Two-stage trigger procedure
View Patent ↗The invention relates to a user equipment for being scheduled with uplink radio resources. The user equipment receives from a radio base station a first-stage uplink resource scheduling message, indicating uplink radio resources usable by the UE to perform an uplink transmission via an unlicensed cell. The receiver further receives a second-stage uplink resource scheduling message, which is related to the first-stage uplink resource scheduling message. Upon reception of the second-stage uplink resource scheduling message, a processor of the UE determines that an uplink transmission is scheduled in case the first-stage uplink resource scheduling message is valid. The first-stage uplink resource scheduling message is determined valid based on a determination as to whether an uplink transmission has been triggered by another second-stage uplink resource scheduling message within a predetermined time period prior to reception of the second-stage uplink resource scheduling message. The UE then performs an uplink transmission.
1. An integrated circuit configured to operate a user equipment, the integrated circuit comprising:
reception circuitry, which, in operation, receives from a radio base station:
a first-stage uplink resource scheduling message, which indicates uplink radio resources usable by the user equipment to perform an uplink transmission via an unlicensed cell, and
a second-stage uplink resource scheduling message, which is related to the first-stage uplink resource scheduling message;
control circuitry, which is coupled to the reception circuitry and which, in operation, determines that the first-stage uplink resource scheduling message is valid responsive to the uplink transmission not being triggered by another second-stage uplink resource scheduling message in a defined time period prior to reception of the second-stage uplink resource scheduling message; and
transmission circuitry, which is coupled to the control circuitry and which, in operation, performs the uplink transmission via the unlicensed cell responsive to the first-stage uplink resource scheduling message determined to be valid.
2. The integrated circuit according to claim 1 , wherein the control circuitry, in operation, invalidates the first-stage uplink resource scheduling message responsive to the uplink transmission being triggered by the another second-stage uplink resource scheduling message in the defined time period.
3. The integrated circuit according to claim 1 , wherein the first-stage uplink resource scheduling message is addressed to the user equipment, and the second-stage resource scheduling message is commonly addressed to a plurality of user equipments receiving the second-stage uplink resource scheduling message.
4. The integrated circuit according to claim 3 , wherein the first-stage uplink resource scheduling message is addressed to the user equipment by means of a user-equipment-specific identity employed in a transmission of the first-stage uplink resource scheduling message, and wherein the user-equipment-specific identity is configurable.
5. The integrated circuit according to claim 3 , wherein the second-stage uplink resource scheduling message is commonly addressed to the plurality of user equipments receiving the second-stage uplink resource scheduling message by means of a shared identity employed in a transmission of the second-stage uplink resource scheduling message, wherein the shared identity is pre-defined and common to the plurality of user equipments.
6. The integrated circuit according to claim 1 , wherein the first-stage uplink resource scheduling message indicates the defined time period.
7. The integrated circuit according to claim 1 , wherein the first-stage uplink resource scheduling message further indicates a first time offset to be considered when performing the uplink transmission.
8. The integrated circuit according to claim 7 , wherein the second-stage uplink resource scheduling message indicates a second time offset to be considered when performing the uplink transmission.
9. The integrated circuit according to claim 8 , wherein the transmission circuitry, in operation, performs the uplink transmission at least after a sum of the first time offset and the second time offset following reception of the second-stage uplink resource scheduling message.
10. The integrated circuit according to claim 1 , wherein the first-stage uplink resource scheduling message is a downlink control information (DCI) message of format 0A, 0B, 4A, or 4B, respectively comprising a first-stage flag indicating that the DCI message is a first uplink resource scheduling message of a two-stage uplink resource scheduling.
11. The integrated circuit according to claim 10 , wherein the second-stage uplink resource scheduling message is a DCI message of format 1C comprising a second-stage flag indicating that the DCI message is a second uplink resource scheduling message of the two-stage uplink resource scheduling.
12. An integrated circuit embodying logic which, when executed by a user equipment, controls the user equipment to:
receive, from a radio base station, a first-stage uplink resource scheduling message, which indicates uplink radio resources usable by the user equipment to perform an uplink transmission via an unlicensed cell, and a second-stage uplink resource scheduling message, which is related to the first-stage uplink resource scheduling message;
determine that the first-stage uplink resource scheduling message is valid responsive to the uplink transmission not being triggered by another second-stage uplink resource scheduling message in a defined time period prior to reception of the second-stage uplink resource scheduling message; and
perform the uplink transmission via the unlicensed cell responsive to the first-stage uplink resource scheduling message determined to be valid.
13. The integrated circuit according to claim 12 , wherein the logic, when executed by the user equipment, controls the user equipment to invalidate the first-stage uplink resource scheduling message responsive to the uplink transmission being triggered by the another second-stage uplink resource scheduling message in the defined time period.
14. The integrated circuit according to claim 12 , wherein the first-stage uplink resource scheduling message is addressed to the user equipment, and the second-stage resource scheduling message is commonly addressed to a plurality of user equipments receiving the second-stage uplink resource scheduling message.
15. The integrated circuit according to claim 12 , wherein the first-stage uplink resource scheduling message indicates the defined time period.
16. The integrated circuit according to claim 12 , wherein the first-stage uplink resource scheduling message further indicates a first time offset to be considered when performing the uplink transmission.
17. The integrated circuit according to claim 16 , wherein the second-stage uplink resource scheduling message indicates a second time offset to be considered when performing the uplink transmission.
18. The integrated circuit according to claim 17 , wherein the uplink transmission is performed at least after a sum of the first time offset and the second time offset following reception of the second-stage uplink resource scheduling message.
19. The integrated circuit according to claim 12 , wherein the first-stage uplink resource scheduling message is a downlink control information (DCI) message of format 0A, 0B, 4A, or 4B, respectively comprising a first-stage flag indicating that the DCI message is a first uplink resource scheduling message of a two-stage uplink resource scheduling.
20. The integrated circuit according to claim 19 , wherein the second-stage uplink resource scheduling message is a DCI message of format 1C comprising a second-stage flag indicating that the DCI message is a second uplink resource scheduling message of the two-stage uplink resource scheduling.