Abstract: Disclosed is a channel access method. A first station acquires a first transmission time period and sends indication information to a second station in the first transmission time period, the indication information being used for informing the second station of acquiring a second transmission time period; and the second station acquires the second transmission time period and performs radio frame transmission in the second transmission time period. Also disclosed are a channel access system and stations.

Abstract: A method for start control of photovoltaic inverter, a system thereof, and a photovoltaic power generation system are provided. A fan of the photovoltaic inverter is controlled to operate in a case that input voltage of the photovoltaic inverter is greater than a start threshold, and the fan operation is used as a load. Input voltage drop before and after the fan operates is obtained, and in a case that the input voltage drop is less than or equal to a voltage determination threshold, the photovoltaic inverter is controlled to start a grid connection. The voltage determination threshold is changed based on a power determination threshold of the photovoltaic inverter.

Abstract: The present invention belongs to the technical field of bioreactors, and particularly relates to a disposable bioreactor. The disposable bioreactor comprises a reactor cavity and a communicating pipe located at the top of the reactor cavity. The reactor cavity is formed by more than two cavity walls through fusion connection or adhesion connection, and is provided with an intersection part and at least one hollow arm part which is communicated with the communicating pipe through the intersection part in an intersection manner. The tail end of the hollow arm part is sealed. Liquid in the reactor cavity is driven by a rocking table, a plane convolution shaking table, and a three-dimensional convolution shaking table to flow along a long shaft of the disposable bioreactor, so that waves and turbulence are mixed.

Abstract: A method and a device for generating PWM pulses for an inverter are provided. The three-phase inverter's characteristic of including high frequency complementary switches is used. Only three PWM peripheral units of a DSP control unit are used to output PWM high frequency signals, and a detection control unit determine for each phase two currently high frequency complementary switches according to the states of detected level signals outputted by a preset number of GPIO interfaces. The PWM high frequency signals are distributed for each phase to one of the two switches, and the PWM high frequency signals are inversed and then sent to the other one of the two switches. In addition, the states of other switches are maintained unchanged according to a preset correspondence between states of switches of a multi-level inverter and outputted level signals in different switching periods.

Abstract: The present document provides a method for avoiding downlink data collision, an Access Point (AP) and a Station (STA). The method for avoiding downlink data collision includes: an AP receiving a radio frame for inquiring whether the AP has a Bufferable Unit (BU) of an STA transmitted by the STA; and after determining that there is a BU of the STA and the BU is larger than a predetermined threshold, the AP exchanging radio frames with the STA to reserve a channel, and transmitting the BU to the STA after succeeding in reserving the channel. The method can guarantee the fairness among various STAs and the reasonable utilization of channel resources, thus avoiding the collision; furthermore, the channel reservation frame transmitted by the AP can reserve a longer period of time, i.e. a plurality of BUs can be transmitted to the STA at a time, thus saving the link overhead.

Abstract: A method and a device for generating PWM pulses for an inverter are provided. The three-phase inverter's characteristic of including high frequency complementary switches is used. Only three PWM peripheral units of a DSP control unit are used to output PWM high frequency signals, and a detection control unit determine for each phase two currently high frequency complementary switches according to the states of detected level signals outputted by a preset number of GPIO interfaces. The PWM high frequency signals are distributed for each phase to one of the two switches, and the PWM high frequency signals are inversed and then sent to the other one of the two switches. In addition, the states of other switches are maintained unchanged according to a preset correspondence between states of switches of a multi-level inverter and outputted level signals in different switching periods.

Abstract: A method for start control of photovoltaic inverter, a system thereof, and a photovoltaic power generation system are provided. A fan of the photovoltaic inverter is controlled to operate in a case that input voltage of the photovoltaic inverter is greater than a start threshold, and the fan operation is used as a load. Input voltage drop before and after the fan operates is obtained, and in a case that the input voltage drop is less than or equal to a voltage determination threshold, the photovoltaic inverter is controlled to start a grid connection. The voltage determination threshold is changed based on a power determination threshold of the photovoltaic inverter.

Abstract: Provided are a service data transmission processing method and device applied to a STA of a WLAN, and a service data transmission method and device. The transmission processing method includes that service data of a designated service type required to be sent by the STA is acquired; notification information is sent to an AP of the WLAN, wherein the notification information is used for instructing the AP to preferentially allocate a wireless transmission resource for sending the service data of the designated service type. Technical problems including a delay in sending emergency burst data due to the fact that an AP fails to identify the priority of the burst data during the sending of the emergency service data are solved by means of the technical solution, thereby reducing transmission delay of the emergency service data while improving the success rate of burst transmission of the emergency service data.

Abstract: Disclosed are a method and system for transmitting data in a wireless local access network. The method includes: a first station sending a radio frame to a second station in an obtained transmission opportunity, and carrying, in the radio frame, notification information indicating that the second station uses the transmission opportunity to communicate with a third station. The technical scheme provided in embodiments of the present invention are applicable to transmission opportunity management in a data relay process in the wireless local area network, to achieve the control right management of transmission opportunity under the control of the first station.

Abstract: The embodiments of the disclosure provides a method and device for processing the sending and receiving of service indication information, wherein the method is applied to an Access Point (AP) of a Wireless Local Area Network (WLAN). The method includes that sending time information of grouping indication information of Stations (STA) in the WLAN is acquired, wherein the sending time information is used for instructing the STAs to receive, according to sending moments indicated by the sending time information, service indication information corresponding to the STAs indicated by the grouping indication information; and the STAs indicated by the grouping indication information are notified of the sending time information.

Abstract: It is disclosed a method for transmitting wireless frame, including: the wireless frame is transmitted by using any access category. The wireless frame is a beginning frame for performing channel information measurement. It is further disclosed an apparatus for transmitting wireless frame, including: a selection unit and a transmitting unit, where the selection unit is configured to select any access category for a beginning frame for performing the channel information measurement; and the transmitting unit is configured to transmit the beginning frame. It is further disclosed a communication network element provided with the apparatus for transmitting wireless frame mentioned above. It is ensured that the wireless frames subsequent to the frame exchange sequence for performing the channel information measurement may be smoothly transmitted, and the channel information measurement may be smoothly performed, and thereby transmitting communication data based on the acquired channel information.

Abstract: Access to a wireless medium is controlled based on contention arbitration. A certain number of wireless devices are allowed to contend for a transmission opportunity. Requests from these wireless devices are processed based on codes contained in the requests. Winning wireless devices are given access to the wireless medium by transmitting a contention arbitration message. In some implementation, codes in the request are selected from an orthogonal or pseudo orthogonal code set.

Abstract: Disclosed are a method and device for receiving the radio frame. The method comprises: a first functional entity of a station detects that a channel signal intensity reaches a preset threshold, and the first functional entity starts receiving a radio frame and sends an indication that a channel detection result is busy to a second functional entity of the station; the first functional entity determines that the station is not a target station for receiving the radio frame, and sends an indication of ending up receiving the radio frame to the second functional entity; and when transmission of the radio frame ends, the first functional entity sends an indication that the channel detection result is idle to the second functional entity. The disclosure provides a reception operation processing procedure of a station having the function of discarding the radio frame while not updating a network allocation vector (NAV).

Abstract: Provided are a radio frame sending method and apparatus. In the method, when entering an awake state from a doze state, a station selects a pre-defined access category or an access category which is pre-negotiated with a centre station to contend for a wireless channel. Afterwards, the station sends a radio frame to the centre station via the wireless channel obtained through the contention, and then notifies the centre station to send buffered data to the station. The method and apparatus can be applied to flexibly and dynamically regulate an access category used for contending for a wireless channel when a station sends a radio frame which is used for notifying a centre station to send buffered data to the station.

Abstract: The present document provides a method for avoiding downlink data collision, an Access Point (AP) and a Station (STA). The method for avoiding downlink data collision includes: an AP receiving a radio frame for inquiring whether the AP has a Bufferable Unit (BU) of an STA transmitted by the STA; and after determining that there is a BU of the STA and the BU is larger than a predetermined threshold, the AP exchanging radio frames with the STA to reserve a channel, and transmitting the BU to the STA after succeeding in reserving the channel. The method can guarantee the fairness among various STAs and the reasonable utilization of channel resources, thus avoiding the collision; furthermore, the channel reservation frame transmitted by the AP can reserve a longer period of time, i.e. a plurality of BUs can be transmitted to the STA at a time, thus saving the link overhead.

Abstract: Provided are a method and a device for sending traffic indication information. In the method, an AP sends a radio frame to multiple STAs associated with the AP, wherein the radio frame carries an indication field, and the indication field is used to indicate whether the radio frame carries traffic indication virtual bitmap information. According to the technical solution provided, in the case where the AP has no unicast cache data for any station, multiple STAs associated with the AP can know whether the AP has their respective unicast cache data to be sent.

Abstract: A sleeping method and device are disclosed in the disclosure. The method comprises: a station confirms a first sleeping time for the station to enter a long sleep; the station informs an access point the first sleeping time; the station enters a long sleep according to the first sleeping time. In the disclosure, the station informs the first sleeping time to the access point, which enables the access point to acquire the first sleeping time of the station and cache data for the station, and at the same time, the access point may acquire the state of the station, which saves the cost for sending service indication information.

Abstract: A data transmission method and system are disclosed. The method comprises: a sending station sends a radio frame and notifies group transmission time interval information; a group station receives the radio frame and acquires group transmission time interval information of a group to which the group station belongs; and the group station competes for a sending opportunity within the group transmission time interval of the group to which the group station belongs. In accordance with the scheme provided in embodiments of the disclosure, a sending station allocates specific group transmission time intervals (subsections) to stations of different groups, and in the case of a large number of users stations, user stations in different groups compete for channels within different time intervals, thereby avoiding the simultaneous or approximately simultaneous competition among a large number of users, reducing the probability of collisions and improving the utilization efficiency of wireless resources.

Abstract: It is disclosed a method for transmitting wireless frame, including: the wireless frame is transmitted by using any access category. The wireless frame is a beginning frame for performing channel information measurement. It is further disclosed an apparatus for transmitting wireless frame, including: a selection unit and a transmitting unit, where the selection unit is configured to select any access category for a beginning frame for performing the channel information measurement; and the transmitting unit is configured to transmit the beginning frame. It is further disclosed a communication network element provided with the apparatus for transmitting wireless frame mentioned above. It is ensured that the wireless frames subsequent to the frame exchange sequence for performing the channel information measurement may be smoothly transmitted, and the channel information measurement may be smoothly performed, and thereby transmitting communication data based on the acquired channel information.

Abstract: The invention includes a method for separating polynucleotides, such as DNA, RNA and PNA, from a solution containing polynucleotides by reversibly and non-specifically binding the polynucleotides to a solid surface having a functional amide group-coated surface. The materials containing a solid surface can be in the form of microparticles, fibers, beads, membranes, test tubes, pipette tips or microwells and can further comprise a magnetic core portion. The pH, salt and concentration of crowding reagent, such as polyethylene glycol or alcohol, of the solution is adjusted to levels which result in nucleic acid binding to the solid surface. The magnetic microparticles with bound polynucleotides are separated from the solution under mild alkaline conditions and the nucleic acids are eluted from the magnetic microparticles. Solutions having different nucleic acid concentrations can be normalized by restricting the availability of the solid phase surface.