A method and apparatus for receiving a notification of missing packets include receiving a set of data packets transmitted by a device and having a corresponding set of sequence numbers, identifying one or more data packets having corresponding sequence numbers that fall within the set of sequence numbers and are yet to be received, receiving an indication from the device that the one or more data packets will not be transmitted by the device, and processing the set of data packets without the one or more data packets in response to receiving the indication.

Disclosed in the present invention are: a method for controlling a contention window size (CWS) for uplink listen-before-talk (LBT) in a wireless communication system supporting an unlicensed band; and a device for supporting the same. More particularly, disclosed are a base station centric CWS controlling method, a terminal centric CWS controlling method, and devices for supporting the same.

A communications device acting as a relay device configured to communicate with an infrastructure equipment of a mobile communications network and a receiving communications device operating with the mobile communications network. The communications device acting as the relay device comprises receives signals representing protocol data units formed from one or more service data units via a first wireless access interface from the infrastructure equipment according to a first automatic repeat request protocol for transmission to the receiving communications device, transmits signals representing the received protocol data units via a second wireless access interface to the receiving communications device according to a second automatic repeat request protocol, and stores, in a buffer, the protocol data units received from the infrastructure equipment according to the first automatic repeat request protocol.

A communication method and system for converging a 5.sup.th-Generation (5G) communication system for supporting higher data rates beyond a 4.sup.th-Generation (4G) system with a technology for Internet of Things (IoT) is provided. The method includes intelligent services based on the 5G communication technology and the IoT-related technology, such as smart home, smart building, smart city, smart car, connected car, health care, digital education, smart retail, security and safety services. The disclosure provides a packet processing method of a transmitter that include transmitting a radio link control (RLC) service data unit (SDU) to a receiver; receiving, from the receiver, a first message including information about whether the RLC SDU is successfully transmitted; and transmitting a first indicator indicating successful transmission of the RLC SDU from an RLC entity of the transmitter to a packet data convergence protocol (PDCP) entity of the transmitter when the receiver receives the RLC SDU.

A first communication apparatus dynamically controls data flow in aggregated medium access control (MAC) protocol data unit (AMPDU) aggregation by negotiating an initial block acknowledgement (Block-ACK) window size for the AMPDU aggregation with the second communication apparatus. The first communication apparatus adjusts the AMPDU aggregation during subsequent communication with the second communication apparatus by creating a Block-ACK frame with a reserved field, which has a value indicating a change to the AMPDU aggregation, and then transmitting the Block-ACK frame to the second communication apparatus.

When a base station has reason to increase the extent of MU-MIMO service that it can provide or in other contexts, the base station could select at least one of the base station's served UEs to have its MIMO rank reduced, with the selecting being based at least on a determination that the selected UE has had a threshold high rate of data retransmissions such as a threshold high rate of HARQ retransmissions for instance.

Methods, systems, and devices for wireless communications are described. In some systems, base stations and user equipment (UEs) may use beamforming for transmitting random access channel (RACH) messages. A UE may transmit multiple RACH preamble messages (e.g., within a random access response (RAR) window) to initiate a RACH procedure. The UE may transmit the RACH preamble messages in transmission opportunities corresponding to reference signals received from the base station. In some cases, the UE may determine the number of RACH preamble messages to transmit within the RAR window based on an ability of the UE to simultaneously monitor for a RAR message in response to each of the transmitted messages. In other cases, the UE may transmit an indication of UE capabilities to the base station. The base station may determine a RACH resource configuration for the UE based on the capabilities and may indicate the configuration to the UE.

Provided is a mobile station which communicates with abase station using a radio channel, the mobile station comprising: a switching unit configured to switch from a packet reception period, during which packet reception can be executed, to a packet reception halt period, during which packet reception is halted; a transmission unit configured to transmit, to the base station, a result of receiving a packet sent from the base station, as a reception result notification signal; a packet reception determination unit configured to determine a packet reception fault; and a reception period determination unit configured to extend the packet reception period if the packet reception fault is determined by the packet reception determination unit.

Systems and methods presented herein provide for increasing a contention window of a UE employing a LTE communications operating in a radio frequency (RF) band comprising a conflicting wireless technology. In one embodiment, an eNodeB receives a transport block of data from a user equipment (UE). The transport block includes a cyclic redundancy check (CRC). The eNodeB then determines a checksum of the transport block based on the CRC, fails the checksum, and transmits a non-acknowledgement (NACK) of the transport block to the UE based on the failed checksum. The UE, in response to the NACK, increases a contention window and re-transmits the transport block to the eNodeB.

A packet is received from a first link, and includes identification of a sender and a destination. An acknowledgement of receiving the packet is transmitted toward the sender, and the packet is forwarded, over a second link, toward the destination. A copy of the packet is stored in a queue. Upon detecting that the destination failed to receive the packet forwarded over the second link, the copy of the packet is retrieved from the queue and re-transmitted over the second link to the destination.