Base-station-initiated grant revoke
This document describes techniques and systems that enable a base-station-initiated grant revoke. The techniques and systems allow a base station to generate and send a grant-revocation message (GRM) to a user equipment (UE) to revoke a scheduled uplink (UL) or downlink (DL) grant from the base station. The base station can transmit the GRM to the UE using a variety of techniques. For example, based on a trigger event, the base station may assign a UE identifier, such as a specific radio network temporary identifier (RNTI), to the UE and transmit the GRM to the UE using a revoke-physical-downlink-control-channel (R PDCCH) transmission that is associated with the UE identifier. These techniques allow the base station to revoke a scheduled UL or DL grant, which can enable the UE to quickly address timing-critical resource allocation issues and mitigate the effects of adverse operating conditions.
1. A method performed by a base station for reallocating a scheduled grant for a first user equipment (UE) in a wireless network to a second UE in the wireless network, the method comprising:
detecting a trigger event;
in response to detecting the trigger event, determining to revoke at least a portion of the scheduled grant;
generating a grant-revocation message (GRM) that indicates to terminate a scheduled transmission that uses at least the portion of the scheduled grant;
revoking at least the portion of the scheduled grant by transmitting the GRM to the first UE; and
reallocating at least the portion of the scheduled grant to the second UE.
2. The method as recited in claim 1 , wherein detecting the trigger event further comprises:
detecting a priority conflict exists between the first UE and the second UE.
3. The method as recited in claim 2 , wherein detecting the priority conflict further comprises:
detecting a quality of service (QoS) issue associated with the second UE; or
detecting the second UE has a higher-priority grant request than the scheduled grant for the first UE.
4. The method as recited in claim 1 , wherein determining to revoke at least the portion of the scheduled grant further comprises:
determining to revoke a partial grant of the scheduled grant, and
wherein reallocating at least the portion of the scheduled grant to the second UE further comprises:
reallocating the partial grant to the second UE.
5. The method as recited in claim 4 , wherein determining to revoke the partial grant further comprises:
determining to revoke at least one of:
a beam of the scheduled grant;
a layer of the scheduled grant; or
a subset of granted resource units or blocks of the scheduled grant.
6. The method as recited in claim 5 , further comprising:
selecting, as the partial grant of the scheduled grant to revoke, a first beam of the scheduled grant that has a higher modulation and coding scheme (MCS) relative to a second MCS of a second beam of the scheduled grant.
7. The method as recited in claim 5 , further comprising:
selecting, as the partial grant of the scheduled grant to revoke, at least one of:
a physical downlink shared channel (PDSCH) layer of multiple PDSCH layers in the scheduled grant; or
a physical uplink shared channel (PUSCH) layer of multiple PUSCH layers in the scheduled grant.
8. The method as recited in claim 1 , further comprising:
rescheduling the scheduled transmission that uses at least the portion of the scheduled grant.
9. The method as recited in claim 8 , wherein rescheduling the scheduled transmission further comprises:
rescheduling the scheduled transmission using:
an automatic repeat request (ARQ); or
a hybrid automatic repeat request (HARD).
10. The method as recited in claim 1 , further comprising:
providing at least the portion of the scheduled grant to be revoked using a first radio access technology, RAT; and
transmitting the GRM using a second RAT.
11. A base station, comprising:
a radio-frequency (RF) transceiver;
at least one processor; and
a computer-readable storage memory system including processor-executable instructions that, responsive to execution by at least the one processor, cause the base station to perform operations comprising:
detecting a trigger event;
in response to detecting the trigger event, determining to revoke at least a portion of a scheduled grant for a first user equipment (UE) in a wireless network;
generating a grant-revocation message (GRM) that indicates to terminate a scheduled transmission that uses at least the portion of the scheduled grant;
revoking at least the portion of the scheduled grant by transmitting the GRM to the first UE; and
reallocating at least the portion of the scheduled grant to a second UE in the wireless network.
12. The base station as recited in claim 11 , wherein the computer-readable storage memory system includes processor-executable instructions that, responsive to execution by at least the one processor, cause the base station to detect the trigger event by:
detecting a priority conflict exists between the first UE and the second UE.
13. The base station as recited in claim 12 , wherein the computer-readable storage memory system includes processor-executable instructions that, responsive to execution by at least the one processor, cause the base station to detect the priority conflict exists by:
detecting a quality of service (QoS) issue associated with the second UE; or
detecting the second UE has a higher-priority grant request than the scheduled grant for the first UE.
14. The base station as recited in claim 11 , wherein the computer-readable storage memory system includes processor-executable instructions that, responsive to execution by at least the one processor, cause the base station to perform further operations comprising:
determining to revoke a partial grant of the scheduled grant, and
reallocating the partial grant to the second UE.
15. The base station as recited in claim 14 , wherein the computer-readable storage memory system includes processor-executable instructions that, responsive to execution by at least the one processor, cause the base station to determine to revoke the partial grant by:
determining to revoke at least one of:
a beam of the scheduled grant;
a layer of the scheduled grant; or
a subset of granted resource units or blocks of the scheduled grant.
16. The base station as recited in claim 15 , wherein the computer-readable storage memory system includes processor-executable instructions that, responsive to execution by at least the one processor, cause the base station to perform further operations comprising:
selecting, as the partial grant of the scheduled grant to revoke, a first beam of the scheduled grant that has a higher modulation and coding scheme (MCS) relative to a second MCS of a second beam of the scheduled grant.
17. The base station as recited in claim 15 , wherein the computer-readable storage memory system includes processor-executable instructions that, responsive to execution by at least the one processor, cause the base station to determine to perform further operations comprising:
selecting, as the partial grant of the scheduled grant to revoke, at least one of:
a physical downlink shared channel (PDSCH) layer of multiple PDSCH layers in the scheduled grant; or
a physical uplink shared channel (PUSCH) layer of multiple PUSCH layers in the scheduled grant.
18. The base station as recited in claim 11 , wherein the computer-readable storage memory system includes processor-executable instructions that, responsive to execution by at least the one processor, cause the base station to perform further operations comprising:
rescheduling the scheduled transmission that uses at least the portion of the scheduled grant.
19. The base station as recited in claim 18 , wherein the computer-readable storage memory system includes processor-executable instructions that, responsive to execution by at least the one processor, cause the base station to reschedule the scheduled transmission by:
rescheduling the scheduled transmission using:
an automatic repeat request (ARQ); or
a hybrid automatic repeat request (HARQ).
20. The base station as recited in claim 11 , wherein the computer-readable storage memory system includes processor-executable instructions that, responsive to execution by at least the one processor, cause the base station to perform further operations comprising:
providing at least the portion of the scheduled grant to be revoked using a first radio access technology, RAT; and
transmitting the GRM using a second RAT.