Techniques and apparatuses for supplementary uplink random access configuration
Certain aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment may receive RACH configuration information on a downlink carrier of a first set of carriers, wherein the RACH configuration information pertains to the first set of carriers and to a second set of carriers; and selectively perform a RACH procedure with regard to the first set of carriers or the second set of carriers based at least in part on the RACH configuration information. Numerous other aspects are provided.
1. A method of wireless communication performed by a user equipment, comprising:
receiving random access channel (RACH) configuration information,
wherein the RACH configuration information includes:
a threshold associated with a first set of carriers and a second set of carriers,
wherein the first set of carriers includes an uplink carrier that is a primary uplink carrier, and
wherein the second set of carriers includes an uplink carrier that is a supplementary uplink carrier; and
selectively performing a RACH procedure with regard to the first set of carriers or the second set of carriers based at least in part on the RACH configuration information.
2. The method of claim 1 , wherein the first set of carriers is associated with a higher frequency band than the second set of carriers.
3. The method of claim 1 , wherein the RACH configuration information is received in system information or radio resource control configuration information of the user equipment.
4. The method of claim 1 , wherein the user equipment is configured to perform the RACH procedure with regard to a particular set of carriers, of the first set of carriers and the second set of carriers, associated with a lowest frequency band supported by the user equipment.
5. The method of claim 4 , wherein the RACH procedure is performed with regard to the particular set of carriers using information, of the RACH configuration information, that is pertinent to the particular set of carriers.
6. The method of claim 1 , wherein the user equipment is configured to select a particular set of carriers, of the first set of carriers and the second set of carriers, to use to perform the RACH procedure based at least in part on the threshold.
7. The method of claim 6 , wherein the threshold is configured to balance a load, relating to the RACH procedure, between the first set of carriers and the second set of carriers.
8. The method of claim 6 , wherein the threshold is based at least in part on a hash function performed using an identifier associated with the user equipment.
9. The method of claim 1 , wherein the user equipment is configured to perform the RACH procedure with regard to a particular set of carriers, of the first set of carriers and the second set of carriers, based at least in part on a flag or value received by the user equipment and indicating to perform the RACH procedure with regard to the particular set of carriers.
10. The method of claim 1 , wherein a random access radio network temporary identifier (RA-RNTI) of the user equipment is determined based at least in part on a particular set of carriers, of the first set of carriers and the second set of carriers, with regard to which the RACH procedure is performed.
11. The method of claim 1 , wherein a random access radio network temporary identifier (RA-RNTI) for a random access response (RAR) of the RACH procedure identifies a particular set of carriers, of the first set of carriers and the second set of carriers, on which the RACH procedure is performed.
12. The method of claim 1 , wherein the RACH configuration information is received on a downlink carrier of the first set of carriers.
13. A user equipment (UE) for wireless communication, comprising:
memory; and
one or more processors operatively coupled to the memory, the memory and the one or more processors configured to:
receive random access channel (RACH) configuration information,
wherein the RACH configuration information includes:
a threshold associated with a first set of carriers and a second set of carriers,
wherein the first set of carriers includes an uplink carrier that is a primary uplink carrier, and
wherein the second set of carriers includes an uplink carrier that is a supplementary uplink carrier; and
selectively perform a RACH procedure with regard to the first set of carriers or the second set of carriers based at least in part on the RACH configuration information.
14. The UE of claim 13 , wherein the first set of carriers is associated with a higher frequency band than the second set of carriers.
15. The UE of claim 13 , wherein the RACH configuration information is received in system information or radio resource control configuration information of the UE.
16. The UE of claim 13 , wherein the UE is configured to perform the RACH procedure with regard to a particular set of carriers, of the first set of carriers and the second set of carriers, associated with a lowest frequency band supported by the UE.
17. The UE of claim 16 , wherein the RACH procedure is performed with regard to the particular set of carriers using information, of the RACH configuration information, that is pertinent to the particular set of carriers.
18. The UE of claim 13 , wherein the UE is configured to select a particular set of carriers, of the first set of carriers and the second set of carriers, to use to perform the RACH procedure based at least in part on the threshold.
19. The UE of claim 18 , wherein the threshold is configured to balance a load, relating to the RACH procedure, between the first set of carriers and the second set of carriers.
20. The UE of claim 18 , wherein the threshold is based at least in part on a hash function performed using an identifier associated with the UE.
21. The UE of claim 13 , wherein the UE is configured to perform the RACH procedure with regard to a particular set of carriers, of the first set of carriers and the second set of carriers, based at least in part on a flag or value received by the UE and indicating to perform the RACH procedure with regard to the particular set of carriers.
22. The UE of claim 13 , wherein a random access radio network temporary identifier (RA-RNTI) of the UE is determined based at least in part on a particular set of carriers, of the first set of carriers and the second set of carriers, with regard to which the RACH procedure is performed.
23. The UE of claim 13 , wherein a random access radio network temporary identifier (RA-RNTI) for a random access response (RAR) of the RACH procedure identifies a particular set of carriers, of the first set of carriers and the second set of carriers, on which the RACH procedure is performed.
24. A non-transitory computer-readable medium storing one or more instructions for wireless communication, the one or more instructions comprising:
one or more instructions that, when executed by one or more processors of a user equipment (UE), cause the one or more processors to:
receive random access channel (RACH) configuration information,
wherein the RACH configuration information includes:
a threshold associated with a first set of carriers and a second set of carriers,
wherein the first set of carriers includes an uplink carrier that is a primary uplink carrier, and
wherein the second set of carriers includes an uplink carrier that is a supplementary uplink carrier; and
selectively perform a RACH procedure with regard to the first set of carriers or the second set of carriers based at least in part on the RACH configuration information.
25. The non-transitory computer-readable medium of claim 24 , wherein the first set of carriers is associated with a higher frequency band than the second set of carriers.
26. The UE of claim 13 , wherein the RACH configuration information is received on a downlink carrier of the first set of carriers.
27. The non-transitory computer-readable medium of claim 24 , wherein the UE is configured to select a particular set of carriers, of the first set of carriers and the second set of carriers, to use to perform the RACH procedure based at least in part on the threshold.
28. The non-transitory computer-readable medium of claim 27 , wherein the threshold is configured to balance a load, relating to the RACH procedure, between the first set of carriers and the second set of carriers.
29. The non-transitory computer-readable medium of claim 27 , wherein the threshold is based at least in part on a hash function performed using an identifier associated with the UE.
30. The non-transitory computer-readable medium of claim 24 , wherein a random access radio network temporary identifier (RA-RNTI) of the UE is determined based at least in part on a particular set of carriers, of the first set of carriers and the second set of carriers, with regard to which the RACH procedure is performed.
31. The non-transitory computer-readable medium of claim 24 , wherein a random access radio network temporary identifier (RA-RNTI) for a random access response (RAR) of the RACH procedure identifies a particular set of carriers, of the first set of carriers and the second set of carriers, on which the RACH procedure is performed.
32. An apparatus for wireless communication, comprising:
means for receiving random access channel (RACH) configuration information,
wherein the RACH configuration information includes:
a threshold associated with a first set of carriers and a second set of carriers,
wherein the first set of carriers includes an uplink carrier that is a primary uplink carrier, and
wherein the second set of carriers includes an uplink carrier that is a supplementary uplink carrier; and
means for selectively performing a RACH procedure with regard to the first set of carriers or the second set of carriers based at least in part on the RACH configuration information.
33. The non-transitory computer-readable medium of claim 24 , wherein the RACH configuration information is received on a downlink carrier of the first set of carriers.
34. The apparatus of claim 32 , wherein the first set of carriers is associated with a higher frequency band than the second set of carriers.
35. The apparatus of claim 32 , wherein the apparatus is configured to select a particular set of carriers, of the first set of carriers and the second set of carriers, to use to perform the RACH procedure based at least in part on the threshold.
36. The apparatus of claim 35 , wherein the threshold is configured to balance a load, relating to the RACH procedure, between the first set of carriers and the second set of carriers.
37. The apparatus of claim 35 , wherein the threshold is based at least in part on a hash function performed using an identifier associated with the apparatus.
38. The apparatus of claim 32 , wherein a random access radio network temporary identifier (RA-RNTI) of the apparatus is determined based at least in part on a particular set of carriers, of the first set of carriers and the second set of carriers, with regard to which the RACH procedure is performed.
39. The apparatus of claim 32 , wherein a random access radio network temporary identifier (RA-RNTI) for a random access response (RAR) of the RACH procedure identifies a particular set of carriers, of the first set of carriers and the second set of carriers, on which the RACH procedure is performed.
40. The apparatus of claim 32 , wherein the RACH configuration information is received on a downlink carrier of the first set of carriers.