Multiple TRPs and panels transmission with dynamic bandwidth for NR
The present application describes a WTRU including a non-transitory memory including instructions stored thereon for re-establishing a remote radio control (RRC) connection with a base station. The apparatus also includes a processor capable of executing instructions of determining, based upon a measurement in an active downlink bandwidth part (DL BWP), to initiate a random access channel (RACH) procedure. The processor also executes instructions of switching to a default uplink bandwidth part (UL BWP). The processor also executes instructions of initiating the RACH procedure. The process further executes instructions of transmitting a RA preamble using one of the RACH resources configured for the default UL BWP. The processor even further executes instructions of receiving a RA response. The processor yet even further executes instructions of switching from the default UL BWP to either an active UL BWP or another active UL BWP after re-establishing the RRC connection.
1. A wireless transmit/receive unit (WTRU) comprising a processor and memory, wherein the processor and memory are configured to:
determine, based upon a measurement in an active downlink bandwidth part (DL BWP), to initiate a random access channel (RACH) procedure;
switch to a default uplink bandwidth part (UL BWP), wherein at least one RACH resource is configured for the default UL BWP;
initiate the RACH procedure;
transmit, to a base station, a random access (RA) preamble using one of the RACH resources configured for the default UL BWP;
receive a RA response from the base station; and
switch from the default UL BWP to an active UL BWP.
2. The WTRU of claim 1 , wherein the processor and memory are further configured to receive a request from the base station to initiate RA based upon expiration of an alignment timer.
3. The WTRU of claim 1 , wherein the RA preamble is transmitted one symbol after reception of downlink control information (DCI).
4. The WTRU of claim 1 , wherein the transmitted RA preamble is associated with a synchronization signal block (SSB).
5. The WTRU of claim 1 , wherein the RACH procedure is initiated based on a radio link failure with the base station.
6. The WTRU of claim 1 , wherein the processor and memory are further configured to switch to the default UL BWP after expiration of an inactivity timer.
7. The WTRU of claim 1 , wherein the RA response includes radio resource control (RRC) reconfiguration information.
8. A method comprising:
determining, based upon a measurement in an active downlink bandwidth part (DL BWP), to initiate a random access channel (RACH) procedure;
switching to a default uplink bandwidth part (UL BWP), wherein at least one RACH resource is configured for the default UL BWP;
initiating the RACH procedure;
transmitting, to a base station, a random access (RA) preamble using one of the RACH resources configured for the default UL BWP;
receiving a RA response from the base station; and
switching from the default UL BWP to an active UL BWP.
9. The method of claim 8 , further comprising: receiving a request from the base station to initiate RA based upon expiration of an alignment timer.
10. The method of claim 8 , wherein the RA preamble is transmitted one symbol after reception of downlink control information (DCI).
11. The method of claim 8 , wherein the transmitted RA preamble is associated with a synchronization signal block (SSB).
12. The method of claim 8 , wherein the RACH procedure is initiated based on a radio link failure with the base station.
13. The method of claim 8 , further comprising: switching to the default UL BWP after expiration of an inactivity timer.
14. The method of claim 8 , wherein the RA response includes radio resource control (RRC) reconfiguration information.