Techniques for configuring bandwidth parts and synchronization signal blocks
Methods, systems, and devices for wireless communications are described. A synchronization signal block (SSB) may be dynamically scheduled within an operating bandwidth of a user equipment (UE), where the operating bandwidth of the UE is outside of a frequency resource in which a cell defining SSB (CD-SSB) is scheduled. For example, a UE may operate in a reduced capability mode or an enhanced reduced capability mode where the UE may operate in a narrower bandwidth than the serving cell bandwidth. Control signaling may dynamically configure an SSB for the UE within the operating bandwidth of the UE. The UE may monitor for the non-cell defining SSB (NCD-SSB) and skip monitoring for the CD-SSB based on the dynamically configured NCD-SSB. For example, a reduced capability UE or an enhanced reduced capability UE may monitor for the NCD-SSB without performing RF retuning between receiving the control signaling and monitoring for the NCD-SSB.
1. A method for wireless communications at a user equipment (UE), comprising:
receiving a downlink control information (DCI) message or a medium access control (MAC) control element (CE), in an operating bandwidth of the UE, that schedules or enables a first synchronization signal block in a first resource of the operating bandwidth of the UE, the first synchronization signal block being different from a second synchronization signal block that is associated with system information of a cell that operates across a radio frequency bandwidth that includes the operating bandwidth of the UE, wherein the second synchronization signal block is scheduled for receipt in a second resource that is outside of the operating bandwidth of the UE; and
monitoring, while still operating in the operating bandwidth of the UE, for the first synchronization signal block in the first resource based at least in part on the DCI message or the MAC-CE.
2. The method of claim 1 , further comprising:
receiving the first synchronization signal block without performing radio frequency retuning between receiving the DCI message or the MAC-CE and monitoring for the first synchronization signal block.
3. The method of claim 1 , further comprising:
monitoring, prior to receiving the DCI message or the MAC-CE, for a third synchronization signal block that is associated with system information of the cell, wherein the third synchronization signal block is scheduled for receipt in the second resource; and
performing radio frequency retuning from the second resource to the operating bandwidth of the UE between monitoring for the third synchronization signal block and receiving the DCI message or the MAC-CE.
4. The method of claim 1 , wherein receiving the DCI message or the MAC-CE comprises:
receiving the DCI message that includes one or more fields that schedule the first synchronization signal block on the first resource.
5. The method of claim 1 , wherein receiving the DCI message or the MAC-CE comprises:
receiving the DCI message that includes a field that enables the monitoring for the first synchronization signal block, the DCI message also including scheduling information for one or more shared channel transmissions.
6. The method of claim 5 , further comprising:
receiving additional control signaling that schedules a frequency position of the first synchronization signal block within the radio frequency bandwidth, the additional control signaling received prior to the DCI message.
7. The method of claim 1 , wherein receiving the DCI message or the MAC-CE comprises:
receiving the DCI message that includes an indication of one or more measurements associated with the first synchronization signal block.
8. The method of claim 1 , wherein the DCI or the MAC-CE is a group common DCI message.
9. The method of claim 1 , wherein receiving the DCI message or the MAC-CE comprises:
receiving the MAC-CE that enables the monitoring for the first synchronization signal block.
10. The method of claim 9 , further comprising:
receiving control signaling that schedules a set of semi-persistent synchronization signal blocks in a respective set of resources within the operating bandwidth of the UE, the set of semi-persistent synchronization signal blocks comprising the first synchronization signal block, and the MAC-CE enabling the monitoring for the set of semi-persistent synchronization signal blocks.
11. The method of claim 10 , further comprising:
receiving second control signaling deactivating the set of semi-persistent synchronization signal blocks; and
monitoring for a third synchronization signal block in a third resource outside of the operating bandwidth of the UE based at least in part on the second control signaling, wherein the second synchronization signal block and the third synchronization signal block are each part of a periodic set of synchronization signal blocks in a respective set of resources outside of the operating bandwidth of the UE.
12. The method of claim 1 , further comprising:
performing one of a radio resource management procedure, a radio link monitoring procedure, or a bidirectional forwarding detection procedure based at least in part on the monitoring of the first synchronization signal block.
13. The method of claim 1 , wherein the second synchronization signal block comprises a cell-defining synchronization signal block and the first synchronization signal block comprises a non-cell-defining synchronization signal block.
14. The method of claim 1 , further comprising:
transmitting, to a network entity, a first control message indicating that the UE is entering a reduced capability mode; and
receiving, from the network entity, a second control message configuring the operating bandwidth of the UE based at least in part on the first control message.
15. A method for wireless communications at a network entity, comprising:
identifying an operating bandwidth for communications with a user equipment (UE), wherein a first synchronization signal block is scheduled for transmission in a first resource that is outside of the operating bandwidth of the UE, and wherein the first synchronization signal block is associated with system information of a cell that operates across a radio frequency bandwidth that includes the operating bandwidth of the UE;
transmitting, based at least in part on identifying the operating bandwidth for communications with the UE, a downlink control information (DCI) message or a medium access control (MAC) control element (CE) that schedules or enables a second synchronization signal block in a second resource of the operating bandwidth of the UE; and
transmitting the second synchronization signal block in the second resource.
16. The method of claim 15 , further comprising:
identifying that a latency target associated with a data transmission for the UE exceeds a threshold, wherein transmitting the DCI message or the MAC-CE is based at least in part on the identifying.
17. The method of claim 15 , further comprising:
identifying that a payload size associated with a data transmission for the UE exceeds a threshold, wherein transmitting the DCI message or the MAC-CE is based at least in part on the identifying.
18. The method of claim 15 , wherein transmitting the DCI message or the MAC-CE comprises:
transmitting the DCI message that includes one or more fields that schedule the second synchronization signal block on the second resource.
19. The method of claim 15 , wherein transmitting the DCI message or the MAC-CE comprises:
transmitting the DCI message that includes a field that enables monitoring at the UE for the second synchronization signal block, the DCI message also including scheduling information for one or more shared channel transmissions.
20. The method of claim 19 , further comprising:
transmitting additional control signaling that schedules a frequency position of the second synchronization signal block within the radio frequency bandwidth, the additional control signaling received prior to the DCI message.
21. The method of claim 15 , wherein transmitting the DCI message or the MAC-CE comprises:
transmitting the DCI message that includes an indication of one or more measurements associated with the second synchronization signal block.
22. The method of claim 15 , wherein the DCI message or the MAC-CE is a group common DCI message.
23. The method of claim 15 , wherein transmitting the DCI message or the MAC-CE comprises:
transmitting the MAC-CE that enables monitoring at the UE for the second synchronization signal block.
24. The method of claim 23 , further comprising:
transmitting control signaling that schedules a set of semi-persistent synchronization signal blocks in a respective set of resources within the operating bandwidth of the UE, the set of semi-persistent synchronization signal blocks comprising the second synchronization signal block, and the MAC-CE enabling monitoring at the UE for the set of semi-persistent synchronization signal blocks.
25. The method of claim 24 , further comprising:
transmitting second control signaling deactivating the set of semi-persistent synchronization signal blocks; and
transmitting a third synchronization signal block in a third resource outside of the operating bandwidth of the UE based at least in part on the second control signaling, wherein the second synchronization signal block and the third synchronization signal block are each part of a periodic set of synchronization signal blocks in a respective set of resources outside of the operating bandwidth of the UE.
26. The method of claim 15 , wherein the first synchronization signal block comprises a cell-defining synchronization signal block and the second synchronization signal block comprises a non-cell-defining synchronization signal block.
27. The method of claim 15 , further comprising:
receiving, from the UE, a first control message indicating that the UE is entering a reduced capability mode; and
transmitting, to the UE, a second control message configuring the operating bandwidth of the UE based at least in part on the first control message.
28. An apparatus for wireless communications at a user equipment (UE), comprising:
at least one processor; and
memory coupled with the at least one processor, the memory storing instructions executable by the at least one processor to cause the UE to:
receive a downlink control information (DCI) message or a medium access control (MAC) control element (CE), in an operating bandwidth of the UE, that schedules or enables a first synchronization signal block in a first resource of the operating bandwidth of the UE, the first synchronization signal block being different from a second synchronization signal block that is associated with system information of a cell that operates across a radio frequency bandwidth that includes the operating bandwidth of the UE, wherein the second synchronization signal block is scheduled for receipt in a second resource that is outside of the operating bandwidth of the UE; and
monitor, while still operating in the operating bandwidth of the UE, for the first synchronization signal block in the first resource based at least in part on the DCI message or the MAC-CE.
29. The apparatus of claim 28 , wherein the instructions are further executable by the at least one processor to cause the UE to:
receive the first synchronization signal block without performing radio frequency retuning between receiving the DCI message or the MAC-CE and monitoring for the first synchronization signal block.
30. An apparatus for wireless communications at a network entity, comprising:
at least one processor; and
memory coupled with the at least one processor, the memory storing instructions executable by the at least one processor to cause the network entity to:
identify an operating bandwidth for communications with a user equipment (UE), wherein a first synchronization signal block is scheduled for transmission in a first resource that is outside of the operating bandwidth of the UE, and wherein the first synchronization signal block is associated with system information of a cell that operates across a radio frequency bandwidth that includes the operating bandwidth of the UE;
transmit, based at least in part on identifying the operating bandwidth for communications with the UE, a downlink control information (DCI) message or a medium access control (MAC) control element (CE) that schedules or enables a second synchronization signal block in a second resource of the operating bandwidth of the UE; and
transmit the second synchronization signal block in the second resource.