Devices and methods for dynamic RACH
Devices, methods, user equipment (UE), base stations, storage media, and other embodiments are provided for a dynamic random access channel (RACH). In one embodiment, an apparatus includes a memory configured to store a configuration communication from a base station, the configuration communication comprising a dynamic dedicated random access channel (RACH) configuration (RACH-ConfigDedicated) information element, the RACH-ConfigDedicated information element comprising a plurality of dedicated random access parameters. Processing circuitry coupled to the memory is then configured to decode the configuration communication from the base station to identify the plurality of dedicated random access parameters and set up a RACH procedure for connection to the base station using the plurality of dedicated random access parameters. In various embodiments, different communications may be used for the dedicated random access parameters which are used in the RACH procedure.
1. A method, comprising:
at an apparatus:
receiving, from a source cell of a cellular network, a configuration communication in a handover command as part of a handover procedure to a target cell, wherein the configuration communication comprises a first random access channel (RACH) configuration and an additional RACH configuration, wherein time and frequency RACH resource information is configured separately for the first RACH configuration and the additional RACH configuration; and
performing a RACH procedure with the target cell using a plurality of additional random access parameters indicated by the additional RACH configuration, wherein the plurality of additional random access parameters indicates a number of beams per time and frequency resources.
2. The method of claim 1 , wherein the configuration communication comprises a radio resource control (RRC) reconfiguration message.
3. The method of claim 1 , further comprising:
determining, at a first time during the handover procedure, to perform the RACH procedure using the additional RACH configuration before attempting a different RACH procedure using the first RACH configuration.
4. The method of claim 1 , further comprising:
determining, at a first time during the handover procedure, to perform a different RACH procedure using the first RACH configuration.
5. The method of claim 1 , wherein the plurality of additional random access parameters include dedicated random access parameters.
6. The method of claim 5 , wherein the dedicated random access parameters comprise at least a PreambleIndex parameter and a timing resource parameter.
7. The method of claim 6 , wherein the timing resource parameter indicates reuse of a T304 timer.
8. The method of claim 6 , further comprising:
performing the RACH procedure until a timer associated with the timing resource parameter expires; and
performing a fallback RACH procedure after the timer expires.
9. An apparatus, comprising:
at least one processor configured to cause a user equipment (UE) to:
receive, from a source cell of a cellular network, a configuration communication in a handover command as part of a handover procedure to a target cell, wherein the configuration communication comprises a first random access channel (RACH) configuration and an additional RACH configuration, wherein time and frequency RACH resource information is configured separately for the first RACH configuration and the additional RACH configuration; and
perform a RACH procedure with the target cell using a plurality of additional random access parameters indicated by the additional RACH configuration, wherein the plurality of additional random access parameters indicates a number of beams per time and frequency resources.
10. The apparatus of claim 9 , wherein the configuration communication comprises a radio resource control (RRC) reconfiguration message.
11. The apparatus of claim 9 , wherein the at least one processor is further configured to cause the UE to:
determine, at a first time during the handover procedure, to perform the RACH procedure using the additional RACH configuration before attempting a different RACH procedure using the first RACH configuration.
12. The apparatus of claim 9 , wherein the at least one processor is further configured to cause the UE to:
determine, at a first time during the handover procedure, to perform a different RACH procedure using the first RACH configuration.
13. The apparatus of claim 9 , wherein the plurality of additional random access parameters include dedicated random access parameters.
14. The apparatus of claim 13 , wherein the dedicated random access parameters comprise at least a Preamblelndex parameter and a timing resource parameter.
15. The apparatus of claim 14 , wherein the timing resource parameter indicates reuse of a T304 timer.
16. The apparatus of claim 14 , wherein the at least one processor is further configured to cause the UE to:
perform the RACH procedure until a timer associated with the timing resource parameter expires; and
perform a fallback RACH procedure after the timer expires.
17. A method, comprising:
at an apparatus:
transmitting, to a user equipment (UE), a configuration communication in a handover command as part of a handover procedure to a target cell, wherein the configuration communication comprises a first random access channel (RACH) configuration and an additional RACH configuration, wherein time and frequency RACH resource information is configured separately for the first RACH configuration and the additional RACH configuration, wherein the additional RACH configuration comprises a plurality of dedicated random access parameters; and
enabling a RACH procedure for connection of the UE with the target cell using the plurality of dedicated random access parameters, wherein the plurality of dedicated random access parameters include an indication of a set of beams of a plurality of transmit beams at the target cell associated with respective potential RACH transmissions.
18. The method of claim 17 , wherein the configuration communication comprises a radio resource control (RRC) reconfiguration message.
19. The method of claim 17 , wherein:
the RACH procedure is performed, at a first time during the handover procedure, using the additional RACH configuration before attempting a different RACH procedure using the first RACH configuration.
20. The method of claim 17 , wherein:
a different RACH procedure is performed, at a first time during the handover procedure, using the first RACH configuration.