The present disclosure provides methods and apparatuses for HARQ retransmission on an unlicensed carrier in an LTE-LAA system. A method in the base station includes: performing a CCA detection on the unlicensed carrier to determine energy on the unlicensed carrier and, at the same time, :initiating an HARQ discarding timer for the unlicensed carrier, when the base station and a UE operate on the unlicensed carrier; comparing the determined energy with a predetermined CCA threshold; if the determined energy on the unlicensed carrier is not smaller than the CCA threshold until the HARQ discarding timer is expired, giving up the HARQ retransmission on the unlicensed carrier; and if the energy is detected to be smaller than the CCA threshold before the HARQ discarding timer is expired, continuing the HARQ retransmission on the unlicensed carrier.

A method and apparatus for allocating resources to a wireless transmit receive unit (WTRU) includes the WTRU transmitting a signature sequence to a Node B, receiving an acknowledge signal from the Node B, and determining a default resource index. The resource index is associated with enhanced dedicated channel (E-DCH) parameters.

A method and a first node (700) for handling a feedback procedure requiring transmission of feedback messages indicating either an acknowledgement, ACK, or a non-acknowledgement, NACK, of correct reception of data transmitted on a forward link in a radio communication with a second node (702) in a radio network. The first node (700) obtains (300) a latency requirement of the radio communication corresponding to the time from transmission of the data until the data becomes outdated. The first node (700) further applies (304) a first transmission mode employing said feedback procedure when the latency requirement is above a latency threshold, and applies (306) a second transmission mode omitting said feed back procedure when the latency requirement is below the latency threshold.

A wireless device receives configuration parameters of a plurality uplink grants of a cell. The wireless device determines, for transmission of a transport block (TB), a first hybrid automatic repeat request (HARQ) process associated with a first uplink grant of the plurality uplink grants. The wireless device determines that a listen before talk (LBT) process for transmission of the TB via the first uplink grant indicates a busy channel. In response to the LBT process indicating the busy channel, the TB is transmitted via a second uplink grant, of the plurality uplink grants of the cell, associated with a second HARQ process.

Disclosed is a method for processing code blocks as implemented by a baseband processor. The method involves performing a cyclic redundancy check on decoded and deinterleaved code blocks until one fails its CRC check. On first failure the baseband processor requests a retransmission of the code blocks and resumes CRC checks on the retransmitted code blocks, beginning at the code block that had failed. In the event of subsequent failures, the baseband processor performs a soft combine on the failed retransmitted block with its original transmitted counterpart. Only if the soft combined code block fails does the baseband processor request another retransmission. In this case, subsequent CRC failures result in soft combines of three corresponding code words, making the process more robust. The method reduces the number of retransmissions as well as the computing resources needed for processing incoming code blocks.

For a source stream of input data where FEC scheme(s) have been used to create a repair stream, transmitting by a network node packet(s) comprising data of the source stream or the repair stream packaged as at least part of PDU(s). An ARQ or HARQ process is applied to the PDU(s). The network node receives feedback information as part of the process corresponding to the PDU(s), including positive ACK/NACK response for the PDUs. The retransmissions of the negatively acknowledged PDU(s) are controlled when the FEC scheme is known not to be able to compensate for loss(e)s of packet(s) contained in the PDU(s) indicated as being negatively acknowledged. A UE receives packet(s), determines loss(es), and, in response to a determination the FEC scheme is known to be able to recover from the loss(es), sends at least one ACK for any lost packets that correspond to the one or more loss(es).

A method and apparatus for improving performance in communication systems is provided. In order to maintain the real time constraints of the communication systems, time intervals and indication signals are used in various implementations to indicate and/or force subsequent transmissions of encoded data. An indication signal can include, for example, modulation modification information for subsequent transmissions. In various other implementations, a quality metric is computed for the communication channel and is used to provide modified modulation scheme information to be subsequently used on the communication channel.

A method for discarding a data packet includes: receiving an instruction message sent by a base station, the instruction message instructing start of monitoring transmission timeout of a data packet in an SDAP layer; when detecting that a target session is initiated, starting, according to the instruction message, a packet discarding timer corresponding to each data packet in a data stream of the target session in the SDAP layer; and when the packet discarding timer expires and it is detected that the data packet corresponding to the packet discarding timer fails to be transmitted, discarding the data packet corresponding to the packet discarding timer.

Apparatus and methods for improving a coverage of an uplink Voice over IP (VoIP) transmission of a wireless device are disclosed. A wireless device assigns a first hybrid automatic repeat request (HARQ) process to a first VoIP packet of the wireless device. The wireless device then assigns a second HARQ process to a second VoIP packet of the wireless device. The wireless device then transmits the first and second VoIP packets to a base station.

A method and system for facilitating communication between an Evolved Node B (eNB) and a user equipment (UE) in a Long Term Evolution (LTE) network. In particular the technology addresses downlink transmission via potentially large TTI bundles. The eNB transmits a downlink grant message to the UE, indicating a pending TTI bundle for downlink transmission. The UE transmits an acknowledgement message to the eNB if the DL grant message is successfully received and decoded. The eNB aborts transmission of the TTI bundle if it fails to timely receive the acknowledgement and may reassign the network resources scheduled for use in the transmission. In some embodiments, the eNB may introduce a delay between the downlink grant message and the TTI bundle.