The present technology relates to a transmission device, a reception device, a transmission system, and a transmission method capable of improving transmission efficiency of subdata added to main data. A transmission device includes a frame sequence number setting unit that, on the basis of a frame number indicating an order of a subframe in a main frame, assigns to the subframe a frame sequence number indicating an order of the subframe in a frame sequence including a plurality of the subframes, and a multiplexing unit that arranges a data packet at a predetermined position in the subframe on the basis of the frame sequence number. The present technology can be applied to a CCU, for example.

An embodiment is a data sequence correction method. The data sequence correction method including temporarily saving data with sequence information imparted thereto in a ring buffer, the ring buffer having a predetermined number of storage regions corresponding to the sequence information, and being provided with a monitoring section made up of one, or two or more consecutive sequence numbers, and an acceptance section in which a start or a second sequence number of the monitoring section is a start sequence number, and the sequence number ahead by a count of storage regions of the ring buffer including the start of the monitoring section is an end sequence number.

In one embodiment, a network device, including packet processing circuitry, which includes at least one interface configured to receive packets, and packet forwarding circuitry configured to make respective forwarding decisions for respective ones of the packets, wherein the packet processing circuitry is configured to assign sequence numbers to the packets in at least one stage of packet processing, find missing packets in at least one corresponding later stage of the packet processing responsively to checking for missing sequence numbers among the assigned sequence numbers, and report the missing packets.

According to embodiments, a method includes: A transmit end receives a first selective acknowledgment SACK packet from a receive end; the transmit end retransmits the at least one packet to the receive end; and the transmit end retransmits a first packet to the receive end again when the transmit end receives a second SACK packet and a packet sequence number of a packet carried in the second SACK packet is greater than or equal to the packet sequence number of the first new packet, and if the transmit end still has not received an ACK packet corresponding to the first packet in the at least one packet.

In one embodiment, a network device, including packet processing circuitry, which includes at least one interface configured to receive packets, and packet forwarding circuitry configured to make respective forwarding decisions for respective ones of the packets, wherein the packet processing circuitry is configured to assign sequence numbers to the packets in at least one stage of packet processing, find missing packets in at least one corresponding later stage of the packet processing responsively to checking for missing sequence numbers among the assigned sequence numbers, and report the missing packets.

In a packet loss indication method, a user plane function (UPF) entity receives first indication information from a first base station, where the first indication information indicates that a first data packet was unsuccessfully sent, and that the first data packet was unsuccessfully sent includes that the UPF entity unsuccessfully sent the first data packet to the first base station or the first base station unsuccessfully sent the first data packet to a first terminal device. Second indication information is sent to a second base station, where the second indication information indicates that the first data packet was unsuccessfully sent.

A sequence recovery method is executed by a node in a time-sensitive network configured to transmit and receive packets The method includes providing a state variable, having a first state in which a packet loss counter is disabled, and a second state in which the packet loss counter is enabled. The packet loss counter can only be incremented to count lost packets when the loss state variable is in the second state. This method enhances the IEEE 802.1CB standard.

This application provides an acknowledgment packet transmission method and a communications device. The method includes: receiving, by a first device, data sent by a second device; sending, by the first device, the acknowledgment packet to the second device, where the acknowledgment packet includes an acknowledgment field, the acknowledgment field carries data lengths of K groups of data packets, and the data lengths vary with a data amount included in each group of data packets received/lost by the first device.

Aspects of the present disclosure include methods, apparatuses, and computer readable media for configuring, in a slot, a first code block group (CBG) occupying one or more first frequency resources, a second CBG occupying one or more second frequency resources different from the one or more first frequency resources, and sidelink control information (SCI) indicating the first CBG is frequency divisional multiplexed with the second CBG, and transmitting the first CBG, the second CBG, and the SCI via a physical sidelink shared channel (PSSCH) to a second UE.

The present technology relates to a wireless communication device and a method that enable reliable transmission of data even in communication using a plurality of bands. The wireless communication device collectively manages a sequence number of data transmitted using each band in communication using a plurality of bands and controls of transmission of information on a notification method of a reception result of the data and information on a management method. The present technology can be applied to wireless communication systems.