A method and apparatus for wireless communication in the unlicensed spectrum between an eNB and UEs having different bandwidths, e.g., between a narrowband UE and a wideband eNB. A base station apparatus may perform a dual CCA procedure for a frame, wherein the dual CCA procedure comprises a first type of CCA procedure followed by a second type of CCA procedure when the first type of CCA procedure is unsuccessful. The apparatus may transmit during the frame when at least one CCA procedure of the dual CCA procedure is successful and may refrain from transmitting during the frame when both CCA procedures of the dual CCA procedure are unsuccessful. In performing the dual CCA procedure, the apparatus may perform CCA for a first period of time then perform eCCA for a second period of time following the CCA, when the CCA is unsuccessful.

A method and apparatus for wireless communication in the unlicensed spectrum between an eNB and UEs having different bandwidths, e.g., between a narrowband UE and a wideband eNB. A base station apparatus may perform a dual CCA procedure for a frame, wherein the dual CCA procedure comprises a first type of CCA procedure followed by a second type of CCA procedure when the first type of CCA procedure is unsuccessful. The apparatus may transmit during the frame when at least one CCA procedure of the dual CCA procedure is successful and may refrain from transmitting during the frame when both CCA procedures of the dual CCA procedure are unsuccessful. In performing the dual CCA procedure, the apparatus may perform CCA for a first period of time then perform eCCA for a second period of time following the CCA, when the CCA is unsuccessful.

The present disclosure discloses a method for performing a hybrid automatic repeat request (HARQ) feedback, method comprises: receiving data units; performing group bundling on the data units, wherein at least one data unit is bundled into more than one groups; determining, according to decoding results of the data units in each of the groups, ACK/NACK information of corresponding groups; feeding back ACK/NACK information of different bundled groups to the transmitter. Compared with the prior art, according to the present disclosure, a receiver performs grouping on data units in a way of overlapping bundling, group is used as a unit for feedback of ACK/NACK information, thus feedback overhead of HARQ feedback is reduced, data amount of HARQ-transmitter error retransmission is significantly reduced and efficiency of error retransmission is improved. In addition, the present disclosure further provides an HARQ retransmission method.

A method for transmitting feedback information includes receiving, by a terminal device, trigger signaling used for triggering transmission of feedback information for at least one downlink channel group by the terminal device. The method also includes determining by the terminal device a feedback information codebook based on the trigger signaling. The feedback information codebook includes the feedback information for the at least one downlink channel group.

Techniques are disclosed for an adaptive and causal random linear network coding (AC-RLNC) with forward error correction (FEC) for a communication channel with delayed feedback. An example methodology implementing the techniques includes transmitting one or more coded packets in a communication channel, determining a channel behavior of the channel, and adaptively adjusting a transmission of a subsequent coded packet in the first channel based on the determined channel behavior. The communication channel may be a point-to-point communication channel between a sender and a receiver. The channel behavior may be determined based on feedback acknowledgements provided by the receiver. The subsequent coded packet may be a random linear combination of one or more information packets.

Multicast error detection and recovery may be provided. A join request for a multicast stream may be sent from a first network node to a second network node. The join request may be sent over a first link of a plurality of links between the first network node and the second network node. A redirect message indicating that the second network node cannot accommodate the join request may be received by the first network node from the second network node. In response to receiving the redirect message, the join request for the multicast stream may not be sent on a second link of the plurality of links by the first network node to the second network node. And in response to receiving the redirect message, an alternate upstream network node may be determined by the first network node to send the join request for the multicast stream to.

Multicast error detection and recovery may be provided. A join request for a multicast stream may be sent from a first network node to a second network node. The join request may be sent over a first link of a plurality of links between the first network node and the second network node. A redirect message indicating that the second network node cannot accommodate the join request may be received by the first network node from the second network node. In response to receiving the redirect message, the join request for the multicast stream may not be sent on a second link of the plurality of links by the first network node to the second network node. And in response to receiving the redirect message, an alternate upstream network node may be determined by the first network node to send the join request for the multicast stream to.

The present invention relates to a wireless communication system. More specifically, the present invention relates to a method and a device for determining number of retransmissions of sidelink data in wireless communication system, the method comprising: determining number of retransmissions of sidelink data when the sidelink data is available for transmission; transmitting the sidelink data via direct interface between UEs; and retransmitting the sidelink data as many as the determined number of retransmissions.

The present invention relates to a wireless communication system. More specifically, the present invention relates to a method and a device for determining number of retransmissions of sidelink data in wireless communication system, the method comprising: determining number of retransmissions of sidelink data when the sidelink data is available for transmission; transmitting the sidelink data via direct interface between UEs; and retransmitting the sidelink data as many as the determined number of retransmissions.

The present invention generally relates to wireless communication, more particularly, relates to recovery from beam failure in a wireless access network where beamforming technique is used in communication between network elements. According to one aspect of the present invention, there is provided a method for recovery from beam failure in a wireless access network accessed by a user equipment (UE). The method comprises: at the wireless access network, determining whether the beam failure occurs on the basis of presence of a response from the UE during communicating between the wireless access network and the UE via a first beam; and if it is determined that the beam failure occurs, communicating with the UE via an available beam selected from the first beam and one or more second beams.