Method and apparatus for handling radio link failure in system using multiple reference signals
A communication method and a system for converging a 5th-generation (5G) communication system for supporting higher data rates beyond a 4th-generation (4G) system with a technology for internet of things (IoT) are provided. The present disclosure may be applied to intelligent services based on the 5G communication technology and the IoT-related technology, such as smart home, smart building, smart city, smart car, connected car, etc. The method includes receiving a radio resource control (RRC) message including first information associated with a reference signal for a radio link monitoring (RLM) and second information associated with a threshold for the RLM, monitoring a radio link quality of at least one reference signal indicated by the first information, comparing the radio link quality of the at least one reference signal with the threshold and indicating an in-sync or an out-of-sync to a higher layer of the terminal based on the comparison result.
1. A method performed by a terminal in a communication system, the method comprising:
receiving, from a base station, a radio resource control (RRC) message including first information associated with a reference signal for a radio link monitoring (RLM) and second information associated with a threshold for the RLM, the first information being configured for a bandwidth part (BWP) of a primary cell (PCell);
monitoring a radio link quality of at least one reference signal indicated by the first information;
comparing the radio link quality of the at least one reference signal based on a first threshold and a second threshold; and
indicating an in-sync to a higher layer of the terminal in case that the radio link quality of the at least one reference signal is greater than the first threshold.
2. The method of claim 1 , wherein the radio link quality is monitored on an active BWP on the PCell.
3. The method of claim 1 , wherein the first information includes at least one of a synchronization signal block (SSB) index or a channel state information-reference signal (CSI-RS) index.
4. The method of claim 1 ,
wherein the first information includes an identity of the reference signal and a resource for the reference signal,
wherein the second information includes a block error rate (BLER) threshold pair index, and
wherein the BLER threshold pair index corresponds to the first threshold for the in-sync and the second threshold for the out-of-sync.
5. The method of claim 1 , further comprising:
indicating an out-of-sync to the higher layer of the terminal, in a case that all radio link quality of all reference signals configured for the RLM is lower than the second threshold.
6. A method performed by a base station in a communication system, the method comprising:
transmitting, to a terminal, a radio resource control (RRC) message including first information associated with a reference signal for a radio link monitoring (RLM) and second information associated with a threshold for the RLM, the first information being configured for a bandwidth part (BWP) of a primary cell (PCell); and
transmitting at least one of a synchronization signal block (SSB) or a channel state information-reference signal (CSI-RS),
wherein the first information is used for indicating at least one of the SSB or the CSI-RS to be monitored for a radio link quality,
wherein the second information is used for indicating a first threshold for an in-sync and a second threshold for an out-of-sync, and
wherein the in-sync is indicated to a higher layer of the terminal in case that the radio link quality of the at least one of the SSB or the CSI-RS is greater than the first threshold.
7. The method of claim 6 , wherein the radio link quality is monitored on an active BWP on the PCell.
8. The method of claim 6 , wherein the first information includes at least one of an SSB index or a CSI-RS index.
9. The method of claim 6 ,
wherein the first information includes an identity of the reference signal and a resource for the reference signal,
wherein the second information includes a block error rate (BLER) threshold pair index, and
wherein the BLER threshold pair index corresponds to the first threshold for the in-sync and the second threshold for the out-of-sync.
10. The method of claim 6 , wherein the out-of-sync is indicated to the higher layer of the terminal, in a case that all radio link quality of all SSBs and CSI-RSs for the RLM is lower than the second threshold.
11. A terminal in a communication system, the terminal comprising:
a transceiver; and
at least one processor configured to:
receive, from a base station via the transceiver, a radio resource control (RRC) message including first information associated with a reference signal for a radio link monitoring (RLM) and second information associated with a threshold for the RLM, the first information being configured for a bandwidth part (BWP) of a primary cell (PCell),
monitor a radio link quality of at least one reference signal indicated by the first information,
compare the radio link quality of the at least one reference signal based on a first threshold and a second threshold, and
indicate an in-sync to a higher layer of the terminal in case that the radio link quality of the at least one reference signal is greater than the first threshold.
12. The terminal of claim 11 , wherein the radio link quality is monitored on an active BWP on the PCell.
13. The terminal of claim 11 , wherein the first information includes at least one of a synchronization signal block (SSB) index or a channel state information-reference signal (CSI-RS) index.
14. The terminal of claim 11 ,
wherein the first information includes an identity of the reference signal and a resource for the reference signal,
wherein the second information includes a block error rate (BLER) threshold pair index, and
wherein the BLER threshold pair index corresponds to the first threshold for the in-sync and the second threshold for the out-of-sync.
15. The terminal of claim 14 , wherein the at least one processor is further configured to indicate an out-of-sync to the higher layer of the terminal, in case that all radio link quality of all reference signal configured for the RLM is lower than the second threshold.
16. A base station in a communication system, the base station comprising:
a transceiver; and
at least one processor configured to:
transmit, to a terminal via the transceiver, a radio resource control (RRC) message including first information associated with a reference signal for a radio link monitoring (RLM) and second information associated with a threshold for the RLM, the first information being configured for a bandwidth part (BWP) of a primary cell (PCell), and
transmit, via the transceiver, at least one of a synchronization signal block (SSB) or a channel state information-reference signal (CSI-RS),
wherein the first information is used for indicating at least one of the SSB or the CSI-RS to be monitored for a radio link quality,
wherein the second information is used for indicating a first threshold for an in-sync and a second threshold for an out-of-sync, and
wherein the in-sync is indicated to a higher layer of the terminal in case that the radio link quality of the at least one of the SSB or the CSI-RS is greater than the first threshold.
17. The base station of claim 16 , wherein the radio link quality is monitored on an active BWP on the PCell.
18. The base station of claim 16 , wherein the first information includes at least one of an SSB index or a CSI-RS index.
19. The base station of claim 16 ,
wherein the first information includes an identity of the reference signal and a resource for the reference signal,
wherein the second information includes a block error rate (BLER) threshold pair index, and
wherein the BLER threshold pair index corresponds to the first threshold for the in-sync and the second threshold for the out-of-sync.
20. The base station of claim 16 , wherein the out-of-sync is indicated to the higher layer of the terminal, in a case that all radio link quality of all SSBs and CSI-RSs for the RLM is lower than the second threshold.