Communication system
A communication system is disclosed in which a communication device transmits, to a base station and using communication resources that may be used for grant-free uplink communications, uplink data and information from which the communication device can be identified, wherein the information from which the communication device can be identified comprises a Cyclic Redundancy Check (CRC) value that is encoded with identity information identifying the communication device (for example, a C-RNTI of the communication device).
1. A user equipment (UE) comprising: at least one memory storing instructions; and
at least one processor configured lo process the instructions to:
receive, from a base station, a Radio Resource Control (RRC) message including at least one parameter for transmitting uplink data without a dynamic grant;
configure:
i) a first radio network temporary identifier (RNTI) for uplink data transmitted without the scheduling grant; and
ii) a second RNTI for uplink data transmitted with the scheduling grant;
determine a Hybrid Automatic Repeat Request (HARQ) process identifier corresponding to a transmission without a dynamic grant based on a resource in a predetermined radio frame and the at least one parameter, in a case where the transmission without a dynamic grant is available based on a timing of the transmission without a dynamic grant and a timing of a transmission with a dynamic grant;
transmit the uplink data to the base station, via the transmissions without a dynamic grant;
retransmit, to the base station, the uplink data using a resource scheduled by an uplink grant in downlink control information corresponding to the first RNTI; and
transmit and retransmit, to the base station, another uplink data using a resource scheduled by an uplink grant in downlink control information corresponding to the second RNTI.
2. The UE according to claim 1 , wherein the transmission without a dynamic grant is linked to a HARQ process corresponding to the HARQ process identifier.
3. The UE according to claim 1 , wherein the first RNTI is derived based on the RRC message.
4. A method for a user equipment (UE), the method comprising:
receiving, from a base station, a Radio Resource Control (RRC) message including at least one parameter for transmitting uplink data without a dynamic grant;
configuring:
i) a first radio network temporary identifier (RNTI) for transmitting uplink data without a dynamic grant; and
ii) a second RNTI for transmitting uplink data with a dynamic grant;
determining a Hybrid Automatic Repeat Request (HARQ) process identifier corresponding to a transmission without a dynamic grant based on a resource in a predetermined radio frame and at least one parameter, in a case where the transmission without a dynamic grant is available based on a timing of the transmission without a dynamic grant and a timing of a transmission with a dynamic grant;
transmitting the uplink data to the base station, via the transmission without a dynamic grant;
retransmitting, to the base station, the uplink data using a resource scheduled by an uplink grant in downlink control information corresponding to the first RNTI; and
transmitting and retransmitting, to the base station, another uplink data using a resource scheduled by an uplink grant in downlink control information corresponding to the second RNTI.
5. The method according to claim 4 , wherein the transmission without a dynamic grant is linked to a HARQ process corresponding to the HARQ process identifier.
6. The method according to claim 4 , wherein the first RNTI is derived based on the RRC message.