A method for data communication between a first node and a second node over a data path includes determining one or more redundancy messages from data messages at the first node using an error correcting code and transmitting messages from the first node to the second node. The transmitted messages include the data messages and the redundancy messages. The method includes, receiving, at the first node, a first plurality of messages including messages indicative of a rate of arrival at the second node of the messages transmitted from the first node and messages indicative of successful and unsuccessful delivery of the messages transmitted from the first node to the second node. A first transmission limit and a second transmission limit are maintained according to the first plurality of messages. Transmission of messages from the first node to the second node is limited according to the maintained first transmission limit, and according to the second transmission limit.

The present invention relates to a wireless access system that supports an unlicensed band, and provides various methods for adjusting a contention window size, methods for determining the time when the adjusted contention window size is applied, methods for distinguishing between a collision and a channel error, and devices for supporting the same. As an embodiment of the present invention, a method for adjusting a contention window size in a wireless access system supporting an unlicensed band may comprise the steps of: performing a channel access procedure; when it is determined through the performed channel access procedure that a serving cell (Scell) in the unlicensed band is in an idle state, transmitting a transmission burst including a downlink signal through the unlicensed band; receiving hybrid automatic repeat and request acknowledgment (HARQ-ACK) information corresponding to the transmission burst; and adjusting the CWS using the number of DTX states in the HARQ-ACK information when the transmission burst is scheduled in a self-carrier scheduling scheme.

Disclosed are a method, an apparatus, and a system for adjusting a contention window size for performing channel access. In detail, the method includes: receiving a plurality of hybrid automatic repeat request acknowledgement (HARQ-ACK) responses for downlink channel(s) of the specific cell; generating a random number N (N≥0) in a contention window size; and performing the downlink transmission in the specific cell after standing by for N slots while the specific cell is idle, wherein when a ratio of negative acknowledgement (NACK) among the plurality of HARQ-ACK responses is equal to or more than a reference value, the contention window size becomes larger than a previous value, and when the ratio of the NACK among the plurality of HARQ-ACK responses is less than the reference value, the contention window size is reset to a minimum value.

A data packet transmission method and device, a storage medium and a terminal are provided. The method includes: during multi-link transmission, duplicating a first failed data packet in a transmission window to at least one other link of multiple links, wherein the multiple links include a first link on which the first failed data packet is transmitted and the at least one other link; and retransmitting the first failed data packet on the at least one other link and the first link, wherein the first failed data packet is a data packet whose transmission does not succeed and which has a smallest sequence number in the transmission window. Embodiments of the present disclosure may mitigate data packet transmission blocking caused by failed data packets in a WLAN multi-link system.

Disclosed are a method and an apparatus for transmitting or receiving feedback information in a communication system. An operation method of a terminal comprises the steps of: receiving, from a base station, DCI #1 including scheduling information of PDSCH #1 and transmission resource information of HARQ response #1 with respect to PDSCH #1; receiving, from the base station, DCI #2 including scheduling information of PDSCH #2 and transmission resource information of HARQ response #2 with respect to PDSCH #2; and when the transmission resource information of HARQ response #1 is configured as undefined, transmitting, to the base station, HARQ response #1 and HARQ response #2 by using a resource indicated by the transmission resource information of HARQ response #2. Therefore, the performance of the communication system can be improved.

An apparatus, method, and computer readable media for requesting and sending block acknowledgement requests (BARs) and block acknowledgments (BAs) is disclosed. A method for BARs is disclosed. The method may include transmitting data frames to two or more wireless communication devices in accordance with a multi-user multiple-input and multiple-output (MU-MIMO). The method may include transmitting block acknowledgement requests (BARs) for the transmitted data frames to the two or more wireless communication devices in accordance with MU-MIMO. The method may include receiving block acknowledges (BA) of the data frames from the two or more wireless communication devices in accordance with MU-MIMO. A method for BAs is disclosed. The method may include receiving data frames from a second wireless communication device. The method may include receiving a block acknowledgement request from the second wireless communication device The method may include sending a block acknowledgement to the second wireless communication device using MU-MIMO.

Systems, apparatuses, methods, and computer-readable media are provided for wireless communication using an unlicensed spectrum. An access point (AP) operating in the unlicensed spectrum includes a processor circuitry, a transmitter, and a receiver. The processor circuitry is configured to perform a listen before talk (LBT) procedure using an LBT parameter and a maximum channel occupancy time (MCOT) that is compatible with another wireless protocol using the unlicensed spectrum. The processor circuitry is configured to divide a transport block (TB) into a plurality of code block groups (CBGs) for transmission over the unlicensed spectrum. The transmitter is configured to transmit the plurality of CBGs to a destination, and a receiver is configured to receive hybrid automatic repeat and request acknowledgment (HARQ-ACK) information corresponding to the transmitted plurality of CBGs. The processor circuitry is further configured to determine a HARQ-ACK assessment for the TB based on the HARQ-ACK information corresponding to the transmitted plurality of CBGs, and adjust a contention window size based on the HARQ-ACK assessment for the TB.

A wireless device determines a reference duration for contention window adjustment. The reference duration is from a beginning of a channel occupancy and until an end of a first slot where at least one physical uplink shared channel (PUSCH) is transmitted. The wireless device determines a contention window value based on one or more new data indicators (NDIs) of one or more first transport blocks transmitted during the reference duration. The wireless device performs a listen before talk (LBT) procedure based on the contention window value. The wireless device transmits one or more second transport blocks based on the LBT procedure indicating a clear channel.

A communications device acting as a relay device is configured to communicate with a transmitting node and a receiving node. The communications device acting as the relay is configured to receive signals representing protocol data units formed from one or more service data units via a first wireless access interface from the transmitting node according to a first automatic repeat request process for transmission to the receiving node, transmit signals representing the received protocol data units via a second wireless access interface to the receiving node according to a second automatic repeat request process, and store the protocol data units received by the receiver circuitry for transmission to the receiving node according to the second automatic repeat request process.

A method and an apparatus for sending Hybrid Automatic Repeat Request acknowledgement (HARQ-ACK) feedback information are provided. The User Equipment (UE) receives a Physical Downlink Control Channel (PDCCH) and a Physical Downlink Shared Channel (PDSCH) sent by a base station, determines a number of downlink subframes corresponding to the HARQ-ACK feedback information sent in the PUSCH of each CC in the current uplink subframe, the Uplink (UL) Downlink Assignment Index (UL DAI) obtained from the UL Grant of the PDCCH, a sum of the number of PDSCH subframes received from a HARQ-ACK bundling window and a number of PDCCHs indicating the downlink SPS releasing, and a size of the HARQ-ACK bundling window, and sends HARQ-ACK feedback information of each CC via the PUSCH in the current uplink subframe. A number of bits of the HARQ-ACK feedback information of each CC is determined according to the number of the downlink subframes.