Method for determining result of transmission for contention-based PUSCH in a wireless communication system and a device therefor
The present invention relates to a wireless communication system. More specifically, the present invention relates to a method and a device for determining result of transmission for contention-based PUSCH in a wireless communication system, the method comprising: transmitting a MAC PDU using a CB grant to an eNB; starting a timer when the UE transmits the MAC PDU using the CB grant; monitoring an ACK indication transmitted by the eNB while the timer is running; considering that the MAC PDU transmission using the CB grant is failed if the UE doesn't receive the ACK indication from the eNB until the timer expires; and retransmitting the MAC PDU to the eNB.
1 . A method for a User Equipment (UE) operating in a wireless communication system, the method comprising:
configuring an uplink (UL) grant, wherein the configured UL grant is a grant configured to the UE with an opportunity to send UL packets without requiring the UE to send a scheduling request;
transmitting a physical uplink shared channel (PUSCH) on the configured UL grant;
starting a timer related to the configured UL grant when the UE transmits the PUSCH on the configured UL grant;
determining whether a hybrid automatic repeat request (HARQ) feedback related to the PUSCH physical downlink control channel (PDCCH) masked by a cell-radio network temporary identifier (C-RNTI) is received while the timer is running;
stopping the timer based on a determination that the HARQ feedback PDCCH masked by the C-RNTI is received while the timer is running; and
retransmitting the PUSCH on the configured UL grant based on a decision of the UE that the transmission of the PUSCH is negative acknowledged based on a determination that the HARQ feedback PDCCH masked by the C-RNTI has not been received until the timer expires,
wherein a value of the timer is configured via the RRC message per configured UL grant not per UE.
2 . The method according to claim 1 , wherein the UE keeps monitoring the HARQ feedback from a base station in each time interval with a physical downlink control channel (PDCCH), while the timer is running.
3 . The method according to claim 1 , wherein the HARQ feedback includes an ACK indication, and the ACK indication is at least one of a Physical Downlink Control Channel (PDCCH) masked by Radio Network Temporary Identifier (RNTI) related to the configured UL grant, a PDCCH masked by Cell-RNTI (C-RNTI), or Physical Downlink Shared Channel (PDSCH) including a UL grant associated with new transmission related to the PDCCH masked by the C-RNTI.
4 . The method according to claim 1 , wherein when the UE receives an ACK indication included in the HARQ feedback the PDCCH masked by the C-RNTI from a base station, the UE discards a Medium Access Control Protocol Data Unit (MAC PDU) transmitted in the PUSCH on the configured UL grant, and generates a new MAC PDU to be transmitted in a new PUSCH on the configured UL grant.
5 . The method according to claim 1 , wherein the PUSCH is retransmitted on the configured UL grant without obtaining a new UL grant related to the uplink retransmission when the transmission of the PUSCH is negative acknowledged based on the determination that the PDCCH masked by the C-RNTI has not been received until the timer expires.
6 . A User Equipment (UE) operating in a wireless communication system, the UE comprising:
a Radio Frequency (RF) module; and
a processor configured to:
control the RF module,
configure an uplink (UL) grant, wherein the configured UL grant is a grant configured to the UE with an opportunity to send UL packets without requiring the UE to send a scheduling request;
control the RF module to transmit a physical uplink shared channel (PUSCH) on the configured UL grant;
start a timer related to the configured UL grant when the UE transmits the PUSCH on the configured UL grant;
determining whether a hybrid automatic repeat request (HARQ) feedback related to the PUSCH physical downlink control channel (PDCCH) masked by a cell-radio network temporary identifier (C-RNTI) is received while the timer is running;
stop the timer based on a determination that the HARQ feedback PDCCH masked by the C-RNTI is received while the timer is running; and
control the RF module to retransmit the PUSCH on the configured UL grant based on a decision of the UE that the transmission of the PUSCH is negative acknowledged based on a determination that the HARQ feedback PDCCH masked by the C-RNTI has not been received until the timer expires,
wherein a value of the timer is configured via the RRC message per configured UL grant not per UE.
7 . The UE according to claim 6 , wherein the UE keeps monitoring the HARQ feedback from a base station in each time interval with a physical downlink control channel (PDCCH), while the timer is running.
8 . The UE according to claim 6 , wherein the HARQ feedback includes an ACK indication, and the ACK indication is at least one of a Physical Downlink Control Channel (PDCCH) masked by Radio Network Temporary Identifier (RNTI) related to the configured UL grant, a PDCCH masked by Cell-RNTI (C-RNTI), or a Physical Downlink Shared Channel (PDSCH) including a UL grant associated with new transmission related to the PDCCH masked by the C-RNTI.
9 . The UE according to claim 6 , wherein when the UE receives an ACK indication included in the HARQ feedback the PDCCH masked by the C-RNTI from a base station, the UE discards a Medium Access Control Protocol Data Unit (MAC PDU) transmitted in the PUSCH on the configured UL grant, and generates a new MAC PDU to be transmitted in a new PUSCH on the configured UL grant.
10 . The UE according to claim 6 , wherein the PUSCH is retransmitted on the configured UL grant without obtaining a new UL grant related to the uplink retransmission when the transmission of the PUSCH is negative acknowledged based on the determination that the PDCCH masked by the C-RNTI has not been received until the timer expires.