interrogators transmits, each of the plurality of interrogators selecting a transmit time after the quiet period during which each of the interrogator will attempt to transmit, each of the plurality of interrogators monitoring their associated receive path, an interrogator of the plurality of interrogators transmitting an instruction during its selected transmit time indicating the beginning of a session when the interrogator does not detect data on its receive path prior to its select transmit time, the interrogator comparing its receive path to its transmit path when it transmits the instruction, the interrogator returning to the quiet state when the receive path does not match the transmit path, and the interrogator completing the session when the receive path matches the transmit path.

The present invention provides a system and a method for improving the wireless local area network (WLAN) throughput performance in a collocated WLAN / Bluetooth system that uses packet traffic arbitration (PTA) to schedule WLAN and Bluetooth transmissions. The method includes detecting a Bluetooth transmission, where the Bluetooth transmission comprises one or more quiet periods; and scheduling a WLAN transmission, where frames of the WLAN transmission are received during the quiet periods of the Bluetooth transmission. The method according to the present invention allows the collocated WLAN to receive a frame send by the access point (AP) and acknowledge its reception without the AP reducing the data transmission rate due to unacknowledged frames.; Also, the present invention discloses a mechanism where a collocated Bluetooth device (BTD) and WLAN device can communicate to the AP through a single antenna.

A periodic quiet interval is provided for base stations attempting to access a shared transmission medium in NR-U. The base station activates a quiet interval at a periodic interval and transmits on the medium based on the quiet interval. The base station may reduce a Tx power, not transmit, and / or may increase a minimum value of a contention window for BEB during the quiet interval. The base station may receive a request from a second base station to activate the quiet interval, and may determine if a Tx power of the base station is larger than the maximum Tx power of the second base station. The base station may also receive the request as relayed through a UE. The quiet interval can thus ameliorate a starvation effect of BEB in NR-U by allowing base stations with smaller Tx power greater opportunity to control the medium while maintaining BEB in NR-U.

A method for obtaining high-quality well logging data acquired during a drilling operation includes acquiring well logging data during a pump-off period when a mud pump is turned off; and extracting a subset of data from the acquired well logging data, wherein the subset of data corresponds to a quiet period within the pump-off period, wherein the quiet period is substantially free of interference from turning the mud pump on or off.

The invention discloses a method, a device and a data frame for sensing spectrum. The method for sensing spectrum includes ensuring configuration information of a spectrum sensing protection interval used to avoid a protection time GP from being interfered. The spectrum sensing protection interval is used to avoid the spectrum sensing being interfered from the signal transmission and the configuration information aims at indicating the location of the spectrum sensing protection interval in the protection time. A quiet period is set in the protection time based on the configuration information of the spectrum sensing protection interval and, in the quiet period, the spectrum sensing is performed. The method guarantees the compatibility with the present agreement through reusing the protection time in data frame and setting quiet time in the protection time. Further, through setting the spectrum sensing protection interval which includes a front protection interval and / or a back protection interval, the method effectively avoids the interference of signal transmission to spectrum sensing and the spectrum sensing can be performed without affecting the signal transmission.

A method of recovering timing information in a packet network, involves detecting quiet periods in the packet network when network packet delay variation (PDV) is low. A frequency prediction unit is trained during the quiet periods to learn output clock variations of a timing recovery unit to permit the frequency prediction unit to predict frequency update values for a local oscillator during non quiet periods taking into account the historical output clock variations during quiet periods. The output of the frequency prediction unit is used as the active frequency update values during non quiet periods.

A method of recovering timing information in a packet network, involves detecting quiet periods in the packet network when network packet delay variation (PDV) is low. A frequency prediction unit is trained during the quiet periods to learn output clock variations of a timing recovery unit to permit the frequency prediction unit to predict frequency update values for a local oscillator during non quiet periods taking into account the historical output clock variations during quiet periods. The output of the frequency prediction unit is used as the active frequency update values during non quiet periods.

A method and apparatus are described including defining a neighbor set for each access point, selecting a first clock in a first access point, the selected clock having a highest accuracy as a grand master clock, advising neighboring access points to synchronize with the selected grand master clock and transmitting a message to schedule a quiet period based on the grand master clock. Also described are a method and apparatus including receiving a beacon message, inspecting clock descriptors in the beacon message, selecting a best master clock responsive to the inspection and transmitting a message to schedule a quiet period based on the selected best master clock.

A method of maintaining signal convergence of a transmitter and a receiver of an adaptive differential pulse code modulated (ADPCM) communication system during discontinuous transmission, by generating synchronized comfort noise frame in the transmitter and in the receiver during quiet periods and mutually updating the receiver's decoder and encoder on their states.

The invention relates to a UW-CSMA / CA based node quieting method for hydroacoustic network communication. The method comprises the steps: in a hydroacoustic network, a neighbor node A surrounding a source node or destination node of a certain communication process monitors frames sent by other nodes in the hydroacoustic network, the quiet period of the node A is set to be max{Qlocal, QUIET_RTS} if xRTS is monitored, the quiet period of the node A is set to be max{Qlocal, QUIET_CTS} if xCTS is monitored, monitored xDATA is matched with current quiet period if the xDATA is monitored, the quiet period is reset to be QUIET_DATA if the xDATA is matched with the current quiet period, the quiet period is set to be max{Qlocal, QUIET_ DATA } if the xDATA is not matched with the current quiet period, xACK is matched with the current quiet period if the xACK is monitored, quieting is ended immediately if the xACK is matched with the current quiet period, and the quiet period is kept invariable if the xACK is not matched with the current quiet period.

The invention provides a cognitive radio system capable of realizing spectrum sensing without a quiet period, which is applied to cognitive radio networks. The system comprises a cognitive radio transmitting set and a cognitive radio receiving set, wherein the cognitive radio transmitting set is used for transmitting information by using chaotic signals; and the cognitive radio receiving set is used for simultaneously carrying out spectrum sensing and chaotic signal demodulation on the received signals. By using the system, a cognitive radio user does not need to use the quiet period when spectrum sensing is carried out, thereby increasing the time for the cognitive radio user to carry out data transmission, ensuring the continuity of data transmission and enhancing the communication QoS (Quality of Service) of the cognitive wireless user.

A apparatus or method for detecting CPD in an HFC network, comprising: (a) acquiring digital RF downstream signals from a CMTS or CM; (b) emulating even and odd order IM distortion products from the downstream signals; (c) acquiring RF upstream signals from the CMTS during a quiet period; (d) cross-correlating the RF upstream signals with the emulated even and odd order IM products to produce even and odd order cross-correlation functions, respectively; (e) accumulating, separately, a multiplicity of even and odd order cross-correlation functions; (f) calculating even and odd order cross-correlation envelopes from the accumulated even and odd order cross-correlation functions, respectively; and (g) detecting a CPD source from either or both of the even and odd order cross-correlation envelopes by the presence of a peak in either or both of the envelopes.

A method and system for scheduling and protecting quiet periods (QP) in a quiet zone (105) for incumbent signal (121) detection in a wireless communications system. The communication system includes a plurality of wireless networks (103, 104), each of the plurality of wireless networks contains at least a master device (101, 401 ) and a client device (111, 411). In each of the plurality of wireless networks, the master device (101, 401) transmits a beacon (402) that contains a QP schedule (500) and a reservation of a time slot (405) for the client device (411 ). The client device (111, 411) transmits a request-to-quiet (RTQ) message (412) during the time slot, wherein the RTQ message (412) includes the client device's QP schedule information. The master and client devices within the quiet zone (105) keep quiet during scheduled quiet periods according to the QP schedule information contained in the received beacons and RTQ messages.

A singular spectrum analysis-based ionized layer anomaly detection method provided by the present invention comprises the steps of obtaining the historical ionized layer observation data ION; utilizing a singular spectrum analysis method to obtain an ionized layer normal variation component IONmain; calculating the normal background noise epsilon based on an ionized layer quiet period; according to the ionized layer normal variation component IONmain and the normal background noise epsilon, obtaining a normal variation range of the ionized layer observation data ION; when the actual ionized layer observation data exceeds the normal variation range of the ionized layer observation data ION, representing that an ionized layer is abnormal. According to the present invention, by the singular spectrum analysis, a periodic signal can be identified and reinforced, the extracted normal variation component contains the influences, such as the season change of the ionized layer along with the revolution of the earth, the 9-day, 13.5-day and 27-day periodic variation of the ionized layer caused by a sun 27-day rotation period, etc., so that the interferences caused by different external environments of the earth at a background field time period and the anomaly detection time period are removed from an anomaly detection result, and the ionized layer anomaly information can be detected effectively.