Method and apparatus for terminal self-reselecting resource based on priority in wireless communication system
Suggested is a novel condition for a media access control (MAC) entity in user equipment (UE) reselecting a sidelink resource in a wireless communication system. The MAC entity of the UE can reselect a sidelink resource when a configured sidelink grant does not satisfy a latency requirement according to ProSe per-packet priority (PPPP). More particularly, configuration is performed by an upper layer so that the MAC entity transmits on the basis of sensing using a resource pool; the MAC entity selects generation of a configured sidelink grant corresponding to transmission of a plurality of MAC protocol data units (PDU); and when data is available in a sidelink traffic channel (STCH) and the configured sidelink grant does not satisfy the latency requirement according to the PPPP, a sidelink resource is reselected.
1. A method performed by a media access control (MAC) entity of a user equipment (UE) in a wireless communication system, the method comprising:
based on the MAC entity being configured by an upper layer to transmit using a pool of resources, creating a configured sidelink grant that corresponds to transmissions of multiple MAC protocol data units (PDUs);
determining that there is data for a vehicle-to-everything (V2X) communication in a sidelink traffic channel (STCH) associated with the configured sidelink grant;
determining that first sidelink resources of the STCH associated with the configured sidelink grant do not fulfill a latency requirement for transmitting the data in the V2X communication according to a ProSe per-packet priority (PPPP);
selecting, from among the pool of resources, second sidelink resources for the transmissions of the multiple MAC PDUs based on determining that the first sidelink resources of the STCH do not fulfill the latency requirement; and
transmitting the multiple MAC PDUs using the second sidelink resources.
2. The method of claim 1 , wherein selecting the second sidelink resources is performed for each sidelink process that is configured for the transmissions of the multiple MAC PDUs.
3. The method of claim 1 , wherein selecting the second sidelink resources comprises:
clearing the configured sidelink grant.
4. The method of claim 1 , wherein selecting the second sidelink resources comprises:
randomly selecting, with equal probability, an integer value in an interval from 5 to 15, and
setting a value of a sidelink resource reselection counter to the selected integer value.
5. The method of claim 1 , wherein selecting the second sidelink resources comprises:
selecting (i) a number of hybrid automatic repeat request (HARD) retransmissions from an allowed number that is configured by the upper layer in allowedRebcNumberPSSCH, and (ii) an amount of frequency resources within a range that is configured by the upper layer from minRB-NumberPSSCH to maxRB-NumberPSSCH.
6. The method of claim 1 , wherein selecting the second sidelink resources comprises:
selecting an integer value in an interval from 1 to 10, from among allowed values that are configured by the upper layer in restrictResourceReservationPeriod, and
setting a resource reservation interval by multiplying 100 with the selected integer value.
7. The method of claim 6 , wherein selecting the second sidelink resources comprises:
randomly selecting, from among the pool of resources, time resources and frequency resources for transmission opportunities of sidelink control information (SCI) and sidelink shared channel (SL-SCH) corresponding to a number of the transmissions of the multiple MAC PDUs with the resource reservation interval, excluding resources that are indicated by a physical layer.
8. The method of claim 1 , wherein the upper layer is a radio resource control (RRC) layer of the UE.
9. The method of claim 1 , wherein selecting the second sidelink resources is performed based on sensing using the pool of resources.
10. The method of claim 1 , wherein selecting the second sidelink resources is performed so as to fulfill the latency requirement for transmitting the data in the V2X communication according to the PPPP.
11. A user equipment (UE) configured to operate in a wireless communication system, the UE comprising:
a transceiver;
at least one processor; and
at least one computer memory operably connectable to the at least one processor and storing instructions that, when executed by the at least one processor, perform operations that comprise:
based on a media access control (MAC) entity of the UE being configured by an upper layer to transmit using a pool of resources, creating a configured sidelink grant that corresponds to transmissions of multiple MAC protocol data units (PDUs);
determining that there is data for a vehicle-to-everything (V2X) communication in a sidelink traffic channel (STCH) associated with the configured sidelink grant;
determining that first sidelink resources of the STCH associated with the configured sidelink grant do not fulfill a latency requirement for transmitting the data in the V2X communication according to a ProSe per-packet priority (PPPP);
selecting, from among the pool of resources, second sidelink resources for the transmissions of the multiple MAC PDUs based on determining that the first sidelink resources of the STCH do not fulfill the latency requirement; and
transmitting the multiple MAC PDUs using the second sidelink resources.
12. The UE of claim 11 , wherein selecting the second sidelink resources is performed for each sidelink process that is configured for the transmissions of the multiple MAC PDUs.
13. The UE of claim 11 , wherein selecting the second sidelink resources comprises:
clearing the configured sidelink grant.
14. The UE of claim 11 , wherein selecting the second sidelink resources comprises:
randomly selecting, with equal probability, an integer value in an interval from 5 to 15, and
setting a value of a sidelink resource reselection counter to the selected integer value.
15. The UE of claim 11 , wherein selecting the second sidelink resources comprises:
selecting (i) a number of hybrid automatic repeat request (HARD) retransmissions from an allowed number that is configured by the upper layer in allowedRetxNumberPSSCH, and (ii) an amount of frequency resources within a range that is configured by the upper layer from minRB-NumberPSSCH to maxRB-NumberPSSCH.
16. The UE of claim 11 , wherein selecting the second sidelink resources comprises:
selecting an integer value in an interval from 1 to 10, from among allowed values that are configured by the upper layer in restrictResourceReservationPeriod, and
setting a resource reservation interval by multiplying 100 with the selected integer value.
17. The UE of claim 16 , wherein selecting the second sidelink resources comprises:
randomly selecting, from among the pool of resources, time resources and frequency resources for transmission opportunities of sidelink control information (SCI) and sidelink shared channel (SL-SCH) corresponding to a number of the transmissions of the multiple MAC PDUs with the resource reservation interval, excluding resources that are indicated by a physical layer.
18. The UE of claim 11 , wherein the upper layer is a radio resource control (RRC) layer of the UE.