Inter-cell mobility across serving and non-serving cells
Inter-cell mobility across serving and non-serving cells based on layer 3 measurements is accomplished at the cost of increased delay. Inter-cell mobility across serving and non-serving cells based on layer 1 measurements minimized delay. A user equipment (UE) apparatus that is served by a serving cell of a base station receives, from the serving cell, a configuration to perform layer 1 (L1) measurements based on one or more reference signals from a non-serving cell. The UE also receives the one or more reference signals from the non-serving cell. The UE performs the L1 measurements on the one or more reference signals received from the non-serving cell based on the configuration received from the base station. The UE may perform the L1 measurements on a synchronization signal block (SSB), a channel state information reference signal (CSI-RS), or a positioning reference signal (PRS) from the non-serving cell.
1. An apparatus for wireless communication at a user equipment (UE), comprising:
memory; and
at least one processor coupled to the memory and the at least one processor configured to cause the UE to:
receive, from a serving cell, a resource configuration configuring resources of one or more reference signals, wherein the resource configuration includes a cell identity of a non-serving cell for the one or more reference signals that are from the non-serving cell but does not include a cell identity of a serving cell for the one or more reference signals that are from the serving cell;
receive the one or more reference signals from the non-serving cell;
perform layer 1 (L1) measurements of the non-serving cell on the one or more reference signals received from the non-serving cell based on the resource configuration; and
report, to the serving cell, the L1 measurements of the non-serving cell.
2. The apparatus of claim 1 , wherein the resource configuration includes a non-serving cell identifier for each reference signal to be measured by the UE.
3. The apparatus of claim 2 , wherein the non-serving cell identifier includes a physical cell identity (PCI) for the non-serving cell or a transmission reception point (TRP) identifier for the non-serving cell.
4. The apparatus of claim 1 , wherein the one or more reference signals comprises at least one of a synchronization signal block (SSB), a channel state information reference signal (CSI-RS), or a positioning reference signal (PRS) from the non-serving cell.
5. The apparatus of claim 1 , wherein the resource configuration configures a synchronization signal block (SSB) resource set that indicates a cell identifier for each SSB.
6. The apparatus of claim 5 , wherein the SSB resource set includes an SSB resource list indicating a sequence of SSB indexes and a cell identifier list that indicates a sequence of cell identifiers associated with the sequence of SSB indexes.
7. The apparatus of claim 1 , wherein the at least one processor is further configured to cause the UE to:
receive a report configuration to report the L1 measurements of the non-serving cell, the report, to the serving cell, of the L1 measurements of the non-serving cell being based, at least in part, on the report configuration.
8. The apparatus of claim 7 , wherein the report configuration configures the UE to report an L1 metric comprising at least one of:
a layer 1 reference signal received power (L1-RSRP) for the one or more reference signals of the non-serving cell,
a layer 1 reference signal received quality (L1-RSRQ) for the one or more reference signals of the non-serving cell, or
a layer 1 signal to interference and noise ratio (L1-SINR) for the one or more reference signals of the non-serving cell.
9. The apparatus of claim 1 , wherein the at least one processor is further configured to:
receive a transmission configuration indication (TCI) activation of a TCI state based on the one or more reference signals from the non-serving cell.
10. The apparatus of claim 1 , wherein, to report the L1 measurements of the non-serving cell, the at least one processor is further configured to:
report a highest L1 metric or a lowest L1 metric across multiples cells, including the non-serving cell, associated with different cell identities.
11. The apparatus of claim 1 , wherein, to report the L1 measurements of the non-serving cell, the at least one processor is further configured to:
report an L1 metric value for a first reference signal of the one or more reference signals and a relative L1 metric value for a remaining reference signal of the one or more reference signals.
12. A method of wireless communication at a user equipment (UE) served by a serving cell, comprising:
receiving, from the serving cell, a resource configuration configuring resources of one or more reference signals, wherein the resource configuration includes a cell identity of a non-serving cell for the one or more reference signals that are from the non-serving cell but does not include a cell identity of a serving cell for the one or more reference signals that are from the serving cell;
receiving the one or more reference signals from the non-serving cell;
performing layer 1 (L1) measurements of the non-serving cell on the one or more reference signals received from the non-serving cell based on the resource configuration; and
reporting, to the serving cell, the L1 measurements of the non-serving cell.
13. The method of claim 12 , wherein the resource configuration includes a non-serving cell identifier for each reference signal to be measured by the UE.
14. The method of claim 13 , wherein the non-serving cell identifier includes a physical cell identity (PCI) for the non-serving cell or a transmission reception point (TRP) identifier for the non-serving cell.
15. The method of claim 12 , wherein the one or more reference signals comprises at least one of a synchronization signal block (SSB), a channel state information reference signal (CSI-RS), or a positioning reference signal (PRS) from the non-serving cell.
16. The method of claim 12 , wherein the resource configuration configures a synchronization signal block (SSB) resource set that indicates a cell identifier for each SSB.
17. The method of claim 12 , further comprising:
receiving a report configuration to report the L1 measurements of the non-serving cell, the reporting, to the serving cell, of the L1 measurements of the non-serving cell being based, at least in part, on the report configuration.
18. The method of claim 16 , wherein the SSB resource set includes an SSB resource list indicating a sequence of SSB indexes and a cell identifier list that indicates a sequence of cell identifiers associated with the sequence of SSB indexes.
19. The method of claim 17 , wherein the report configuration configures the UE to report an L1 metric comprising at least one of:
a layer 1 reference signal received power (L1-RSRP) for the one or more reference signals of the non-serving cell,
a layer 1 reference signal received quality (L1-RSRQ) for the one or more reference signals of the non-serving cell, or
a layer 1 signal to interference and noise ratio (L1-SINR) for the one or more reference signals of the non-serving cell.
20. The method of claim 12 , further comprising:
receiving a transmission configuration indication (TCI) activation of a TCI state based on the one or more reference signals from the non-serving cell.
21. The method of claim 12 , wherein reporting the L1 measurements of the non-serving cell further comprises:
reporting a highest L1 metric or a lowest L1 metric across multiples cells, including the non-serving cell, associated with different cell identities.
22. The method of claim 12 , wherein reporting the L1 measurements of the non-serving cell further comprises:
reporting an L1 metric value for a first reference signal of the one or more reference signals and a relative L1 metric value for a remaining reference signal of the one or more reference signals.