Abstract: The present application relates to an olefin polymerization method and system in the field of olefin polymerization. The method combines a supported double catalyst with a series process, introduces a liquid material obtained after heat exchange and gas-liquid separation of a circulation gas flow into a separate first reactor to get into contact with the supported double catalyst for polymerization reaction, and then introduces the reaction material and the first polyolefin generated by reaction into a second reactor to continue polymerization reaction, thereby enabling particles to circulate between first reactor and second reactor, improving mixing effect of two polyolefins with obvious differences in properties, avoiding the occurrence of phase separation, and facilitating the production of polyolefins with excellent performance.

Abstract: A method for multiple access point (AP) transmission is disclosed. The method comprises receiving a repetition beacon from each of a plurality of APs, each received repetition beacon comprising a common information part and an AP-specific information part; decoding at least a subset of the received common information parts to obtain a first parameter; decoding the received AP-specific information parts to obtain a second parameter for each of the plurality of APs; performing a calculation based on the first parameter, the obtained second parameters and a number of the plurality of APs to obtain a calculation result; and transmitting a feedback based on the calculation result to the plurality of AP.

Abstract: Systems, methods, and instrumentalities are disclosed for adaptation of multiple input multiple output (MIMO) mode in mmW Wireless Local Area Network (WLAN) systems. A first station (STA) may receive a mode change request from a second STA. The mode change request may indicate a mode change for a MIMO mode, a polarization mode, and/or an orthogonal frequency-division multiple access (OFDMA) mode. The mode change request may include one or more STA fields. The one or more STA fields may include a STA field associated with the first STA. Each of the one or more STA fields may include a MIMO mode subfield, a polarization mode subfield, and/or an OFDMA mode subfield. The first STA may change the MIMO mode, the polarization mode, and/or the OFDMA mode, for example, based on the mode change request. The first STA may send a mode change response to the second STA.

Abstract: Presently disclosed are systems and methods for beamforming training in WLANs. In various embodiments, there are unified MIMO beamforming training procedure, which includes a training period in which an initiator transmits multiple unified training frames for performing a transmit-beamforming training of the initiator and a receive-beamforming training of one or more responders; a feedback period in which each responder replies with a beamforming-feedback response; and an acknowledgement period during which the initiator transmits respective acknowledgement frames to the one or more responders from which responses were received. Rules for restricted random access in various slots of the feedback period may be implemented, to address response contention between multiple qualifying responders.

Abstract: Systems, methods, and instrumentalities are described to implement an interference management method. A method performed by an Access Point (AP) may include receiving, from a station (STA) associated with a first basic service set (BSS), information indicating support for coordinated carrier sense multiple access with collision avoidance (CSMA/CA) and receiving information associated with a second BSS. The method may further include coordinating, based on the received information associated with the second BSS, carrier sense multiple access with collision avoidance (CSMA/CA) access among STAs of the first BSS to minimize interference of the STA.

Abstract: Methods and apparatuses for multiple input-multiple output (MIMO) channel access are provided herein. A method performed by a station may include receiving, from an access point (AP), a frame including information indicating a broadcast address. The frame may further include a control trailer including information indicating that a multi-user multiple input-multiple output (MU-MIMO) frame is to be transmitted by the AP and information indicative of a designation of a plurality of STAs, the plurality of STAs including the STA. The frame may solicit response frames from at least the designated plurality of STAs. The method may further include transmitting a response frame to the indicated broadcast address and receiving the MU-MIMO frame from the AP.

Abstract: The present disclosure relates to a video connection method and apparatus. The method includes: obtaining matched video connection requests from a plurality of video connection requests; creating a video connection room for the matched video connection requests; generating identification information of the video connection room; and informing a first client and a second client of entering the video connection room and making a video connection by sending the identification information of the video connection room to the first client and the second client corresponding to the matched video connection requests respectively.

Abstract: An enhanced sector level sweep procedure is provided herein. A method may include transmitting a plurality of beacon frames in a corresponding plurality of transmit sectors, wherein the plurality of beacon frames are transmitted within a beacon interval. The method may include receiving, from a second communication device, a first transmission including information indicating a first ranking. The first ranking is based on a characteristic of at least a first subset of the transmit sectors. The first transmission is received in a sector corresponding to one of the first subset of transmit sectors. The method may include receiving, from a third communication device, a second transmission including information indicating a second ranking. The second ranking is based on a characteristic of at least a second subset of the transmit sectors. The first transmission is received in a sector corresponding to one of the second subset of transmit sectors.

Abstract: Systems, methods, and instrumentalities are provided to implement a method of communicating a feedback in a wireless local area network (WLAN). A WLAN device may receive a data frame with a hybrid automatic repeat request (HARQ) data indicator in a frame header. The WLAN device may send an acknowledgement frame when the data frame is correctly received and decoded. The WLAN device may send a negative acknowledgement frame when the data frame is not correctly received and decoded.

Abstract: A recovery device for an unmanned underwater vehicle (UUV) includes a first recovery component arranged on an unmanned ship and a second recovery component arranged on the UUV. Two magnets are provided on an end of the first recovery component and an end of the second recovery component which are opposite to each other, respectively. A first cable of the unmanned ship is provided on an end of the first recovery component away from the magnet, and a second cable is provided on an end of the second recovery component away from the magnet. A thruster is provided on a side of the first recovery component. The UUV is recovered using the unmanned ship through the recovery components connected to the cables, which allows the locating and navigation errors to a large extent.

Abstract: A method for use in a wireless transmit/receive unit (WTRU) is disclosed. The method comprises: generating, by a Station Management Entity (SME), a request primitive enabling a wake-up radio (WUR) scanning process for WUR discovery frames transmitted by one or more access points (APs), the request primitive comprising a plurality of first parameters; conducting the WUR scanning process using WUR based on the plurality of the first parameters; generating, at a MAC layer, at least one confirm primitive based on a result of the WUR scanning process and at least a part of the plurality of first parameters; and communicating, from the MAC layer to the SME, the at least one confirm primitive.

Abstract: Methods, devices and systems are provided for performing for multi-user (MU) transmission. A wireless transmit/receive unit (WTRU) may be configured to receive a frame, decode the received frame and determine whether the received frame is a null data packet (NDP) multi-user (MU) media access control (MAC) physical layer convergence protocol (PLCP) protocol data unit (PPDU) (NDP MU MAC PPDU) based on meeting an NDP condition. The NDP MU MAC PPDU may correspond to an MU transmission and may include a PLCP header which includes an NDP signal (SIG) field having MU control information. Based on the received frame meeting the NDP condition, the WTRU may be further configured to process the NDP SIG field, generate a response based on the NDP SIG field and the MU control information, and transmit the response.

Abstract: Methods and apparatus are described. A station includes a transceiver and a processor, which detect a trigger frame for an uplink (UL) multi-user (MU) transmission. The trigger frame includes a user information field with an allocation of one or more random access resource units (RUs) and a common information field with information to set high efficiency (HE) SIGNAL-A (HE-SIG-A) fields in the UL MU transmission. The transceiver and the processor generate an HE trigger-based (TB) physical layer protocol data unit (PPDU) and set an HE-SIG-A field in the HE TB PPDU using the information in the trigger frame. The transceiver and the processor select one of the one or more random access RUs and transmit the HE TB PPDU, using the selected one of the one or more random access RUs, a short inter-frame space after the trigger frame.

Abstract: A wireless transmit/receive unit (WTRU) or access point (AP) may transmit a protocol data unit (PDU) of a first 802.11 protocol and a preamble and data of a second 802.11 protocol. The preamble and data of the second 802.11 protocol may be transmitted on resources of the PDU of the first 802.11 protocol with shaping sequences for concurrent transmission.

Abstract: Disclosed is a method for stitching dual-camera images. The method includes collecting two images having overlapping photographic content; extracting and matching feature points of the two images; roughly aligning the two images by using a homography matrix; and accurately aligning the two images by using a least squares method to complete stitching the two images. Further disclosed is an apparatus corresponding to the method.

Abstract: Systems, methods, and devices for beamforming (BF) training are disclosed. In some examples, a receiver is configured to receive sector sweep (SSW) training frames from an initiator device that each indicate an antenna sector of the initiator device. A transmitter is configured to transmit sector sweep (SSW) training frames to the initiator device that indicate a best received antenna sector of the initiator device. The receiver receives a sector sweep feedback (SSW FB) frame from the initiator device, and the transmitter transmits transmit a sector sweep acknowledgement (SSW ACK) frame to the initiator device that indicates an antenna sector of the initiator device that is different from the antenna sector indicated by the SSW FB frame, if the SSW FB frame was best received by an antenna not corresponding to the best received antenna sector of the initiator device.

Abstract: A method for use in a wireless transmit/receive unit (WTRU). The method comprises: receiving LRRE information from an AP; determining whether a first condition is satisfied by the WTRU, wherein the first condition is satisfied by the WTRU, on a condition that the first condition is satisfied, sending a mode change request to the AP to change an operation mode to a LRRE HARQ mode; receiving a response regarding the mode change request from the AP; and communicating with the AP using a plurality of PPDUs, each of the PPDUs comprising at least one field enabling transmissions between the WTRU and the AP under the first condition and a LRRE HARQ mode indication.

Abstract: A method and apparatus may be used in multi-AP and multi-wireless transmit/receive unit joint transmissions. The apparatus may be configured to transmit a joint transmission request on a first medium, and receive a joint transmission response on the first medium. In response, the apparatus my perform a joint transmission negotiation on a second medium and transmit data on the second medium based on the joint transmission negotiation. The apparatus may be configured to perform coordinated sectorized or beamformed transmissions through access point (AP)/PCP negotiations. The apparatus may provide an indication of support for joint transmission and coordinated sectorized or beamformed transmissions. The method and apparatus may also implement multi-AP/WTRU request-to-send (RTS)/clear-to-send (CTS) procedures. The apparatus may be configured to perform coordinated sectorized or beamforming grouping.

Abstract: Devices, methods, and systems for scheduling of an enhanced sector level sweep (SLS). A wireless transmit/receive unit (WTRU) monitors beacon frames transmitted from one or more access points associated with the WTRU. The WTRU receive the beacon frames over multiple transmission sectors during a time interval. The WTRU then compiles the transmission sectors information in a list and ranks the sectors in the list, based on the sectors' characteristics. Then, the WTRU transmits the list over one sector of the list to the one or more access points.

Abstract: Systems, methods, and instrumentalities are disclosed for concurrent link setup and downlink data retrieval, e.g., for high efficiency WLAN. An access point (AP) may send a trigger element that allocates a resource for pre-association transmissions with the AP. The trigger element may allocate the resource for random access and/or deterministic access. The AP may receive, from an unassociated STA, a first frame via one or more resource units (RUs) allocated in the trigger element. The AP may determine a pre-association identifier (PID) that identifies the unassociated STA. The AP may send the PID to the unassociated STA, for example, in the trigger element or in the multi-STA ACK. The AP may send a second frame associated with a multi-user (MU) transmission that includes the PID. The AP may send a trigger frame that includes the PID.