Some embodiments include an apparatus, method, and computer program product for enhanced Hybrid Automatic Repeat Request (HARQ)-ACK in a fifth generation (5G) wireless communications system. A user equipment (UE) can receive, during a HARQ-ACK window, a semi-persistent scheduling (SPS) Physical Downlink Shared Channel (PDSCH) transmission or a Physical Downlink Control Channel (PDCCH) transmission corresponding to a SPS PDSCH release. The UE can generate a Hybrid Automatic Repeat Request (HARQ)-ACK information bit corresponding to the reception. The UE can be configured with an offset value, k, and a length, l, of the HARQ-ACK window associated with an uplink transmission slot n, of a Physical Uplink Control Channel (PUCCH) transmission, and determine a starting slot of the HARQ-ACK window as n−k. When a corresponding valid uplink transmission slot is not available, the UE can transmit the HARQ-ACK information bit in the uplink transmission slot n of the PUCCH transmission.

Methods, systems, and devices for wireless communication are described to support entering a fast-negative acknowledgement (NACK) mode. A user equipment (UE) may enter a fast-NACK mode and may decrease a value of a respective timer for one or more wireless connections (e.g., may override the timer independently for each connection). The timer may be referred to as a retransmission request time duration. If configured with two or more component carriers (CCs), the UE may determine a value of the timer based on a location of a data hole within the two or more CCs. Based on entering the fast-NACK mode, the UE may override a configured timer for the respective wireless connection with a new, shorter timer. Based on expiration of the new timer, the UE may transmit an RLC NACK to a base station via the corresponding wireless connection.

A communication protocol system is provided for reliable transport of packets. Transport of packets includes transmitting, by a sender entity over a connection to a receiver entity, a plurality of packets in a first order, maintaining, by the sender entity, one or more sliding windows including a plurality of bits, wherein each bit of the sliding window represents a respective packet of the plurality of packets, receiving, by the sender entity, one or more acknowledgments indicating that one or more of the plurality of packets have been received by the receiver entity, each of the acknowledgments referencing a respective packet of the plurality of packets and modifying, by the sender entity, values of one or more of the plurality of bits in the sliding window corresponding to the one or more acknowledgments received.

A system and method for transmitting and relaying data packets within an ARQ 3G HDL framework includes populating unused packet positions with unacknowledged packets during retransmission. The unused packet positions are populated according to lowest unacknowledged sequence numbers. Unused packet positions may be populated with multiple copies of the lowest unacknowledged sequence number or some set of the lowest unacknowledged sequence numbers. A set of lowest sequence unacknowledged sequence numbers may be weighted toward the lowest unacknowledged sequence number to increase the probability of the lowest unacknowledged sequence number being received so that the send window can be slid forward.

A communication protocol system is provided for reliable transport of packets. In this regard, an initiator entity may determine that outgoing data is to be transmitted to a target entity. The initiator entity may transmit, to the target entity, a solicited push request requesting the outgoing data to be placed at the target entity. In response to the solicited push request, the initiator entity may receive a push grant from the target entity. In response to the push grant, the initiator entity may transmit to the target entity the outgoing data to be placed at the target entity.

Disclosed is a hybrid automatic repeat request (HARD) feedback enhancement method. The method comprises: sending downlink control information comprising first indication information to a terminal, the first indication information being used for indicating the number of downlink transport blocks received by the terminal on a sub-frame after the current sub-frame and a sub-carrier after the current sub-carrier within the current HARO feedback window.

A communication protocol system is provided for reliable transport of packets. In this regard, an initiator entity may determine that outgoing data is to be transmitted to a target entity. The initiator entity may transmit, to the target entity, a solicited push request requesting the outgoing data to be placed at the target entity. In response to the solicited push request, the initiator entity may receive a push grant from the target entity. In response to the push grant, the initiator entity may transmit to the target entity the outgoing data to be placed at the target entity.

Embodiments of the present disclosure provide a method and system for adjusting a physical uplink control channel (PUCCH) format in a wireless communication network. In particular, the method is implemented for adjusting a PUCCH format in an uplink transmission from a terminal device to a network device in a wireless communication network. The method comprises: using a first PUCCH format having a first duration for a service between the terminal device and the network device; and using (804) a second PUCCH format having a second and different duration for the service of the terminal device responsive to a determination that the first PUCCH format is in need of change based on one or more events.

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a receiving (Rx) user equipment (UE) may receive, from a transmitting (Tx) UE, sidelink control information (SCI). The Rx UE may determine an Rx-side block error rate (BLER) based at least in part on the SCI. The Rx UE may perform a beam failure recovery based at least in part on the Rx-side BLER satisfying a threshold. Numerous other aspects are described.

A technique for packet processing may include maintaining a data structure representing transport status information associated with a sliding window of sequential packets for a host system. When a packet targeted for the host system is received, a packet validation process can be performed on the packet. The packet validation process may include validating that the packet belongs to the sliding window of the sequential packets by comparing the packet serial number of the packet against the packets being expected in the sliding window. The packet validation process may also include validating that the packet is being received for the first time and is not a duplicate packet. Upon validating the packet, the packet can be placed into the host system, and the status information can be updated to indicate that the packet has been received.