Selection of different initial bandwidth parts for reduced capability user equipment
This disclosure provides systems, methods and apparatus, including computer programs encoded on computer storage media for a reduced capability (RedCap) user equipment (UE) and supporting cell. The RedCap UE is configured with multiple bandwidth parts (BWPs). A maximum bandwidth of the RedCap UE is lower than a maximum bandwidth of a non-RedCap UEs. The UE receives a cell-defining synchronization signal block (CD-SSB) that defines a shared initial downlink BWP for RedCap UEs and non-RedCap UEs. The UE switches to a separate initial downlink BWP for RedCap UEs. The UE accesses the cell via the separate initial downlink BWP. The UE receives a configuration of an active downlink BWP for RedCap UEs. The UE determines whether to switch from the active downlink BWP to the shared initial BWP or the separate initial downlink BWP to obtain information such as updated system information, system measurements, and uplink configuration information.
1. An apparatus for wireless communication for a reduced capability (RedCap) user equipment (UE), comprising:
a transceiver;
a memory storing computer-executable instructions; and
a processor coupled with the transceiver and the memory and configured to execute the computer-executable instructions to:
receive a cell-defining synchronization signal block (CD-SSB) that defines a shared initial downlink bandwidth part (BWP) for RedCap UEs and non-RedCap UEs;
switch to a separate initial downlink BWP for RedCap UEs based on system information for the separate initial downlink BWP indicated in the shared initial downlink BWP;
access a cell via the separate initial downlink BWP;
receive a configuration of an active downlink BWP for RedCap UEs; and
determine whether to switch from the active downlink BWP to the shared initial BWP or the separate initial downlink BWP to obtain information.
2. The apparatus of claim 1 , wherein the configuration of the active downlink BWP for RedCap UEs includes a paging search space, and wherein to determine whether to switch to the shared initial BWP or the separate initial downlink BWP to obtain the information, the processor is configured to receive a paging physical downlink control channel (PDCCH) indicating that system information has been updated.
3. The apparatus of claim 2 , wherein to determine whether to switch to the shared initial BWP or the separate initial downlink BWP to obtain the information, the processor is configured to switch from the active downlink BWP to the shared initial BWP or the separate initial downlink BWP to obtain updated system information.
4. The apparatus of claim 2 , wherein to determine whether to switch to the shared initial BWP or the separate initial downlink BWP to obtain the information, the processor is configured to decode a broadcast or multicast physical downlink shared channel (PDSCH) carrying updated system information scheduled by the paging PDCCH on the active downlink BWP for RedCap UEs.
5. The apparatus of claim 2 , wherein the paging search space is jointly or separately configured with a wake-up signal search space.
6. The apparatus of claim 2 , wherein the RedCap UE operates in half-duplex frequency domain duplexing (HD-FDD) on the active downlink BWP and receiving the paging search space is prioritized over uplink transmissions when paging occasions overlap with semi-static or dynamically configured uplink transmissions.
7. The apparatus of claim 1 , wherein no paging search space is configured on the active downlink BWP for RedCap UEs and wherein to determine whether to switch to the shared initial BWP or the separate initial downlink BWP to obtain information, the processor is configured to switch to the separate initial downlink BWP to receive a paging PDCCH.
8. The apparatus of claim 1 , wherein to determine whether to switch to the shared initial BWP or the separate initial downlink BWP to obtain information, the processor is configured to determine whether to switch to perform measurements based on an indication of a measurement resource on one of the active downlink BWP, the separate initial downlink BWP, or the shared initial downlink BWP.
9. The apparatus of claim 8 , wherein the measurement resource is one or more of a synchronization signal block (SSB), a channel state information reference signal (CSI-RS), or a positioning reference signal (PRS).
10. The apparatus of claim 8 , wherein the measurements are layer 3 measurements including a reference signal received power (RSRP), a reference signal received quality (RSRQ), a signal to interference plus noise ratio (SINR), a signal to noise ratio (SNR), or a combination thereof.
11. The apparatus of claim 8 , wherein the measurements include neighbor cell measurements based on system information of neighbor cells received in the configuration of the active downlink BWP for RedCap UEs.
12. The apparatus of claim 1 , wherein the configuration of the active downlink BWP for RedCap UEs includes different measurement gaps to measure the CD-SSB of the shared initial downlink BWP and a non-CD-SSB of the separate initial downlink BWP.
13. The apparatus of claim 1 , wherein to determine whether to switch to the shared initial BWP or the separate initial downlink BWP to obtain information, the processor is configured to determine a fallback BWP for RRC re-establishment or RRC release with redirection.
14. A method comprising, at a reduced capability user equipment (RedCap UE):
receiving a cell-defining synchronization signal block (CD-SSB) that defines a shared initial downlink bandwidth part (BWP) for RedCap UEs and non-RedCap UEs;
switching to a separate initial downlink BWP for RedCap UEs based on system information for the separate initial downlink BWP indicated in the shared initial downlink BWP;
accessing a cell via the separate initial downlink BWP;
receiving a configuration of an active downlink BWP for RedCap UEs; and
determining whether to switch from the active downlink BWP to the shared initial BWP or the separate initial downlink BWP to obtain information.
15. The method of claim 14 , wherein the configuration of the active downlink BWP for RedCap UEs includes a paging search space, and wherein determining whether to switch to the shared initial BWP or the separate initial downlink BWP to obtain the information comprises receiving a paging physical downlink control channel (PDCCH) indicating that system information has been updated.
16. The method of claim 15 , wherein determining whether to switch to the shared initial BWP or the separate initial downlink BWP to obtain the information comprises switching from the active downlink BWP to the shared initial BWP or the separate initial downlink BWP to obtain updated system information.
17. The method of claim 14 , wherein determining whether to switch to the shared initial BWP or the separate initial downlink BWP to obtain information comprises determining whether to switch to perform measurements based on an indication of a measurement resource on one of the active downlink BWP, the separate initial downlink BWP, or the shared initial downlink BWP.
18. The method of claim 17 , wherein the measurement resource is one or more of a synchronization signal block (SSB), a channel state information reference signal (CSI-RS), or a positioning reference signal (PRS).
19. The method of claim 18 , wherein the measurements are layer 3 measurements including a reference signal received power (RSRP), a reference signal received quality (RSRQ), a signal to interference plus noise ratio (SINR), a signal to noise ratio (SNR), or a combination thereof.
20. The method of claim 18 , wherein the measurements include neighbor cell measurements based on system information of neighbor cells received in the configuration of the active downlink BWP for RedCap UEs.
21. The method of claim 14 , wherein the configuration of the active downlink BWP for RedCap UEs includes different measurement gaps to measure the CD-SSB of the shared initial downlink BWP and a non-CD-SSB of the separate initial downlink BWP.
22. The method of claim 14 , wherein determining whether to switch to the shared initial BWP or the separate initial downlink BWP to obtain information comprises determining a fallback BWP for RRC re-establishment or RRC release with redirection.
23. An apparatus for a base station to support a reduced capability user equipment (RedCap UE), comprising:
a transceiver;
a memory storing computer-executable instructions; and
a processor coupled with the transceiver and the memory and configured to execute the computer-executable instructions to:
transmit a cell-defining synchronization signal block (CD-SSB) that defines a shared initial downlink bandwidth part (BWP) for RedCap UEs and non-RedCap UEs;
transmit a non-CD-SSB for a separate initial downlink BWP for RedCap UEs based on system information for the separate initial downlink BWP indicated in the shared initial downlink BWP;
configure an active downlink BWP for the RedCap UE including a paging search space;
transmit a paging physical downlink control channel (PDCCH) indicating that system information has been updated; and
transmit updated system information on the shared initial downlink BWP, the separate initial downlink BWP, or the active downlink BWP as indicated by the paging PDCCH.
24. The apparatus of claim 23 , wherein the processor is further configured to transmit an indication of measurement resource on one of the active downlink BWP, the separate initial downlink BWP, or the shared initial downlink BWP.
25. The apparatus of claim 24 , wherein the measurement resource is one or more of a synchronization signal block (SSB), a channel state information reference signal (CSI-RS), or a positioning reference signal (PRS).
26. The apparatus of claim 24 , wherein the measurements are layer 3 measurements including a reference signal received power (RSRP), a reference signal received quality (RSRQ), a signal to interference plus noise ratio (SINR), a signal to noise ratio (SNR), or a combination thereof.
27. The apparatus of claim 23 , wherein the configuration of the active downlink BWP for the RedCap UE includes system information of neighbor cells to measure.
28. The apparatus of claim 23 , wherein the configuration of the active downlink BWP for RedCap UEs includes different measurement gaps to measure the CD-SSB of the shared initial downlink BWP and a non-CD-SSB of the separate initial downlink BWP.
29. The apparatus of claim 23 , further comprising transmitting an indication that all neighbor cells transmit system information on the separate initial BWP for RedCap UEs, which is available as a fallback BWP for RRC re-establishment or RRC release with redirection.
30. A method of supporting a reduced capability user equipment (RedCap UE), comprising:
transmitting a cell-defining synchronization signal block (CD-SSB) that defines a shared initial downlink bandwidth part (BWP) for RedCap UEs and non-RedCap UEs;
transmitting a non-CD-SSB for a separate initial downlink BWP for RedCap UEs based on system information for the separate initial downlink BWP indicated in the shared initial downlink BWP;
configuring an active downlink BWP for the RedCap UE including a paging search space;
transmitting a paging physical downlink control channel (PDCCH) indicating that system information has been updated; and
transmitting updated system information on the shared initial downlink BWP, the separate initial downlink BWP, or the active downlink BWP as indicated by the paging PDCCH.